[PATCH 1/2] drm/amdgpu: fix start calculation in amdgpu_vram_mgr_new

[PATCH 1/2] drm/amdgpu: fix start calculation in amdgpu_vram_mgr_new

[Christian König]

We still need to calculate a virtual start address for the resource to
aid checking of it is visible or not.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 22 +++++++++++++-------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index 49e4092f447f..51d9d3a4456c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -496,16 +496,22 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 			list_splice_tail(trim_list, &vres->blocks);
 	}
 
-	list_for_each_entry(block, &vres->blocks, link)
-		vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
+	vres->base.start = 0;
+	list_for_each_entry(block, &vres->blocks, link) {
+		unsigned long start;
 
-	block = amdgpu_vram_mgr_first_block(&vres->blocks);
-	if (!block) {
-		r = -EINVAL;
-		goto error_fini;
-	}
+		start = amdgpu_vram_mgr_block_start(block) +
+			amdgpu_vram_mgr_block_size(block);
+		start >>= PAGE_SHIFT;
 
-	vres->base.start = amdgpu_vram_mgr_block_start(block) >> PAGE_SHIFT;
+		if (start > vres->base.num_pages)
+			start -= vres->base.num_pages;
+		else
+			start = 0;
+		vres->base.start = max(vres->base.start, start);
+
+		vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
+	}
 
 	if (amdgpu_is_vram_mgr_blocks_contiguous(&vres->blocks))
 		vres->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
-- 
2.25.1

[PATCH 2/2] drm/amdgpu: move internal vram_mgr function into the C file

[Christian König]

No need to have those in the header.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 29 ++++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h | 27 ------------------
 2 files changed, 29 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index 51d9d3a4456c..7a5e8a7b4a1b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -50,6 +50,35 @@ to_amdgpu_device(struct amdgpu_vram_mgr *mgr)
 	return container_of(mgr, struct amdgpu_device, mman.vram_mgr);
 }
 
+static inline struct drm_buddy_block *
+amdgpu_vram_mgr_first_block(struct list_head *list)
+{
+	return list_first_entry_or_null(list, struct drm_buddy_block, link);
+}
+
+static inline bool amdgpu_is_vram_mgr_blocks_contiguous(struct list_head *head)
+{
+	struct drm_buddy_block *block;
+	u64 start, size;
+
+	block = amdgpu_vram_mgr_first_block(head);
+	if (!block)
+		return false;
+
+	while (head != block->link.next) {
+		start = amdgpu_vram_mgr_block_start(block);
+		size = amdgpu_vram_mgr_block_size(block);
+
+		block = list_entry(block->link.next, struct drm_buddy_block, link);
+		if (start + size != amdgpu_vram_mgr_block_start(block))
+			return false;
+	}
+
+	return true;
+}
+
+
+
 /**
  * DOC: mem_info_vram_total
  *
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
index 9a2db87186c7..4b267bf1c5db 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
@@ -53,33 +53,6 @@ static inline u64 amdgpu_vram_mgr_block_size(struct drm_buddy_block *block)
 	return PAGE_SIZE << drm_buddy_block_order(block);
 }
 
-static inline struct drm_buddy_block *
-amdgpu_vram_mgr_first_block(struct list_head *list)
-{
-	return list_first_entry_or_null(list, struct drm_buddy_block, link);
-}
-
-static inline bool amdgpu_is_vram_mgr_blocks_contiguous(struct list_head *head)
-{
-	struct drm_buddy_block *block;
-	u64 start, size;
-
-	block = amdgpu_vram_mgr_first_block(head);
-	if (!block)
-		return false;
-
-	while (head != block->link.next) {
-		start = amdgpu_vram_mgr_block_start(block);
-		size = amdgpu_vram_mgr_block_size(block);
-
-		block = list_entry(block->link.next, struct drm_buddy_block, link);
-		if (start + size != amdgpu_vram_mgr_block_start(block))
-			return false;
-	}
-
-	return true;
-}
-
 static inline struct amdgpu_vram_mgr_resource *
 to_amdgpu_vram_mgr_resource(struct ttm_resource *res)
 {
-- 
2.25.1

