Re: [patch RFC 10/38] x86/ioapic: Consolidate IOAPIC allocation

2020-08-26 Thread Thomas Gleixner
On Wed, Aug 26 2020 at 16:40, Boqun Feng wrote:
> I hit a compiler error while I was trying to compile this patchset:
>
> arch/x86/kernel/devicetree.c: In function ‘dt_irqdomain_alloc’:
> arch/x86/kernel/devicetree.c:232:6: error: ‘struct irq_alloc_info’ has no 
> member named ‘ioapic_id’; did you mean ‘ioapic’?
>   232 |  tmp.ioapic_id = mpc_ioapic_id(mp_irqdomain_ioapic_idx(domain));

Yeah, noticed myself already and 0day complained as well :)

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[RESEND PATCH v4] iommu/mediatek: check 4GB mode by reading infracfg

2020-08-26 Thread Miles Chen
In previous discussion [1] and [2], we found that it is risky to
use max_pfn or totalram_pages to tell if 4GB mode is enabled.

Check 4GB mode by reading infracfg register, remove the usage
of the un-exported symbol max_pfn.

This is a step towards building mtk_iommu as a kernel module.

[1] https://lore.kernel.org/lkml/20200603161132.2441-1-miles.c...@mediatek.com/
[2] https://lore.kernel.org/lkml/20200604080120.2628-1-miles.c...@mediatek.com/
[3] https://lore.kernel.org/lkml/20200715205120.GA778876@bogus/

Cc: Mike Rapoport 
Cc: David Hildenbrand 
Cc: Yong Wu 
Cc: Yingjoe Chen 
Cc: Christoph Hellwig 
Cc: Rob Herring 
Cc: Matthias Brugger 
Signed-off-by: Miles Chen 

---

Change since v3
- use lore.kernel.org links
- move "change since..." after "---"

Change since v2:
- determine compatible string by m4u_plat
- rebase to next-20200720
- add "---"

Change since v1:
- remove the phandle usage, search for infracfg instead [3]
- use infracfg instead of infracfg_regmap
- move infracfg definitaions to linux/soc/mediatek/infracfg.h
- update enable_4GB only when has_4gb_mode
---
 drivers/iommu/mtk_iommu.c | 34 +++
 include/linux/soc/mediatek/infracfg.h |  3 +++
 2 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 785b228d39a6..adc350150492 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -3,7 +3,6 @@
  * Copyright (c) 2015-2016 MediaTek Inc.
  * Author: Yong Wu 
  */
-#include 
 #include 
 #include 
 #include 
@@ -15,13 +14,16 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 #include 
 #include 
 #include 
 #include 
+#include 
 #include 
 #include 
+#include 
 #include 
 #include 
 
@@ -640,8 +642,11 @@ static int mtk_iommu_probe(struct platform_device *pdev)
struct resource *res;
resource_size_t ioaddr;
struct component_match  *match = NULL;
+   struct regmap   *infracfg;
void*protect;
int i, larb_nr, ret;
+   u32 val;
+   char*p;
 
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
@@ -655,10 +660,29 @@ static int mtk_iommu_probe(struct platform_device *pdev)
return -ENOMEM;
data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
 
-   /* Whether the current dram is over 4GB */
-   data->enable_4GB = !!(max_pfn > (BIT_ULL(32) >> PAGE_SHIFT));
-   if (!MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE))
-   data->enable_4GB = false;
+   data->enable_4GB = false;
+   if (MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE)) {
+   switch (data->plat_data->m4u_plat) {
+   case M4U_MT2712:
+   p = "mediatek,mt2712-infracfg";
+   break;
+   case M4U_MT8173:
+   p = "mediatek,mt8173-infracfg";
+   break;
+   default:
+   p = NULL;
+   }
+
+   infracfg = syscon_regmap_lookup_by_compatible(p);
+
+   if (IS_ERR(infracfg))
+   return PTR_ERR(infracfg);
+
+   ret = regmap_read(infracfg, REG_INFRA_MISC, );
+   if (ret)
+   return ret;
+   data->enable_4GB = !!(val & F_DDR_4GB_SUPPORT_EN);
+   }
 
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
data->base = devm_ioremap_resource(dev, res);
diff --git a/include/linux/soc/mediatek/infracfg.h 
b/include/linux/soc/mediatek/infracfg.h
index fd25f0148566..233463d789c6 100644
--- a/include/linux/soc/mediatek/infracfg.h
+++ b/include/linux/soc/mediatek/infracfg.h
@@ -32,6 +32,9 @@
 #define MT7622_TOP_AXI_PROT_EN_WB  (BIT(2) | BIT(6) | \
 BIT(7) | BIT(8))
 
+#define REG_INFRA_MISC 0xf00
+#define F_DDR_4GB_SUPPORT_EN   BIT(13)
+
 int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
bool reg_update);
 int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,
-- 
2.18.0
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Re: [patch RFC 10/38] x86/ioapic: Consolidate IOAPIC allocation

2020-08-26 Thread Boqun Feng
Hi Thomas,

I hit a compiler error while I was trying to compile this patchset:

arch/x86/kernel/devicetree.c: In function ‘dt_irqdomain_alloc’:
arch/x86/kernel/devicetree.c:232:6: error: ‘struct irq_alloc_info’ has no 
member named ‘ioapic_id’; did you mean ‘ioapic’?
  232 |  tmp.ioapic_id = mpc_ioapic_id(mp_irqdomain_ioapic_idx(domain));
  |  ^
  |  ioapic
arch/x86/kernel/devicetree.c:233:6: error: ‘struct irq_alloc_info’ has no 
member named ‘ioapic_pin’; did you mean ‘ioapic’?
  233 |  tmp.ioapic_pin = fwspec->param[0]
  |  ^~
  |  ioapic

with CONFIG_OF=y. IIUC, the following changes are needed to fold into
this patch. (At least I can continue to compile the kernel with this
change)

diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index a0e8fc7d85f1..ddffd80f5c52 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -229,8 +229,8 @@ static int dt_irqdomain_alloc(struct irq_domain *domain, 
unsigned int virq,
 
it = _ioapic_type[type_index];
ioapic_set_alloc_attr(, NUMA_NO_NODE, it->trigger, it->polarity);
-   tmp.ioapic_id = mpc_ioapic_id(mp_irqdomain_ioapic_idx(domain));
-   tmp.ioapic_pin = fwspec->param[0];
+   tmp.devid = mpc_ioapic_id(mp_irqdomain_ioapic_idx(domain));
+   tmp.ioapic.pin = fwspec->param[0];
 
return mp_irqdomain_alloc(domain, virq, nr_irqs, );
 }

Regards,
Boqun

On Fri, Aug 21, 2020 at 02:24:34AM +0200, Thomas Gleixner wrote:
> Move the IOAPIC specific fields into their own struct and reuse the common
> devid. Get rid of the #ifdeffery as it does not matter at all whether the
> alloc info is a couple of bytes longer or not.
> 
> Signed-off-by: Thomas Gleixner 
> Cc: Wei Liu 
> Cc: "K. Y. Srinivasan" 
> Cc: Stephen Hemminger 
> Cc: Joerg Roedel 
> Cc: linux-hyp...@vger.kernel.org
> Cc: iommu@lists.linux-foundation.org
> Cc: Haiyang Zhang 
> Cc: Jon Derrick 
> Cc: Lu Baolu 
> ---
>  arch/x86/include/asm/hw_irq.h   |   23 ++-
>  arch/x86/kernel/apic/io_apic.c  |   70 
> ++--
>  drivers/iommu/amd/iommu.c   |   14 +++
>  drivers/iommu/hyperv-iommu.c|2 -
>  drivers/iommu/intel/irq_remapping.c |   18 -
>  5 files changed, 64 insertions(+), 63 deletions(-)
> 
> --- a/arch/x86/include/asm/hw_irq.h
> +++ b/arch/x86/include/asm/hw_irq.h
> @@ -44,6 +44,15 @@ enum irq_alloc_type {
>   X86_IRQ_ALLOC_TYPE_HPET_GET_PARENT,
>  };
>  
> +struct ioapic_alloc_info {
> + int pin;
> + int node;
> + u32 trigger : 1;
> + u32 polarity : 1;
> + u32 valid : 1;
> + struct IO_APIC_route_entry  *entry;
> +};
> +
>  /**
>   * irq_alloc_info - X86 specific interrupt allocation info
>   * @type:X86 specific allocation type
> @@ -53,6 +62,8 @@ enum irq_alloc_type {
>   * @mask:CPU mask for vector allocation
>   * @desc:Pointer to msi descriptor
>   * @data:Allocation specific data
> + *
> + * @ioapic:  IOAPIC specific allocation data
>   */
>  struct irq_alloc_info {
>   enum irq_alloc_type type;
> @@ -64,6 +75,7 @@ struct irq_alloc_info {
>   void*data;
>  
>   union {
> + struct ioapic_alloc_infoioapic;
>   int unused;
>  #ifdef   CONFIG_PCI_MSI
>   struct {
> @@ -71,17 +83,6 @@ struct irq_alloc_info {
>   irq_hw_number_t msi_hwirq;
>   };
>  #endif
> -#ifdef   CONFIG_X86_IO_APIC
> - struct {
> - int ioapic_id;
> - int ioapic_pin;
> - int ioapic_node;
> - u32 ioapic_trigger : 1;
> - u32 ioapic_polarity : 1;
> - u32 ioapic_valid : 1;
> - struct IO_APIC_route_entry *ioapic_entry;
> - };
> -#endif
>  #ifdef   CONFIG_DMAR_TABLE
>   struct {
>   int dmar_id;
> --- a/arch/x86/kernel/apic/io_apic.c
> +++ b/arch/x86/kernel/apic/io_apic.c
> @@ -860,10 +860,10 @@ void ioapic_set_alloc_attr(struct irq_al
>  {
>   init_irq_alloc_info(info, NULL);
>   info->type = X86_IRQ_ALLOC_TYPE_IOAPIC;
> - info->ioapic_node = node;
> - info->ioapic_trigger = trigger;
> - info->ioapic_polarity = polarity;
> - info->ioapic_valid = 1;
> + info->ioapic.node = node;
> + info->ioapic.trigger = trigger;
> + info->ioapic.polarity = polarity;
> + info->ioapic.valid = 1;
>  }
>  
>  #ifndef CONFIG_ACPI
> @@ -878,32 +878,32 @@ static void ioapic_copy_alloc_attr(struc
>  
>   copy_irq_alloc_info(dst, src);
>   dst->type = X86_IRQ_ALLOC_TYPE_IOAPIC;
> - dst->ioapic_id = 

Re: [PATCH] iommu: Add support to filter non-strict/lazy mode based on device names

2020-08-26 Thread Sai Prakash Ranjan

Hi,

On 2020-08-26 03:45, Doug Anderson wrote:

Hi,

On Tue, Aug 25, 2020 at 12:01 PM Sai Prakash Ranjan
 wrote:


Hi,

On 2020-08-25 21:40, Doug Anderson wrote:
> Hi,
>
> On Tue, Aug 25, 2020 at 8:43 AM Sai Prakash Ranjan
>  wrote:
>>
>> Currently the non-strict or lazy mode of TLB invalidation can only be
>> set
>> for all or no domains. This works well for development platforms where
>> setting to non-strict/lazy mode is fine for performance reasons but on
>> production devices, we need a more fine grained control to allow only
>> certain peripherals to support this mode where we can be sure that it
>> is
>> safe. So add support to filter non-strict/lazy mode based on the
>> device
>> names that are passed via cmdline parameter "iommu.nonstrict_device".
>>
>> Example:
>> iommu.nonstrict_device="7c4000.sdhci,a60.dwc3,6048000.etr"


Just curious: are device names like this really guaranteed to be
stable across versions?



Good question, AFAIK the device names are based on the DT node address 
and
the node name, for ex:  etr@6048000 and device name - "6048000.etr", now 
I
believe these are pretty stable for a particular SoC or board since 
there
is no reason to change the device node name or the address unless 
something
has gone terribly wrong. I don't know about ACPI systems, but however 
they
are described can be specified in this command line parameter. This is 
an
advantage over the DT property where ACPI systems get left out unless 
someone

goes and adds the same/similar property over there.




