Re: centralize SWIOTLB config symbol and misc other cleanups V3

2018-05-08 Thread Christoph Hellwig 
On Wed, May 02, 2018 at 05:46:17AM -0700, Christoph Hellwig wrote:
> Any more comments?  Especially from the x86, mips and powerpc arch
> maintainers?  I'd like to merge this in a few days as various other
> patches depend on it.

I've pulled it in to make forward progress.  Any additional comments
will have to be sent in the form of incremental patches.
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Re: [PATCH v5 1/2] iommu - Enable debugfs exposure of IOMMU driver internals

2018-05-08 Thread Joe Perches 
On Tue, 2018-05-08 at 15:07 -0500, Gary R Hook wrote:
> On 05/08/2018 01:48 PM, Joe Perches wrote:
> > On Tue, 2018-05-08 at 12:08 -0500, Hook, Gary wrote:
> > > On 5/7/2018 6:47 PM, kbuild test robot wrote:
> > > > 
> > > > All error/warnings (new ones prefixed by >>):
> > > > 
> > > >  In file included from include/linux/intel-iommu.h:32:0,
> > > >   from drivers/gpu/drm/i915/i915_drv.h:41,
> > > >   from drivers/gpu/drm/i915/i915_oa_bxt.c:31:
> > > >  include/linux/iommu.h: In function 'iommu_debugfs_new_driver_dir':
> > > > > > include/linux/iommu.h:706:8: error: parameter name omitted
> > > > 
> > > >   struct dentry *iommu_debugfs_new_driver_dir(char *) {};
> > > >  ^~
> > > >  In file included from include/linux/intel-iommu.h:32:0,
> > > >   from drivers/gpu/drm/i915/i915_drv.h:41,
> > > >   from drivers/gpu/drm/i915/i915_oa_bxt.c:31:
> > > > > > include/linux/iommu.h:706:8: warning: control reaches end of 
> > > > > > non-void function [-Wreturn-type]
> > > > 
> > > >   struct dentry *iommu_debugfs_new_driver_dir(char *) {};
> > > >  ^~
> > > > 
> > > > vim +706 include/linux/iommu.h
> > > > 
> > > >  700
> > > >  701#ifdef CONFIG_IOMMU_DEBUGFS
> > > >  702void iommu_debugfs_setup(void);
> > > >  703struct dentry *iommu_debugfs_new_driver_dir(char *);
> > > >  704#else
> > > >  705static inline void iommu_debugfs_setup(void) {}
> > > >> 706struct dentry *iommu_debugfs_new_driver_dir(char *) {};
> > > >  707#endif
> > > >  708
> > > 
> > > I have no problems with adding parameter names. But
> > > scripts/checkpatch.pl doesn't seem to check for this, nor require it.
> > > Should checkpatch be updated?
> > 
> > I'm pretty sure that's not feasible.
> 
> Ugh. This is a definition, not a declaration. My bad. Which is likely 
> why I decided to apologize up front.
> 
> > And when the compiler tells you you've stuffed up some
> > syntactical bit, why should checkpatch duplicate the
> > output error message too?
> 
> Well, that's the point: neither the 4.8 nor 5.4 compiler complained 
> about this.

Perhaps because CONFIG_IOMMU_DEBUGFS was set in the .config
for all the compilation previously performed?

>  Not as an error, despite the fact that (now that I read what 
> is actually here, as opposed to what I think is there) this is wrong. 
> Had an error message been emitted, and the make stopped, I would have 
> figure this out before embarrassing myself in front of the entire interwebs.

There's no reason for that figuring out to be necessary.
Linux compilation complexity is pretty high and almost
no one understands it completely.

cheers, Joe
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Re: [PATCH v5 1/2] iommu - Enable debugfs exposure of IOMMU driver internals

2018-05-08 Thread Gary R Hook 

On 05/08/2018 03:42 PM, Joe Perches wrote:

On Tue, 2018-05-08 at 15:07 -0500, Gary R Hook wrote:

On 05/08/2018 01:48 PM, Joe Perches wrote:

On Tue, 2018-05-08 at 12:08 -0500, Hook, Gary wrote:

On 5/7/2018 6:47 PM, kbuild test robot wrote:


All error/warnings (new ones prefixed by >>):

  In file included from include/linux/intel-iommu.h:32:0,
   from drivers/gpu/drm/i915/i915_drv.h:41,
   from drivers/gpu/drm/i915/i915_oa_bxt.c:31:
  include/linux/iommu.h: In function 'iommu_debugfs_new_driver_dir':

include/linux/iommu.h:706:8: error: parameter name omitted


   struct dentry *iommu_debugfs_new_driver_dir(char *) {};
  ^~
  In file included from include/linux/intel-iommu.h:32:0,
   from drivers/gpu/drm/i915/i915_drv.h:41,
   from drivers/gpu/drm/i915/i915_oa_bxt.c:31:

include/linux/iommu.h:706:8: warning: control reaches end of non-void function 
[-Wreturn-type]


   struct dentry *iommu_debugfs_new_driver_dir(char *) {};
  ^~

vim +706 include/linux/iommu.h

  700   
  701   #ifdef CONFIG_IOMMU_DEBUGFS
  702   void iommu_debugfs_setup(void);
  703   struct dentry *iommu_debugfs_new_driver_dir(char *);
  704   #else
  705   static inline void iommu_debugfs_setup(void) {}
> 706struct dentry *iommu_debugfs_new_driver_dir(char *) {};
  707   #endif
  708   


I have no problems with adding parameter names. But
scripts/checkpatch.pl doesn't seem to check for this, nor require it.
Should checkpatch be updated?


I'm pretty sure that's not feasible.


Ugh. This is a definition, not a declaration. My bad. Which is likely
why I decided to apologize up front.


And when the compiler tells you you've stuffed up some
syntactical bit, why should checkpatch duplicate the
output error message too?


Well, that's the point: neither the 4.8 nor 5.4 compiler complained
about this.


Perhaps because CONFIG_IOMMU_DEBUGFS was set in the .config
for all the compilation previously performed?


Well, you'd think maybe so, but I forced a recompilation of that one 
file (i915_oa_bxt.c) and no complaint with 5.4. Weird.


Ah, well. Onward to patch version 6.

Thanks again.

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Re: [PATCH v5 1/2] iommu - Enable debugfs exposure of IOMMU driver internals

2018-05-08 Thread Gary R Hook 

On 05/08/2018 01:48 PM, Joe Perches wrote:

On Tue, 2018-05-08 at 12:08 -0500, Hook, Gary wrote:

On 5/7/2018 6:47 PM, kbuild test robot wrote:


All error/warnings (new ones prefixed by >>):

 In file included from include/linux/intel-iommu.h:32:0,
  from drivers/gpu/drm/i915/i915_drv.h:41,
  from drivers/gpu/drm/i915/i915_oa_bxt.c:31:
 include/linux/iommu.h: In function 'iommu_debugfs_new_driver_dir':

include/linux/iommu.h:706:8: error: parameter name omitted


  struct dentry *iommu_debugfs_new_driver_dir(char *) {};
 ^~
 In file included from include/linux/intel-iommu.h:32:0,
  from drivers/gpu/drm/i915/i915_drv.h:41,
  from drivers/gpu/drm/i915/i915_oa_bxt.c:31:

include/linux/iommu.h:706:8: warning: control reaches end of non-void function 
[-Wreturn-type]


  struct dentry *iommu_debugfs_new_driver_dir(char *) {};
 ^~

vim +706 include/linux/iommu.h

 700
 701#ifdef CONFIG_IOMMU_DEBUGFS
 702void iommu_debugfs_setup(void);
 703struct dentry *iommu_debugfs_new_driver_dir(char *);
 704#else
 705static inline void iommu_debugfs_setup(void) {}
   > 706 struct dentry *iommu_debugfs_new_driver_dir(char *) {};
 707#endif
 708


I have no problems with adding parameter names. But
scripts/checkpatch.pl doesn't seem to check for this, nor require it.
Should checkpatch be updated?


I'm pretty sure that's not feasible.


Ugh. This is a definition, not a declaration. My bad. Which is likely 
why I decided to apologize up front.



And when the compiler tells you you've stuffed up some
syntactical bit, why should checkpatch duplicate the
output error message too?


Well, that's the point: neither the 4.8 nor 5.4 compiler complained 
about this. Not as an error, despite the fact that (now that I read what 
is actually here, as opposed to what I think is there) this is wrong. 
Had an error message been emitted, and the make stopped, I would have 
figure this out before embarrassing myself in front of the entire interwebs.



btw:  That's an unnecessary ; at the end of that non-void
function and it should probably be something like:


You are correct, sir. I've made a change on this.



static inline struct dentry *iommu_debugfs_new_driver_dir(char *dir)
{
return NULL;
}


Thanks for taking a few moments to comment. Much appreciated.

