[PATCH v9 2/3] drm/amdgpu: Enable clear page functionality
Paneer Selvam, Arunpravin
arunpravin.paneerselvam at amd.com
Tue Mar 19 11:41:01 UTC 2024
Hi Christian,
On 3/19/2024 3:58 PM, Christian König wrote:
>
>
> Am 18.03.24 um 22:40 schrieb Arunpravin Paneer Selvam:
>> Add clear page support in vram memory region.
>>
>> v1(Christian):
>> - Dont handle clear page as TTM flag since when moving the BO back
>> in from GTT again we don't need that.
>> - Make a specialized version of amdgpu_fill_buffer() which only
>> clears the VRAM areas which are not already cleared
>> - Drop the TTM_PL_FLAG_WIPE_ON_RELEASE check in
>> amdgpu_object.c
>>
>> v2:
>> - Modify the function name amdgpu_ttm_* (Alex)
>> - Drop the delayed parameter (Christian)
>> - handle amdgpu_res_cleared(&cursor) just above the size
>> calculation (Christian)
>> - Use AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE for clearing the buffers
>> in the free path to properly wait for fences etc.. (Christian)
>>
>> v3(Christian):
>> - Remove buffer clear code in VRAM manager instead change the
>> AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE handling to set
>> the DRM_BUDDY_CLEARED flag.
>> - Remove ! from amdgpu_res_cleared(&cursor) check.
>>
>> Signed-off-by: Arunpravin Paneer Selvam
>> <Arunpravin.PaneerSelvam at amd.com>
>> Suggested-by: Christian König <christian.koenig at amd.com>
>> Acked-by: Felix Kuehling <felix.kuehling at amd.com>
>
> Just a few nit picks below, but in general already looks good to me.
>
>> ---
>> drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 22 ++++---
>> .../gpu/drm/amd/amdgpu/amdgpu_res_cursor.h | 25 ++++++++
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 61 ++++++++++++++++++-
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 5 +-
>> drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 6 +-
>> drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h | 5 ++
>> 6 files changed, 111 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> index 8bc79924d171..c92d92b28a57 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> @@ -39,6 +39,7 @@
>> #include "amdgpu.h"
>> #include "amdgpu_trace.h"
>> #include "amdgpu_amdkfd.h"
>> +#include "amdgpu_vram_mgr.h"
>> /**
>> * DOC: amdgpu_object
>> @@ -601,8 +602,7 @@ int amdgpu_bo_create(struct amdgpu_device *adev,
>> if (!amdgpu_bo_support_uswc(bo->flags))
>> bo->flags &= ~AMDGPU_GEM_CREATE_CPU_GTT_USWC;
>> - if (adev->ras_enabled)
>> - bo->flags |= AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE;
>> + bo->flags |= AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE;
>> bo->tbo.bdev = &adev->mman.bdev;
>> if (bp->domain & (AMDGPU_GEM_DOMAIN_GWS | AMDGPU_GEM_DOMAIN_OA |
>> @@ -632,15 +632,17 @@ int amdgpu_bo_create(struct amdgpu_device *adev,
>> if (bp->flags & AMDGPU_GEM_CREATE_VRAM_CLEARED &&
>> bo->tbo.resource->mem_type == TTM_PL_VRAM) {
>> - struct dma_fence *fence;
>> + struct dma_fence *fence = NULL;
>> - r = amdgpu_fill_buffer(bo, 0, bo->tbo.base.resv, &fence,
>> true);
>> + r = amdgpu_ttm_clear_buffer(bo, bo->tbo.base.resv, &fence);
>> if (unlikely(r))
>> goto fail_unreserve;
>> - dma_resv_add_fence(bo->tbo.base.resv, fence,
>> - DMA_RESV_USAGE_KERNEL);
>> - dma_fence_put(fence);
>> + if (fence) {
>> + dma_resv_add_fence(bo->tbo.base.resv, fence,
>> + DMA_RESV_USAGE_KERNEL);
>> + dma_fence_put(fence);
>> + }
>> }
>> if (!bp->resv)
>> amdgpu_bo_unreserve(bo);
>> @@ -1365,8 +1367,12 @@ void amdgpu_bo_release_notify(struct
>> ttm_buffer_object *bo)
>> if (WARN_ON_ONCE(!dma_resv_trylock(bo->base.resv)))
>> return;
>> - r = amdgpu_fill_buffer(abo, AMDGPU_POISON, bo->base.resv,
>> &fence, true);
>> + r = amdgpu_fill_buffer(abo, 0, bo->base.resv, &fence, true);
>> if (!WARN_ON(r)) {
>> + struct amdgpu_vram_mgr_resource *vres;
>> +
>> + vres = to_amdgpu_vram_mgr_resource(bo->resource);
>> + vres->flags |= DRM_BUDDY_CLEARED;
>
> Those lines should probably be in the VRAM manager.