> I have an inherent dislike of jamming things like this onto the
> command line.  IMHO the command line is the last resort for specifying
> configuration and generally should be limited to some specialized
> debug options and cases where the person running the kernel needs to
> override a config that was set by the person (or company) compiling
> the kernel.  Specifically, having a long/unwieldy command line makes
> it harder to use for the case when an end user actually wants to use
> it to override something.  It's also just another place to look for
> config.
>

Good thing about command line parameters are that they are optional,
they do
not specify any default behaviour (I mean they are not mandatory to be
set
for the system to be functional), so I would like to view it as an
optional
config. And this command line parameter (nonstrict_device) is strictly
optional
with default being strict already set in the driver.

They can be passed from the bootloader via chosen node for DT 
platforms

or choose
a new *bootconfig* as a way to pass the cmdline but finally it does 
boil

down to
just another config.


Never looked at bootconfig.  Unfortunately it seems to require
initramfs so that pretty much means it's out for my usage.  :(



Yes that won't fit everywhere.




I agree with general boolean or single value command line parameters
being just
more messy which could just be Kconfigs instead but for multiple value
parameters
like these do not fit in Kconfig.

As you might already know, command line also gives an advantage to the
end user
to configure system without building kernel, for this specific command
line its
very useful because the performance bump is quite noticeable when the
iommu.strict
is off. Now for end user who would not be interested in building 
entire

kernel(majority)
and just cares about good speeds or throughput can find this very
beneficial.
I am not talking about one specific OS usecase here but more in 
general

term.

> The other problem is that this doesn't necessarily scale very well.
> While it works OK for embedded cases it doesn't work terribly well for
> distributions.  I know that in an out-of-band thread you indicated
> that it doesn't break anything that's not already broken (AKA this
> doesn't fix the distro case but it doesn't make it worse), it would be
> better to come up with a more universal solution.
>

Is the universal solution here referring to fix all the command line
parameters
in the kernel or this specific command line? Are we going to remove 
any

more
addition to the cmdline ;)


There are very few cases where a kernel command line parameter is the
only way to configure something.  Most of the time it's just there to
override a config.  I wouldn't suggest removing those.  I just don't
want a kernel command line parameter to be the primary way to enable
something.



Agreed that command line parameters are not supposed to be some primary
way of setting things but an optional way to override settings, in this
case to override the strict mode already set by the driver. Then we can
probably agree that this command line is just an optional way provided
to the end user for his convenience? We would still need to find a 
primary
way to set this non-strict mode in drivers via DT passing the 
information

or some other way.




So possible other solution is the *bootconfig* which is again just
another place
to look for a config. So thing is that this universal 

[PATCH v9 31/32] media: pci: fix common ALSA DMA-mapping related codes

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that dma_map_sg returns the
numer of the created entries in the DMA address space. However the
subsequent calls to dma_sync_sg_for_{device,cpu} and dma_unmap_sg must be
called with the original number of entries passed to dma_map_sg. The
sg_table->nents in turn holds the result of the dma_map_sg call as stated
in include/linux/scatterlist.h. Adapt the code to obey those rules.

Signed-off-by: Marek Szyprowski 
---
 drivers/media/pci/cx23885/cx23885-alsa.c | 2 +-
 drivers/media/pci/cx25821/cx25821-alsa.c | 2 +-
 drivers/media/pci/cx88/cx88-alsa.c   | 2 +-
 drivers/media/pci/saa7134/saa7134-alsa.c | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/media/pci/cx23885/cx23885-alsa.c 
b/drivers/media/pci/cx23885/cx23885-alsa.c
index df44ed7393a0..3f366e4e4685 100644
--- a/drivers/media/pci/cx23885/cx23885-alsa.c
+++ b/drivers/media/pci/cx23885/cx23885-alsa.c
@@ -129,7 +129,7 @@ static int cx23885_alsa_dma_unmap(struct cx23885_audio_dev 
*dev)
if (!buf->sglen)
return 0;
 
-   dma_unmap_sg(>pci->dev, buf->sglist, buf->sglen, 
PCI_DMA_FROMDEVICE);
+   dma_unmap_sg(>pci->dev, buf->sglist, buf->nr_pages, 
PCI_DMA_FROMDEVICE);
buf->sglen = 0;
return 0;
 }
diff --git a/drivers/media/pci/cx25821/cx25821-alsa.c 
b/drivers/media/pci/cx25821/cx25821-alsa.c
index 301616426d8a..c40304d33776 100644
--- a/drivers/media/pci/cx25821/cx25821-alsa.c
+++ b/drivers/media/pci/cx25821/cx25821-alsa.c
@@ -193,7 +193,7 @@ static int cx25821_alsa_dma_unmap(struct cx25821_audio_dev 
*dev)
if (!buf->sglen)
return 0;
 
-   dma_unmap_sg(>pci->dev, buf->sglist, buf->sglen, 
PCI_DMA_FROMDEVICE);
+   dma_unmap_sg(>pci->dev, buf->sglist, buf->nr_pages, 
PCI_DMA_FROMDEVICE);
buf->sglen = 0;
return 0;
 }
diff --git a/drivers/media/pci/cx88/cx88-alsa.c 
b/drivers/media/pci/cx88/cx88-alsa.c
index 7d7aceecc985..3c6fe6ceb0b7 100644
--- a/drivers/media/pci/cx88/cx88-alsa.c
+++ b/drivers/media/pci/cx88/cx88-alsa.c
@@ -332,7 +332,7 @@ static int cx88_alsa_dma_unmap(struct cx88_audio_dev *dev)
if (!buf->sglen)
return 0;
 
-   dma_unmap_sg(>pci->dev, buf->sglist, buf->sglen,
+   dma_unmap_sg(>pci->dev, buf->sglist, buf->nr_pages,
 PCI_DMA_FROMDEVICE);
buf->sglen = 0;
return 0;
diff --git a/drivers/media/pci/saa7134/saa7134-alsa.c 
b/drivers/media/pci/saa7134/saa7134-alsa.c
index 544ca57eee75..398c47ff473d 100644
--- a/drivers/media/pci/saa7134/saa7134-alsa.c
+++ b/drivers/media/pci/saa7134/saa7134-alsa.c
@@ -313,7 +313,7 @@ static int saa7134_alsa_dma_unmap(struct saa7134_dev *dev)
if (!dma->sglen)
return 0;
 
-   dma_unmap_sg(>pci->dev, dma->sglist, dma->sglen, 
PCI_DMA_FROMDEVICE);
+   dma_unmap_sg(>pci->dev, dma->sglist, dma->nr_pages, 
PCI_DMA_FROMDEVICE);
dma->sglen = 0;
return 0;
 }
-- 
2.17.1

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[PATCH v9 28/32] misc: fastrpc: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
---
 drivers/misc/fastrpc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 7939c55daceb..9d6867749316 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -518,7 +518,7 @@ fastrpc_map_dma_buf(struct dma_buf_attachment *attachment,
 
table = >sgt;
 
-   if (!dma_map_sg(attachment->dev, table->sgl, table->nents, dir))
+   if (!dma_map_sgtable(attachment->dev, table, dir, 0))
return ERR_PTR(-ENOMEM);
 
return table;
@@ -528,7 +528,7 @@ static void fastrpc_unmap_dma_buf(struct dma_buf_attachment 
*attach,
  struct sg_table *table,
  enum dma_data_direction dir)
 {
-   dma_unmap_sg(attach->dev, table->sgl, table->nents, dir);
+   dma_unmap_sgtable(attach->dev, table, dir, 0);
 }
 
 static void fastrpc_release(struct dma_buf *dmabuf)
-- 
2.17.1

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[PATCH v9 32/32] videobuf2: use sgtable-based scatterlist wrappers

2020-08-26 Thread Marek Szyprowski
Use recently introduced common wrappers operating directly on the struct
sg_table objects and scatterlist page iterators to make the code a bit
more compact, robust, easier to follow and copy/paste safe.

No functional change, because the code already properly did all the
scaterlist related calls.

Signed-off-by: Marek Szyprowski 
---
 .../common/videobuf2/videobuf2-dma-contig.c   | 34 ---
 .../media/common/videobuf2/videobuf2-dma-sg.c | 32 +++--
 .../common/videobuf2/videobuf2-vmalloc.c  | 12 +++
 3 files changed, 31 insertions(+), 47 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c 
b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
index ec3446cc45b8..1b242d844dde 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -58,10 +58,10 @@ static unsigned long vb2_dc_get_contiguous_size(struct 
sg_table *sgt)
unsigned int i;
unsigned long size = 0;
 
-   for_each_sg(sgt->sgl, s, sgt->nents, i) {
+   for_each_sgtable_dma_sg(sgt, s, i) {
if (sg_dma_address(s) != expected)
break;
-   expected = sg_dma_address(s) + sg_dma_len(s);
+   expected += sg_dma_len(s);
size += sg_dma_len(s);
}
return size;
@@ -103,8 +103,7 @@ static void vb2_dc_prepare(void *buf_priv)
if (!sgt)
return;
 
-   dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
-  buf->dma_dir);
+   dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);
 }
 
 static void vb2_dc_finish(void *buf_priv)
@@ -115,7 +114,7 @@ static void vb2_dc_finish(void *buf_priv)
if (!sgt)
return;
 
-   dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
+   dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);
 }
 
 /*/
@@ -275,8 +274,8 @@ static void vb2_dc_dmabuf_ops_detach(struct dma_buf *dbuf,
 * memory locations do not require any explicit cache
 * maintenance prior or after being used by the device.
 */
-   dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents,
-  attach->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+   dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
sg_free_table(sgt);
kfree(attach);
db_attach->priv = NULL;
@@ -301,8 +300,8 @@ static struct sg_table *vb2_dc_dmabuf_ops_map(
 
/* release any previous cache */
if (attach->dma_dir != DMA_NONE) {
-   dma_unmap_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents,
-  attach->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+   dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
attach->dma_dir = DMA_NONE;
}
 
@@ -310,9 +309,8 @@ static struct sg_table *vb2_dc_dmabuf_ops_map(
 * mapping to the client with new direction, no cache sync
 * required see comment in vb2_dc_dmabuf_ops_detach()
 */
-   sgt->nents = dma_map_sg_attrs(db_attach->dev, sgt->sgl, sgt->orig_nents,
- dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
-   if (!sgt->nents) {
+   if (dma_map_sgtable(db_attach->dev, sgt, dma_dir,
+   DMA_ATTR_SKIP_CPU_SYNC)) {
pr_err("failed to map scatterlist\n");
mutex_unlock(lock);
return ERR_PTR(-EIO);
@@ -455,8 +453,8 @@ static void vb2_dc_put_userptr(void *buf_priv)
 * No need to sync to CPU, it's already synced to the CPU
 * since the finish() memop will have been called before this.
 */
-   dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
-  buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+   dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
pages = frame_vector_pages(buf->vec);
/* sgt should exist only if vector contains pages... */
BUG_ON(IS_ERR(pages));
@@ -553,9 +551,8 @@ static void *vb2_dc_get_userptr(struct device *dev, 
unsigned long vaddr,
 * No need to sync to the device, this will happen later when the
 * prepare() memop is called.
 */
-   sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
- buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
-   if (sgt->nents <= 0) {
+   if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
+   DMA_ATTR_SKIP_CPU_SYNC)) {
pr_err("failed to map scatterlist\n");

[PATCH v9 30/32] samples: vfio-mdev/mbochs: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

While touching this code, also add missing call to dma_unmap_sgtable.