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Re: [PATCH v5 1/2] iommu - Enable debugfs exposure of IOMMU driver internals

2018-05-08 Thread Joe Perches 
On Tue, 2018-05-08 at 12:08 -0500, Hook, Gary wrote:
> On 5/7/2018 6:47 PM, kbuild test robot wrote:
> > Hi Gary,
> > 
> 
> I imagine these questions have been asked before, so I'll ask for
> forgiveness up front.
> 
> 
> > Thank you for the patch! Yet something to improve:
> > 
> > [auto build test ERROR on iommu/next]
> > [also build test ERROR on v4.17-rc4 next-20180507]
> > [if your patch is applied to the wrong git tree, please drop us a note to 
> > help improve the system]
> > 
> > url:
> > https://github.com/0day-ci/linux/commits/Gary-R-Hook/iommu-Enable-debugfs-exposure-of-IOMMU-driver-internals/20180508-062918
> > base:   https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git next
> > config: x86_64-randconfig-x016-201818 (attached as .config)
> > compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
> > reproduce:
> >  # save the attached .config to linux build tree
> >  make ARCH=x86_64
> 
> Is the gcc 7 compiler now a requirement to build the kernel? Or only to 
> run krobot tests?
> 
> Is this the earliest version of the compiler that can be used? I'm still 
> using 4.8 and 5.4, which seems to suffice for the kernel.
> 
> Googling about this has been fruitless.
> 
> > 
> > All error/warnings (new ones prefixed by >>):
> > 
> > In file included from include/linux/intel-iommu.h:32:0,
> >  from drivers/gpu/drm/i915/i915_drv.h:41,
> >  from drivers/gpu/drm/i915/i915_oa_bxt.c:31:
> > include/linux/iommu.h: In function 'iommu_debugfs_new_driver_dir':
> > > > include/linux/iommu.h:706:8: error: parameter name omitted
> > 
> >  struct dentry *iommu_debugfs_new_driver_dir(char *) {};
> > ^~
> > In file included from include/linux/intel-iommu.h:32:0,
> >  from drivers/gpu/drm/i915/i915_drv.h:41,
> >  from drivers/gpu/drm/i915/i915_oa_bxt.c:31:
> > > > include/linux/iommu.h:706:8: warning: control reaches end of non-void 
> > > > function [-Wreturn-type]
> > 
> >  struct dentry *iommu_debugfs_new_driver_dir(char *) {};
> > ^~
> > 
> > vim +706 include/linux/iommu.h
> > 
> > 700 
> > 701 #ifdef CONFIG_IOMMU_DEBUGFS
> > 702 void iommu_debugfs_setup(void);
> > 703 struct dentry *iommu_debugfs_new_driver_dir(char *);
> > 704 #else
> > 705 static inline void iommu_debugfs_setup(void) {}
> >   > 706 struct dentry *iommu_debugfs_new_driver_dir(char *) {};
> > 707 #endif
> > 708 
> 
> I have no problems with adding parameter names. But 
> scripts/checkpatch.pl doesn't seem to check for this, nor require it. 
> Should checkpatch be updated?

I'm pretty sure that's not feasible.

And when the compiler tells you you've stuffed up some
syntactical bit, why should checkpatch duplicate the
output error message too?

btw:  That's an unnecessary ; at the end of that non-void
function and it should probably be something like:

static inline struct dentry *iommu_debugfs_new_driver_dir(char *dir)
{
return NULL;
}

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[PATCH v1 9/9] iommu/tegra: gart: Optimize mapping / unmapping performance

2018-05-08 Thread Dmitry Osipenko 
Currently GART writes one page entry at a time. More optimal would be to
aggregate the writes and flush BUS buffer in the end, this gives map/unmap
10-40% (depending on size of mapping) performance boost compared to a
flushing after each entry update.

Signed-off-by: Dmitry Osipenko 
---
 drivers/iommu/tegra-gart.c | 12 ++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c
index ebc105c201bd..26d8735d26e8 100644
--- a/drivers/iommu/tegra-gart.c
+++ b/drivers/iommu/tegra-gart.c
@@ -226,7 +226,6 @@ static int gart_iommu_map(struct iommu_domain *domain, 
unsigned long iova,
}
}
gart_set_pte(gart, iova, GART_PTE(pfn));
-   FLUSH_GART_REGS(gart);
spin_unlock_irqrestore(>pte_lock, flags);
return 0;
 }
@@ -243,7 +242,6 @@ static size_t gart_iommu_unmap(struct iommu_domain *domain, 
unsigned long iova,
 
spin_lock_irqsave(>pte_lock, flags);
gart_set_pte(gart, iova, 0);
-   FLUSH_GART_REGS(gart);
spin_unlock_irqrestore(>pte_lock, flags);
return bytes;
 }
@@ -319,6 +317,14 @@ static int gart_iommu_of_xlate(struct device *dev,
return 0;
 }
 
+static void gart_iommu_sync(struct iommu_domain *domain)
+{
+   struct gart_domain *gart_domain = to_gart_domain(domain);
+   struct gart_device *gart = gart_domain->gart;
+
+   FLUSH_GART_REGS(gart);
+}
+
 static const struct iommu_ops gart_iommu_ops = {
.capable= gart_iommu_capable,
.domain_alloc   = gart_iommu_domain_alloc,
@@ -334,6 +340,8 @@ static const struct iommu_ops gart_iommu_ops = {
.iova_to_phys   = gart_iommu_iova_to_phys,
.pgsize_bitmap  = GART_IOMMU_PGSIZES,
.of_xlate   = gart_iommu_of_xlate,
+   .iotlb_sync_map = gart_iommu_sync,
+   .iotlb_sync = gart_iommu_sync,
 };
 
 static int gart_iommu_check_device(struct gart_device *gart,
-- 
2.17.0

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[PATCH v1 8/9] iommu: Introduce iotlb_sync_map callback

2018-05-08 Thread Dmitry Osipenko 
Introduce iotlb_sync_map() callback that is invoked in the end of
iommu_map(). This new callback allows IOMMU drivers to avoid syncing
on mapping of each contiguous chunk and sync only when whole mapping
is completed, optimizing performance of the mapping operation.

Signed-off-by: Dmitry Osipenko 
---
 drivers/iommu/iommu.c | 8 ++--
 include/linux/iommu.h | 1 +
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index d2aa23202bb9..39b2ee66aa96 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1508,13 +1508,14 @@ static size_t iommu_pgsize(struct iommu_domain *domain,
 int iommu_map(struct iommu_domain *domain, unsigned long iova,
  phys_addr_t paddr, size_t size, int prot)
 {
+   const struct iommu_ops *ops = domain->ops;
unsigned long orig_iova = iova;
unsigned int min_pagesz;
size_t orig_size = size;
phys_addr_t orig_paddr = paddr;
int ret = 0;
 
-   if (unlikely(domain->ops->map == NULL ||
+   if (unlikely(ops->map == NULL ||
 domain->pgsize_bitmap == 0UL))
return -ENODEV;
 
@@ -1543,7 +1544,7 @@ int iommu_map(struct iommu_domain *domain, unsigned long 
iova,
pr_debug("mapping: iova 0x%lx pa %pa pgsize 0x%zx\n",
 iova, , pgsize);
 
-   ret = domain->ops->map(domain, iova, paddr, pgsize, prot);
+   ret = ops->map(domain, iova, paddr, pgsize, prot);
if (ret)
break;
 
@@ -1552,6 +1553,9 @@ int iommu_map(struct iommu_domain *domain, unsigned long 
iova,
size -= pgsize;
}
 
+   if (ops->iotlb_sync_map)
+   ops->iotlb_sync_map(domain);
+
/* unroll mapping in case something went wrong */
if (ret)
iommu_unmap(domain, orig_iova, orig_size - size);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 19938ee6eb31..5224aa376377 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -206,6 +206,7 @@ struct iommu_ops {
void (*flush_iotlb_all)(struct iommu_domain *domain);
void (*iotlb_range_add)(struct iommu_domain *domain,
unsigned long iova, size_t size);
+   void (*iotlb_sync_map)(struct iommu_domain *domain);
void (*iotlb_sync)(struct iommu_domain *domain);
phys_addr_t (*iova_to_phys)(struct iommu_domain *domain, dma_addr_t 
iova);
int (*add_device)(struct device *dev);
-- 
2.17.0

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[PATCH v1 7/9] iommu/tegra: gart: Provide single domain and group for all devices

2018-05-08 Thread Dmitry Osipenko 
GART aperture is shared by all devices, hence there is a single IOMMU
domain and group shared by these devices. Allocation of a group per
device only wastes resources and allowance of having more than one domain
is simply wrong because IOMMU mappings made by the users of "different"
domains will stomp on each other.

