Hi Am 06.04.21 um 11:35 schrieb Christian König:
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@xxxxxxx> --- 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.cindex 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.hindex 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.cindex 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.cindex 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?
This is somewhat confusing.I took this check as-is, including the comment, from amdgpu's verify_access function. The verify_access function was called by ttm_bo_mmap. It returned 0 and ttm_bo_mmap did the mapping.
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.cindex 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); -}
Here's the orignal verification code. It gives a free pass to KFD.
- /** * 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; -}
And this was the mmap callback in struct file_operations. It calls ttm_bo_mmap(), which skips verification for KFD BOs. To the best of my knowledge, there was no additional verification for these KFD BOs.
The original code in amdgpu_gem_prime_mmap() did seom verification, but didn't handle KFD specially. I guess, PRIME needs GEM and KFD BOs wouldn't quailify.
In the end I went with the semantics I found in amdgpu_mmap() and handled KFD specially. Let me know if this requires to be changed.
Best regards Thomas
- 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.hindex 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);_______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Felix Imendörffer
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