Re: [Intel-gfx] [PATCH v2 13/15] drm/ttm: Add BO and offset arguments for vm_access and vm_fault ttm handlers.

+ Christian König

On 5/18/21 10:26 AM, Thomas Hellström wrote:

From: Maarten Lankhorst maarten.lankhorst@linux.intel.com

This allows other drivers that may not setup the vma in the same way to use the ttm bo helpers.

Also clarify the documentation a bit, especially related to VM_FAULT_RETRY.

Signed-off-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com

Lgtm. Reviewed-by: Thomas Hellström thomas.hellstrom@linux.intel.com

---

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 4 +- drivers/gpu/drm/nouveau/nouveau_ttm.c | 4 +- drivers/gpu/drm/radeon/radeon_ttm.c | 4 +- drivers/gpu/drm/ttm/ttm_bo_vm.c | 84 +++++++++++++--------- drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c | 8 ++- include/drm/ttm/ttm_bo_api.h | 9 ++- 6 files changed, 75 insertions(+), 38 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c index d5a9d7a88315..89dafe14f828 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -1919,7 +1919,9 @@ static vm_fault_t amdgpu_ttm_fault(struct vm_fault *vmf) if (ret) goto unlock;

• ret = ttm_bo_vm_fault_reserved(vmf, vmf->vma->vm_page_prot,

• ret = ttm_bo_vm_fault_reserved(bo, vmf,

• 		       drm_vma_node_start(&bo->base.vma_node),
  

• 		       vmf->vma->vm_page_prot,
  	       TTM_BO_VM_NUM_PREFAULT, 1);
  

  if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) return ret;

diff --git a/drivers/gpu/drm/nouveau/nouveau_ttm.c b/drivers/gpu/drm/nouveau/nouveau_ttm.c index b81ae90b8449..555fb6d8be8b 100644 --- a/drivers/gpu/drm/nouveau/nouveau_ttm.c +++ b/drivers/gpu/drm/nouveau/nouveau_ttm.c @@ -144,7 +144,9 @@ static vm_fault_t nouveau_ttm_fault(struct vm_fault *vmf)

nouveau_bo_del_io_reserve_lru(bo); prot = vm_get_page_prot(vma->vm_flags);

• ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT, 1);

• ret = ttm_bo_vm_fault_reserved(bo, vmf,

• 		       drm_vma_node_start(&bo->base.vma_node),
  

• 		       prot, TTM_BO_VM_NUM_PREFAULT, 1);
  

  nouveau_bo_add_io_reserve_lru(bo); if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) return ret;

diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c index 3361d11769a2..ba48a2acdef0 100644 --- a/drivers/gpu/drm/radeon/radeon_ttm.c +++ b/drivers/gpu/drm/radeon/radeon_ttm.c @@ -816,7 +816,9 @@ static vm_fault_t radeon_ttm_fault(struct vm_fault *vmf) if (ret) goto unlock_resv;

• ret = ttm_bo_vm_fault_reserved(vmf, vmf->vma->vm_page_prot,

• ret = ttm_bo_vm_fault_reserved(bo, vmf,

• 		       drm_vma_node_start(&bo->base.vma_node),
  

• 		       vmf->vma->vm_page_prot,
  	       TTM_BO_VM_NUM_PREFAULT, 1);
  

  if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) goto unlock_mclk;

diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index b31b18058965..ed00ccf1376e 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -42,7 +42,7 @@ #include <linux/mem_encrypt.h>

static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,

• 		struct vm_fault *vmf)
  

• 		       struct vm_fault *vmf)
  

  { vm_fault_t ret = 0; int err = 0;

@@ -122,7 +122,8 @@ static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo,

• Return:
• 0 on success and the bo was reserved.
• VM_FAULT_RETRY if blocking wait.

• • VM_FAULT_NOPAGE if blocking wait and retrying was not allowed.