Signed-off-by: Dmitry Osipenko 
---
 drivers/iommu/tegra-gart.c | 107 +
 1 file changed, 24 insertions(+), 83 deletions(-)

diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c
index 5b2d27620350..ebc105c201bd 100644
--- a/drivers/iommu/tegra-gart.c
+++ b/drivers/iommu/tegra-gart.c
@@ -19,7 +19,6 @@
 
 #include 
 #include 
-#include 
 #include 
 #include 
 #include 
@@ -44,22 +43,17 @@
 #define GART_PAGE_MASK \
(~(GART_PAGE_SIZE - 1) & ~GART_ENTRY_PHYS_ADDR_VALID)
 
-struct gart_client {
-   struct device   *dev;
-   struct list_headlist;
-};
-
 struct gart_device {
void __iomem*regs;
u32 *savedata;
u32 page_count; /* total remappable size */
dma_addr_t  iovmm_base; /* offset to vmm_area */
spinlock_t  pte_lock;   /* for pagetable */
-   struct list_headclient;
-   spinlock_t  client_lock;/* for client list */
struct device   *dev;
 
struct iommu_device iommu;  /* IOMMU Core handle */
+   struct iommu_group  *group; /* Common IOMMU group */
+   struct gart_domain  *domain;/* Unique IOMMU domain */
 
struct tegra_mc_gart_handle mc_gart_handle;
 };
@@ -169,81 +163,31 @@ static inline bool gart_iova_range_valid(struct 
gart_device *gart,
 static int gart_iommu_attach_dev(struct iommu_domain *domain,
 struct device *dev)
 {
-   struct gart_domain *gart_domain = to_gart_domain(domain);
-   struct gart_device *gart = gart_domain->gart;
-   struct gart_client *client, *c;
-   int err = 0;
-
-   client = devm_kzalloc(gart->dev, sizeof(*c), GFP_KERNEL);
-   if (!client)
-   return -ENOMEM;
-   client->dev = dev;
-
-   spin_lock(>client_lock);
-   list_for_each_entry(c, >client, list) {
-   if (c->dev == dev) {
-   dev_err(gart->dev,
-   "%s is already attached\n", dev_name(dev));
-   err = -EINVAL;
-   goto fail;
-   }
-   }
-   list_add(>list, >client);
-   spin_unlock(>client_lock);
-   dev_dbg(gart->dev, "Attached %s\n", dev_name(dev));
return 0;
-
-fail:
-   devm_kfree(gart->dev, client);
-   spin_unlock(>client_lock);
-   return err;
 }
 
 static void gart_iommu_detach_dev(struct iommu_domain *domain,
  struct device *dev)
 {
-   struct gart_domain *gart_domain = to_gart_domain(domain);
-   struct gart_device *gart = gart_domain->gart;
-   struct gart_client *c;
-
-   spin_lock(>client_lock);
-
-   list_for_each_entry(c, >client, list) {
-   if (c->dev == dev) {
-   list_del(>list);
-   devm_kfree(gart->dev, c);
-   dev_dbg(gart->dev, "Detached %s\n", dev_name(dev));
-   goto out;
-   }
-   }
-   dev_err(gart->dev, "Couldn't find\n");
-out:
-   spin_unlock(>client_lock);
 }
 
 static struct iommu_domain *gart_iommu_domain_alloc(unsigned type)
 {
-   struct gart_domain *gart_domain;
-   struct gart_device *gart;
-
-   if (type != IOMMU_DOMAIN_UNMANAGED)
-   return NULL;
+   struct gart_device *gart = gart_handle;
 
-   gart = gart_handle;
-   if (!gart)
+   if (type != IOMMU_DOMAIN_UNMANAGED || gart->domain)
return NULL;
 
-   gart_domain = kzalloc(sizeof(*gart_domain), GFP_KERNEL);
-   if (!gart_domain)
-   return NULL;
-
-   gart_domain->gart = gart;
-   gart_domain->domain.geometry.aperture_start = gart->iovmm_base;
-   gart_domain->domain.geometry.aperture_end = gart->iovmm_base +
+   gart->domain = kzalloc(sizeof(*gart->domain), GFP_KERNEL);
+   if (gart->domain) {
+   gart->domain->domain.geometry.aperture_start = gart->iovmm_base;
+   gart->domain->domain.geometry.aperture_end = gart->iovmm_base +
gart->page_count * GART_PAGE_SIZE - 1;
-   gart_domain->domain.geometry.force_aperture = true;
+   gart->domain->domain.geometry.force_aperture = true;
+   gart->domain->gart = gart;
+   }
 
-   return _domain->domain;
+   return >domain->domain;
 }
 
 static void gart_iommu_domain_free(struct iommu_domain *domain)
@@ -251,18 +195,7 @@ static

[PATCH v1 6/9] iommu/tegra: gart: Ignore devices without IOMMU phandle in DT

2018-05-08 Thread Dmitry Osipenko 
GART can't handle all devices, ignore devices that aren't related to GART.
Device tree must explicitly assign GART IOMMU to the devices.

Signed-off-by: Dmitry Osipenko 
---
 drivers/iommu/tegra-gart.c | 33 -
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c
index 39305224c48d..5b2d27620350 100644
--- a/drivers/iommu/tegra-gart.c
+++ b/drivers/iommu/tegra-gart.c
@@ -366,6 +366,26 @@ static void gart_iommu_remove_device(struct device *dev)
iommu_device_unlink(_handle->iommu, dev);
 }
 
+static int gart_iommu_check_device(struct gart_device *gart,
+  struct device *dev);
+
+struct iommu_group *gart_iommu_device_group(struct device *dev)
+{
+   int err;
+
+   err = gart_iommu_check_device(gart_handle, dev);
+   if (err)
+   return ERR_PTR(err);
+
+   return generic_device_group(dev);
+}
+
+static int gart_iommu_of_xlate(struct device *dev,
+  struct of_phandle_args *args)
+{
+   return 0;
+}
+
 static const struct iommu_ops gart_iommu_ops = {
.capable= gart_iommu_capable,
.domain_alloc   = gart_iommu_domain_alloc,
@@ -374,14 +394,24 @@ static const struct iommu_ops gart_iommu_ops = {
.detach_dev = gart_iommu_detach_dev,
.add_device = gart_iommu_add_device,
.remove_device  = gart_iommu_remove_device,
-   .device_group   = generic_device_group,
+   .device_group   = gart_iommu_device_group,
.map= gart_iommu_map,
.map_sg = default_iommu_map_sg,
.unmap  = gart_iommu_unmap,
.iova_to_phys   = gart_iommu_iova_to_phys,
.pgsize_bitmap  = GART_IOMMU_PGSIZES,
+   .of_xlate   = gart_iommu_of_xlate,
 };
 
+static int gart_iommu_check_device(struct gart_device *gart,
+  struct device *dev)
+{
+   if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != _iommu_ops)
+   return -ENODEV;
+
+   return 0;
+}
+
 static int tegra_gart_suspend(struct device *dev)
 {
struct gart_device *gart = dev_get_drvdata(dev);
@@ -462,6 +492,7 @@ static int tegra_gart_probe(struct platform_device *pdev)
}
 
iommu_device_set_ops(>iommu, _iommu_ops);
+   iommu_device_set_fwnode(>iommu, dev->fwnode);
 
ret = iommu_device_register(>iommu);
if (ret) {
-- 
2.17.0

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[PATCH v1 5/9] iommu/tegra: gart: Clean up driver probe failure unwinding

2018-05-08 Thread Dmitry Osipenko 
Properly clean up allocated resources on driver probe failure.

