Re: [PATCH v5 05/07] iommu/ipmmu-vmsa: Add new IOMMU_DOMAIN_DMA ops

2016-10-19 Thread Magnus Damm 
Hi Joerg,

On Thu, Sep 22, 2016 at 11:45 PM, Joerg Roedel  wrote:
> On Tue, Sep 20, 2016 at 10:44:46PM +0900, Magnus Damm wrote:
>> +#ifdef CONFIG_IOMMU_DMA
>> +
>> +static struct iommu_domain *ipmmu_domain_alloc_dma(unsigned type)
>> +{
>> + struct iommu_domain *io_domain;
>> +
>> + if (type != IOMMU_DOMAIN_DMA)
>> + return NULL;
>> +
>> + io_domain = __ipmmu_domain_alloc(type);
>> + if (io_domain)
>> + iommu_get_dma_cookie(io_domain);
>> +
>> + return io_domain;
>> +}
>> +
>> +static void ipmmu_domain_free_dma(struct iommu_domain *io_domain)
>> +{
>> + iommu_put_dma_cookie(io_domain);
>> + ipmmu_domain_free(io_domain);
>> +}
>
>> [...]
>
>> +static const struct iommu_ops ipmmu_ops = {
>> + .domain_alloc = ipmmu_domain_alloc_dma,
>> + .domain_free = ipmmu_domain_free_dma,
>
> Okay, so when CONFIG_IOMMU_DMA is enabled, you only support allocation
> of DMA domains, not UNMANAGED domains anymore. Is there a reason for
> that?

Just historical reason migrating from UNMANAGED only to DMA only.

> You can reduce the #ifdef'ed coded by supporting both types of domains
> and call into allocation-subfunctions for DMA and UNMANAGED domains. The
> #ifdef could then only let the dma-allocation function return NULL.
>
> This would be much more compatible to what other IOMMU drivers do and
> will allow VFIO usage in the future.

Thanks for your suggestion. I've now updated the code in V6, hopefully
it would match your expectation better.

Cheers,

/ magnus

Re: [PATCH v5 05/07] iommu/ipmmu-vmsa: Add new IOMMU_DOMAIN_DMA ops

2016-09-22 Thread Joerg Roedel 
On Tue, Sep 20, 2016 at 10:44:46PM +0900, Magnus Damm wrote:
> +#ifdef CONFIG_IOMMU_DMA
> +
> +static struct iommu_domain *ipmmu_domain_alloc_dma(unsigned type)
> +{
> + struct iommu_domain *io_domain;
> +
> + if (type != IOMMU_DOMAIN_DMA)
> + return NULL;
> +
> + io_domain = __ipmmu_domain_alloc(type);
> + if (io_domain)
> + iommu_get_dma_cookie(io_domain);
> +
> + return io_domain;
> +}
> +
> +static void ipmmu_domain_free_dma(struct iommu_domain *io_domain)
> +{
> + iommu_put_dma_cookie(io_domain);
> + ipmmu_domain_free(io_domain);
> +}

> [...]

> +static const struct iommu_ops ipmmu_ops = {
> + .domain_alloc = ipmmu_domain_alloc_dma,
> + .domain_free = ipmmu_domain_free_dma,

Okay, so when CONFIG_IOMMU_DMA is enabled, you only support allocation
of DMA domains, not UNMANAGED domains anymore. Is there a reason for
that?

You can reduce the #ifdef'ed coded by supporting both types of domains
and call into allocation-subfunctions for DMA and UNMANAGED domains. The
#ifdef could then only let the dma-allocation function return NULL.

This would be much more compatible to what other IOMMU drivers do and
will allow VFIO usage in the future.



Joerg

[PATCH v5 05/07] iommu/ipmmu-vmsa: Add new IOMMU_DOMAIN_DMA ops

2016-09-20 Thread Magnus Damm 
From: Magnus Damm 

Introduce an alternative set of iommu_ops suitable for 64-bit ARM
as well as 32-bit ARM when CONFIG_IOMMU_DMA=y. Also adjust the
Kconfig to depend on ARM or IOMMU_DMA.

