On device removal reroute all CPU mappings to dummy page per drm_file instance or imported GEM object.
v3: Remove loop to find DRM file and instead access it by vma->vm_file->private_data. Move dummy page installation into a separate function.
Signed-off-by: Andrey Grodzovsky andrey.grodzovsky@amd.com --- drivers/gpu/drm/ttm/ttm_bo_vm.c | 54 +++++++++++++++++++++++++++++++++++------ 1 file changed, 46 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 01693e8..f2dbb93 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -35,6 +35,8 @@ #include <drm/ttm/ttm_bo_driver.h> #include <drm/ttm/ttm_placement.h> #include <drm/drm_vma_manager.h> +#include <drm/drm_drv.h> +#include <drm/drm_file.h> #include <linux/mm.h> #include <linux/pfn_t.h> #include <linux/rbtree.h> @@ -420,23 +422,59 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, } EXPORT_SYMBOL(ttm_bo_vm_fault_reserved);
+vm_fault_t ttm_bo_vm_dummy_page(struct vm_fault *vmf) +{ + struct vm_area_struct *vma = vmf->vma; + struct ttm_buffer_object *bo = vma->vm_private_data; + struct drm_file *file = NULL; + struct page *dummy_page = NULL; + + /* We are faulting on imported BO from dma_buf */ + if (bo->base.dma_buf && bo->base.import_attach) { + dummy_page = bo->base.dummy_page; + /* We are faulting on local BO */ + } else { + file = vma->vm_file->private_data; + dummy_page = file->dummy_page; + } + + /* Let do_fault complete the PTE install e.t.c using vmf->page */ + get_page(dummy_page); + vmf->page = dummy_page; + + return 0; +} + vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; pgprot_t prot; struct ttm_buffer_object *bo = vma->vm_private_data; vm_fault_t ret; + int idx; + struct drm_device *ddev = bo->base.dev;
- ret = ttm_bo_vm_reserve(bo, vmf); - if (ret) - return ret;
- prot = vma->vm_page_prot; - ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT, 1); - if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) - return ret; + if (!drm_dev_enter(ddev, &idx)) { + ret = ttm_bo_vm_dummy_page(vmf); + if (ret) + return ret; + } else { + ret = ttm_bo_vm_reserve(bo, vmf); + if (ret) + goto exit;
- dma_resv_unlock(bo->base.resv); + prot = vma->vm_page_prot; + + ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT, 1); + if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) + goto exit; + + dma_resv_unlock(bo->base.resv); + +exit: + drm_dev_exit(idx); + }
return ret; }