Signed-off-by: Dmitry Osipenko 
---
 drivers/iommu/tegra-gart.c | 13 ++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c
index 08e0de4087d1..39305224c48d 100644
--- a/drivers/iommu/tegra-gart.c
+++ b/drivers/iommu/tegra-gart.c
@@ -466,8 +466,7 @@ static int tegra_gart_probe(struct platform_device *pdev)
ret = iommu_device_register(>iommu);
if (ret) {
dev_err(dev, "Failed to register IOMMU\n");
-   iommu_device_sysfs_remove(>iommu);
-   return ret;
+   goto remove_sysfs;
}
 
gart->dev = >dev;
@@ -483,7 +482,8 @@ static int tegra_gart_probe(struct platform_device *pdev)
gart->savedata = vmalloc(sizeof(u32) * gart->page_count);
if (!gart->savedata) {
dev_err(dev, "failed to allocate context save area\n");
-   return -ENOMEM;
+   ret = -ENOMEM;
+   goto iommu_unregister;
}
 
platform_set_drvdata(pdev, gart);
@@ -493,6 +493,13 @@ static int tegra_gart_probe(struct platform_device *pdev)
tegra_mc_register_gart(>mc_gart_handle);
 
return 0;
+
+iommu_unregister:
+   iommu_device_unregister(>iommu);
+remove_sysfs:
+   iommu_device_sysfs_remove(>iommu);
+
+   return ret;
 }
 
 static const struct dev_pm_ops tegra_gart_pm_ops = {
-- 
2.17.0

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[PATCH v1 3/9] iommu/tegra: gart: Remove code related to module unloading

2018-05-08 Thread Dmitry Osipenko 
GART driver is built-in, hence it can't be unloaded. This patch merely
removes the dead code.

Signed-off-by: Dmitry Osipenko 
---
 drivers/iommu/tegra-gart.c | 25 +++--
 1 file changed, 3 insertions(+), 22 deletions(-)

diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c
index de48943bf843..268d29fb9097 100644
--- a/drivers/iommu/tegra-gart.c
+++ b/drivers/iommu/tegra-gart.c
@@ -502,20 +502,6 @@ static int tegra_gart_probe(struct platform_device *pdev)
return 0;
 }
 
-static int tegra_gart_remove(struct platform_device *pdev)
-{
-   struct gart_device *gart = platform_get_drvdata(pdev);
-
-   iommu_device_unregister(>iommu);
-   iommu_device_sysfs_remove(>iommu);
-
-   writel(0, gart->regs + GART_CONFIG);
-   if (gart->savedata)
-   vfree(gart->savedata);
-   gart_handle = NULL;
-   return 0;
-}
-
 static const struct dev_pm_ops tegra_gart_pm_ops = {
.suspend= tegra_gart_suspend,
.resume = tegra_gart_resume,
@@ -529,26 +515,21 @@ MODULE_DEVICE_TABLE(of, tegra_gart_of_match);
 
 static struct platform_driver tegra_gart_driver = {
.probe  = tegra_gart_probe,
-   .remove = tegra_gart_remove,
.driver = {
.name   = "tegra-gart",
.pm = _gart_pm_ops,
.of_match_table = tegra_gart_of_match,
+   .suppress_bind_attrs = true,
},
+   .prevent_deferred_probe = true,
 };
 
 static int tegra_gart_init(void)
 {
return platform_driver_register(_gart_driver);
 }
-
-static void __exit tegra_gart_exit(void)
-{
-   platform_driver_unregister(_gart_driver);
-}
-
 subsys_initcall(tegra_gart_init);
-module_exit(tegra_gart_exit);
+
 module_param(gart_debug, bool, 0644);
 
 MODULE_PARM_DESC(gart_debug, "Enable GART debugging");
-- 
2.17.0

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[PATCH v1 1/9] memory: tegra: Provide facility for integration with the GART driver

2018-05-08 Thread Dmitry Osipenko 
In order to report clients name and access direction on GART page fault,
MC driver needs to access GART registers. Add facility that provides
access to the GART.

Signed-off-by: Dmitry Osipenko 
---
 drivers/memory/tegra/mc.c | 26 +++---
 include/soc/tegra/mc.h| 13 +
 2 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index c81d01caf1a8..49dd7ad1459f 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -72,6 +72,8 @@ static const struct of_device_id tegra_mc_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, tegra_mc_of_match);
 
+static struct tegra_mc_gart_handle *gart_handle;
+
 static int terga_mc_block_dma_common(struct tegra_mc *mc,
 const struct tegra_mc_reset *rst)
 {
@@ -543,6 +545,11 @@ static irqreturn_t tegra_mc_irq(int irq, void *data)
return IRQ_HANDLED;
 }
 
+void tegra_mc_register_gart(struct tegra_mc_gart_handle *handle)
+{
+   WRITE_ONCE(gart_handle, handle);
+}
+
 static __maybe_unused irqreturn_t tegra20_mc_irq(int irq, void *data)
 {
struct tegra_mc *mc = data;
@@ -565,6 +572,7 @@ static __maybe_unused irqreturn_t tegra20_mc_irq(int irq, 
void *data)
switch (BIT(bit)) {
case MC_INT_DECERR_EMEM:
reg = MC_DECERR_EMEM_OTHERS_STATUS;
+   addr = mc_readl(mc, reg + sizeof(u32));
value = mc_readl(mc, reg);
 
id = value & mc->soc->client_id_mask;
@@ -575,11 +583,24 @@ static __maybe_unused irqreturn_t tegra20_mc_irq(int irq, 
void *data)
break;
 
case MC_INT_INVALID_GART_PAGE:
-   dev_err_ratelimited(mc->dev, "%s\n", error);
-   continue;
+   if (READ_ONCE(gart_handle) == NULL) {
+   dev_err_ratelimited(mc->dev, "%s\n", error);
+   continue;
+   }
+
+   addr = gart_handle->error_addr(gart_handle);
+   value = gart_handle->error_req(gart_handle);
+
+   id = (value >> 1) & mc->soc->client_id_mask;
+   desc = error_names[2];
+
+   if (value & BIT(0))
+   direction = "write";
+   break;
 
case MC_INT_SECURITY_VIOLATION:
reg = MC_SECURITY_VIOLATION_STATUS;
+   addr = mc_readl(mc, reg + sizeof(u32));
value = mc_readl(mc, reg);
 
id = value & mc->soc->client_id_mask;
@@ -596,7 +617,6 @@ static __maybe_unused irqreturn_t tegra20_mc_irq(int irq, 
void *data)
}
 
client = mc->soc->clients[id].name;
-   addr = mc_readl(mc, reg + sizeof(u32));
 
dev_err_ratelimited(mc->dev, "%s: %s%s @%pa: %s (%s)\n",
client, secure, direction, , error,
diff --git a/include/soc/tegra/mc.h b/include/soc/tegra/mc.h
index b43f37fea096..5bf72eb4dd51 100644
--- a/include/soc/tegra/mc.h
+++ b/include/soc/tegra/mc.h
@@ -162,4 +162,17 @@ struct tegra_mc {
 void tegra_mc_write_emem_configuration(struct tegra_mc *mc, unsigned long 
rate);
 unsigned int tegra_mc_get_emem_device_count(struct tegra_mc *mc);
 
+struct tegra_mc_gart_handle {
+   u32 (*error_addr)(struct tegra_mc_gart_handle *handle);
+   u32 (*error_req)(struct tegra_mc_gart_handle *handle);
+};
+
+#ifdef CONFIG_TEGRA_MC
+void tegra_mc_register_gart(struct tegra_mc_gart_handle *handle);
+#else
+static inline void tegra_mc_register_gart(struct tegra_mc_gart_handle *handle)
+{
+}
+#endif
+
 #endif /* __SOC_TEGRA_MC_H__ */
-- 
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[PATCH v1 0/9] Tegra GART driver clean up and optimization

2018-05-08 Thread Dmitry Osipenko 
Hello,

This series addresses multiple shortcomings of the GART driver:

1. Thierry noticed that Memory Controller driver uses registers that belong
   to GART in [0] and for now MC driver only reports the fact of GART's page
   fault. The first two patches of the series are addressing this shortcoming.

   [0] https://www.spinics.net/lists/linux-tegra/msg33072.html

2. Currently GART is kept disabled by the commit c7e3ca515e784 ("iommu/tegra:
   gart: Do not register with bus"). If GART is re-enabled than all devices
   in the system are getting assigned to the GART as it is a global systems
   IOMMU provider. This is wrong simply because GART doesn't handle all those
   devices. This series makes GART to accept only devices that are explicitly
   assigned to GART in device tree using 'iommu' phandle.

3. This series makes a generic clean up of the driver by removing dead code,
   allowing to have one IOMMU domain at max, etc.

4. This series introduces and utilizes iotlb_sync_map() callback that was
   previously suggested by Joerg Roedel in [1].