Re: [PATCH 2/2] drm/amdgpu: move internal vram_mgr function into the C file

[Alex Deucher]

On Tue, May 10, 2022 at 7:36 AM Christian König
<ckoenig.leichtzumerken@gmail.com> wrote:
>
> No need to have those in the header.
>
> Signed-off-by: Christian König <christian.koenig@amd.com>

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 29 ++++++++++++++++++++
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h | 27 ------------------
>  2 files changed, 29 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> index 51d9d3a4456c..7a5e8a7b4a1b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> @@ -50,6 +50,35 @@ to_amdgpu_device(struct amdgpu_vram_mgr *mgr)
>         return container_of(mgr, struct amdgpu_device, mman.vram_mgr);
>  }
>
> +static inline struct drm_buddy_block *
> +amdgpu_vram_mgr_first_block(struct list_head *list)
> +{
> +       return list_first_entry_or_null(list, struct drm_buddy_block, link);
> +}
> +
> +static inline bool amdgpu_is_vram_mgr_blocks_contiguous(struct list_head *head)
> +{
> +       struct drm_buddy_block *block;
> +       u64 start, size;
> +
> +       block = amdgpu_vram_mgr_first_block(head);
> +       if (!block)
> +               return false;
> +
> +       while (head != block->link.next) {
> +               start = amdgpu_vram_mgr_block_start(block);
> +               size = amdgpu_vram_mgr_block_size(block);
> +
> +               block = list_entry(block->link.next, struct drm_buddy_block, link);
> +               if (start + size != amdgpu_vram_mgr_block_start(block))
> +                       return false;
> +       }
> +
> +       return true;
> +}
> +
> +
> +
>  /**
>   * DOC: mem_info_vram_total
>   *
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
> index 9a2db87186c7..4b267bf1c5db 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
> @@ -53,33 +53,6 @@ static inline u64 amdgpu_vram_mgr_block_size(struct drm_buddy_block *block)
>         return PAGE_SIZE << drm_buddy_block_order(block);
>  }
>
> -static inline struct drm_buddy_block *
> -amdgpu_vram_mgr_first_block(struct list_head *list)
> -{
> -       return list_first_entry_or_null(list, struct drm_buddy_block, link);
> -}
> -
> -static inline bool amdgpu_is_vram_mgr_blocks_contiguous(struct list_head *head)
> -{
> -       struct drm_buddy_block *block;
> -       u64 start, size;
> -
> -       block = amdgpu_vram_mgr_first_block(head);
> -       if (!block)
> -               return false;
> -
> -       while (head != block->link.next) {
> -               start = amdgpu_vram_mgr_block_start(block);
> -               size = amdgpu_vram_mgr_block_size(block);
> -
> -               block = list_entry(block->link.next, struct drm_buddy_block, link);
> -               if (start + size != amdgpu_vram_mgr_block_start(block))
> -                       return false;
> -       }
> -
> -       return true;
> -}
> -
>  static inline struct amdgpu_vram_mgr_resource *
>  to_amdgpu_vram_mgr_resource(struct ttm_resource *res)
>  {
> --
> 2.25.1
>

Re: [PATCH 1/2] drm/amdgpu: fix start calculation in amdgpu_vram_mgr_new

[Alex Deucher]

On Tue, May 10, 2022 at 7:36 AM Christian König
<ckoenig.leichtzumerken@gmail.com> wrote:
>
> We still need to calculate a virtual start address for the resource to
> aid checking of it is visible or not.

Does this fix a known issue or is it just something you noticed?

