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* [PATCH] gpu: drm: ttm: Adding new return type vm_fault_t
@ 2018-05-23 18:55 Souptick Joarder
  2018-05-31  5:07 ` Souptick Joarder
  0 siblings, 1 reply; 4+ messages in thread
From: Souptick Joarder @ 2018-05-23 18:55 UTC (permalink / raw)
  To: christian.koenig, Hongbo.He, airlied; +Cc: dri-devel, linux-kernel, willY

Use new return type vm_fault_t for fault handler. For
now, this is just documenting that the function returns
a VM_FAULT value rather than an errno. Once all instances
are converted, vm_fault_t will become a distinct type.

Ref-> commit 1c8f422059ae ("mm: change return type to vm_fault_t")

Previously vm_insert_{mixed,pfn} returns err which driver
mapped into VM_FAULT_* type. The new function
vmf_insert_{mixed,pfn} will replace this inefficiency by
returning VM_FAULT_* type.

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
---
 drivers/gpu/drm/ttm/ttm_bo_vm.c | 45 ++++++++++++++++++++---------------------
 1 file changed, 22 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index 8eba95b..2d13f03 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -43,10 +43,11 @@
 
 #define TTM_BO_VM_NUM_PREFAULT 16
 
-static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
+static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
 				struct vm_fault *vmf)
 {
-	int ret = 0;
+	int err = 0;
+	vm_fault_t ret = 0;
 
 	if (likely(!bo->moving))
 		goto out_unlock;
@@ -77,9 +78,9 @@ static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
 	/*
 	 * Ordinary wait.
 	 */
-	ret = dma_fence_wait(bo->moving, true);
-	if (unlikely(ret != 0)) {
-		ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
+	err = dma_fence_wait(bo->moving, true);
+	if (unlikely(err != 0)) {
+		ret = (err != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
 			VM_FAULT_NOPAGE;
 		goto out_unlock;
 	}
@@ -104,7 +105,7 @@ static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo,
 		+ page_offset;
 }
 
-static int ttm_bo_vm_fault(struct vm_fault *vmf)
+static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;
 	struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
@@ -115,8 +116,9 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
 	unsigned long pfn;
 	struct ttm_tt *ttm = NULL;
 	struct page *page;
-	int ret;
+	int err;
 	int i;
+	vm_fault_t ret = VM_FAULT_NOPAGE;
 	unsigned long address = vmf->address;
 	struct ttm_mem_type_manager *man =
 		&bdev->man[bo->mem.mem_type];
@@ -128,9 +130,9 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
 	 * for reserve, and if it fails, retry the fault after waiting
 	 * for the buffer to become unreserved.
 	 */
-	ret = ttm_bo_reserve(bo, true, true, NULL);
-	if (unlikely(ret != 0)) {
-		if (ret != -EBUSY)
+	err = ttm_bo_reserve(bo, true, true, NULL);
+	if (unlikely(err != 0)) {
+		if (err != -EBUSY)
 			return VM_FAULT_NOPAGE;
 
 		if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
@@ -162,8 +164,8 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
 	}
 
 	if (bdev->driver->fault_reserve_notify) {
-		ret = bdev->driver->fault_reserve_notify(bo);
-		switch (ret) {
+		err = bdev->driver->fault_reserve_notify(bo);
+		switch (err) {
 		case 0:
 			break;
 		case -EBUSY:
@@ -191,13 +193,13 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
 		goto out_unlock;
 	}
 