This flag is set based on the amdgpu_fill_buffer() function return
value, can we move the amdgpu_fill_buffer() function call and
DRM_BUDDY_CLEARED flag set lines to amdgpu_vram_mgr_del() in VRAM
manager and does it require to wipe the VRAM buffers here as well
without setting the DRM_BUDDY_CLEARED.
>
>> amdgpu_bo_fence(abo, fence, false);
>> dma_fence_put(fence);
>> }
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_res_cursor.h
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_res_cursor.h
>> index 381101d2bf05..50fcd86e1033 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_res_cursor.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_res_cursor.h
>> @@ -164,4 +164,29 @@ static inline void amdgpu_res_next(struct
>> amdgpu_res_cursor *cur, uint64_t size)
>> }
>> }
>> +/**
>> + * amdgpu_res_cleared - check if blocks are cleared
>> + *
>> + * @cur: the cursor to extract the block
>> + *
>> + * Check if the @cur block is cleared
>> + */
>> +static inline bool amdgpu_res_cleared(struct amdgpu_res_cursor *cur)
>> +{
>> + struct drm_buddy_block *block;
>> +
>> + switch (cur->mem_type) {
>> + case TTM_PL_VRAM:
>> + block = cur->node;
>> +
>> + if (!amdgpu_vram_mgr_is_cleared(block))
>> + return false;
>> + break;
>> + default:
>> + return false;
>> + }
>> +
>> + return true;
>> +}
>> +
>> #endif
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> index 8722beba494e..bcbffe909b47 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>> @@ -378,11 +378,15 @@ static int amdgpu_move_blit(struct
>> ttm_buffer_object *bo,
>> (abo->flags & AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE)) {
>> struct dma_fence *wipe_fence = NULL;
>> - r = amdgpu_fill_buffer(abo, AMDGPU_POISON, NULL, &wipe_fence,
>> - false);
>> + r = amdgpu_fill_buffer(abo, 0, NULL, &wipe_fence,
>> + false);
>> if (r) {
>> goto error;
>> } else if (wipe_fence) {
>> + struct amdgpu_vram_mgr_resource *vres;
>> +
>> + vres = to_amdgpu_vram_mgr_resource(bo->resource);
>> + vres->flags |= DRM_BUDDY_CLEARED;
Does it require to set the DRM_BUDDY_CLEARED flag as we are not freeing
the VRAM buffers?
>> dma_fence_put(fence);
>> fence = wipe_fence;
>> }
>> @@ -2214,6 +2218,59 @@ static int amdgpu_ttm_fill_mem(struct
>> amdgpu_ring *ring, uint32_t src_data,
>> return 0;
>> }
>
> Some kerneldoc here what the function does would ne nice to have.
>
>> +int amdgpu_ttm_clear_buffer(struct amdgpu_bo *bo,
>> + struct dma_resv *resv,
>> + struct dma_fence **fence)
>> +{
>> + struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
>> + struct amdgpu_ring *ring = adev->mman.buffer_funcs_ring;
>> + struct amdgpu_res_cursor cursor;
>> + struct dma_fence *f = NULL;
>
> It might be cleaner to just use the stub fence here (see
> dma_fence_get_stub()).
>
> This would avoid to local variable init in the caller and the if which
> checks if the function returned a fence or not.
>
>> + u64 addr;
>> + int r;
>> +
>> + if (!adev->mman.buffer_funcs_enabled)
>> + return -EINVAL;
>> +
>> + amdgpu_res_first(bo->tbo.resource, 0, amdgpu_bo_size(bo), &cursor);
>> +
>> + mutex_lock(&adev->mman.gtt_window_lock);
>> + while (cursor.remaining) {
>> + struct dma_fence *next = NULL;
>> + u64 size;
>> +
>> + if (amdgpu_res_cleared(&cursor)) {
>> + amdgpu_res_next(&cursor, cursor.size);
>> + continue;
>> + }
>> +
>> + /* Never clear more than 256MiB at once to avoid timeouts */
>> + size = min(cursor.size, 256ULL << 20);
>> +
>> + r = amdgpu_ttm_map_buffer(&bo->tbo, bo->tbo.resource, &cursor,
>> + 1, ring, false, &size, &addr);
>> + if (r)
>> + goto err;
>> +
>> + r = amdgpu_ttm_fill_mem(ring, 0, addr, size, resv,
>> + &next, true, true);
>> + if (r)
>> + goto err;
>> +
>> + dma_fence_put(f);
>> + f = next;
>> +
>> + amdgpu_res_next(&cursor, size);
>> + }
>> +err:
>> + mutex_unlock(&adev->mman.gtt_window_lock);
>> + if (fence)
>
> Just make fence a mandatory parameter and drop the if and the get/put
> dance.