>
> Signed-off-by: Christian König <christian.koenig@amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 22 +++++++++++++-------
>  1 file changed, 14 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> index 49e4092f447f..51d9d3a4456c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> @@ -496,16 +496,22 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
>                         list_splice_tail(trim_list, &vres->blocks);
>         }
>
> -       list_for_each_entry(block, &vres->blocks, link)
> -               vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
> +       vres->base.start = 0;
> +       list_for_each_entry(block, &vres->blocks, link) {
> +               unsigned long start;
>
> -       block = amdgpu_vram_mgr_first_block(&vres->blocks);
> -       if (!block) {
> -               r = -EINVAL;
> -               goto error_fini;
> -       }
> +               start = amdgpu_vram_mgr_block_start(block) +
> +                       amdgpu_vram_mgr_block_size(block);
> +               start >>= PAGE_SHIFT;
>
> -       vres->base.start = amdgpu_vram_mgr_block_start(block) >> PAGE_SHIFT;
> +               if (start > vres->base.num_pages)
> +                       start -= vres->base.num_pages;
> +               else
> +                       start = 0;
> +               vres->base.start = max(vres->base.start, start);
> +
> +               vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
> +       }
>
>         if (amdgpu_is_vram_mgr_blocks_contiguous(&vres->blocks))
>                 vres->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
> --
> 2.25.1
>

Re: [PATCH 1/2] drm/amdgpu: fix start calculation in amdgpu_vram_mgr_new

[Christian König]

Am 10.05.22 um 16:42 schrieb Alex Deucher:
> On Tue, May 10, 2022 at 7:36 AM Christian König
> <ckoenig.leichtzumerken@gmail.com> wrote:
>> We still need to calculate a virtual start address for the resource to
>> aid checking of it is visible or not.
> Does this fix a known issue or is it just something you noticed?

Just something I've noticed. Judging from the bug reports we get large 
BAR systems are so common by now that only a few people are left where 
that actually matters.

Christian.

>
>> Signed-off-by: Christian König <christian.koenig@amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 22 +++++++++++++-------
>>   1 file changed, 14 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> index 49e4092f447f..51d9d3a4456c 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> @@ -496,16 +496,22 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
>>                          list_splice_tail(trim_list, &vres->blocks);
>>          }
>>
>> -       list_for_each_entry(block, &vres->blocks, link)
>> -               vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
>> +       vres->base.start = 0;
>> +       list_for_each_entry(block, &vres->blocks, link) {
>> +               unsigned long start;
>>
>> -       block = amdgpu_vram_mgr_first_block(&vres->blocks);
>> -       if (!block) {
>> -               r = -EINVAL;
>> -               goto error_fini;
>> -       }
>> +               start = amdgpu_vram_mgr_block_start(block) +
>> +                       amdgpu_vram_mgr_block_size(block);
>> +               start >>= PAGE_SHIFT;
>>
>> -       vres->base.start = amdgpu_vram_mgr_block_start(block) >> PAGE_SHIFT;
>> +               if (start > vres->base.num_pages)
>> +                       start -= vres->base.num_pages;
>> +               else
>> +                       start = 0;
>> +               vres->base.start = max(vres->base.start, start);
>> +
>> +               vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
>> +       }
>>
>>          if (amdgpu_is_vram_mgr_blocks_contiguous(&vres->blocks))
>>                  vres->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
>> --
>> 2.25.1
>>

Re: [PATCH 1/2] drm/amdgpu: fix start calculation in amdgpu_vram_mgr_new

[Alex Deucher]

On Tue, May 10, 2022 at 11:08 AM Christian König
<christian.koenig@amd.com> wrote:
>
> Am 10.05.22 um 16:42 schrieb Alex Deucher:
> > On Tue, May 10, 2022 at 7:36 AM Christian König
> > <ckoenig.leichtzumerken@gmail.com> wrote:
> >> We still need to calculate a virtual start address for the resource to
> >> aid checking of it is visible or not.
> > Does this fix a known issue or is it just something you noticed?
>
> Just something I've noticed. Judging from the bug reports we get large
> BAR systems are so common by now that only a few people are left where
> that actually matters.
>