-	ret = ttm_mem_io_lock(man, true);
-	if (unlikely(ret != 0)) {
+	err = ttm_mem_io_lock(man, true);
+	if (unlikely(err != 0)) {
 		ret = VM_FAULT_NOPAGE;
 		goto out_unlock;
 	}
-	ret = ttm_mem_io_reserve_vm(bo);
-	if (unlikely(ret != 0)) {
+	err = ttm_mem_io_reserve_vm(bo);
+	if (unlikely(err != 0)) {
 		ret = VM_FAULT_SIGBUS;
 		goto out_io_unlock;
 	}
@@ -265,23 +267,20 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
 		}
 
 		if (vma->vm_flags & VM_MIXEDMAP)
-			ret = vm_insert_mixed(&cvma, address,
+			ret = vmf_insert_mixed(&cvma, address,
 					__pfn_to_pfn_t(pfn, PFN_DEV));
 		else
-			ret = vm_insert_pfn(&cvma, address, pfn);
+			ret = vmf_insert_pfn(&cvma, address, pfn);
 
 		/*
 		 * Somebody beat us to this PTE or prefaulting to
 		 * an already populated PTE, or prefaulting error.
 		 */
 
-		if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
+		if (unlikely((ret == VM_FAULT_NOPAGE && i > 0)))
 			break;
-		else if (unlikely(ret != 0)) {
-			ret =
-			    (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
+		else if (unlikely(ret & VM_FAULT_ERROR))
 			goto out_io_unlock;
-		}
 
 		address += PAGE_SIZE;
 		if (unlikely(++page_offset >= page_last))
-- 
1.9.1

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] gpu: drm: ttm: Adding new return type vm_fault_t
  2018-05-23 18:55 [PATCH] gpu: drm: ttm: Adding new return type vm_fault_t Souptick Joarder
@ 2018-05-31  5:07 ` Souptick Joarder
  2018-06-01 11:48   ` Christian König
  0 siblings, 1 reply; 4+ messages in thread
From: Souptick Joarder @ 2018-05-31  5:07 UTC (permalink / raw)
  To: Christian König, Hongbo.He, airlied
  Cc: dri-devel, linux-kernel, Matthew Wilcox