• • VM_FAULT_NOPAGE if blocking wait and retrying was not allowed, or wait interrupted.
• • VM_FAULT_SIGBUS if wait on bo->moving failed for reason other than a signal.
  */ vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo, struct vm_fault *vmf)

@@ -254,7 +255,9 @@ static vm_fault_t ttm_bo_vm_insert_huge(struct vm_fault *vmf,

/**

• ttm_bo_vm_fault_reserved - TTM fault helper

• • @bo: The buffer object
  • @vmf: The struct vm_fault given as argument to the fault callback
• • @mmap_base: The base of the mmap, to which the @vmf fault is relative to.
  • @prot: The page protection to be used for this memory area.
  • @num_prefault: Maximum number of prefault pages. The caller may want to
  • specify this based on madvice settings and the size of the GPU object

@@ -265,19 +268,28 @@ static vm_fault_t ttm_bo_vm_insert_huge(struct vm_fault *vmf,

• memory backing the buffer object, and then returns a return code
• instructing the caller to retry the page access.

• • This function ensures any pipelined wait is finished.
• • WARNING:
• • On VM_FAULT_RETRY, the bo will be unlocked by this function when
• • #FAULT_FLAG_RETRY_NOWAIT is not set inside @vmf->flags. In this
• • case, the caller should not unlock the @bo.
• • Return:

• • VM_FAULT_NOPAGE on success or pending signal

• • 0 on success.
• • VM_FAULT_NOPAGE on pending signal
  • VM_FAULT_SIGBUS on unspecified error
  • VM_FAULT_OOM on out-of-memory

• • VM_FAULT_RETRY if retryable wait

• • VM_FAULT_RETRY if retryable wait, see WARNING above.
  */

-vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, +vm_fault_t ttm_bo_vm_fault_reserved(struct ttm_buffer_object *bo,

• 		    struct vm_fault *vmf,
  

• 		    unsigned long mmap_base,
  	    pgprot_t prot,
  	    pgoff_t num_prefault,
  	    pgoff_t fault_page_size)
  

  { struct vm_area_struct *vma = vmf->vma;

• struct ttm_buffer_object *bo = vma->vm_private_data; struct ttm_device *bdev = bo->bdev; unsigned long page_offset; unsigned long page_last;

@@ -286,15 +298,11 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, struct page *page; int err; pgoff_t i;

• vm_fault_t ret = VM_FAULT_NOPAGE;

• vm_fault_t ret; unsigned long address = vmf->address;

• /*

• * Wait for buffer data in transit, due to a pipelined
  

• * move.
  

• */
  

  ret = ttm_bo_vm_fault_idle(bo, vmf);
• if (unlikely(ret != 0))

• if (ret) return ret;

  err = ttm_mem_io_reserve(bdev, &bo->mem);

@@ -302,9 +310,8 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, return VM_FAULT_SIGBUS;

page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +

• vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node);
  

• page_last = vma_pages(vma) + vma->vm_pgoff -

• drm_vma_node_start(&bo->base.vma_node);
  

• vma->vm_pgoff - mmap_base;
  

• page_last = vma_pages(vma) + vma->vm_pgoff - mmap_base;

  if (unlikely(page_offset >= bo->mem.num_pages)) return VM_FAULT_SIGBUS;

@@ -344,8 +351,7 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, } else if (unlikely(!page)) { break; }

• 	page->index = drm_vma_node_start(&bo->base.vma_node) +
  

• 		page_offset;
  

• 	page->index = mmap_base + page_offset;
  pfn = page_to_pfn(page);
  

  }

@@ -392,7 +398,10 @@ vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) return ret;

prot = vma->vm_page_prot;

• ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT, 1);

• ret = ttm_bo_vm_fault_reserved(bo, vmf,

• 		       drm_vma_node_start(&bo->base.vma_node),
  

• 		       prot, TTM_BO_VM_NUM_PREFAULT, 1);
  

• if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) return ret;

@@ -460,22 +469,16 @@ static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo, return len; }

-int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,

•      void *buf, int len, int write)
  