If you add that to the commit message, the patch is:
Acked-by: Alex Deucher <alexander.deucher@amd.com>

> Christian.
>
> >
> >> Signed-off-by: Christian König <christian.koenig@amd.com>
> >> ---
> >>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 22 +++++++++++++-------
> >>   1 file changed, 14 insertions(+), 8 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> >> index 49e4092f447f..51d9d3a4456c 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> >> @@ -496,16 +496,22 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
> >>                          list_splice_tail(trim_list, &vres->blocks);
> >>          }
> >>
> >> -       list_for_each_entry(block, &vres->blocks, link)
> >> -               vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
> >> +       vres->base.start = 0;
> >> +       list_for_each_entry(block, &vres->blocks, link) {
> >> +               unsigned long start;
> >>
> >> -       block = amdgpu_vram_mgr_first_block(&vres->blocks);
> >> -       if (!block) {
> >> -               r = -EINVAL;
> >> -               goto error_fini;
> >> -       }
> >> +               start = amdgpu_vram_mgr_block_start(block) +
> >> +                       amdgpu_vram_mgr_block_size(block);
> >> +               start >>= PAGE_SHIFT;
> >>
> >> -       vres->base.start = amdgpu_vram_mgr_block_start(block) >> PAGE_SHIFT;
> >> +               if (start > vres->base.num_pages)
> >> +                       start -= vres->base.num_pages;
> >> +               else
> >> +                       start = 0;
> >> +               vres->base.start = max(vres->base.start, start);
> >> +
> >> +               vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
> >> +       }
> >>
> >>          if (amdgpu_is_vram_mgr_blocks_contiguous(&vres->blocks))
> >>                  vres->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
> >> --
> >> 2.25.1
> >>
>

Re: [PATCH 1/2] drm/amdgpu: fix start calculation in amdgpu_vram_mgr_new

[Arunpravin Paneer Selvam]

Hi Christian,

On 5/10/2022 5:06 PM, Christian König wrote:
> We still need to calculate a virtual start address for the resource to
> aid checking of it is visible or not.
>
> Signed-off-by: Christian König <christian.koenig@amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 22 +++++++++++++-------
>   1 file changed, 14 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> index 49e4092f447f..51d9d3a4456c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> @@ -496,16 +496,22 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
>   			list_splice_tail(trim_list, &vres->blocks);
>   	}
>   
> -	list_for_each_entry(block, &vres->blocks, link)
> -		vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
> +	vres->base.start = 0;
> +	list_for_each_entry(block, &vres->blocks, link) {
> +		unsigned long start;
>   
> -	block = amdgpu_vram_mgr_first_block(&vres->blocks);
> -	if (!block) {
> -		r = -EINVAL;
> -		goto error_fini;
> -	}
> +		start = amdgpu_vram_mgr_block_start(block) +
> +			amdgpu_vram_mgr_block_size(block);
> +		start >>= PAGE_SHIFT;
>   
> -	vres->base.start = amdgpu_vram_mgr_block_start(block) >> PAGE_SHIFT;
> +		if (start > vres->base.num_pages)
> +			start -= vres->base.num_pages;
I think this works for continuous blocks of addresses, but for a non 
continuous blocks allocated at different
locations and linked together using list, this might fetch an invalid 
address. I will check this patch on my
setup and inform you.

Regards,
Arun
> +		else
> +			start = 0;
> +		vres->base.start = max(vres->base.start, start);
> +
> +		vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
> +	}
>   
>   	if (amdgpu_is_vram_mgr_blocks_contiguous(&vres->blocks))
>   		vres->base.placement |= TTM_PL_FLAG_CONTIGUOUS;

Re: [PATCH 1/2] drm/amdgpu: fix start calculation in amdgpu_vram_mgr_new

[Christian König]