Signed-off-by: Marek Szyprowski 
---
 samples/vfio-mdev/mbochs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index 3cc5e5921682..e03068917273 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -846,7 +846,7 @@ static struct sg_table *mbochs_map_dmabuf(struct 
dma_buf_attachment *at,
if (sg_alloc_table_from_pages(sg, dmabuf->pages, dmabuf->pagecount,
  0, dmabuf->mode.size, GFP_KERNEL) < 0)
goto err2;
-   if (!dma_map_sg(at->dev, sg->sgl, sg->nents, direction))
+   if (dma_map_sgtable(at->dev, sg, direction, 0))
goto err3;
 
return sg;
@@ -868,6 +868,7 @@ static void mbochs_unmap_dmabuf(struct dma_buf_attachment 
*at,
 
dev_dbg(dev, "%s: %d\n", __func__, dmabuf->id);
 
+   dma_unmap_sgtable(at->dev, sg, direction, 0);
sg_free_table(sg);
kfree(sg);
 }
-- 
2.17.1

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[PATCH v9 27/32] staging: tegra-vde: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
Reviewed-by: Dmitry Osipenko 
---
 drivers/staging/media/tegra-vde/iommu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/media/tegra-vde/iommu.c 
b/drivers/staging/media/tegra-vde/iommu.c
index 6af863d92123..adf8dc7ee25c 100644
--- a/drivers/staging/media/tegra-vde/iommu.c
+++ b/drivers/staging/media/tegra-vde/iommu.c
@@ -36,8 +36,8 @@ int tegra_vde_iommu_map(struct tegra_vde *vde,
 
addr = iova_dma_addr(>iova, iova);
 
-   size = iommu_map_sg(vde->domain, addr, sgt->sgl, sgt->nents,
-   IOMMU_READ | IOMMU_WRITE);
+   size = iommu_map_sgtable(vde->domain, addr, sgt,
+IOMMU_READ | IOMMU_WRITE);
if (!size) {
__free_iova(>iova, iova);
return -ENXIO;
-- 
2.17.1

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[PATCH v9 24/32] drm: host1x: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
---
 drivers/gpu/host1x/job.c | 22 --
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/host1x/job.c b/drivers/gpu/host1x/job.c
index 89b6c14b7392..82d0a60ba3f7 100644
--- a/drivers/gpu/host1x/job.c
+++ b/drivers/gpu/host1x/job.c
@@ -170,11 +170,9 @@ static unsigned int pin_job(struct host1x *host, struct 
host1x_job *job)
goto unpin;
}
 
-   err = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
-   if (!err) {
-   err = -ENOMEM;
+   err = dma_map_sgtable(dev, sgt, dir, 0);
+   if (err)
goto unpin;
-   }
 
job->unpins[job->num_unpins].dev = dev;
job->unpins[job->num_unpins].dir = dir;
@@ -228,7 +226,7 @@ static unsigned int pin_job(struct host1x *host, struct 
host1x_job *job)
}
 
if (host->domain) {
-   for_each_sg(sgt->sgl, sg, sgt->nents, j)
+   for_each_sgtable_sg(sgt, sg, j)
gather_size += sg->length;
gather_size = iova_align(>iova, gather_size);
 
@@ -240,9 +238,9 @@ static unsigned int pin_job(struct host1x *host, struct 
host1x_job *job)
goto put;
}
 
-   err = iommu_map_sg(host->domain,
+   err = iommu_map_sgtable(host->domain,
iova_dma_addr(>iova, alloc),
-   sgt->sgl, sgt->nents, IOMMU_READ);
+   sgt, IOMMU_READ);
if (err == 0) {
__free_iova(>iova, alloc);
err = -EINVAL;
@@ -252,12 +250,9 @@ static unsigned int pin_job(struct host1x *host, struct 
host1x_job *job)
job->unpins[job->num_unpins].size = gather_size;
phys_addr = iova_dma_addr(>iova, alloc);
} else if (sgt) {
-   err = dma_map_sg(host->dev, sgt->sgl, sgt->nents,
-DMA_TO_DEVICE);
-   if (!err) {
-   err = -ENOMEM;
+   err = dma_map_sgtable(host->dev, sgt, DMA_TO_DEVICE, 0);
+   if (err)
goto put;
-   }
 
job->unpins[job->num_unpins].dir = DMA_TO_DEVICE;
job->unpins[job->num_unpins].dev = host->dev;
@@ -660,8 +655,7 @@ void host1x_job_unpin(struct host1x_job *job)
}
 
if (unpin->dev && sgt)
-   dma_unmap_sg(unpin->dev, sgt->sgl, sgt->nents,
-unpin->dir);
+   dma_unmap_sgtable(unpin->dev, sgt, unpin->dir, 0);
 
host1x_bo_unpin(dev, unpin->bo, sgt);
host1x_bo_put(unpin->bo);
-- 
2.17.1

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[PATCH v9 25/32] drm: rcar-du: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

dma_map_sgtable() function returns zero or an error code, so adjust the
return value check for the vsp1_du_map_sg() function.

Signed-off-by: Marek Szyprowski 
Reviewed-by: Laurent Pinchart 
---
 drivers/gpu/drm/rcar-du/rcar_du_vsp.c  | 3 +--
 drivers/media/platform/vsp1/vsp1_drm.c | 8 
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c 
b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
index f1a81c9b184d..a27bff999649 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
@@ -197,9 +197,8 @@ int rcar_du_vsp_map_fb(struct rcar_du_vsp *vsp, struct 
drm_framebuffer *fb,
goto fail;
 
ret = vsp1_du_map_sg(vsp->vsp, sgt);
-   if (!ret) {
+   if (ret) {
sg_free_table(sgt);
-   ret = -ENOMEM;
goto fail;
}
}
diff --git a/drivers/media/platform/vsp1/vsp1_drm.c 
b/drivers/media/platform/vsp1/vsp1_drm.c
index a4a45d68a6ef..86d5e3f4b1ff 100644
--- a/drivers/media/platform/vsp1/vsp1_drm.c
+++ b/drivers/media/platform/vsp1/vsp1_drm.c
@@ -912,8 +912,8 @@ int vsp1_du_map_sg(struct device *dev, struct sg_table *sgt)
 * skip cache sync. This will need to be revisited when support for
 * non-coherent buffers will be added to the DU driver.
 */
-   return dma_map_sg_attrs(vsp1->bus_master, sgt->sgl, sgt->nents,
-   DMA_TO_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
+   return dma_map_sgtable(vsp1->bus_master, sgt, DMA_TO_DEVICE,
+  DMA_ATTR_SKIP_CPU_SYNC);
 }
 EXPORT_SYMBOL_GPL(vsp1_du_map_sg);
 
@@ -921,8 +921,8 @@ void vsp1_du_unmap_sg(struct device *dev, struct sg_table 
*sgt)
 {
struct vsp1_device *vsp1 = dev_get_drvdata(dev);
 
-   dma_unmap_sg_attrs(vsp1->bus_master, sgt->sgl, sgt->nents,
-  DMA_TO_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
+   dma_unmap_sgtable(vsp1->bus_master, sgt, DMA_TO_DEVICE,
+ DMA_ATTR_SKIP_CPU_SYNC);
 }
 EXPORT_SYMBOL_GPL(vsp1_du_unmap_sg);
 
-- 
2.17.1

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[PATCH v9 00/32] DRM: fix struct sg_table nents vs. orig_nents misuse

2020-08-26 Thread Marek Szyprowski
Dear All,

During the Exynos DRM GEM rework and fixing the issues in the.
drm_prime_sg_to_page_addr_arrays() function [1] I've noticed that most
drivers in DRM framework incorrectly use nents and orig_nents entries of
the struct sg_table.

In case of the most DMA-mapping implementations exchanging those two
entries or using nents for all loops on the scatterlist is harmless,
because they both have the same value. There exists however a DMA-mapping
implementations, for which such incorrect usage breaks things. The nents
returned by dma_map_sg() might be lower than the nents passed as its
parameter and this is perfectly fine. DMA framework or IOMMU is allowed
to join consecutive chunks while mapping if such operation is supported
by the underlying HW (bus, bridge, IOMMU, etc). Example of the case
where dma_map_sg() might return 1 'DMA' chunk for the 4 'physical' pages
is described here [2]

The DMA-mapping framework documentation [3] states that dma_map_sg()
returns the numer of the created entries in the DMA address space.
However the subsequent calls to dma_sync_sg_for_{device,cpu} and
dma_unmap_sg must be called with the original number of entries passed to
dma_map_sg. The common pattern in DRM drivers were to assign the
dma_map_sg() return value to sg_table->nents and use that value for
the subsequent calls to dma_sync_sg_* or dma_unmap_sg functions. Also
the code iterated over nents times to access the pages stored in the
processed scatterlist, while it should use orig_nents as the numer of
the page entries.

I've tried to identify all such incorrect usage of sg_table->nents and
this is a result of my research. It looks that the incorrect pattern has
been copied over the many drivers mainly in the DRM subsystem. Too bad in
most cases it even worked correctly if the system used a simple, linear
DMA-mapping implementation, for which swapping nents and orig_nents
doesn't make any difference. To avoid similar issues in the future, I've
introduced a common wrappers for DMA-mapping calls, which operate directly
on the sg_table objects. I've also added wrappers for iterating over the
scatterlists stored in the sg_table objects and applied them where
possible. This, together with some common DRM prime helpers, allowed me
to almost get rid of all nents/orig_nents usage in the drivers. I hope
that such change makes the code robust, easier to follow and copy/paste
safe.

The biggest TODO is DRM/i915 driver and I don't feel brave enough to fix
it fully. The driver creatively uses sg_table->orig_nents to store the
size of the allocate scatterlist and ignores the number of the entries
returned by dma_map_sg function. In this patchset I only fixed the
sg_table objects exported by dmabuf related functions. I hope that I
didn't break anything there.

Patches are based on top of Linux next-20200825. The required changes to
DMA-mapping framework has been already merged to v5.8-rc1.

I would like ask for merging of the 1-27 patches via DRM misc tree.

Best regards,
Marek Szyprowski


References:

[1] https://lkml.org/lkml/2020/3/27/555
[2] https://lkml.org/lkml/2020/3/29/65
[3] Documentation/DMA-API-HOWTO.txt
[4] 
https://lore.kernel.org/linux-iommu/20200512121931.gd20...@lst.de/T/#ma18c958a48c3b241d5409517fa7d192eef87459b

Changelog:

v9:
- rebased onto Linux next-20200825, which is based on v5.9-rc2; fixed conflicts
- dropped merged patches

v8:
- rapidio: fixed issues pointed by kbuilt test robot (use of uninitialized
variable
- vb2: rebased after recent changes in the code

v7: 
https://lore.kernel.org/linux-iommu/20200619103636.11974-1-m.szyprow...@samsung.com/T/
- changed DMA page interators to standard DMA SG iterators in drm/prime and
  videobuf2-dma-contig as suggested by Robin Murphy
- fixed build issues

v6: 
https://lore.kernel.org/linux-iommu/20200618153956.29558-1-m.szyprow...@samsung.com/T/
- rebased onto Linux next-20200618, which is based on v5.8-rc1; fixed conflicts

v5: 
https://lore.kernel.org/linux-iommu/20200513132114.6046-1-m.szyprow...@samsung.com/T/
- fixed some minor style issues and typos
- fixed lack of the attrs argument in ion, dmabuf, rapidio, fastrpc and
  vfio patches

v4: https://lore.kernel.org/linux-iommu/20200512121931.gd20...@lst.de/T/
- added for_each_sgtable_* wrappers and applied where possible
- added drm_prime_get_contiguous_size() and applied where possible
- applied drm_prime_sg_to_page_addr_arrays() where possible to remove page
  extraction from sg_table objects
- added documentation for the introduced wrappers
- improved patches description a bit

v3: 
https://lore.kernel.org/dri-devel/20200505083926.28503-1-m.szyprow...@samsung.com/
- introduce dma_*_sgtable_* wrappers and use them in all patches

v2: 
https://lore.kernel.org/linux-iommu/c01c9766-9778-fd1f-f36e-2dc7bd376...@arm.com/T/
- dropped most of the changes to drm/i915
- added fixes for rcar-du, xen, media and ion
- fixed a few issues pointed by kbuild test robot
- added wide cc: list for each patch

v1: 

[PATCH v9 17/32] drm: rockchip: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
---
 drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 23 +
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c 
b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index 2970e534e2bb..cb50f2ba2e46 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -36,8 +36,8 @@ static int rockchip_gem_iommu_map(struct rockchip_gem_object 
*rk_obj)
 
rk_obj->dma_addr = rk_obj->mm.start;
 
-   ret = iommu_map_sg(private->domain, rk_obj->dma_addr, rk_obj->sgt->sgl,
-  rk_obj->sgt->nents, prot);
+   ret = iommu_map_sgtable(private->domain, rk_obj->dma_addr, rk_obj->sgt,
+   prot);
if (ret < rk_obj->base.size) {
DRM_ERROR("failed to map buffer: size=%zd request_size=%zd\n",
  ret, rk_obj->base.size);
@@ -98,11 +98,10 @@ static int rockchip_gem_get_pages(struct 
rockchip_gem_object *rk_obj)
 * TODO: Replace this by drm_clflush_sg() once it can be implemented
 * without relying on symbols that are not exported.
 */
-   for_each_sg(rk_obj->sgt->sgl, s, rk_obj->sgt->nents, i)
+   for_each_sgtable_sg(rk_obj->sgt, s, i)
sg_dma_address(s) = sg_phys(s);
 