Signed-off-by: Magnus Damm 
---

 Changes since V4:
 - Added Kconfig hunk to depend on ARM or IOMMU_DMA

 Changes since V3:
 - Removed group parameter from ipmmu_init_platform_device()

 Changes since V2:
 - Included this new patch from the following series:
   [PATCH 00/04] iommu/ipmmu-vmsa: IPMMU CONFIG_IOMMU_DMA update
 - Use only a single iommu_ops structure with #ifdef CONFIG_IOMMU_DMA
 - Folded in #ifdefs to handle CONFIG_ARM and CONFIG_IOMMU_DMA
 - of_xlate() is now used without #ifdefs
 - Made sure code compiles on both 32-bit and 64-bit ARM.

 drivers/iommu/Kconfig  |1 
 drivers/iommu/ipmmu-vmsa.c |  111 
 2 files changed, 104 insertions(+), 8 deletions(-)

--- 0001/drivers/iommu/Kconfig
+++ work/drivers/iommu/Kconfig  2016-09-20 22:10:15.280607110 +0900
@@ -274,6 +274,7 @@ config EXYNOS_IOMMU_DEBUG
 
 config IPMMU_VMSA
bool "Renesas VMSA-compatible IPMMU"
+   depends on ARM || IOMMU_DMA
depends on ARM_LPAE
depends on ARCH_RENESAS || COMPILE_TEST
select IOMMU_API
--- 0006/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c 2016-09-20 22:08:58.300607110 +0900
@@ -10,6 +10,7 @@
 
 #include 
 #include 
+#include 
 #include 
 #include 
 #include 
@@ -22,8 +23,10 @@
 #include 
 #include 
 
+#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
 #include 
 #include 
+#endif
 
 #include "io-pgtable.h"
 
@@ -520,14 +523,6 @@ static struct iommu_domain *__ipmmu_doma
return &domain->io_domain;
 }
 
-static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
-{
-   if (type != IOMMU_DOMAIN_UNMANAGED)
-   return NULL;
-
-   return __ipmmu_domain_alloc(type);
-}
-
 static void ipmmu_domain_free(struct iommu_domain *io_domain)
 {
struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
@@ -714,6 +709,8 @@ error:
return ret;
 }
 
+#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
+
 static int ipmmu_add_device(struct device *dev)
 {
struct ipmmu_vmsa_archdata *archdata;
@@ -807,6 +804,14 @@ static void ipmmu_remove_device(struct d
dev->archdata.iommu = NULL;
 }
 
+static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
+{
+   if (type != IOMMU_DOMAIN_UNMANAGED)
+   return NULL;
+
+   return __ipmmu_domain_alloc(type);
+}
+
 static const struct iommu_ops ipmmu_ops = {
.domain_alloc = ipmmu_domain_alloc,
.domain_free = ipmmu_domain_free,
@@ -821,6 +826,94 @@ static const struct iommu_ops ipmmu_ops
.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
 };
 
+#endif /* !CONFIG_ARM && CONFIG_IOMMU_DMA */
+
+#ifdef CONFIG_IOMMU_DMA
+
+static struct iommu_domain *ipmmu_domain_alloc_dma(unsigned type)
+{
+   struct iommu_domain *io_domain;
+
+   if (type != IOMMU_DOMAIN_DMA)
+   return NULL;
+
+   io_domain = __ipmmu_domain_alloc(type);
+   if (io_domain)
+   iommu_get_dma_cookie(io_domain);
+
+   return io_domain;
+}
+
+static void ipmmu_domain_free_dma(struct iommu_domain *io_domain)
+{
+   iommu_put_dma_cookie(io_domain);
+   ipmmu_domain_free(io_domain);
+}
+
+static int ipmmu_add_device_dma(struct device *dev)
+{
+   struct iommu_group *group;
+
+   /* only accept devices with iommus property */
+   if (of_count_phandle_with_args(dev->of_node, "iommus",
+  "#iommu-cells") < 0)
+   return -ENODEV;
+
+   group = iommu_group_get_for_dev(dev);
+   if (IS_ERR(group))
+   return PTR_ERR(group);
+
+   return 0;
+}
+
+static void ipmmu_remove_device_dma(struct device *dev)
+{
+   iommu_group_remove_device(dev);
+}
+
+static struct iommu_group *ipmmu_device_group_dma(struct device *dev)
+{
+   struct iommu_group *group;
+   int ret;
+
+   group = generic_device_group(dev);
+   if (IS_ERR(group))
+   return group;
+
+   ret = ipmmu_init_platform_device(dev);
+   if (ret) {
+   iommu_group_put(group);
+   group = ERR_PTR(ret);
+   }
+
+   return group;
+}
+
+static int ipmmu_of_xlate_dma(struct device *dev,
+ struct of_phandle_args *spec)
+{
+   /* dummy callback to satisfy of_iommu_configure() */
+   return 0;
+}
+
+static const struct iommu_ops ipmmu_ops = {
+   .domain_alloc = ipmmu_domain_alloc_dma,
+   .domain_free = ipmmu_domain_free_dma,
+   .attach_dev = ipmmu_attach_device,
+   .detach_dev = ipmmu_detach_device,
+   .map = ipmmu_map,
+   .unmap = ipmmu_unmap,
+   .map_sg = default_iommu_map_sg,
+   .iova_to_phys = ipmmu_iova_to_phys,
+   .add_device = ipmmu_add_device_dma,
+   .remove_device = ipmmu_remove_device_dma,
+   .device_group = ipmm