Am 10.05.22 um 17:20 schrieb Arunpravin Paneer Selvam:
> Hi Christian,
>
> On 5/10/2022 5:06 PM, Christian König wrote:
>> We still need to calculate a virtual start address for the resource to
>> aid checking of it is visible or not.
>>
>> Signed-off-by: Christian König <christian.koenig@amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 22 +++++++++++++-------
>>   1 file changed, 14 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> index 49e4092f447f..51d9d3a4456c 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> @@ -496,16 +496,22 @@ static int amdgpu_vram_mgr_new(struct 
>> ttm_resource_manager *man,
>>               list_splice_tail(trim_list, &vres->blocks);
>>       }
>>   -    list_for_each_entry(block, &vres->blocks, link)
>> -        vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
>> +    vres->base.start = 0;
>> +    list_for_each_entry(block, &vres->blocks, link) {
>> +        unsigned long start;
>>   -    block = amdgpu_vram_mgr_first_block(&vres->blocks);
>> -    if (!block) {
>> -        r = -EINVAL;
>> -        goto error_fini;
>> -    }
>> +        start = amdgpu_vram_mgr_block_start(block) +
>> +            amdgpu_vram_mgr_block_size(block);
>> +        start >>= PAGE_SHIFT;
>>   -    vres->base.start = amdgpu_vram_mgr_block_start(block) >> 
>> PAGE_SHIFT;
>> +        if (start > vres->base.num_pages)
>> +            start -= vres->base.num_pages;
> I think this works for continuous blocks of addresses, but for a non 
> continuous blocks allocated at different
> locations and linked together using list, this might fetch an invalid 
> address. I will check this patch on my
> setup and inform you.

It indeed does fetch an invalid address and that is perfectly expected 
behavior.

See the resource->start value for non-contiguous allocations is just the 
maximum allocated address.

This makes it possible to easily check if a buffer is inside the CPU 
accessible VRAM window or not.

As I said we should probably get rid of that, but for now it's necessary.

Regards,
Christian.

>
> Regards,
> Arun
>> +        else
>> +            start = 0;
>> +        vres->base.start = max(vres->base.start, start);
>> +
>> +        vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
>> +    }
>>         if (amdgpu_is_vram_mgr_blocks_contiguous(&vres->blocks))
>>           vres->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
>

Re: [PATCH 2/2] drm/amdgpu: move internal vram_mgr function into the C file

[Arunpravin Paneer Selvam]

On 5/10/2022 5:06 PM, Christian König wrote:
> No need to have those in the header.
>
> Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 29 ++++++++++++++++++++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h | 27 ------------------
>   2 files changed, 29 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> index 51d9d3a4456c..7a5e8a7b4a1b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> @@ -50,6 +50,35 @@ to_amdgpu_device(struct amdgpu_vram_mgr *mgr)
>   	return container_of(mgr, struct amdgpu_device, mman.vram_mgr);
>   }
>   
> +static inline struct drm_buddy_block *
> +amdgpu_vram_mgr_first_block(struct list_head *list)
> +{
> +	return list_first_entry_or_null(list, struct drm_buddy_block, link);
> +}
> +
> +static inline bool amdgpu_is_vram_mgr_blocks_contiguous(struct list_head *head)
> +{
> +	struct drm_buddy_block *block;
> +	u64 start, size;
> +
> +	block = amdgpu_vram_mgr_first_block(head);
> +	if (!block)
> +		return false;
> +
> +	while (head != block->link.next) {
> +		start = amdgpu_vram_mgr_block_start(block);
> +		size = amdgpu_vram_mgr_block_size(block);
> +
> +		block = list_entry(block->link.next, struct drm_buddy_block, link);
> +		if (start + size != amdgpu_vram_mgr_block_start(block))
> +			return false;
> +	}
> +
> +	return true;
> +}
> +
> +
> +
>   /**
>    * DOC: mem_info_vram_total
>    *
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
> index 9a2db87186c7..4b267bf1c5db 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
> @@ -53,33 +53,6 @@ static inline u64 amdgpu_vram_mgr_block_size(struct drm_buddy_block *block)
>   	return PAGE_SIZE << drm_buddy_block_order(block);
>   }
>   
> -static inline struct drm_buddy_block *
> -amdgpu_vram_mgr_first_block(struct list_head *list)
> -{
> -	return list_first_entry_or_null(list, struct drm_buddy_block, link);
> -}
> -
> -static inline bool amdgpu_is_vram_mgr_blocks_contiguous(struct list_head *head)
> -{
> -	struct drm_buddy_block *block;
> -	u64 start, size;
> -
> -	block = amdgpu_vram_mgr_first_block(head);
> -	if (!block)
> -		return false;
> -
> -	while (head != block->link.next) {
> -		start = amdgpu_vram_mgr_block_start(block);
> -		size = amdgpu_vram_mgr_block_size(block);
> -
> -		block = list_entry(block->link.next, struct drm_buddy_block, link);
> -		if (start + size != amdgpu_vram_mgr_block_start(block))
> -			return false;
> -	}
> -
> -	return true;
> -}
> -
>   static inline struct amdgpu_vram_mgr_resource *
>   to_amdgpu_vram_mgr_resource(struct ttm_resource *res)
>   {