-   dma_sync_sg_for_device(drm->dev, rk_obj->sgt->sgl, rk_obj->sgt->nents,
-  DMA_TO_DEVICE);
+   dma_sync_sgtable_for_device(drm->dev, rk_obj->sgt, DMA_TO_DEVICE);
 
return 0;
 
@@ -350,8 +349,8 @@ void rockchip_gem_free_object(struct drm_gem_object *obj)
if (private->domain) {
rockchip_gem_iommu_unmap(rk_obj);
} else {
-   dma_unmap_sg(drm->dev, rk_obj->sgt->sgl,
-rk_obj->sgt->nents, DMA_BIDIRECTIONAL);
+   dma_unmap_sgtable(drm->dev, rk_obj->sgt,
+ DMA_BIDIRECTIONAL, 0);
}
drm_prime_gem_destroy(obj, rk_obj->sgt);
} else {
@@ -476,15 +475,13 @@ rockchip_gem_dma_map_sg(struct drm_device *drm,
struct sg_table *sg,
struct rockchip_gem_object *rk_obj)
 {
-   int count = dma_map_sg(drm->dev, sg->sgl, sg->nents,
-  DMA_BIDIRECTIONAL);
-   if (!count)
-   return -EINVAL;
+   int err = dma_map_sgtable(drm->dev, sg, DMA_BIDIRECTIONAL, 0);
+   if (err)
+   return err;
 
if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
DRM_ERROR("failed to map sg_table to contiguous linear 
address.\n");
-   dma_unmap_sg(drm->dev, sg->sgl, sg->nents,
-DMA_BIDIRECTIONAL);
+   dma_unmap_sgtable(drm->dev, sg, DMA_BIDIRECTIONAL, 0);
return -EINVAL;
}
 
-- 
2.17.1

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[PATCH v9 23/32] xen: gntdev: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
Acked-by: Juergen Gross 
---
 drivers/xen/gntdev-dmabuf.c | 13 ++---
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/xen/gntdev-dmabuf.c b/drivers/xen/gntdev-dmabuf.c
index b1b6eebafd5d..4c13cbc99896 100644
--- a/drivers/xen/gntdev-dmabuf.c
+++ b/drivers/xen/gntdev-dmabuf.c
@@ -247,10 +247,9 @@ static void dmabuf_exp_ops_detach(struct dma_buf *dma_buf,
 
if (sgt) {
if (gntdev_dmabuf_attach->dir != DMA_NONE)
-   dma_unmap_sg_attrs(attach->dev, sgt->sgl,
-  sgt->nents,
-  gntdev_dmabuf_attach->dir,
-  DMA_ATTR_SKIP_CPU_SYNC);
+   dma_unmap_sgtable(attach->dev, sgt,
+ gntdev_dmabuf_attach->dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
sg_free_table(sgt);
}
 
@@ -288,8 +287,8 @@ dmabuf_exp_ops_map_dma_buf(struct dma_buf_attachment 
*attach,
sgt = dmabuf_pages_to_sgt(gntdev_dmabuf->pages,
  gntdev_dmabuf->nr_pages);
if (!IS_ERR(sgt)) {
-   if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
- DMA_ATTR_SKIP_CPU_SYNC)) {
+   if (dma_map_sgtable(attach->dev, sgt, dir,
+   DMA_ATTR_SKIP_CPU_SYNC)) {
sg_free_table(sgt);
kfree(sgt);
sgt = ERR_PTR(-ENOMEM);
@@ -633,7 +632,7 @@ dmabuf_imp_to_refs(struct gntdev_dmabuf_priv *priv, struct 
device *dev,
 
/* Now convert sgt to array of pages and check for page validity. */
i = 0;
-   for_each_sg_page(sgt->sgl, _iter, sgt->nents, 0) {
+   for_each_sgtable_page(sgt, _iter, 0) {
struct page *page = sg_page_iter_page(_iter);
/*
 * Check if page is valid: this can happen if we are given
-- 
2.17.1

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[PATCH v9 03/32] drm: core: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
Reviewed-by: Andrzej Hajda 
---
 drivers/gpu/drm/drm_cache.c|  2 +-
 drivers/gpu/drm/drm_gem_shmem_helper.c | 14 +-
 drivers/gpu/drm/drm_prime.c| 11 ++-
 3 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
index 03e01b000f7a..0fe3c496002a 100644
--- a/drivers/gpu/drm/drm_cache.c
+++ b/drivers/gpu/drm/drm_cache.c
@@ -127,7 +127,7 @@ drm_clflush_sg(struct sg_table *st)
struct sg_page_iter sg_iter;
 
mb(); /*CLFLUSH is ordered only by using memory barriers*/
-   for_each_sg_page(st->sgl, _iter, st->nents, 0)
+   for_each_sgtable_page(st, _iter, 0)
drm_clflush_page(sg_page_iter_page(_iter));
mb(); /*Make sure that all cache line entry is flushed*/
 
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c 
b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 4b7cfbac4daa..47d8211221f2 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -126,8 +126,8 @@ void drm_gem_shmem_free_object(struct drm_gem_object *obj)
drm_prime_gem_destroy(obj, shmem->sgt);
} else {
if (shmem->sgt) {
-   dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
-shmem->sgt->nents, DMA_BIDIRECTIONAL);
+   dma_unmap_sgtable(obj->dev->dev, shmem->sgt,
+ DMA_BIDIRECTIONAL, 0);
sg_free_table(shmem->sgt);
kfree(shmem->sgt);
}
@@ -424,8 +424,7 @@ void drm_gem_shmem_purge_locked(struct drm_gem_object *obj)
 
WARN_ON(!drm_gem_shmem_is_purgeable(shmem));
 
-   dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
-shmem->sgt->nents, DMA_BIDIRECTIONAL);
+   dma_unmap_sgtable(obj->dev->dev, shmem->sgt, DMA_BIDIRECTIONAL, 0);
sg_free_table(shmem->sgt);
kfree(shmem->sgt);
shmem->sgt = NULL;
@@ -697,12 +696,17 @@ struct sg_table *drm_gem_shmem_get_pages_sgt(struct 
drm_gem_object *obj)
goto err_put_pages;
}
/* Map the pages for use by the h/w. */
-   dma_map_sg(obj->dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL);
+   ret = dma_map_sgtable(obj->dev->dev, sgt, DMA_BIDIRECTIONAL, 0);
+   if (ret)
+   goto err_free_sgt;
 
shmem->sgt = sgt;
 
return sgt;
 
+err_free_sgt:
+   sg_free_table(sgt);
+   kfree(sgt);
 err_put_pages:
drm_gem_shmem_put_pages(shmem);
return ERR_PTR(ret);
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 5d181bf60a44..c45b0cc6e31d 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -617,6 +617,7 @@ struct sg_table *drm_gem_map_dma_buf(struct 
dma_buf_attachment *attach,
 {
struct drm_gem_object *obj = attach->dmabuf->priv;
struct sg_table *sgt;
+   int ret;
 
if (WARN_ON(dir == DMA_NONE))
return ERR_PTR(-EINVAL);
@@ -626,11 +627,12 @@ struct sg_table *drm_gem_map_dma_buf(struct 
dma_buf_attachment *attach,
else
sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
 
-   if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
- DMA_ATTR_SKIP_CPU_SYNC)) {
+   ret = dma_map_sgtable(attach->dev, sgt, dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
+   if (ret) {
sg_free_table(sgt);
kfree(sgt);
-   sgt = ERR_PTR(-ENOMEM);
+   sgt = ERR_PTR(ret);
}
 
return sgt;
@@ -652,8 +654,7 @@ void drm_gem_unmap_dma_buf(struct 

[PATCH v9 26/32] dmabuf: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
Acked-by: Gerd Hoffmann 
---
 drivers/dma-buf/heaps/heap-helpers.c | 13 ++---
 drivers/dma-buf/udmabuf.c|  7 +++
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/dma-buf/heaps/heap-helpers.c 
b/drivers/dma-buf/heaps/heap-helpers.c
index 9f964ca3f59c..d0696cf937af 100644
--- a/drivers/dma-buf/heaps/heap-helpers.c
+++ b/drivers/dma-buf/heaps/heap-helpers.c
@@ -140,13 +140,12 @@ struct sg_table *dma_heap_map_dma_buf(struct 
dma_buf_attachment *attachment,
  enum dma_data_direction direction)
 {
struct dma_heaps_attachment *a = attachment->priv;
-   struct sg_table *table;
-
-   table = >table;
+   struct sg_table *table = >table;
+   int ret;
 
-   if (!dma_map_sg(attachment->dev, table->sgl, table->nents,
-   direction))
-   table = ERR_PTR(-ENOMEM);
+   ret = dma_map_sgtable(attachment->dev, table, direction, 0);
+   if (ret)
+   table = ERR_PTR(ret);
return table;
 }
 
@@ -154,7 +153,7 @@ static void dma_heap_unmap_dma_buf(struct 
dma_buf_attachment *attachment,
   struct sg_table *table,
   enum dma_data_direction direction)
 {
-   dma_unmap_sg(attachment->dev, table->sgl, table->nents, direction);
+   dma_unmap_sgtable(attachment->dev, table, direction, 0);
 }
 
 static vm_fault_t dma_heap_vm_fault(struct vm_fault *vmf)
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index acb26c627d27..89e293bd9252 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -63,10 +63,9 @@ static struct sg_table *get_sg_table(struct device *dev, 
struct dma_buf *buf,
GFP_KERNEL);
if (ret < 0)
goto err;
-   if (!dma_map_sg(dev, sg->sgl, sg->nents, direction)) {
-   ret = -EINVAL;
+   ret = dma_map_sgtable(dev, sg, direction, 0);
+   if (ret < 0)
goto err;
-   }
return sg;
 
 err:
@@ -78,7 +77,7 @@ static struct sg_table *get_sg_table(struct device *dev, 
struct dma_buf *buf,
 static void put_sg_table(struct device *dev, struct sg_table *sg,
 enum dma_data_direction direction)
 {
-   dma_unmap_sg(dev, sg->sgl, sg->nents, direction);
+   dma_unmap_sgtable(dev, sg, direction, 0);
sg_free_table(sg);
kfree(sg);
 }
-- 
2.17.1

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[PATCH v9 16/32] drm: rockchip: use common helper for a scatterlist contiguity check

2020-08-26 Thread Marek Szyprowski
Use common helper for checking the contiguity of the imported dma-buf.

