Re: [PATCH 3/8] drm/amdgpu: Implement mmap as GEM object function

Am 06.04.21 um 11:08 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 check for kfd_bo has been taken from amdgpu_verify_access(), which is not called any longer and has been removed.

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

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

drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 46 ------------- drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h | 2 - drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 4 +- drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 64 +++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 71 --------------------- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 1 - 6 files changed, 66 insertions(+), 122 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c index e0c4f7c7f1b9..19c5ab08d9ec 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c @@ -42,52 +42,6 @@ #include <linux/pci-p2pdma.h> #include <linux/pm_runtime.h>

-/**

• • amdgpu_gem_prime_mmap - &drm_driver.gem_prime_mmap implementation
• • @obj: GEM BO
• • @vma: Virtual memory area
• • Sets up a userspace mapping of the BO's memory in the given
• • virtual memory area.
• • Returns:
• • 0 on success or a negative error code on failure.
• */

-int amdgpu_gem_prime_mmap(struct drm_gem_object *obj,

• 	  struct vm_area_struct *vma)
  

-{

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

• return -ENODEV;
  

• if (adev == NULL)

• return -ENODEV;
  

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

• return -EINVAL;
  

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

•    (bo->flags & AMDGPU_GEM_CREATE_NO_CPU_ACCESS)) {
  

• return -EPERM;
  

• }
• vma->vm_pgoff += amdgpu_bo_mmap_offset(bo) >> PAGE_SHIFT;
• /* prime mmap does not need to check access, so allow here */
• ret = drm_vma_node_allow(&obj->vma_node, vma->vm_file->private_data);
• if (ret)

• return ret;
  

• ret = ttm_bo_mmap(vma->vm_file, vma, &adev->mman.bdev);
• drm_vma_node_revoke(&obj->vma_node, vma->vm_file->private_data);
• return ret;

-}

• static int __dma_resv_make_exclusive(struct dma_resv *obj) {

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h index 39b5b9616fd8..3e93b9b407a9 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h @@ -31,8 +31,6 @@ struct drm_gem_object *amdgpu_gem_prime_import(struct drm_device *dev, struct dma_buf *dma_buf); bool amdgpu_dmabuf_is_xgmi_accessible(struct amdgpu_device *adev, struct amdgpu_bo *bo); -int amdgpu_gem_prime_mmap(struct drm_gem_object *obj,

• 	  struct vm_area_struct *vma);
  
  

  extern const struct dma_buf_ops amdgpu_dmabuf_ops;

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index 76f48f79c70b..e96d2758f4bb 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -1656,7 +1656,7 @@ static const struct file_operations amdgpu_driver_kms_fops = { .flush = amdgpu_flush, .release = drm_release, .unlocked_ioctl = amdgpu_drm_ioctl,

• .mmap = amdgpu_mmap,

• .mmap = drm_gem_mmap, .poll = drm_poll, .read = drm_read, #ifdef CONFIG_COMPAT

@@ -1719,7 +1719,7 @@ static const struct drm_driver amdgpu_kms_driver = { .prime_handle_to_fd = drm_gem_prime_handle_to_fd, .prime_fd_to_handle = drm_gem_prime_fd_to_handle, .gem_prime_import = amdgpu_gem_prime_import,

• .gem_prime_mmap = amdgpu_gem_prime_mmap,

• .gem_prime_mmap = drm_gem_prime_mmap,

  .name = DRIVER_NAME, .desc = DRIVER_DESC,

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c index fb7171e5507c..fe93faad05f2 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c @@ -41,6 +41,36 @@

static const struct drm_gem_object_funcs amdgpu_gem_object_funcs;

+static vm_fault_t amdgpu_ttm_fault(struct vm_fault *vmf)

Please name that function amdgpu_gem_fault or amdgpu_gem_object_fault

+{

• 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

+};

• static void amdgpu_gem_object_free(struct drm_gem_object *gobj) { struct amdgpu_bo *robj = gem_to_amdgpu_bo(gobj);

@@ -201,6 +231,38 @@ static void amdgpu_gem_object_close(struct drm_gem_object *obj, ttm_eu_backoff_reservation(&ticket, &list); }

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

• 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;
  

• /*

• * Don't verify access for KFD BOs. They don't have a GEM
  

• * object associated with them.
  

• */
  

• if (bo->kfd_bo)

• goto out;
  

Who does the access verification now?

Christian.

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

•    (bo->flags & AMDGPU_GEM_CREATE_NO_CPU_ACCESS)) {
  

• return -EPERM;
  

• }

+out:

• 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,

@@ -208,6 +270,8 @@ 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_ttm_vm_ops, };

  /*

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c index 1c6131489a85..d9de91a517c6 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -152,32 +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);
• /*

• * Don't verify access for KFD BOs. They don't have a GEM
  

• * object associated with them.
  

• */
  

• if (abo->kfd_bo)

• return 0;
  

• 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

@@ -1531,7 +1505,6 @@ 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,

@@ -1906,50 +1879,6 @@ 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);