Re: [PATCH 1/2] drm/amdgpu: fix start calculation in amdgpu_vram_mgr_new

[Arunpravin Paneer Selvam]

On 5/10/2022 8:56 PM, Christian König wrote:
> Am 10.05.22 um 17:20 schrieb Arunpravin Paneer Selvam:
>> Hi Christian,
>>
>> On 5/10/2022 5:06 PM, Christian König wrote:
>>> We still need to calculate a virtual start address for the resource to
>>> aid checking of it is visible or not.
>>>
>>> Signed-off-by: Christian König <christian.koenig@amd.com>
>>> ---
>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 22 
>>> +++++++++++++-------
>>>   1 file changed, 14 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c 
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>> index 49e4092f447f..51d9d3a4456c 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>> @@ -496,16 +496,22 @@ static int amdgpu_vram_mgr_new(struct 
>>> ttm_resource_manager *man,
>>>               list_splice_tail(trim_list, &vres->blocks);
>>>       }
>>>   -    list_for_each_entry(block, &vres->blocks, link)
>>> -        vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
>>> +    vres->base.start = 0;
>>> +    list_for_each_entry(block, &vres->blocks, link) {
>>> +        unsigned long start;
>>>   -    block = amdgpu_vram_mgr_first_block(&vres->blocks);
>>> -    if (!block) {
>>> -        r = -EINVAL;
>>> -        goto error_fini;
>>> -    }
>>> +        start = amdgpu_vram_mgr_block_start(block) +
>>> +            amdgpu_vram_mgr_block_size(block);
>>> +        start >>= PAGE_SHIFT;
>>>   -    vres->base.start = amdgpu_vram_mgr_block_start(block) >> 
>>> PAGE_SHIFT;
>>> +        if (start > vres->base.num_pages)
>>> +            start -= vres->base.num_pages;
>> I think this works for continuous blocks of addresses, but for a non 
>> continuous blocks allocated at different
>> locations and linked together using list, this might fetch an invalid 
>> address. I will check this patch on my
>> setup and inform you.
>
> It indeed does fetch an invalid address and that is perfectly expected 
> behavior.
>
> See the resource->start value for non-contiguous allocations is just 
> the maximum allocated address.
>
> This makes it possible to easily check if a buffer is inside the CPU 
> accessible VRAM window or not.
>
> As I said we should probably get rid of that, but for now it's necessary.

ah. good point.
Reviewed-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
>
> Regards,
> Christian.
>
>>
>> Regards,
>> Arun
>>> +        else
>>> +            start = 0;
>>> +        vres->base.start = max(vres->base.start, start);
>>> +
>>> +        vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
>>> +    }
>>>         if (amdgpu_is_vram_mgr_blocks_contiguous(&vres->blocks))
>>>           vres->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
>>
>