On Thu, May 24, 2018 at 12:25 AM, Souptick Joarder <jrdr.linux@gmail.com> wrote:
> Use new return type vm_fault_t for fault handler. For
> now, this is just documenting that the function returns
> a VM_FAULT value rather than an errno. Once all instances
> are converted, vm_fault_t will become a distinct type.
>
> Ref-> commit 1c8f422059ae ("mm: change return type to vm_fault_t")
>
> Previously vm_insert_{mixed,pfn} returns err which driver
> mapped into VM_FAULT_* type. The new function
> vmf_insert_{mixed,pfn} will replace this inefficiency by
> returning VM_FAULT_* type.
>
> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
> ---
>  drivers/gpu/drm/ttm/ttm_bo_vm.c | 45 ++++++++++++++++++++---------------------
>  1 file changed, 22 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
> index 8eba95b..2d13f03 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
> @@ -43,10 +43,11 @@
>
>  #define TTM_BO_VM_NUM_PREFAULT 16
>
> -static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
> +static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
>                                 struct vm_fault *vmf)
>  {
> -       int ret = 0;
> +       int err = 0;
> +       vm_fault_t ret = 0;
>
>         if (likely(!bo->moving))
>                 goto out_unlock;
> @@ -77,9 +78,9 @@ static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
>         /*
>          * Ordinary wait.
>          */
> -       ret = dma_fence_wait(bo->moving, true);
> -       if (unlikely(ret != 0)) {
> -               ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
> +       err = dma_fence_wait(bo->moving, true);
> +       if (unlikely(err != 0)) {
> +               ret = (err != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
>                         VM_FAULT_NOPAGE;
>                 goto out_unlock;
>         }
> @@ -104,7 +105,7 @@ static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo,
>                 + page_offset;
>  }
>
> -static int ttm_bo_vm_fault(struct vm_fault *vmf)
> +static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
>  {
>         struct vm_area_struct *vma = vmf->vma;
>         struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
> @@ -115,8 +116,9 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
>         unsigned long pfn;
>         struct ttm_tt *ttm = NULL;
>         struct page *page;
> -       int ret;
> +       int err;
>         int i;
> +       vm_fault_t ret = VM_FAULT_NOPAGE;
>         unsigned long address = vmf->address;
>         struct ttm_mem_type_manager *man =
>                 &bdev->man[bo->mem.mem_type];
> @@ -128,9 +130,9 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
>          * for reserve, and if it fails, retry the fault after waiting
>          * for the buffer to become unreserved.
>          */
> -       ret = ttm_bo_reserve(bo, true, true, NULL);
> -       if (unlikely(ret != 0)) {
> -               if (ret != -EBUSY)
> +       err = ttm_bo_reserve(bo, true, true, NULL);
> +       if (unlikely(err != 0)) {
> +               if (err != -EBUSY)
>                         return VM_FAULT_NOPAGE;
>
>                 if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
> @@ -162,8 +164,8 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
>         }
>
>         if (bdev->driver->fault_reserve_notify) {
> -               ret = bdev->driver->fault_reserve_notify(bo);
> -               switch (ret) {
> +               err = bdev->driver->fault_reserve_notify(bo);
> +               switch (err) {
>                 case 0:
>                         break;
>                 case -EBUSY:
> @@ -191,13 +193,13 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
>                 goto out_unlock;
>         }
>
> -       ret = ttm_mem_io_lock(man, true);
> -       if (unlikely(ret != 0)) {
> +       err = ttm_mem_io_lock(man, true);
> +       if (unlikely(err != 0)) {
>                 ret = VM_FAULT_NOPAGE;
>                 goto out_unlock;
>         }
> -       ret = ttm_mem_io_reserve_vm(bo);
> -       if (unlikely(ret != 0)) {
> +       err = ttm_mem_io_reserve_vm(bo);
> +       if (unlikely(err != 0)) {
>                 ret = VM_FAULT_SIGBUS;
>                 goto out_io_unlock;
>         }
> @@ -265,23 +267,20 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
>                 }
>
>                 if (vma->vm_flags & VM_MIXEDMAP)
> -                       ret = vm_insert_mixed(&cvma, address,
> +                       ret = vmf_insert_mixed(&cvma, address,
>                                         __pfn_to_pfn_t(pfn, PFN_DEV));
>                 else
> -                       ret = vm_insert_pfn(&cvma, address, pfn);
> +                       ret = vmf_insert_pfn(&cvma, address, pfn);
>
>                 /*
>                  * Somebody beat us to this PTE or prefaulting to
>                  * an already populated PTE, or prefaulting error.
>                  */
>
> -               if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
> +               if (unlikely((ret == VM_FAULT_NOPAGE && i > 0)))
>                         break;
> -               else if (unlikely(ret != 0)) {
> -                       ret =
> -                           (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
> +               else if (unlikely(ret & VM_FAULT_ERROR))
>                         goto out_io_unlock;
> -               }
>
>                 address += PAGE_SIZE;
>                 if (unlikely(++page_offset >= page_last))
> --
> 1.9.1
>

Any comment for this patch ?

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] gpu: drm: ttm: Adding new return type vm_fault_t
  2018-05-31  5:07 ` Souptick Joarder
@ 2018-06-01 11:48   ` Christian König
  2018-06-01 19:01     ` Souptick Joarder
  0 siblings, 1 reply; 4+ messages in thread
From: Christian König @ 2018-06-01 11:48 UTC (permalink / raw)
  To: Souptick Joarder, Hongbo.He, airlied
  Cc: dri-devel, linux-kernel, Matthew Wilcox