   [1] https://www.spinics.net/lists/linux-tegra/msg32914.html

Dmitry Osipenko (9):
  memory: tegra: Provide facility for integration with the GART driver
  iommu/tegra: gart: Provide access to Memory Controller driver
  iommu/tegra: gart: Remove code related to module unloading
  iommu/tegra: gart: Remove pr_fmt and clean up includes
  iommu/tegra: gart: Clean up driver probe failure unwinding
  iommu/tegra: gart: Ignore devices without IOMMU phandle in DT
  iommu/tegra: gart: Provide single domain and group for all devices
  iommu: Introduce iotlb_sync_map callback
  iommu/tegra: gart: Optimize mapping / unmapping performance

 drivers/iommu/iommu.c  |   8 +-
 drivers/iommu/tegra-gart.c | 216 +
 drivers/memory/tegra/mc.c  |  26 -
 include/linux/iommu.h  |   1 +
 include/soc/tegra/mc.h |  13 +++
 5 files changed, 143 insertions(+), 121 deletions(-)

-- 
2.17.0

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[PATCH v1 4/9] iommu/tegra: gart: Remove pr_fmt and clean up includes

2018-05-08 Thread Dmitry Osipenko 
Remove unneeded 'includes' and sort them in alphabet order. Also remove
pr_fmt since there is no pr_xxx() and it doesn't affect dev_xxx().

Signed-off-by: Dmitry Osipenko 
---
 drivers/iommu/tegra-gart.c | 17 +
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c
index 268d29fb9097..08e0de4087d1 100644
--- a/drivers/iommu/tegra-gart.c
+++ b/drivers/iommu/tegra-gart.c
@@ -17,24 +17,17 @@
  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define pr_fmt(fmt)"%s(): " fmt, __func__
-
+#include 
+#include 
+#include 
 #include 
-#include 
-#include 
+#include 
 #include 
+#include 
 #include 
-#include 
-#include 
-#include 
-#include 
-#include 
-#include 
 
 #include 
 
-#include 
-
 /* bitmap of the page sizes currently supported */
 #define GART_IOMMU_PGSIZES (SZ_4K)
 
-- 
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[PATCH v1 2/9] iommu/tegra: gart: Provide access to Memory Controller driver

2018-05-08 Thread Dmitry Osipenko 
GART contains registers needed by the Memory Controller driver. Provide
access to the MC driver by utilizing its GART-integration facility.

Signed-off-by: Dmitry Osipenko 
---
 drivers/iommu/tegra-gart.c | 23 +++
 1 file changed, 23 insertions(+)

diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c
index 89ec24c6952c..de48943bf843 100644
--- a/drivers/iommu/tegra-gart.c
+++ b/drivers/iommu/tegra-gart.c
@@ -31,6 +31,8 @@
 #include 
 #include 
 
+#include 
+
 #include 
 
 /* bitmap of the page sizes currently supported */
@@ -41,6 +43,8 @@
 #define GART_ENTRY_ADDR(0x28 - GART_REG_BASE)
 #define GART_ENTRY_DATA(0x2c - GART_REG_BASE)
 #define GART_ENTRY_PHYS_ADDR_VALID (1 << 31)
+#define GART_ERROR_REQ (0x30 - GART_REG_BASE)
+#define GART_ERROR_ADDR(0x34 - GART_REG_BASE)
 
 #define GART_PAGE_SHIFT12
 #define GART_PAGE_SIZE (1 << GART_PAGE_SHIFT)
@@ -63,6 +67,8 @@ struct gart_device {
struct device   *dev;
 
struct iommu_device iommu;  /* IOMMU Core handle */
+
+   struct tegra_mc_gart_handle mc_gart_handle;
 };
 
 struct gart_domain {
@@ -408,6 +414,20 @@ static int tegra_gart_resume(struct device *dev)
return 0;
 }
 
+static u32 tegra_gart_error_addr(struct tegra_mc_gart_handle *handle)
+{
+   struct gart_device *gart = container_of(handle, struct gart_device,
+   mc_gart_handle);
+   return readl(gart->regs + GART_ERROR_ADDR);
+}
+
+static u32 tegra_gart_error_req(struct tegra_mc_gart_handle *handle)
+{
+   struct gart_device *gart = container_of(handle, struct gart_device,
+   mc_gart_handle);
+   return readl(gart->regs + GART_ERROR_REQ);
+}
+
 static int tegra_gart_probe(struct platform_device *pdev)
 {
struct gart_device *gart;
@@ -464,6 +484,8 @@ static int tegra_gart_probe(struct platform_device *pdev)
gart->regs = gart_regs;
gart->iovmm_base = (dma_addr_t)res_remap->start;
gart->page_count = (resource_size(res_remap) >> GART_PAGE_SHIFT);
+   gart->mc_gart_handle.error_addr = tegra_gart_error_addr;
+   gart->mc_gart_handle.error_req = tegra_gart_error_req;
 
gart->savedata = vmalloc(sizeof(u32) * gart->page_count);
if (!gart->savedata) {
@@ -475,6 +497,7 @@ static int tegra_gart_probe(struct platform_device *pdev)
do_gart_setup(gart, NULL);
 
gart_handle = gart;
+   tegra_mc_register_gart(>mc_gart_handle);
 
return 0;
 }
-- 
2.17.0

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Re: [PATCH v5 1/2] iommu - Enable debugfs exposure of IOMMU driver internals

2018-05-08 Thread Hook, Gary 

On 5/7/2018 6:47 PM, kbuild test robot wrote:

Hi Gary,



I imagine these questions have been asked before, so I'll ask for
forgiveness up front.



Thank you for the patch! Yet something to improve:

[auto build test ERROR on iommu/next]
[also build test ERROR on v4.17-rc4 next-20180507]
[if your patch is applied to the wrong git tree, please drop us a note to help 
improve the system]

url:
https://github.com/0day-ci/linux/commits/Gary-R-Hook/iommu-Enable-debugfs-exposure-of-IOMMU-driver-internals/20180508-062918
base:   https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git next
config: x86_64-randconfig-x016-201818 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
reproduce:
 # save the attached .config to linux build tree
 make ARCH=x86_64


Is the gcc 7 compiler now a requirement to build the kernel? Or only to 
run krobot tests?


Is this the earliest version of the compiler that can be used? I'm still 
using 4.8 and 5.4, which seems to suffice for the kernel.


Googling about this has been fruitless.



All error/warnings (new ones prefixed by >>):

In file included from include/linux/intel-iommu.h:32:0,
 from drivers/gpu/drm/i915/i915_drv.h:41,
 from drivers/gpu/drm/i915/i915_oa_bxt.c:31:
include/linux/iommu.h: In function 'iommu_debugfs_new_driver_dir':

include/linux/iommu.h:706:8: error: parameter name omitted

 struct dentry *iommu_debugfs_new_driver_dir(char *) {};
^~
In file included from include/linux/intel-iommu.h:32:0,
 from drivers/gpu/drm/i915/i915_drv.h:41,
 from drivers/gpu/drm/i915/i915_oa_bxt.c:31:

include/linux/iommu.h:706:8: warning: control reaches end of non-void function 
[-Wreturn-type]

 struct dentry *iommu_debugfs_new_driver_dir(char *) {};
^~

vim +706 include/linux/iommu.h

700 
701 #ifdef CONFIG_IOMMU_DEBUGFS
702 void iommu_debugfs_setup(void);
703 struct dentry *iommu_debugfs_new_driver_dir(char *);
704 #else
705 static inline void iommu_debugfs_setup(void) {}
  > 706  struct dentry *iommu_debugfs_new_driver_dir(char *) {};
707 #endif
708 


I have no problems with adding parameter names. But 
scripts/checkpatch.pl doesn't seem to check for this, nor require it. 
Should checkpatch be updated?

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Re: [PATCH 3/3] dma-debug: unexport dma_debug_resize_entries and debug_dma_dump_mappings

2018-05-08 Thread Christoph Hellwig 
On Tue, May 08, 2018 at 11:05:20AM +0100, Robin Murphy wrote:
> On 24/04/18 15:02, Christoph Hellwig wrote:
>> Only used by the AMD GART driver, which must be built in.
>
> FWIW debug_dma_dump_mappings() is also called by the Intel VT-d driver, but 
> the same reasoning still applies.

I'll update the changelog.

> This does rather beg the question of 
> whether it's right to have bits of low-level dma-debug internals *only* 
> called by a couple of IOMMU drivers, but that can wait for another day.