Signed-off-by: Marek Szyprowski 
---
 drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 19 +--
 1 file changed, 1 insertion(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c 
b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index b9275ba7c5a5..2970e534e2bb 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -460,23 +460,6 @@ struct sg_table *rockchip_gem_prime_get_sg_table(struct 
drm_gem_object *obj)
return sgt;
 }
 
-static unsigned long rockchip_sg_get_contiguous_size(struct sg_table *sgt,
-int count)
-{
-   struct scatterlist *s;
-   dma_addr_t expected = sg_dma_address(sgt->sgl);
-   unsigned int i;
-   unsigned long size = 0;
-
-   for_each_sg(sgt->sgl, s, count, i) {
-   if (sg_dma_address(s) != expected)
-   break;
-   expected = sg_dma_address(s) + sg_dma_len(s);
-   size += sg_dma_len(s);
-   }
-   return size;
-}
-
 static int
 rockchip_gem_iommu_map_sg(struct drm_device *drm,
  struct dma_buf_attachment *attach,
@@ -498,7 +481,7 @@ rockchip_gem_dma_map_sg(struct drm_device *drm,
if (!count)
return -EINVAL;
 
-   if (rockchip_sg_get_contiguous_size(sg, count) < attach->dmabuf->size) {
+   if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
DRM_ERROR("failed to map sg_table to contiguous linear 
address.\n");
dma_unmap_sg(drm->dev, sg->sgl, sg->nents,
 DMA_BIDIRECTIONAL);
-- 
2.17.1

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[PATCH v9 21/32] drm: vmwgfx: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
Acked-by: Roland Scheidegger 
---
 drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c | 17 -
 1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c 
b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
index ab524ab3b0b4..f2f2bff1eedf 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
@@ -362,8 +362,7 @@ static void vmw_ttm_unmap_from_dma(struct vmw_ttm_tt 
*vmw_tt)
 {
struct device *dev = vmw_tt->dev_priv->dev->dev;
 
-   dma_unmap_sg(dev, vmw_tt->sgt.sgl, vmw_tt->sgt.nents,
-   DMA_BIDIRECTIONAL);
+   dma_unmap_sgtable(dev, _tt->sgt, DMA_BIDIRECTIONAL, 0);
vmw_tt->sgt.nents = vmw_tt->sgt.orig_nents;
 }
 
@@ -383,16 +382,8 @@ static void vmw_ttm_unmap_from_dma(struct vmw_ttm_tt 
*vmw_tt)
 static int vmw_ttm_map_for_dma(struct vmw_ttm_tt *vmw_tt)
 {
struct device *dev = vmw_tt->dev_priv->dev->dev;
-   int ret;
-
-   ret = dma_map_sg(dev, vmw_tt->sgt.sgl, vmw_tt->sgt.orig_nents,
-DMA_BIDIRECTIONAL);
-   if (unlikely(ret == 0))
-   return -ENOMEM;
 
-   vmw_tt->sgt.nents = ret;
-
-   return 0;
+   return dma_map_sgtable(dev, _tt->sgt, DMA_BIDIRECTIONAL, 0);
 }
 
 /**
@@ -449,10 +440,10 @@ static int vmw_ttm_map_dma(struct vmw_ttm_tt *vmw_tt)
if (unlikely(ret != 0))
goto out_sg_alloc_fail;
 
-   if (vsgt->num_pages > vmw_tt->sgt.nents) {
+   if (vsgt->num_pages > vmw_tt->sgt.orig_nents) {
uint64_t over_alloc =
sgl_size * (vsgt->num_pages -
-   vmw_tt->sgt.nents);
+   vmw_tt->sgt.orig_nents);
 
ttm_mem_global_free(glob, over_alloc);
vmw_tt->sg_alloc_size -= over_alloc;
-- 
2.17.1

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[PATCH v9 19/32] drm: v3d: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
Reviewed-by: Eric Anholt 
---
 drivers/gpu/drm/v3d/v3d_mmu.c | 13 ++---
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/v3d/v3d_mmu.c b/drivers/gpu/drm/v3d/v3d_mmu.c
index 3b81ea28c0bb..5a453532901f 100644
--- a/drivers/gpu/drm/v3d/v3d_mmu.c
+++ b/drivers/gpu/drm/v3d/v3d_mmu.c
@@ -90,18 +90,17 @@ void v3d_mmu_insert_ptes(struct v3d_bo *bo)
struct v3d_dev *v3d = to_v3d_dev(shmem_obj->base.dev);
u32 page = bo->node.start;
u32 page_prot = V3D_PTE_WRITEABLE | V3D_PTE_VALID;
-   unsigned int count;
-   struct scatterlist *sgl;
+   struct sg_dma_page_iter dma_iter;
 
-   for_each_sg(shmem_obj->sgt->sgl, sgl, shmem_obj->sgt->nents, count) {
-   u32 page_address = sg_dma_address(sgl) >> V3D_MMU_PAGE_SHIFT;
+   for_each_sgtable_dma_page(shmem_obj->sgt, _iter, 0) {
+   dma_addr_t dma_addr = sg_page_iter_dma_address(_iter);
+   u32 page_address = dma_addr >> V3D_MMU_PAGE_SHIFT;
u32 pte = page_prot | page_address;
u32 i;
 
-   BUG_ON(page_address + (sg_dma_len(sgl) >> V3D_MMU_PAGE_SHIFT) >=
+   BUG_ON(page_address + (PAGE_SIZE >> V3D_MMU_PAGE_SHIFT) >=
   BIT(24));
-
-   for (i = 0; i < sg_dma_len(sgl) >> V3D_MMU_PAGE_SHIFT; i++)
+   for (i = 0; i < PAGE_SIZE >> V3D_MMU_PAGE_SHIFT; i++)
v3d->pt[page++] = pte + i;
}
 
-- 
2.17.1

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[PATCH v9 08/32] drm: i915: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

This driver creatively uses sg_table->orig_nents to store the size of the
allocated scatterlist and ignores the number of the entries returned by
dma_map_sg function. The sg_table->orig_nents is (mis)used to properly
free the (over)allocated scatterlist.

This patch only introduces the common DMA-mapping wrappers operating
directly on the struct sg_table objects to the dmabuf related functions,
so the other drivers, which might share buffers with i915 could rely on
the properly set nents and orig_nents values.

Signed-off-by: Marek Szyprowski 
---
 drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c   | 11 +++
 drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c |  7 +++
 2 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c 
b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
index 2679380159fc..8a988592715b 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
@@ -48,12 +48,9 @@ static struct sg_table *i915_gem_map_dma_buf(struct 
dma_buf_attachment *attachme
src = sg_next(src);
}
 
-   if (!dma_map_sg_attrs(attachment->dev,
- st->sgl, st->nents, dir,
- DMA_ATTR_SKIP_CPU_SYNC)) {
-   ret = -ENOMEM;
+   ret = dma_map_sgtable(attachment->dev, st, dir, DMA_ATTR_SKIP_CPU_SYNC);
+   if (ret)
goto err_free_sg;
-   }
 
return st;
 
@@ -73,9 +70,7 @@ static void i915_gem_unmap_dma_buf(struct dma_buf_attachment 
*attachment,
 {
struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
 
-   dma_unmap_sg_attrs(attachment->dev,
-  sg->sgl, sg->nents, dir,
-  DMA_ATTR_SKIP_CPU_SYNC);
+   dma_unmap_sgtable(attachment->dev, sg, dir, DMA_ATTR_SKIP_CPU_SYNC);
sg_free_table(sg);
kfree(sg);
 
diff --git a/drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c 
b/drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c
index debaf7b18ab5..be30b27e2926 100644
--- a/drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c
@@ -28,10 +28,9 @@ static struct sg_table *mock_map_dma_buf(struct 
dma_buf_attachment *attachment,
sg = sg_next(sg);
}
 
-   if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) {
-   err = -ENOMEM;
+   err = dma_map_sgtable(attachment->dev, st, dir, 0);
+   if (err)
goto err_st;
-   }
 
return st;
 
@@ -46,7 +45,7 @@ static void mock_unmap_dma_buf(struct dma_buf_attachment 
*attachment,
   struct sg_table *st,
   enum dma_data_direction dir)
 {
-   dma_unmap_sg(attachment->dev, st->sgl, st->nents, dir);
+   dma_unmap_sgtable(attachment->dev, st, dir, 0);
sg_free_table(st);
kfree(st);
 }
-- 
2.17.1

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[PATCH v9 29/32] rapidio: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
---
 drivers/rapidio/devices/rio_mport_cdev.c | 11 ---
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/rapidio/devices/rio_mport_cdev.c 
b/drivers/rapidio/devices/rio_mport_cdev.c
index a30342942e26..89eb3d212652 100644
--- a/drivers/rapidio/devices/rio_mport_cdev.c
+++ b/drivers/rapidio/devices/rio_mport_cdev.c
@@ -573,8 +573,7 @@ static void dma_req_free(struct kref *ref)
refcount);
struct mport_cdev_priv *priv = req->priv;
 
-   dma_unmap_sg(req->dmach->device->dev,
-req->sgt.sgl, req->sgt.nents, req->dir);
+   dma_unmap_sgtable(req->dmach->device->dev, >sgt, req->dir, 0);
sg_free_table(>sgt);
if (req->page_list) {
unpin_user_pages(req->page_list, req->nr_pages);
@@ -814,7 +813,6 @@ rio_dma_transfer(struct file *filp, u32 transfer_mode,
struct mport_dev *md = priv->md;
struct dma_chan *chan;
int ret;
-   int nents;
 
if (xfer->length == 0)
return -EINVAL;
@@ -930,15 +928,14 @@ rio_dma_transfer(struct file *filp, u32 transfer_mode,
xfer->offset, xfer->length);
}
 
-   nents = dma_map_sg(chan->device->dev,
-  req->sgt.sgl, req->sgt.nents, dir);
-   if (nents == 0) {
+   ret = dma_map_sgtable(chan->device->dev, >sgt, dir, 0);
+   if (ret) {
rmcd_error("Failed to map SG list");
ret = -EFAULT;
goto err_pg;
}
 
-   ret = do_dma_request(req, xfer, sync, nents);
+   ret = do_dma_request(req, xfer, sync, req->sgt.nents);
 
if (ret >= 0) {
if (sync == RIO_TRANSFER_ASYNC)
-- 
2.17.1

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[PATCH v9 01/32] drm: prime: add common helper to check scatterlist contiguity

2020-08-26 Thread Marek Szyprowski
It is a common operation done by DRM drivers to check the contiguity
of the DMA-mapped buffer described by a scatterlist in the
sg_table object. Let's add a common helper for this operation.

Signed-off-by: Marek Szyprowski 
Reviewed-by: Andrzej Hajda 
---
 drivers/gpu/drm/drm_gem_cma_helper.c | 23 +++--
 drivers/gpu/drm/drm_prime.c  | 31 
 include/drm/drm_prime.h  |  2 ++
 3 files changed, 36 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c 
b/drivers/gpu/drm/drm_gem_cma_helper.c
index 822edeadbab3..59b9ca207b42 100644
--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -471,26 +471,9 @@ drm_gem_cma_prime_import_sg_table(struct drm_device *dev,
 {
struct drm_gem_cma_object *cma_obj;
 
-   if (sgt->nents != 1) {
-   /* check if the entries in the sg_table are contiguous */
-   dma_addr_t next_addr = sg_dma_address(sgt->sgl);
-   struct scatterlist *s;
-   unsigned int i;
-
-   for_each_sg(sgt->sgl, s, sgt->nents, i) {
-   /*
-* sg_dma_address(s) is only valid for entries
-* that have sg_dma_len(s) != 0
-*/
-   if (!sg_dma_len(s))
-   continue;
-
-   if (sg_dma_address(s) != next_addr)
-   return ERR_PTR(-EINVAL);
-
-   next_addr = sg_dma_address(s) + sg_dma_len(s);
-   }
-   }
+   /* check if the entries in the sg_table are contiguous */
+   if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size)
+   return ERR_PTR(-EINVAL);
 
/* Create a CMA GEM buffer. */
cma_obj = __drm_gem_cma_create(dev, attach->dmabuf->size);
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 1693aa7c14b5..4ed5ed1f078c 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -825,6 +825,37 @@ struct sg_table *drm_prime_pages_to_sg(struct page 
**pages, unsigned int nr_page
 }
 EXPORT_SYMBOL(drm_prime_pages_to_sg);
 
+/**
+ * drm_prime_get_contiguous_size - returns the contiguous size of the buffer
+ * @sgt: sg_table describing the buffer to check
+ *
+ * This helper calculates the contiguous size in the DMA address space
+ * of the the buffer described by the provided sg_table.
+ *
+ * This is useful for implementing
+ * _gem_object_funcs.gem_prime_import_sg_table.
+ */
+unsigned long drm_prime_get_contiguous_size(struct sg_table *sgt)
+{
+   dma_addr_t expected = sg_dma_address(sgt->sgl);
+   struct scatterlist *sg;
+   unsigned long size = 0;
+   int i;
+
+   for_each_sgtable_dma_sg(sgt, sg, i) {
+   unsigned int len = sg_dma_len(sg);
+
+   if (!len)
+   break;
+   if (sg_dma_address(sg) != expected)
+   break;
+   expected += len;
+   size += len;
+   }
+   return size;
+}
+EXPORT_SYMBOL(drm_prime_get_contiguous_size);
+
 /**
  * drm_gem_prime_export - helper library implementation of the export callback
  * @obj: GEM object to export
diff --git a/include/drm/drm_prime.h b/include/drm/drm_prime.h
index 9af7422b44cf..47ef11614627 100644
--- a/include/drm/drm_prime.h
+++ b/include/drm/drm_prime.h
@@ -92,6 +92,8 @@ struct sg_table *drm_prime_pages_to_sg(struct page **pages, 
unsigned int nr_page
 struct dma_buf *drm_gem_prime_export(struct drm_gem_object *obj,
 int flags);
 