Am 31.05.2018 um 07:07 schrieb Souptick Joarder:
> On Thu, May 24, 2018 at 12:25 AM, Souptick Joarder <jrdr.linux@gmail.com> wrote:
>> Use new return type vm_fault_t for fault handler. For
>> now, this is just documenting that the function returns
>> a VM_FAULT value rather than an errno. Once all instances
>> are converted, vm_fault_t will become a distinct type.
>>
>> Ref-> commit 1c8f422059ae ("mm: change return type to vm_fault_t")
>>
>> Previously vm_insert_{mixed,pfn} returns err which driver
>> mapped into VM_FAULT_* type. The new function
>> vmf_insert_{mixed,pfn} will replace this inefficiency by
>> returning VM_FAULT_* type.
>>
>> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
>> ---
>>   drivers/gpu/drm/ttm/ttm_bo_vm.c | 45 ++++++++++++++++++++---------------------
>>   1 file changed, 22 insertions(+), 23 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
>> index 8eba95b..2d13f03 100644
>> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
>> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
>> @@ -43,10 +43,11 @@
>>
>>   #define TTM_BO_VM_NUM_PREFAULT 16
>>
>> -static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
>> +static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
>>                                  struct vm_fault *vmf)
>>   {
>> -       int ret = 0;
>> +       int err = 0;
>> +       vm_fault_t ret = 0;

Please keep reverse xmas tree order for variable declarations.

Except for that it looks good to me,
Christian.

>>
>>          if (likely(!bo->moving))
>>                  goto out_unlock;
>> @@ -77,9 +78,9 @@ static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
>>          /*
>>           * Ordinary wait.
>>           */
>> -       ret = dma_fence_wait(bo->moving, true);
>> -       if (unlikely(ret != 0)) {
>> -               ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
>> +       err = dma_fence_wait(bo->moving, true);
>> +       if (unlikely(err != 0)) {
>> +               ret = (err != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
>>                          VM_FAULT_NOPAGE;
>>                  goto out_unlock;
>>          }
>> @@ -104,7 +105,7 @@ static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo,
>>                  + page_offset;
>>   }
>>
>> -static int ttm_bo_vm_fault(struct vm_fault *vmf)
>> +static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
>>   {
>>          struct vm_area_struct *vma = vmf->vma;
>>          struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
>> @@ -115,8 +116,9 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
>>          unsigned long pfn;
>>          struct ttm_tt *ttm = NULL;
>>          struct page *page;
>> -       int ret;
>> +       int err;
>>          int i;
>> +       vm_fault_t ret = VM_FAULT_NOPAGE;
>>          unsigned long address = vmf->address;
>>          struct ttm_mem_type_manager *man =
>>                  &bdev->man[bo->mem.mem_type];
>> @@ -128,9 +130,9 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
>>           * for reserve, and if it fails, retry the fault after waiting
>>           * for the buffer to become unreserved.
>>           */
>> -       ret = ttm_bo_reserve(bo, true, true, NULL);
>> -       if (unlikely(ret != 0)) {
>> -               if (ret != -EBUSY)
>> +       err = ttm_bo_reserve(bo, true, true, NULL);
>> +       if (unlikely(err != 0)) {
>> +               if (err != -EBUSY)
>>                          return VM_FAULT_NOPAGE;
>>
>>                  if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
>> @@ -162,8 +164,8 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
>>          }
>>
>>          if (bdev->driver->fault_reserve_notify) {
>> -               ret = bdev->driver->fault_reserve_notify(bo);
>> -               switch (ret) {
>> +               err = bdev->driver->fault_reserve_notify(bo);
>> +               switch (err) {
>>                  case 0:
>>                          break;
>>                  case -EBUSY:
>> @@ -191,13 +193,13 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
>>                  goto out_unlock;
>>          }
>>
>> -       ret = ttm_mem_io_lock(man, true);
>> -       if (unlikely(ret != 0)) {
>> +       err = ttm_mem_io_lock(man, true);
>> +       if (unlikely(err != 0)) {
>>                  ret = VM_FAULT_NOPAGE;
>>                  goto out_unlock;
>>          }
>> -       ret = ttm_mem_io_reserve_vm(bo);
>> -       if (unlikely(ret != 0)) {
>> +       err = ttm_mem_io_reserve_vm(bo);
>> +       if (unlikely(err != 0)) {
>>                  ret = VM_FAULT_SIGBUS;
>>                  goto out_io_unlock;
>>          }
>> @@ -265,23 +267,20 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
>>                  }
>>
>>                  if (vma->vm_flags & VM_MIXEDMAP)
>> -                       ret = vm_insert_mixed(&cvma, address,
>> +                       ret = vmf_insert_mixed(&cvma, address,
>>                                          __pfn_to_pfn_t(pfn, PFN_DEV));
>>                  else
>> -                       ret = vm_insert_pfn(&cvma, address, pfn);
>> +                       ret = vmf_insert_pfn(&cvma, address, pfn);
>>
>>                  /*
>>                   * Somebody beat us to this PTE or prefaulting to
>>                   * an already populated PTE, or prefaulting error.
>>                   */
>>
>> -               if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
>> +               if (unlikely((ret == VM_FAULT_NOPAGE && i > 0)))
>>                          break;
>> -               else if (unlikely(ret != 0)) {
>> -                       ret =
>> -                           (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
>> +               else if (unlikely(ret & VM_FAULT_ERROR))
>>                          goto out_io_unlock;
>> -               }
>>
>>                  address += PAGE_SIZE;
>>                  if (unlikely(++page_offset >= page_last))
>> --
>> 1.9.1
>>
> Any comment for this patch ?