My gut feeling is that it is wrong, but I didn't have time to look into
the details and history of how this happened.
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Re: [PATCH v4 05/22] iommu: introduce iommu invalidate API function

2018-05-08 Thread Jean-Philippe Brucker 
Hi Jacob,

Looks mostly good to me, I just have a couple more comments

On 04/05/18 19:07, Jacob Pan wrote:
> Now the passdown invalidation granularities look like:
> (sorted by coarseness), will send out in v5 patchset soon if no issues.
> 
> /**
>  * enum iommu_inv_granularity - Generic invalidation granularity
>  *
>  * @IOMMU_INV_GRANU_DOMAIN:   Device context cache associated with a
>  *domain ID.
>  * @IOMMU_INV_GRANU_DEVICE:   Device context cache associated with a
>  *device ID
>  * @IOMMU_INV_GRANU_DOMAIN_ALL_PASID: TLB entries or PASID caches of all
>  *PASIDs associated with a domain ID
>  * @IOMMU_INV_GRANU_PASID_SEL:TLB entries or PASID cache 
> associated
>  *with a PASID and a domain
>  * @IOMMU_INV_GRANU_PAGE_PASID:   TLB entries of selected page 
> range
>  *within a PASID
>  *
>  * When an invalidation request is passed down to IOMMU to flush translation
>  * caches, it may carry different granularity levels, which can be specific
>  * to certain types of translation caches. For an example, PASID selective
>  * granularity is only applicable PASID cache and IOTLB invalidation but for
>  * device context caches.

Should it be "PASID selective granularity is only applicable to PASID
cache and IOTLB but not device context caches"?

>  * This enum is a collection of granularities for all types of translation
>  * caches. The idea is to make it easy for IOMMU model specific driver to
>  * convert from generic to model specific value. Not all combinations between
>  * translation caches and granularity levels are valid. Each IOMMU driver
>  * can enforce check based on its own conversion table. The conversion is
>  * based on 2D look-up with inputs as follows:
>  * - translation cache types
>  * - granularity
>  * No global granularity is allowed in that passdown invalidation for an
>  * assigned device should only impact the device or domain itself.

That last sentence is a bit confusing, because "global granularity"
might also refer to the "global" TLB flag which is allowed. In my
opinion you can leave this rationale out, I doubt userspace will ever
demand a mechanism for global invalidation.

>  *
>  * type |   DTLB|TLB|   PASID   |  CONTEXT
>  *  granule |   |   |   |
>  * -+---+---+---+---
>  *  DOMAIN  |   |   |   | Y
>  *  DEVICE  |   |   |   | Y

I can't really see a use-case for DOMAIN and DEVICE. It might make more
sense to keep only DN_ALL_PASID, which would then also invalidate the
device context cache. But since they will be very rare events, factoring
them doesn't seem important.

>  *  DN_ALL_PASID|   Y   |   Y   |   Y   |
>  *  PASID_SEL   |   Y   |   Y   |   Y   |
>  *  PAGE_PASID  |   |   Y   |   |

Why not allow PAGE_PASID+DTLB? We need a way to invalidate individual
DTLB entries

Thanks,
Jean
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Re: [PATCH 1/3] dma-debug: move initialization to common code

2018-05-08 Thread Marek Szyprowski 
Hi Christoph,

On 2018-04-24 16:02, Christoph Hellwig wrote:
> Most mainstream architectures are using 65536 entries, so lets stick to
> that.  If someone is really desperate to override it that can still be
> done through , but I'd rather see a really good
> rationale for that.
>
> dma_debug_init is now called as a core_initcall, which for many
> architectures means much earlier, and provides dma-debug functionality
> earlier in the boot process.  This should be safe as it only relies
> on the memory allocator already being available.
>
> Signed-off-by: Christoph Hellwig 

Nice! Unification of this is definitely needed and solves the issues
reported some time ago:

https://patchwork.kernel.org/patch/9429637/ (arm)
https://patchwork.kernel.org/patch/9431161/ (arm64, rejected)

Acked-by: Marek Szyprowski 

> ---
>   arch/arm/mm/dma-mapping-nommu.c |  9 -
>   arch/arm/mm/dma-mapping.c   |  9 -
>   arch/arm64/mm/dma-mapping.c | 10 --
>   arch/c6x/kernel/dma.c   | 11 ---
>   arch/ia64/kernel/dma-mapping.c  | 10 --
>   arch/microblaze/kernel/dma.c| 11 ---
>   arch/mips/mm/dma-default.c  | 10 --
>   arch/openrisc/kernel/dma.c  | 11 ---
>   arch/powerpc/kernel/dma.c   |  3 ---
>   arch/s390/pci/pci_dma.c |  9 -
>   arch/sh/mm/consistent.c |  9 -
>   arch/sparc/kernel/Makefile  |  2 --
>   arch/sparc/kernel/dma.c | 13 -
>   arch/x86/kernel/pci-dma.c   |  4 
>   arch/xtensa/kernel/pci-dma.c|  9 -
>   include/linux/dma-debug.h   |  6 --
>   lib/dma-debug.c | 21 ++---
>   17 files changed, 14 insertions(+), 143 deletions(-)
>   delete mode 100644 arch/sparc/kernel/dma.c
>
> diff --git a/arch/arm/mm/dma-mapping-nommu.c b/arch/arm/mm/dma-mapping-nommu.c
> index 619f24a42d09..f448a0663b10 100644
> --- a/arch/arm/mm/dma-mapping-nommu.c
> +++ b/arch/arm/mm/dma-mapping-nommu.c
> @@ -241,12 +241,3 @@ void arch_setup_dma_ops(struct device *dev, u64 
> dma_base, u64 size,
>   void arch_teardown_dma_ops(struct device *dev)
>   {
>   }
> -
> -#define PREALLOC_DMA_DEBUG_ENTRIES   4096
> -
> -static int __init dma_debug_do_init(void)
> -{
> - dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
> - return 0;
> -}
> -core_initcall(dma_debug_do_init);
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index 8c398fedbbb6..c26bf83f44ca 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -1165,15 +1165,6 @@ int arm_dma_supported(struct device *dev, u64 mask)
>   return __dma_supported(dev, mask, false);
>   }
>   
> -#define PREALLOC_DMA_DEBUG_ENTRIES   4096
> -
> -static int __init dma_debug_do_init(void)
> -{
> - dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
> - return 0;
> -}
> -core_initcall(dma_debug_do_init);
> -
>   #ifdef CONFIG_ARM_DMA_USE_IOMMU
>   
>   static int __dma_info_to_prot(enum dma_data_direction dir, unsigned long 
> attrs)
> diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
> index a96ec0181818..db01f2709842 100644
> --- a/arch/arm64/mm/dma-mapping.c
> +++ b/arch/arm64/mm/dma-mapping.c
> @@ -508,16 +508,6 @@ static int __init arm64_dma_init(void)
>   }
>   arch_initcall(arm64_dma_init);
>   
> -#define PREALLOC_DMA_DEBUG_ENTRIES   4096
> -
> -static int __init dma_debug_do_init(void)
> -{
> - dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
> - return 0;
> -}
> -fs_initcall(dma_debug_do_init);
> -
> -
>   #ifdef CONFIG_IOMMU_DMA
>   #include 
>   #include 
> diff --git a/arch/c6x/kernel/dma.c b/arch/c6x/kernel/dma.c
> index 9fff8be75f58..31e1a9ec3a9c 100644
> --- a/arch/c6x/kernel/dma.c
> +++ b/arch/c6x/kernel/dma.c
> @@ -136,14 +136,3 @@ const struct dma_map_ops c6x_dma_ops = {
>   .sync_sg_for_cpu= c6x_dma_sync_sg_for_cpu,
>   };
>   EXPORT_SYMBOL(c6x_dma_ops);
> -
> -/* Number of entries preallocated for DMA-API debugging */
> -#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
> -
> -static int __init dma_init(void)
> -{
> - dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
> -
> - return 0;
> -}
> -fs_initcall(dma_init);
> diff --git a/arch/ia64/kernel/dma-mapping.c b/arch/ia64/kernel/dma-mapping.c
> index f2d57e66fd86..7a471d8d67d4 100644
> --- a/arch/ia64/kernel/dma-mapping.c
> +++ b/arch/ia64/kernel/dma-mapping.c
> @@ -9,16 +9,6 @@ int iommu_detected __read_mostly;
>   const struct dma_map_ops *dma_ops;
>   EXPORT_SYMBOL(dma_ops);
>   
> -#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
> -
> -static int __init dma_init(void)
> -{
> - dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
> -
> - return 0;
> -}
> -fs_initcall(dma_init);
> -
>   const struct dma_map_ops *dma_get_ops(struct device *dev)
>   {
>   return dma_ops;
> diff --git a/arch/microblaze/kernel/dma.c b/arch/microblaze/kernel/dma.c
> index c91e8cef98dd..3145e7dc8ab1 100644
> ---

Re: [PATCH] dma-debug: Check scatterlist segments

2018-05-08 Thread Robin Murphy 

On 25/04/18 06:58, Christoph Hellwig wrote:

This looks interesting.  I suspect it is going to blow up in
quite a few places, so maybe at least for now it might make sense
to have a separate config option?


