[PATCH v2 13/15] drm/ttm: Add BO and offset arguments for vm_access and vm_fault ttm handlers.
Christian König
christian.koenig at amd.com
Tue May 18 15:07:42 UTC 2021
Am 18.05.21 um 16:55 schrieb Thomas Hellström:
> From: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
>
> This allows other drivers that may not setup the vma in the same way
> to use the ttm bo helpers.
Uff can you please explain why exactly you need that?
Providing the BO is not much of a problem, but having the BO at
different VMA offsets is really a no-go with TTM.
Christian.
>
> Also clarify the documentation a bit, especially related to VM_FAULT_RETRY.
>
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at 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);
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