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] gpu: drm: ttm: Adding new return type vm_fault_t
  2018-06-01 11:48   ` Christian König
@ 2018-06-01 19:01     ` Souptick Joarder
  0 siblings, 0 replies; 4+ messages in thread
From: Souptick Joarder @ 2018-06-01 19:01 UTC (permalink / raw)
  To: Christian König
  Cc: Hongbo.He, airlied, dri-devel, linux-kernel, Matthew Wilcox

On Fri, Jun 1, 2018 at 5:18 PM, Christian König
<christian.koenig@amd.com> wrote:
> Am 31.05.2018 um 07:07 schrieb Souptick Joarder:
>>
>> On Thu, May 24, 2018 at 12:25 AM, Souptick Joarder <jrdr.linux@gmail.com>
>> wrote:
>>>
>>> Use new return type vm_fault_t for fault handler. For
>>> now, this is just documenting that the function returns
>>> a VM_FAULT value rather than an errno. Once all instances
>>> are converted, vm_fault_t will become a distinct type.
>>>
>>> Ref-> commit 1c8f422059ae ("mm: change return type to vm_fault_t")
>>>
>>> Previously vm_insert_{mixed,pfn} returns err which driver
>>> mapped into VM_FAULT_* type. The new function
>>> vmf_insert_{mixed,pfn} will replace this inefficiency by
>>> returning VM_FAULT_* type.
>>>
>>> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
>>> ---
>>>   drivers/gpu/drm/ttm/ttm_bo_vm.c | 45
>>> ++++++++++++++++++++---------------------
>>>   1 file changed, 22 insertions(+), 23 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c
>>> b/drivers/gpu/drm/ttm/ttm_bo_vm.c
>>> index 8eba95b..2d13f03 100644
>>> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
>>> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
>>> @@ -43,10 +43,11 @@
>>>
>>>   #define TTM_BO_VM_NUM_PREFAULT 16
>>>
>>> -static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
>>> +static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
>>>                                  struct vm_fault *vmf)
>>>   {
>>> -       int ret = 0;
>>> +       int err = 0;
>>> +       vm_fault_t ret = 0;
>
>
> Please keep reverse xmas tree order for variable declarations.
>
> Except for that it looks good to me,
> Christian.
>

Sure, I will send v2. We would like to get this patch in
queue for 4.18.

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2018-06-01 19:01 UTC | newest]

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2018-05-23 18:55 [PATCH] gpu: drm: ttm: Adding new return type vm_fault_t Souptick Joarder
2018-05-31  5:07 ` Souptick Joarder
2018-06-01 11:48   ` Christian König
2018-06-01 19:01     ` Souptick Joarder

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