+unsigned long drm_prime_get_contiguous_size(struct sg_table *sgt);
+
 /* helper functions for importing */
 struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev,
struct dma_buf *dma_buf,
-- 
2.17.1

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[PATCH v9 07/32] drm: exynos: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
Reviewed-by: Andrzej Hajda 
Acked-by : Inki Dae 
---
 drivers/gpu/drm/exynos/exynos_drm_g2d.c | 10 +-
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c 
b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
index 03be31427181..967a5cdc120e 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_g2d.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
@@ -395,8 +395,8 @@ static void g2d_userptr_put_dma_addr(struct g2d_data *g2d,
return;
 
 out:
-   dma_unmap_sg(to_dma_dev(g2d->drm_dev), g2d_userptr->sgt->sgl,
-   g2d_userptr->sgt->nents, DMA_BIDIRECTIONAL);
+   dma_unmap_sgtable(to_dma_dev(g2d->drm_dev), g2d_userptr->sgt,
+ DMA_BIDIRECTIONAL, 0);
 
pages = frame_vector_pages(g2d_userptr->vec);
if (!IS_ERR(pages)) {
@@ -511,10 +511,10 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct 
g2d_data *g2d,
 
g2d_userptr->sgt = sgt;
 
-   if (!dma_map_sg(to_dma_dev(g2d->drm_dev), sgt->sgl, sgt->nents,
-   DMA_BIDIRECTIONAL)) {
+   ret = dma_map_sgtable(to_dma_dev(g2d->drm_dev), sgt,
+ DMA_BIDIRECTIONAL, 0);
+   if (ret) {
DRM_DEV_ERROR(g2d->dev, "failed to map sgt with dma region.\n");
-   ret = -ENOMEM;
goto err_sg_free_table;
}
 
-- 
2.17.1

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[PATCH v9 02/32] drm: prime: use sgtable iterators in drm_prime_sg_to_page_addr_arrays()

2020-08-26 Thread Marek Szyprowski
Replace the current hand-crafted code for extracting pages and DMA
addresses from the given scatterlist by the much more robust
code based on the generic scatterlist iterators and recently
introduced sg_table-based wrappers. The resulting code is simple and
easy to understand, so the comment describing the old code is no
longer needed.

Signed-off-by: Marek Szyprowski 
Reviewed-by: Andrzej Hajda 
---
 drivers/gpu/drm/drm_prime.c | 49 -
 1 file changed, 15 insertions(+), 34 deletions(-)

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 4ed5ed1f078c..5d181bf60a44 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -990,45 +990,26 @@ EXPORT_SYMBOL(drm_gem_prime_import);
 int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
 dma_addr_t *addrs, int max_entries)
 {
-   unsigned count;
-   struct scatterlist *sg;
-   struct page *page;
-   u32 page_len, page_index;
-   dma_addr_t addr;
-   u32 dma_len, dma_index;
-
-   /*
-* Scatterlist elements contains both pages and DMA addresses, but
-* one shoud not assume 1:1 relation between them. The sg->length is
-* the size of the physical memory chunk described by the sg->page,
-* while sg_dma_len(sg) is the size of the DMA (IO virtual) chunk
-* described by the sg_dma_address(sg).
-*/
-   page_index = 0;
-   dma_index = 0;
-   for_each_sg(sgt->sgl, sg, sgt->nents, count) {
-   page_len = sg->length;
-   page = sg_page(sg);
-   dma_len = sg_dma_len(sg);
-   addr = sg_dma_address(sg);
-
-   while (pages && page_len > 0) {
-   if (WARN_ON(page_index >= max_entries))
+   struct sg_dma_page_iter dma_iter;
+   struct sg_page_iter page_iter;
+   struct page **p = pages;
+   dma_addr_t *a = addrs;
+
+   if (pages) {
+   for_each_sgtable_page(sgt, _iter, 0) {
+   if (p - pages >= max_entries)
return -1;
-   pages[page_index] = page;
-   page++;
-   page_len -= PAGE_SIZE;
-   page_index++;
+   *p++ = sg_page_iter_page(_iter);
}
-   while (addrs && dma_len > 0) {
-   if (WARN_ON(dma_index >= max_entries))
+   }
+   if (addrs) {
+   for_each_sgtable_dma_page(sgt, _iter, 0) {
+   if (a - addrs >= max_entries)
return -1;
-   addrs[dma_index] = addr;
-   addr += PAGE_SIZE;
-   dma_len -= PAGE_SIZE;
-   dma_index++;
+   *a++ = sg_page_iter_dma_address(_iter);
}
}
+
return 0;
 }
 EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays);
-- 
2.17.1

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[PATCH v9 09/32] drm: lima: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
Reviewed-by: Qiang Yu 
---
 drivers/gpu/drm/lima/lima_gem.c | 11 ---
 drivers/gpu/drm/lima/lima_vm.c  |  5 ++---
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_gem.c
index 155f2b4b4030..11223fe348df 100644
--- a/drivers/gpu/drm/lima/lima_gem.c
+++ b/drivers/gpu/drm/lima/lima_gem.c
@@ -69,8 +69,7 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm)
return ret;
 
if (bo->base.sgt) {
-   dma_unmap_sg(dev, bo->base.sgt->sgl,
-bo->base.sgt->nents, DMA_BIDIRECTIONAL);
+   dma_unmap_sgtable(dev, bo->base.sgt, DMA_BIDIRECTIONAL, 0);
sg_free_table(bo->base.sgt);
} else {
bo->base.sgt = kmalloc(sizeof(*bo->base.sgt), GFP_KERNEL);
@@ -80,7 +79,13 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm)
}
}
 
-   dma_map_sg(dev, sgt.sgl, sgt.nents, DMA_BIDIRECTIONAL);
+   ret = dma_map_sgtable(dev, , DMA_BIDIRECTIONAL, 0);
+   if (ret) {
+   sg_free_table();
+   kfree(bo->base.sgt);
+   bo->base.sgt = NULL;
+   return ret;
+   }
 
*bo->base.sgt = sgt;
 
diff --git a/drivers/gpu/drm/lima/lima_vm.c b/drivers/gpu/drm/lima/lima_vm.c
index 5b92fb82674a..2b2739adc7f5 100644
--- a/drivers/gpu/drm/lima/lima_vm.c
+++ b/drivers/gpu/drm/lima/lima_vm.c
@@ -124,7 +124,7 @@ int lima_vm_bo_add(struct lima_vm *vm, struct lima_bo *bo, 
bool create)
if (err)
goto err_out1;
 
-   for_each_sg_dma_page(bo->base.sgt->sgl, _iter, bo->base.sgt->nents, 
0) {
+   for_each_sgtable_dma_page(bo->base.sgt, _iter, 0) {
err = lima_vm_map_page(vm, sg_page_iter_dma_address(_iter),
   bo_va->node.start + offset);
if (err)
@@ -298,8 +298,7 @@ int lima_vm_map_bo(struct lima_vm *vm, struct lima_bo *bo, 
int pageoff)
mutex_lock(>lock);
 
base = bo_va->node.start + (pageoff << PAGE_SHIFT);
-   for_each_sg_dma_page(bo->base.sgt->sgl, _iter,
-bo->base.sgt->nents, pageoff) {
+   for_each_sgtable_dma_page(bo->base.sgt, _iter, pageoff) {
err = lima_vm_map_page(vm, sg_page_iter_dma_address(_iter),
   base + offset);
if (err)
-- 
2.17.1

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[PATCH v9 13/32] drm: omapdrm: use common helper for extracting pages array

2020-08-26 Thread Marek Szyprowski
Use common helper for converting a sg_table object into struct
page pointer array.

Signed-off-by: Marek Szyprowski 
---
 drivers/gpu/drm/omapdrm/omap_gem.c | 14 --
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c 
b/drivers/gpu/drm/omapdrm/omap_gem.c
index d0d12d5dd76c..ff0c4b0c3fd0 100644
--- a/drivers/gpu/drm/omapdrm/omap_gem.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem.c
@@ -1297,10 +1297,9 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct 
drm_device *dev, size_t size,
omap_obj->dma_addr = sg_dma_address(sgt->sgl);
} else {
/* Create pages list from sgt */
-   struct sg_page_iter iter;
struct page **pages;
unsigned int npages;
-   unsigned int i = 0;
+   unsigned int ret;
 
npages = DIV_ROUND_UP(size, PAGE_SIZE);
pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL);
@@ -1311,14 +1310,9 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct 
drm_device *dev, size_t size,
}
 
omap_obj->pages = pages;
-
-   for_each_sg_page(sgt->sgl, , sgt->orig_nents, 0) {
-   pages[i++] = sg_page_iter_page();
-   if (i > npages)
-   break;
-   }
-
-   if (WARN_ON(i != npages)) {
+   ret = drm_prime_sg_to_page_addr_arrays(sgt, pages, NULL,
+  npages);
+   if (WARN_ON(ret)) {
omap_gem_free_object(obj);
obj = ERR_PTR(-ENOMEM);
goto done;
-- 
2.17.1

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[PATCH v9 11/32] drm: mediatek: use common helper for extracting pages array

2020-08-26 Thread Marek Szyprowski
Use common helper for converting a sg_table object into struct
page pointer array.

Signed-off-by: Marek Szyprowski 
---
 drivers/gpu/drm/mediatek/mtk_drm_gem.c | 9 ++---
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c 
b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
index 3654ec732029..0583e557ad37 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
@@ -233,9 +233,7 @@ void *mtk_drm_gem_prime_vmap(struct drm_gem_object *obj)
 {
struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
struct sg_table *sgt;
-   struct sg_page_iter iter;
unsigned int npages;
-   unsigned int i = 0;
 
if (mtk_gem->kvaddr)
return mtk_gem->kvaddr;
@@ -249,11 +247,8 @@ void *mtk_drm_gem_prime_vmap(struct drm_gem_object *obj)
if (!mtk_gem->pages)
goto out;
 
-   for_each_sg_page(sgt->sgl, , sgt->orig_nents, 0) {
-   mtk_gem->pages[i++] = sg_page_iter_page();
-   if (i > npages)
-   break;
-   }
+   drm_prime_sg_to_page_addr_arrays(sgt, mtk_gem->pages, NULL, npages);
+
mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP,
   pgprot_writecombine(PAGE_KERNEL));
 
-- 
2.17.1

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[PATCH v9 20/32] drm: virtio: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
Acked-by: Gerd Hoffmann 
---
 drivers/gpu/drm/virtio/virtgpu_object.c | 36 ++---
 drivers/gpu/drm/virtio/virtgpu_vq.c | 12 -
 2 files changed, 26 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c 
b/drivers/gpu/drm/virtio/virtgpu_object.c
index e83651b7747d..a0559d3ed362 100644
--- a/drivers/gpu/drm/virtio/virtgpu_object.c
+++ b/drivers/gpu/drm/virtio/virtgpu_object.c
@@ -72,9 +72,8 @@ void virtio_gpu_cleanup_object(struct virtio_gpu_object *bo)
 
if (shmem->pages) {
if (shmem->mapped) {
-   dma_unmap_sg(vgdev->vdev->dev.parent,
-shmem->pages->sgl, shmem->mapped,
-DMA_TO_DEVICE);
+   dma_unmap_sgtable(vgdev->vdev->dev.parent,
+shmem->pages, DMA_TO_DEVICE, 0);
shmem->mapped = 0;
}
 
@@ -158,13 +157,13 @@ static int virtio_gpu_object_shmem_init(struct 
virtio_gpu_device *vgdev,
}
 
if (use_dma_api) {
-   shmem->mapped = dma_map_sg(vgdev->vdev->dev.parent,
-  shmem->pages->sgl,
-  shmem->pages->nents,
-  DMA_TO_DEVICE);
-   *nents = shmem->mapped;
+   ret = dma_map_sgtable(vgdev->vdev->dev.parent,
+ shmem->pages, DMA_TO_DEVICE, 0);
+   if (ret)
+   return ret;
+   *nents = shmem->mapped = shmem->pages->nents;
} else {
-   *nents = shmem->pages->nents;
+   *nents = shmem->pages->orig_nents;
}
 
*ents = kmalloc_array(*nents, sizeof(struct virtio_gpu_mem_entry),
@@ -174,13 +173,20 @@ static int virtio_gpu_object_shmem_init(struct 
virtio_gpu_device *vgdev,
return -ENOMEM;
}
 