+int ttm_bo_vm_access_reserved(struct ttm_buffer_object *bo,

• 	      struct vm_area_struct *vma,
  

• 	      unsigned long offset,
  

• 	      void *buf, int len, int write)
  

  {

• struct ttm_buffer_object *bo = vma->vm_private_data;

• unsigned long offset = (addr) - vma->vm_start +

• ((vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node))
  

•  << PAGE_SHIFT);
  

  int ret;

  if (len < 1 || (offset + len) >> PAGE_SHIFT > bo->mem.num_pages) return -EIO;

• ret = ttm_bo_reserve(bo, true, false, NULL);

• if (ret)

• return ret;
  

• switch (bo->mem.mem_type) { case TTM_PL_SYSTEM: if (unlikely(bo->ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {

@@ -485,16 +488,33 @@ int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr, } fallthrough; case TTM_PL_TT:

• ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, write);
  

• break;
  

• return ttm_bo_vm_access_kmap(bo, offset, buf, len, write);
  

  default: if (bo->bdev->funcs->access_memory)

• 	ret = bo->bdev->funcs->access_memory(
  

• 	return bo->bdev->funcs->access_memory(
  	bo, offset, buf, len, write);
  

  else

• 	ret = -EIO;
  

• 	return -EIO;
  

  }

• return ret;

+} +EXPORT_SYMBOL(ttm_bo_vm_access_reserved);

+int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,

•      void *buf, int len, int write)
  

+{

• struct ttm_buffer_object *bo = vma->vm_private_data;

• unsigned long offset = (addr) - vma->vm_start +

• ((vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node))
  

•  << PAGE_SHIFT);
  

• int ret;

• ret = ttm_bo_reserve(bo, true, false, NULL);

• if (ret)

• return ret;
  

• ret = ttm_bo_vm_access_reserved(bo, vma, offset, buf, len, write); ttm_bo_unreserve(bo);

  return ret;

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c b/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c index 45c9c6a7f1d6..56ecace0cf5c 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c @@ -477,7 +477,9 @@ vm_fault_t vmw_bo_vm_fault(struct vm_fault *vmf) else prot = vm_get_page_prot(vma->vm_flags);

• ret = ttm_bo_vm_fault_reserved(vmf, prot, num_prefault, 1);

• ret = ttm_bo_vm_fault_reserved(bo, vmf,

• 		       drm_vma_node_start(&bo->base.vma_node),
  

• 		       prot, num_prefault, 1);
  

  if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) return ret;

@@ -546,7 +548,9 @@ vm_fault_t vmw_bo_vm_huge_fault(struct vm_fault *vmf, prot = vm_get_page_prot(vma->vm_flags); }

• ret = ttm_bo_vm_fault_reserved(vmf, prot, 1, fault_page_size);

• ret = ttm_bo_vm_fault_reserved(bo, vmf,

• 		       drm_vma_node_start(&bo->base.vma_node),
  

• 		       prot, 1, fault_page_size);
  

  if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) return ret;

diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 639521880c29..434f91f1fdbf 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -605,7 +605,9 @@ int ttm_mem_evict_first(struct ttm_device *bdev, vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo, struct vm_fault *vmf);

-vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, +vm_fault_t ttm_bo_vm_fault_reserved(struct ttm_buffer_object *bo,

• 		    struct vm_fault *vmf,
  

• 		    unsigned long mmap_base,
  	    pgprot_t prot,
  	    pgoff_t num_prefault,
  	    pgoff_t fault_page_size);
  

@@ -616,6 +618,11 @@ void ttm_bo_vm_open(struct vm_area_struct *vma);

void ttm_bo_vm_close(struct vm_area_struct *vma);

+int ttm_bo_vm_access_reserved(struct ttm_buffer_object *bo,

• 	      struct vm_area_struct *vma,
  

• 	      unsigned long offset,
  

• 	      void *buf, int len, int write);
  

• int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr, void *buf, int len, int write); bool ttm_bo_delayed_delete(struct ttm_device *bdev, bool remove_all);