>
>> + *fence = dma_fence_get(f);
>> + dma_fence_put(f);
>> +
>> + return r;
>> +}
>> +
>> int amdgpu_fill_buffer(struct amdgpu_bo *bo,
>> uint32_t src_data,
>> struct dma_resv *resv,
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> index 65ec82141a8e..b404d89d52e5 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> @@ -38,8 +38,6 @@
>> #define AMDGPU_GTT_MAX_TRANSFER_SIZE 512
>> #define AMDGPU_GTT_NUM_TRANSFER_WINDOWS 2
>> -#define AMDGPU_POISON 0xd0bed0be
>> -
>> extern const struct attribute_group amdgpu_vram_mgr_attr_group;
>> extern const struct attribute_group amdgpu_gtt_mgr_attr_group;
>> @@ -155,6 +153,9 @@ int amdgpu_ttm_copy_mem_to_mem(struct
>> amdgpu_device *adev,
>> uint64_t size, bool tmz,
>> struct dma_resv *resv,
>> struct dma_fence **f);
>> +int amdgpu_ttm_clear_buffer(struct amdgpu_bo *bo,
>> + struct dma_resv *resv,
>> + struct dma_fence **fence);
>> int amdgpu_fill_buffer(struct amdgpu_bo *bo,
>> uint32_t src_data,
>> struct dma_resv *resv,
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> index c0c851409241..e494f5bf136a 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> @@ -450,6 +450,7 @@ static int amdgpu_vram_mgr_new(struct
>> ttm_resource_manager *man,
>> {
>> struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
>> struct amdgpu_device *adev = to_amdgpu_device(mgr);
>> + struct amdgpu_bo *bo = ttm_to_amdgpu_bo(tbo);
>> u64 vis_usage = 0, max_bytes, min_block_size;
>> struct amdgpu_vram_mgr_resource *vres;
>> u64 size, remaining_size, lpfn, fpfn;
>> @@ -501,6 +502,9 @@ static int amdgpu_vram_mgr_new(struct
>> ttm_resource_manager *man,
>> if (place->flags & TTM_PL_FLAG_CONTIGUOUS)
>> vres->flags |= DRM_BUDDY_CONTIGUOUS_ALLOCATION;
>> + if (bo->flags & AMDGPU_GEM_CREATE_VRAM_CLEARED)
>> + vres->flags |= DRM_BUDDY_CLEAR_ALLOCATION;
>> +
>
> Mhm, you should probably *not* store this flags in the vres structure.
>
> As soon as the BO is used the VRAM wouldn't be cleared any more.
>
> Regards,
> Christian.
>
>> if (fpfn || lpfn != mgr->mm.size)
>> /* Allocate blocks in desired range */
>> vres->flags |= DRM_BUDDY_RANGE_ALLOCATION;
>> @@ -604,7 +608,7 @@ static void amdgpu_vram_mgr_del(struct
>> ttm_resource_manager *man,
>> amdgpu_vram_mgr_do_reserve(man);
>> - drm_buddy_free_list(mm, &vres->blocks, 0);
>> + drm_buddy_free_list(mm, &vres->blocks, vres->flags);
>> mutex_unlock(&mgr->lock);
>> atomic64_sub(vis_usage, &mgr->vis_usage);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
>> index 0e04e42cf809..8478522d7366 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
>> @@ -53,6 +53,11 @@ static inline u64
>> amdgpu_vram_mgr_block_size(struct drm_buddy_block *block)
>> return (u64)PAGE_SIZE << drm_buddy_block_order(block);
>> }
>> +static inline bool amdgpu_vram_mgr_is_cleared(struct
>> drm_buddy_block *block)
>> +{
>> + return drm_buddy_block_is_clear(block);
>> +}
>> +
>> static inline struct amdgpu_vram_mgr_resource *
>> to_amdgpu_vram_mgr_resource(struct ttm_resource *res)
>> {
>
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