-   for_each_sg(shmem->pages->sgl, sg, *nents, si) {
-   (*ents)[si].addr = cpu_to_le64(use_dma_api
-  ? sg_dma_address(sg)
-  : sg_phys(sg));
-   (*ents)[si].length = cpu_to_le32(sg->length);
-   (*ents)[si].padding = 0;
+   if (use_dma_api) {
+   for_each_sgtable_dma_sg(shmem->pages, sg, si) {
+   (*ents)[si].addr = cpu_to_le64(sg_dma_address(sg));
+   (*ents)[si].length = cpu_to_le32(sg_dma_len(sg));
+   (*ents)[si].padding = 0;
+   }
+   } else {
+   for_each_sgtable_sg(shmem->pages, sg, si) {
+   (*ents)[si].addr = cpu_to_le64(sg_phys(sg));
+   (*ents)[si].length = cpu_to_le32(sg->length);
+   (*ents)[si].padding = 0;
+   }
}
+
return 0;
 }
 
diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c 
b/drivers/gpu/drm/virtio/virtgpu_vq.c
index 53af60d484a4..7947b1047bd0 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -302,7 +302,7 @@ static struct sg_table *vmalloc_to_sgt(char *data, uint32_t 
size, int *sg_ents)
return NULL;
}
 
-   for_each_sg(sgt->sgl, sg, *sg_ents, i) {
+   for_each_sgtable_sg(sgt, sg, i) {
pg = vmalloc_to_page(data);
if (!pg) {
sg_free_table(sgt);
@@ -603,9 +603,8 @@ void virtio_gpu_cmd_transfer_to_host_2d(struct 
virtio_gpu_device *vgdev,
struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo);
 
if (use_dma_api)
-  

[PATCH v9 14/32] drm: omapdrm: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

Fix the code to refer to proper nents or orig_nents entries. This driver
checks for a buffer contiguity in DMA address space, so it should test
sg_table->nents entry.

Signed-off-by: Marek Szyprowski 
---
 drivers/gpu/drm/omapdrm/omap_gem.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c 
b/drivers/gpu/drm/omapdrm/omap_gem.c
index ff0c4b0c3fd0..a7a9a0afe2b6 100644
--- a/drivers/gpu/drm/omapdrm/omap_gem.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem.c
@@ -48,7 +48,7 @@ struct omap_gem_object {
 *   OMAP_BO_MEM_DMA_API flag set)
 *
 * - buffers imported from dmabuf (with the OMAP_BO_MEM_DMABUF flag set)
-*   if they are physically contiguous (when sgt->orig_nents == 1)
+*   if they are physically contiguous (when sgt->nents == 1)
 *
 * - buffers mapped through the TILER when dma_addr_cnt is not zero, in
 *   which case the DMA address points to the TILER aperture
@@ -1279,7 +1279,7 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct 
drm_device *dev, size_t size,
union omap_gem_size gsize;
 
/* Without a DMM only physically contiguous buffers can be supported. */
-   if (sgt->orig_nents != 1 && !priv->has_dmm)
+   if (sgt->nents != 1 && !priv->has_dmm)
return ERR_PTR(-EINVAL);
 
gsize.bytes = PAGE_ALIGN(size);
@@ -1293,7 +1293,7 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct 
drm_device *dev, size_t size,
 
omap_obj->sgt = sgt;
 
-   if (sgt->orig_nents == 1) {
+   if (sgt->nents == 1) {
omap_obj->dma_addr = sg_dma_address(sgt->sgl);
} else {
/* Create pages list from sgt */
-- 
2.17.1

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[PATCH v9 05/32] drm: etnaviv: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
---
 drivers/gpu/drm/etnaviv/etnaviv_gem.c | 12 +---
 drivers/gpu/drm/etnaviv/etnaviv_mmu.c | 13 +++--
 2 files changed, 8 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c 
b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index f06e19e7be04..eaf1949bc2e4 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -27,7 +27,7 @@ static void etnaviv_gem_scatter_map(struct etnaviv_gem_object 
*etnaviv_obj)
 * because display controller, GPU, etc. are not coherent.
 */
if (etnaviv_obj->flags & ETNA_BO_CACHE_MASK)
-   dma_map_sg(dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL);
+   dma_map_sgtable(dev->dev, sgt, DMA_BIDIRECTIONAL, 0);
 }
 
 static void etnaviv_gem_scatterlist_unmap(struct etnaviv_gem_object 
*etnaviv_obj)
@@ -51,7 +51,7 @@ static void etnaviv_gem_scatterlist_unmap(struct 
etnaviv_gem_object *etnaviv_obj
 * discard those writes.
 */
if (etnaviv_obj->flags & ETNA_BO_CACHE_MASK)
-   dma_unmap_sg(dev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL);
+   dma_unmap_sgtable(dev->dev, sgt, DMA_BIDIRECTIONAL, 0);
 }
 
 /* called with etnaviv_obj->lock held */
@@ -404,9 +404,8 @@ int etnaviv_gem_cpu_prep(struct drm_gem_object *obj, u32 op,
}
 
if (etnaviv_obj->flags & ETNA_BO_CACHED) {
-   dma_sync_sg_for_cpu(dev->dev, etnaviv_obj->sgt->sgl,
-   etnaviv_obj->sgt->nents,
-   etnaviv_op_to_dma_dir(op));
+   dma_sync_sgtable_for_cpu(dev->dev, etnaviv_obj->sgt,
+etnaviv_op_to_dma_dir(op));
etnaviv_obj->last_cpu_prep_op = op;
}
 
@@ -421,8 +420,7 @@ int etnaviv_gem_cpu_fini(struct drm_gem_object *obj)
if (etnaviv_obj->flags & ETNA_BO_CACHED) {
/* fini without a prep is almost certainly a userspace error */
WARN_ON(etnaviv_obj->last_cpu_prep_op == 0);
-   dma_sync_sg_for_device(dev->dev, etnaviv_obj->sgt->sgl,
-   etnaviv_obj->sgt->nents,
+   dma_sync_sgtable_for_device(dev->dev, etnaviv_obj->sgt,
etnaviv_op_to_dma_dir(etnaviv_obj->last_cpu_prep_op));
etnaviv_obj->last_cpu_prep_op = 0;
}
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c 
b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
index 3607d348c298..13b100553a0b 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
@@ -79,7 +79,7 @@ static int etnaviv_iommu_map(struct etnaviv_iommu_context 
*context, u32 iova,
if (!context || !sgt)
return -EINVAL;
 
-   for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+   for_each_sgtable_dma_sg(sgt, sg, i) {
u32 pa = sg_dma_address(sg) - sg->offset;
size_t bytes = sg_dma_len(sg) + sg->offset;
 
@@ -95,14 +95,7 @@ static int etnaviv_iommu_map(struct etnaviv_iommu_context 
*context, u32 iova,
return 0;
 
 fail:
-   da = iova;
-
-   for_each_sg(sgt->sgl, sg, i, j) {
-   size_t bytes = sg_dma_len(sg) + sg->offset;
-
-   etnaviv_context_unmap(context, da, bytes);
-   da += bytes;
-   }
+   etnaviv_context_unmap(context, iova, da - iova);
return ret;
 }
 
@@ -113,7 +106,7 @@ static void etnaviv_iommu_unmap(struct 
etnaviv_iommu_context *context, u32 iova,
unsigned int da = iova;
int i;
 
-   for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+   for_each_sgtable_dma_sg(sgt, sg, i) {
size_t bytes = sg_dma_len(sg) + sg->offset;
 
etnaviv_context_unmap(context, da, bytes);
-- 
2.17.1


[PATCH v9 10/32] drm: mediatek: use common helper for a scatterlist contiguity check

2020-08-26 Thread Marek Szyprowski
Use common helper for checking the contiguity of the imported dma-buf and
do this check before allocating resources, so the error path is simpler.

Signed-off-by: Marek Szyprowski 
---
 drivers/gpu/drm/mediatek/mtk_drm_gem.c | 28 ++
 1 file changed, 6 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c 
b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
index 6190cc3b7b0d..3654ec732029 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
@@ -212,37 +212,21 @@ struct drm_gem_object 
*mtk_gem_prime_import_sg_table(struct drm_device *dev,
struct dma_buf_attachment *attach, struct sg_table *sg)
 {
struct mtk_drm_gem_obj *mtk_gem;
-   int ret;
-   struct scatterlist *s;
-   unsigned int i;
-   dma_addr_t expected;
 
-   mtk_gem = mtk_drm_gem_init(dev, attach->dmabuf->size);
+   /* check if the entries in the sg_table are contiguous */
+   if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
+   DRM_ERROR("sg_table is not contiguous");
+   return ERR_PTR(-EINVAL);
+   }
 
+   mtk_gem = mtk_drm_gem_init(dev, attach->dmabuf->size);
if (IS_ERR(mtk_gem))
return ERR_CAST(mtk_gem);
 
-   expected = sg_dma_address(sg->sgl);
-   for_each_sg(sg->sgl, s, sg->nents, i) {
-   if (!sg_dma_len(s))
-   break;
-
-   if (sg_dma_address(s) != expected) {
-   DRM_ERROR("sg_table is not contiguous");
-   ret = -EINVAL;
-   goto err_gem_free;
-   }
-   expected = sg_dma_address(s) + sg_dma_len(s);
-   }
-
mtk_gem->dma_addr = sg_dma_address(sg->sgl);
mtk_gem->sg = sg;
 
return _gem->base;
-
-err_gem_free:
-   kfree(mtk_gem);
-   return ERR_PTR(ret);
 }
 
 void *mtk_drm_gem_prime_vmap(struct drm_gem_object *obj)
-- 
2.17.1

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[PATCH v9 22/32] drm: xen: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

Fix the code to refer to proper nents or orig_nents entries. This driver
reports the number of the pages in the imported scatterlist, so it should
refer to sg_table->orig_nents entry.

Signed-off-by: Marek Szyprowski 
Acked-by: Oleksandr Andrushchenko 
---
 drivers/gpu/drm/xen/xen_drm_front_gem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c 
b/drivers/gpu/drm/xen/xen_drm_front_gem.c
index 39ff95b75357..0e57c80058b2 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
@@ -216,7 +216,7 @@ xen_drm_front_gem_import_sg_table(struct drm_device *dev,
return ERR_PTR(ret);
 
DRM_DEBUG("Imported buffer of size %zu with nents %u\n",
- size, sgt->nents);
+ size, sgt->orig_nents);
 
return _obj->base;
 }
-- 
2.17.1

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[PATCH v9 15/32] drm: panfrost: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
Reviewed-by: Steven Price 
Reviewed-by: Rob Herring 
---
 drivers/gpu/drm/panfrost/panfrost_gem.c | 4 ++--
 drivers/gpu/drm/panfrost/panfrost_mmu.c | 7 +++
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c 
b/drivers/gpu/drm/panfrost/panfrost_gem.c
index 33355dd302f1..1a6cea0e0bd7 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
@@ -41,8 +41,8 @@ static void panfrost_gem_free_object(struct drm_gem_object 
*obj)
 
for (i = 0; i < n_sgt; i++) {
if (bo->sgts[i].sgl) {
-   dma_unmap_sg(pfdev->dev, bo->sgts[i].sgl,
-bo->sgts[i].nents, 
DMA_BIDIRECTIONAL);
+   dma_unmap_sgtable(pfdev->dev, >sgts[i],
+ DMA_BIDIRECTIONAL, 0);
sg_free_table(>sgts[i]);
}
}
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c 
b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index e8f7b11352d2..776448c527ea 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -253,7 +253,7 @@ static int mmu_map_sg(struct panfrost_device *pfdev, struct 
panfrost_mmu *mmu,
struct io_pgtable_ops *ops = mmu->pgtbl_ops;
u64 start_iova = iova;
 
-   for_each_sg(sgt->sgl, sgl, sgt->nents, count) {
+   for_each_sgtable_dma_sg(sgt, sgl, count) {
unsigned long paddr = sg_dma_address(sgl);
size_t len = sg_dma_len(sgl);
 
@@ -517,10 +517,9 @@ static int panfrost_mmu_map_fault_addr(struct 
panfrost_device *pfdev, int as,
if (ret)
goto err_pages;
 
-   if (!dma_map_sg(pfdev->dev, sgt->sgl, sgt->nents, DMA_BIDIRECTIONAL)) {
-   ret = -EINVAL;
+   ret = dma_map_sgtable(pfdev->dev, sgt, DMA_BIDIRECTIONAL, 0);
+   if (ret)
goto err_map;
-   }
 
mmu_map_sg(pfdev, bomapping->mmu, addr,
   IOMMU_WRITE | IOMMU_READ | IOMMU_NOEXEC, sgt);
-- 
2.17.1

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[PATCH v9 06/32] drm: exynos: use common helper for a scatterlist contiguity check

2020-08-26 Thread Marek Szyprowski
Use common helper for checking the contiguity of the imported dma-buf.

