Re: [PATCH v2 2/7] drm/amdgpu: Implement mmap as GEM object function

Am 15.04.21 um 12:17 schrieb Thomas Zimmermann:

Moving the driver-specific mmap code into a GEM object function allows for using DRM helpers for various mmap callbacks.

This change resolves several inconsistencies between regular mmap and prime-based mmap. The vm_ops field in vma is now set for all mmap'ed areas. Previously it way only set for regular mmap calls, prime-based mmap used TTM's default vm_ops. The function amdgpu_verify_access() is no longer being called and therefore removed by this patch.

As a side effect, amdgpu_ttm_vm_ops and amdgpu_ttm_fault() are now implemented in amdgpu's GEM code.

v2:

• rename amdgpu_ttm_vm_ops and amdgpu_ttm_fault() to amdgpu_gem_vm_ops and amdgpu_gem_fault() (Christian)
• the check for kfd_bo has meanwhile been removed

Signed-off-by: Thomas Zimmermann tzimmermann@suse.de

[SNIP]

+static int amdgpu_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) +{

Mhm, just double checking this function is now a core GEM function and not prime specific?

If yes maybe drop the _prime part.

• struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
• struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
• unsigned long asize = amdgpu_bo_size(bo);
• if (!vma->vm_file)

• return -ENODEV;
  

• if (!adev)

• return -ENODEV;
  

• /* Check for valid size. */
• if (asize < vma->vm_end - vma->vm_start)

• return -EINVAL;
  

Shouldn't we have that check in the common code?

Apart from that looks good to me.

Christian.

• if (amdgpu_ttm_tt_get_usermm(bo->tbo.ttm) ||

•    (bo->flags & AMDGPU_GEM_CREATE_NO_CPU_ACCESS)) {
  

• return -EPERM;
  

• }
• return drm_gem_ttm_mmap(obj, vma);

+}

• static const struct drm_gem_object_funcs amdgpu_gem_object_funcs = { .free = amdgpu_gem_object_free, .open = amdgpu_gem_object_open,

@@ -212,6 +266,8 @@ static const struct drm_gem_object_funcs amdgpu_gem_object_funcs = { .export = amdgpu_gem_prime_export, .vmap = drm_gem_ttm_vmap, .vunmap = drm_gem_ttm_vunmap,

• .mmap = amdgpu_gem_prime_mmap,

• .vm_ops = &amdgpu_gem_vm_ops, };

  /*

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c index 1485f33c3cc7..d4083c19402b 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -152,25 +152,6 @@ static void amdgpu_evict_flags(struct ttm_buffer_object *bo, *placement = abo->placement; }

-/**

• • amdgpu_verify_access - Verify access for a mmap call
• • @bo: The buffer object to map
• • @filp: The file pointer from the process performing the mmap
• • This is called by ttm_bo_mmap() to verify whether a process
• • has the right to mmap a BO to their process space.
• */

-static int amdgpu_verify_access(struct ttm_buffer_object *bo, struct file *filp) -{

• struct amdgpu_bo *abo = ttm_to_amdgpu_bo(bo);
• if (amdgpu_ttm_tt_get_usermm(bo->ttm))

• return -EPERM;
  

• return drm_vma_node_verify_access(&abo->tbo.base.vma_node,

• 			  filp->private_data);
  

-}

• /**
  • amdgpu_ttm_map_buffer - Map memory into the GART windows
  • @bo: buffer object to map

@@ -1522,7 +1503,6 @@ static struct ttm_device_funcs amdgpu_bo_driver = { .eviction_valuable = amdgpu_ttm_bo_eviction_valuable, .evict_flags = &amdgpu_evict_flags, .move = &amdgpu_bo_move,

• .verify_access = &amdgpu_verify_access, .delete_mem_notify = &amdgpu_bo_delete_mem_notify, .release_notify = &amdgpu_bo_release_notify, .io_mem_reserve = &amdgpu_ttm_io_mem_reserve,

@@ -1897,50 +1877,6 @@ void amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable) adev->mman.buffer_funcs_enabled = enable; }

-static vm_fault_t amdgpu_ttm_fault(struct vm_fault *vmf) -{

• struct ttm_buffer_object *bo = vmf->vma->vm_private_data;
• vm_fault_t ret;
• ret = ttm_bo_vm_reserve(bo, vmf);
• if (ret)

• return ret;
  

• ret = amdgpu_bo_fault_reserve_notify(bo);
• if (ret)

• goto unlock;
  

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

• 		       TTM_BO_VM_NUM_PREFAULT, 1);
  

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

• return ret;
  

-unlock:

• dma_resv_unlock(bo->base.resv);
• return ret;

-}

-static const struct vm_operations_struct amdgpu_ttm_vm_ops = {

• .fault = amdgpu_ttm_fault,
• .open = ttm_bo_vm_open,
• .close = ttm_bo_vm_close,
• .access = ttm_bo_vm_access

-};

-int amdgpu_mmap(struct file *filp, struct vm_area_struct *vma) -{

• struct drm_file *file_priv = filp->private_data;
• struct amdgpu_device *adev = drm_to_adev(file_priv->minor->dev);
• int r;
• r = ttm_bo_mmap(filp, vma, &adev->mman.bdev);
• if (unlikely(r != 0))

• return r;
  

• vma->vm_ops = &amdgpu_ttm_vm_ops;
• return 0;

-}

• int amdgpu_copy_buffer(struct amdgpu_ring *ring, uint64_t src_offset, uint64_t dst_offset, uint32_t byte_count, 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 dec0db8b0b13..6e51faad7371 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h @@ -146,7 +146,6 @@ int amdgpu_fill_buffer(struct amdgpu_bo *bo, struct dma_resv *resv, struct dma_fence **fence);

-int amdgpu_mmap(struct file *filp, struct vm_area_struct *vma); int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo); int amdgpu_ttm_recover_gart(struct ttm_buffer_object *tbo); uint64_t amdgpu_ttm_domain_start(struct amdgpu_device *adev, uint32_t type);