True, it's nice to verify this for 'traditional' dma_map_sg() usage, but 
places where it's just used as an intermediate shorthand for "prepare 
all these pages for arbitrary future DMA" are liable to be noisy with 
false-positives for not respecting the default values when they arguably 
don't matter. I'll respin this as an additional config under 
DMA_API_DEBUG, and then we can debate "default y" or not.


Robin.


On Tue, Apr 24, 2018 at 05:12:19PM +0100, Robin Murphy wrote:

Drivers/subsystems creating scatterlists for DMA should be taking care
to respect the scatter-gather limitations of the appropriate device, as
described by dma_parms. A DMA API implementation cannot feasibly split
a scatterlist into *more* entries than originally passed, so it is not
well defined what they should do when given a segment larger than the
limit they are also required to respect.

Conversely, devices which are less limited than the rather conservative
defaults, or indeed have no limitations at all (e.g. GPUs with their own
internal MMU), should be encouraged to set appropriate dma_parms, as
they may get more efficient DMA mapping performance out of it.

Signed-off-by: Robin Murphy 
---
  lib/dma-debug.c | 26 ++
  1 file changed, 26 insertions(+)

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 7f5cdc1e6b29..9f158941004d 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -1293,6 +1293,30 @@ static void check_sync(struct device *dev,
put_hash_bucket(bucket, );
  }
  
+static void check_sg_segment(struct device *dev, struct scatterlist *sg)

+{
+   unsigned int max_seg = dma_get_max_seg_size(dev);
+   dma_addr_t start, end, boundary = dma_get_seg_boundary(dev);
+
+   /*
+* Either the driver forgot to set dma_parms appropriately, or
+* whoever generated the list forgot to check them.
+*/
+   if (sg->length > max_seg)
+   err_printk(dev, NULL, "DMA-API: mapping sg segment longer than 
device claims to support [len=%u] [max=%u]\n",
+  sg->length, max_seg);
+   /*
+* In some cases this could potentially be the DMA API
+* implementation's fault, but it would usually imply that
+* the scatterlist was built inappropriately to begin with.
+*/
+   start = sg_dma_address(sg);
+   end = start + sg_dma_len(sg) - 1;
+   if ((start ^ end) & ~boundary)
+   err_printk(dev, NULL, "DMA-API: mapping sg segment across boundary 
[start=0x%016llx] [end=0x%016llx] [boundary=0x%016llx]\n",
+  start, end, boundary);
+}
+
  void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
size_t size, int direction, dma_addr_t dma_addr,
bool map_single)
@@ -1423,6 +1447,8 @@ void debug_dma_map_sg(struct device *dev, struct 
scatterlist *sg,
check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
}
  
+		check_sg_segment(dev, s);

+
add_dma_entry(entry);
}
  }
--
2.17.0.dirty

---end quoted text---


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Re: [PATCH 3/3] dma-debug: unexport dma_debug_resize_entries and debug_dma_dump_mappings

2018-05-08 Thread Robin Murphy 

On 24/04/18 15:02, Christoph Hellwig wrote:

Only used by the AMD GART driver, which must be built in.


FWIW debug_dma_dump_mappings() is also called by the Intel VT-d driver, 
but the same reasoning still applies. This does rather beg the question 
of whether it's right to have bits of low-level dma-debug internals 
*only* called by a couple of IOMMU drivers, but that can wait for 
another day.


Reviewed-by: Robin Murphy 


Signed-off-by: Christoph Hellwig 
---
  lib/dma-debug.c | 2 --
  1 file changed, 2 deletions(-)

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 075253cb613b..6a1ebaa83623 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -444,7 +444,6 @@ void debug_dma_dump_mappings(struct device *dev)
spin_unlock_irqrestore(>lock, flags);
}
  }
-EXPORT_SYMBOL(debug_dma_dump_mappings);
  
  /*

   * For each mapping (initial cacheline in the case of
@@ -753,7 +752,6 @@ int dma_debug_resize_entries(u32 num_entries)
  
  	return ret;

  }
-EXPORT_SYMBOL(dma_debug_resize_entries);
  
  /*

   * DMA-API debugging init code


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Re: [PATCH 4/3] dma-debug: remove CONFIG_HAVE_DMA_API_DEBUG

2018-05-08 Thread Robin Murphy 

On 27/04/18 16:53, Christoph Hellwig wrote:

There is no arch specific code required for dma-debug, so there is no
need to opt into the support either.


Makes sense, and a purely negative diffstat is always pleasing :)

Reviewed-by: Robin Murphy 


Signed-off-by: Christoph Hellwig 
---
  .../io/dma-api-debug/arch-support.txt | 31 ---
  arch/Kconfig  |  3 --
  arch/arm/Kconfig  |  1 -
  arch/arm64/Kconfig|  1 -
  arch/c6x/Kconfig  |  1 -
  arch/ia64/Kconfig |  1 -
  arch/microblaze/Kconfig   |  1 -
  arch/mips/Kconfig |  1 -
  arch/powerpc/Kconfig  |  1 -
  arch/riscv/Kconfig|  1 -
  arch/s390/Kconfig |  1 -
  arch/sh/Kconfig   |  1 -
  arch/sparc/Kconfig|  1 -
  arch/x86/Kconfig  |  1 -
  arch/xtensa/Kconfig   |  1 -
  lib/Kconfig.debug |  1 -
  16 files changed, 48 deletions(-)
  delete mode 100644 Documentation/features/io/dma-api-debug/arch-support.txt

diff --git a/Documentation/features/io/dma-api-debug/arch-support.txt 
b/Documentation/features/io/dma-api-debug/arch-support.txt
deleted file mode 100644
index e438ed675623..
--- a/Documentation/features/io/dma-api-debug/arch-support.txt
+++ /dev/null
@@ -1,31 +0,0 @@
-#
-# Feature name:  dma-api-debug
-# Kconfig:   HAVE_DMA_API_DEBUG
-# description:   arch supports DMA debug facilities
-#
----
-| arch |status|
----
-|   alpha: | TODO |
-| arc: | TODO |
-| arm: |  ok  |
-|   arm64: |  ok  |
-| c6x: |  ok  |
-|   h8300: | TODO |
-| hexagon: | TODO |
-|ia64: |  ok  |
-|m68k: | TODO |
-|  microblaze: |  ok  |
-|mips: |  ok  |
-|   nios2: | TODO |
-|openrisc: | TODO |
-|  parisc: | TODO |
-| powerpc: |  ok  |
-|s390: |  ok  |
-|  sh: |  ok  |
-|   sparc: |  ok  |
-|  um: | TODO |
-|   unicore32: | TODO |
-| x86: |  ok  |
-|  xtensa: |  ok  |
----
diff --git a/arch/Kconfig b/arch/Kconfig
index 8e0d665c8d53..f07a1a99e5db 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -278,9 +278,6 @@ config HAVE_CLK
  The  calls support software clock gating and
  thus are a key power management tool on many systems.
  
-config HAVE_DMA_API_DEBUG

-   bool
-
  config HAVE_HW_BREAKPOINT
bool
depends on PERF_EVENTS
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 676977bdfe33..c43f5bb55ac8 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -60,7 +60,6 @@ config ARM
select HAVE_CONTEXT_TRACKING
select HAVE_C_RECORDMCOUNT
select HAVE_DEBUG_KMEMLEAK
-   select HAVE_DMA_API_DEBUG
select HAVE_DMA_CONTIGUOUS if MMU
select HAVE_DYNAMIC_FTRACE if (!XIP_KERNEL) && !CPU_ENDIAN_BE32 && MMU
select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index db51b6445744..b25ed7834f6c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -105,7 +105,6 @@ config ARM64
select HAVE_CONTEXT_TRACKING
select HAVE_DEBUG_BUGVERBOSE
select HAVE_DEBUG_KMEMLEAK
-   select HAVE_DMA_API_DEBUG
select HAVE_DMA_CONTIGUOUS
select HAVE_DYNAMIC_FTRACE
select HAVE_EFFICIENT_UNALIGNED_ACCESS
diff --git a/arch/c6x/Kconfig b/arch/c6x/Kconfig
index c6b4dd1418b4..8c088b96e372 100644
--- a/arch/c6x/Kconfig
+++ b/arch/c6x/Kconfig
@@ -10,7 +10,6 @@ config C6X
select GENERIC_ATOMIC64
select GENERIC_IRQ_SHOW
select HAVE_ARCH_TRACEHOOK
-   select HAVE_DMA_API_DEBUG
select HAVE_MEMBLOCK
select SPARSE_IRQ
select IRQ_DOMAIN
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 9485b5490eca..2067289fad4a 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -29,7 +29,6 @@ config IA64
select HAVE_FUNCTION_TRACER
select TTY
select HAVE_ARCH_TRACEHOOK
-   select HAVE_DMA_API_DEBUG
select HAVE_MEMBLOCK
select HAVE_MEMBLOCK_NODE_MAP
select HAVE_VIRT_CPU_ACCOUNTING
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 3817a3e2146c..d14782100088 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -19,7 +19,6 @@ config MICROBLAZE
select HAVE_ARCH_HASH
select HAVE_ARCH_KGDB
select HAVE_DEBUG_KMEMLEAK
-   select HAVE_DMA_API_DEBUG
select HAVE_DYNAMIC_FTRACE

Re: [PATCH 2/3] dma-debug: simplify counting of preallocated requests

2018-05-08 Thread Robin Murphy 

On 24/04/18 15:02, Christoph Hellwig wrote:

Just keep a single variable with a descriptive name instead of two
with confusing names.