Signed-off-by: Marek Szyprowski 
Reviewed-by: Andrzej Hajda 
Acked-by : Inki Dae 
---
 drivers/gpu/drm/exynos/exynos_drm_gem.c | 23 +++
 1 file changed, 3 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c 
b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index efa476858db5..1716a023bca0 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -431,27 +431,10 @@ exynos_drm_gem_prime_import_sg_table(struct drm_device 
*dev,
 {
struct exynos_drm_gem *exynos_gem;
 
-   if (sgt->nents < 1)
+   /* check if the entries in the sg_table are contiguous */
+   if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size) {
+   DRM_ERROR("buffer chunks must be mapped contiguously");
return ERR_PTR(-EINVAL);
-
-   /*
-* Check if the provided buffer has been mapped as contiguous
-* into DMA address space.
-*/
-   if (sgt->nents > 1) {
-   dma_addr_t next_addr = sg_dma_address(sgt->sgl);
-   struct scatterlist *s;
-   unsigned int i;
-
-   for_each_sg(sgt->sgl, s, sgt->nents, i) {
-   if (!sg_dma_len(s))
-   break;
-   if (sg_dma_address(s) != next_addr) {
-   DRM_ERROR("buffer chunks must be mapped 
contiguously");
-   return ERR_PTR(-EINVAL);
-   }
-   next_addr = sg_dma_address(s) + sg_dma_len(s);
-   }
}
 
exynos_gem = exynos_drm_gem_init(dev, attach->dmabuf->size);
-- 
2.17.1

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[PATCH v9 12/32] drm: msm: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
Acked-by: Rob Clark 
---
 drivers/gpu/drm/msm/msm_gem.c| 13 +
 drivers/gpu/drm/msm/msm_gpummu.c | 14 ++
 drivers/gpu/drm/msm/msm_iommu.c  |  2 +-
 3 files changed, 12 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index b2f49152b4d4..8c7ae812b813 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -53,11 +53,10 @@ static void sync_for_device(struct msm_gem_object *msm_obj)
struct device *dev = msm_obj->base.dev->dev;
 
if (get_dma_ops(dev) && IS_ENABLED(CONFIG_ARM64)) {
-   dma_sync_sg_for_device(dev, msm_obj->sgt->sgl,
-   msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
+   dma_sync_sgtable_for_device(dev, msm_obj->sgt,
+   DMA_BIDIRECTIONAL);
} else {
-   dma_map_sg(dev, msm_obj->sgt->sgl,
-   msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
+   dma_map_sgtable(dev, msm_obj->sgt, DMA_BIDIRECTIONAL, 0);
}
 }
 
@@ -66,11 +65,9 @@ static void sync_for_cpu(struct msm_gem_object *msm_obj)
struct device *dev = msm_obj->base.dev->dev;
 
if (get_dma_ops(dev) && IS_ENABLED(CONFIG_ARM64)) {
-   dma_sync_sg_for_cpu(dev, msm_obj->sgt->sgl,
-   msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
+   dma_sync_sgtable_for_cpu(dev, msm_obj->sgt, DMA_BIDIRECTIONAL);
} else {
-   dma_unmap_sg(dev, msm_obj->sgt->sgl,
-   msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
+   dma_unmap_sgtable(dev, msm_obj->sgt, DMA_BIDIRECTIONAL, 0);
}
 }
 
diff --git a/drivers/gpu/drm/msm/msm_gpummu.c b/drivers/gpu/drm/msm/msm_gpummu.c
index 310a31b05faa..319f06c28235 100644
--- a/drivers/gpu/drm/msm/msm_gpummu.c
+++ b/drivers/gpu/drm/msm/msm_gpummu.c
@@ -30,21 +30,19 @@ static int msm_gpummu_map(struct msm_mmu *mmu, uint64_t 
iova,
 {
struct msm_gpummu *gpummu = to_msm_gpummu(mmu);
unsigned idx = (iova - GPUMMU_VA_START) / GPUMMU_PAGE_SIZE;
-   struct scatterlist *sg;
+   struct sg_dma_page_iter dma_iter;
unsigned prot_bits = 0;
-   unsigned i, j;
 
if (prot & IOMMU_WRITE)
prot_bits |= 1;
if (prot & IOMMU_READ)
prot_bits |= 2;
 
-   for_each_sg(sgt->sgl, sg, sgt->nents, i) {
-   dma_addr_t addr = sg->dma_address;
-   for (j = 0; j < sg->length / GPUMMU_PAGE_SIZE; j++, idx++) {
-   gpummu->table[idx] = addr | prot_bits;
-   addr += GPUMMU_PAGE_SIZE;
-   }
+   for_each_sgtable_dma_page(sgt, _iter, 0) {
+   dma_addr_t addr = sg_page_iter_dma_address(_iter);
+
+   BUILD_BUG_ON(GPUMMU_PAGE_SIZE != PAGE_SIZE);
+   gpummu->table[idx++] = addr | prot_bits;
}
 
/* we can improve by deferring flush for multiple map() */
diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
index 3a381a9674c9..6c31e65834c6 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -36,7 +36,7 @@ static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova,
struct msm_iommu *iommu = to_msm_iommu(mmu);
size_t ret;
 
-   ret = iommu_map_sg(iommu->domain, iova, sgt->sgl, sgt->nents, prot);
+   ret = iommu_map_sgtable(iommu->domain, iova, sgt, prot);
WARN_ON(!ret);
 
return (ret == len) ? 0 : -EINVAL;
-- 
2.17.1

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[PATCH v9 18/32] drm: tegra: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
---
 drivers/gpu/drm/tegra/gem.c   | 27 ++-
 drivers/gpu/drm/tegra/plane.c | 15 +--
 2 files changed, 15 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index 723df142a981..01d94befab11 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -98,8 +98,8 @@ static struct sg_table *tegra_bo_pin(struct device *dev, 
struct host1x_bo *bo,
 * the SG table needs to be copied to avoid overwriting any
 * other potential users of the original SG table.
 */
-   err = sg_alloc_table_from_sg(sgt, obj->sgt->sgl, 
obj->sgt->nents,
-GFP_KERNEL);
+   err = sg_alloc_table_from_sg(sgt, obj->sgt->sgl,
+obj->sgt->orig_nents, GFP_KERNEL);
if (err < 0)
goto free;
} else {
@@ -196,8 +196,7 @@ static int tegra_bo_iommu_map(struct tegra_drm *tegra, 
struct tegra_bo *bo)
 
bo->iova = bo->mm->start;
 
-   bo->size = iommu_map_sg(tegra->domain, bo->iova, bo->sgt->sgl,
-   bo->sgt->nents, prot);
+   bo->size = iommu_map_sgtable(tegra->domain, bo->iova, bo->sgt, prot);
if (!bo->size) {
dev_err(tegra->drm->dev, "failed to map buffer\n");
err = -ENOMEM;
@@ -264,8 +263,7 @@ static struct tegra_bo *tegra_bo_alloc_object(struct 
drm_device *drm,
 static void tegra_bo_free(struct drm_device *drm, struct tegra_bo *bo)
 {
if (bo->pages) {
-   dma_unmap_sg(drm->dev, bo->sgt->sgl, bo->sgt->nents,
-DMA_FROM_DEVICE);
+   dma_unmap_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
drm_gem_put_pages(>gem, bo->pages, true, true);
sg_free_table(bo->sgt);
kfree(bo->sgt);
@@ -290,12 +288,9 @@ static int tegra_bo_get_pages(struct drm_device *drm, 
struct tegra_bo *bo)
goto put_pages;
}
 
-   err = dma_map_sg(drm->dev, bo->sgt->sgl, bo->sgt->nents,
-DMA_FROM_DEVICE);
-   if (err == 0) {
-   err = -EFAULT;
+   err = dma_map_sgtable(drm->dev, bo->sgt, DMA_FROM_DEVICE, 0);
+   if (err)
goto free_sgt;
-   }
 
return 0;
 
@@ -571,7 +566,7 @@ tegra_gem_prime_map_dma_buf(struct dma_buf_attachment 
*attach,
goto free;
}
 
-   if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0)
+   if (dma_map_sgtable(attach->dev, sgt, dir, 0))
goto free;
 
return sgt;
@@ -590,7 +585,7 @@ static void tegra_gem_prime_unmap_dma_buf(struct 
dma_buf_attachment *attach,
struct tegra_bo *bo = to_tegra_bo(gem);
 
if (bo->pages)
-   dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
+   dma_unmap_sgtable(attach->dev, sgt, dir, 0);
 
sg_free_table(sgt);
kfree(sgt);
@@ -609,8 +604,7 @@ static int tegra_gem_prime_begin_cpu_access(struct dma_buf 
*buf,
struct drm_device *drm = gem->dev;
 
if (bo->pages)
-   dma_sync_sg_for_cpu(drm->dev, bo->sgt->sgl, bo->sgt->nents,
-   DMA_FROM_DEVICE);
+   dma_sync_sgtable_for_cpu(drm->dev, bo->sgt, DMA_FROM_DEVICE);
 
return 0;
 }
@@ -623,8 +617,7 @@ static int tegra_gem_prime_end_cpu_access(struct dma_buf 
*buf,
struct drm_device *drm = gem->dev;
 
if (bo->pages)
-   dma_sync_sg_for_device(drm->dev, bo->sgt->sgl, bo->sgt->nents,
-  DMA_TO_DEVICE);
+   dma_sync_sgtable_for_device(drm->dev, 

[PATCH v9 04/32] drm: armada: fix common struct sg_table related issues

2020-08-26 Thread Marek Szyprowski
The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
---
 drivers/gpu/drm/armada/armada_gem.c | 12 ++--
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/armada/armada_gem.c 
b/drivers/gpu/drm/armada/armada_gem.c
index 8005614d2e6b..bedd8937d8a1 100644
--- a/drivers/gpu/drm/armada/armada_gem.c
+++ b/drivers/gpu/drm/armada/armada_gem.c
@@ -395,7 +395,7 @@ armada_gem_prime_map_dma_buf(struct dma_buf_attachment 
*attach,
 
mapping = dobj->obj.filp->f_mapping;
 
-   for_each_sg(sgt->sgl, sg, count, i) {
+   for_each_sgtable_sg(sgt, sg, i) {
struct page *page;
 
page = shmem_read_mapping_page(mapping, i);
@@ -407,8 +407,8 @@ armada_gem_prime_map_dma_buf(struct dma_buf_attachment 
*attach,
sg_set_page(sg, page, PAGE_SIZE, 0);
}
 
-   if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0) {
-   num = sgt->nents;
+   if (dma_map_sgtable(attach->dev, sgt, dir, 0)) {
+   num = count;
goto release;
}
} else if (dobj->page) {
@@ -418,7 +418,7 @@ armada_gem_prime_map_dma_buf(struct dma_buf_attachment 
*attach,
 
sg_set_page(sgt->sgl, dobj->page, dobj->obj.size, 0);
 
-   if (dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir) == 0)
+   if (dma_map_sgtable(attach->dev, sgt, dir, 0))
goto free_table;
} else if (dobj->linear) {
/* Single contiguous physical region - no struct page */
@@ -449,11 +449,11 @@ static void armada_gem_prime_unmap_dma_buf(struct 
dma_buf_attachment *attach,
int i;
 
if (!dobj->linear)
-   dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
+   dma_unmap_sgtable(attach->dev, sgt, dir, 0);
 
if (dobj->obj.filp) {
struct scatterlist *sg;
-   for_each_sg(sgt->sgl, sg, sgt->nents, i)
+   for_each_sgtable_sg(sgt, sg, i)
put_page(sg_page(sg));
}
 
-- 
2.17.1

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