Reviewed-by: Robin Murphy 


Signed-off-by: Christoph Hellwig 
---
  lib/dma-debug.c | 20 
  1 file changed, 4 insertions(+), 16 deletions(-)

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 712a897174e4..075253cb613b 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -132,7 +132,7 @@ static u32 min_free_entries;
  static u32 nr_total_entries;
  
  /* number of preallocated entries requested by kernel cmdline */

-static u32 req_entries;
+static u32 nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES;
  
  /* debugfs dentry's for the stuff above */

  static struct dentry *dma_debug_dent__read_mostly;
@@ -1011,7 +1011,6 @@ void dma_debug_add_bus(struct bus_type *bus)
  
  static int dma_debug_init(void)

  {
-   u32 num_entries;
int i;
  
  	/* Do not use dma_debug_initialized here, since we really want to be

@@ -1032,12 +1031,7 @@ static int dma_debug_init(void)
return 0;
}
  
-	if (req_entries)

-   num_entries = req_entries;
-   else
-   num_entries = PREALLOC_DMA_DEBUG_ENTRIES;
-
-   if (prealloc_memory(num_entries) != 0) {
+   if (prealloc_memory(nr_prealloc_entries) != 0) {
pr_err("DMA-API: debugging out of memory error - disabled\n");
global_disable = true;
  
@@ -1068,16 +1062,10 @@ static __init int dma_debug_cmdline(char *str)
  
  static __init int dma_debug_entries_cmdline(char *str)

  {
-   int res;
-
if (!str)
return -EINVAL;
-
-   res = get_option(, _entries);
-
-   if (!res)
-   req_entries = 0;
-
+   if (!get_option(, _prealloc_entries))
+   nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES;
return 0;
  }
  


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Re: [PATCH 1/3] dma-debug: move initialization to common code

2018-05-08 Thread Robin Murphy 

On 24/04/18 15:02, Christoph Hellwig wrote:

Most mainstream architectures are using 65536 entries, so lets stick to
that.  If someone is really desperate to override it that can still be
done through , but I'd rather see a really good
rationale for that.

dma_debug_init is now called as a core_initcall, which for many
architectures means much earlier, and provides dma-debug functionality
earlier in the boot process.  This should be safe as it only relies
on the memory allocator already being available.


Reviewed-by: Robin Murphy 


Signed-off-by: Christoph Hellwig 
---
  arch/arm/mm/dma-mapping-nommu.c |  9 -
  arch/arm/mm/dma-mapping.c   |  9 -
  arch/arm64/mm/dma-mapping.c | 10 --
  arch/c6x/kernel/dma.c   | 11 ---
  arch/ia64/kernel/dma-mapping.c  | 10 --
  arch/microblaze/kernel/dma.c| 11 ---
  arch/mips/mm/dma-default.c  | 10 --
  arch/openrisc/kernel/dma.c  | 11 ---
  arch/powerpc/kernel/dma.c   |  3 ---
  arch/s390/pci/pci_dma.c |  9 -
  arch/sh/mm/consistent.c |  9 -
  arch/sparc/kernel/Makefile  |  2 --
  arch/sparc/kernel/dma.c | 13 -
  arch/x86/kernel/pci-dma.c   |  4 
  arch/xtensa/kernel/pci-dma.c|  9 -
  include/linux/dma-debug.h   |  6 --
  lib/dma-debug.c | 21 ++---
  17 files changed, 14 insertions(+), 143 deletions(-)
  delete mode 100644 arch/sparc/kernel/dma.c

diff --git a/arch/arm/mm/dma-mapping-nommu.c b/arch/arm/mm/dma-mapping-nommu.c
index 619f24a42d09..f448a0663b10 100644
--- a/arch/arm/mm/dma-mapping-nommu.c
+++ b/arch/arm/mm/dma-mapping-nommu.c
@@ -241,12 +241,3 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, 
u64 size,
  void arch_teardown_dma_ops(struct device *dev)
  {
  }
-
-#define PREALLOC_DMA_DEBUG_ENTRIES 4096
-
-static int __init dma_debug_do_init(void)
-{
-   dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-   return 0;
-}
-core_initcall(dma_debug_do_init);
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 8c398fedbbb6..c26bf83f44ca 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1165,15 +1165,6 @@ int arm_dma_supported(struct device *dev, u64 mask)
return __dma_supported(dev, mask, false);
  }
  
-#define PREALLOC_DMA_DEBUG_ENTRIES	4096

-
-static int __init dma_debug_do_init(void)
-{
-   dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-   return 0;
-}
-core_initcall(dma_debug_do_init);
-
  #ifdef CONFIG_ARM_DMA_USE_IOMMU
  
  static int __dma_info_to_prot(enum dma_data_direction dir, unsigned long attrs)

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index a96ec0181818..db01f2709842 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -508,16 +508,6 @@ static int __init arm64_dma_init(void)
  }
  arch_initcall(arm64_dma_init);
  
-#define PREALLOC_DMA_DEBUG_ENTRIES	4096

-
-static int __init dma_debug_do_init(void)
-{
-   dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-   return 0;
-}
-fs_initcall(dma_debug_do_init);
-
-
  #ifdef CONFIG_IOMMU_DMA
  #include 
  #include 
diff --git a/arch/c6x/kernel/dma.c b/arch/c6x/kernel/dma.c
index 9fff8be75f58..31e1a9ec3a9c 100644
--- a/arch/c6x/kernel/dma.c
+++ b/arch/c6x/kernel/dma.c
@@ -136,14 +136,3 @@ const struct dma_map_ops c6x_dma_ops = {
.sync_sg_for_cpu= c6x_dma_sync_sg_for_cpu,
  };
  EXPORT_SYMBOL(c6x_dma_ops);
-
-/* Number of entries preallocated for DMA-API debugging */
-#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
-
-static int __init dma_init(void)
-{
-   dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-
-   return 0;
-}
-fs_initcall(dma_init);
diff --git a/arch/ia64/kernel/dma-mapping.c b/arch/ia64/kernel/dma-mapping.c
index f2d57e66fd86..7a471d8d67d4 100644
--- a/arch/ia64/kernel/dma-mapping.c
+++ b/arch/ia64/kernel/dma-mapping.c
@@ -9,16 +9,6 @@ int iommu_detected __read_mostly;
  const struct dma_map_ops *dma_ops;
  EXPORT_SYMBOL(dma_ops);
  
-#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)

-
-static int __init dma_init(void)
-{
-   dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-
-   return 0;
-}
-fs_initcall(dma_init);
-
  const struct dma_map_ops *dma_get_ops(struct device *dev)
  {
return dma_ops;
diff --git a/arch/microblaze/kernel/dma.c b/arch/microblaze/kernel/dma.c
index c91e8cef98dd..3145e7dc8ab1 100644
--- a/arch/microblaze/kernel/dma.c
+++ b/arch/microblaze/kernel/dma.c
@@ -184,14 +184,3 @@ const struct dma_map_ops dma_nommu_ops = {
.sync_sg_for_device = dma_nommu_sync_sg_for_device,
  };
  EXPORT_SYMBOL(dma_nommu_ops);
-
-/* Number of entries preallocated for DMA-API debugging */
-#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
-
-static int __init dma_init(void)
-{
-   dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-
-   return 0;
-}
-fs_initcall(dma_init);
diff --git