Am 21.06.20 um 08:03 schrieb Andrey Grodzovsky:
On device removal reroute all CPU mappings to dummy page per drm_file
instance or imported GEM object.
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@xxxxxxx>
---
drivers/gpu/drm/ttm/ttm_bo_vm.c | 65 ++++++++++++++++++++++++++++++++++++-----
1 file changed, 57 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index 389128b..2f8bf5e 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>
@@ -328,19 +330,66 @@ vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
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;
+ if (drm_dev_enter(ddev, &idx)) {
Better do this like if (!drm_dev_enter(...)) return ttm_bo_vm_dummy(..);
This way you can move all the dummy fault handling into a separate
function without cluttering this one here to much.
Christian.
+ ret = ttm_bo_vm_reserve(bo, vmf);
+ if (ret)
+ goto exit;
+
+ prot = vma->vm_page_prot;
- prot = vma->vm_page_prot;
- ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT);
- if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
+ ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT);
+ 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;
+ } else {
- dma_resv_unlock(bo->base.resv);
+ struct drm_file *file = NULL;
+ struct page *dummy_page = NULL;
+ int handle;
- return ret;
+ /* 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 non imported BO, find drm_file owning the BO*/
+ } else {
+ struct drm_gem_object *gobj;
+
+ mutex_lock(&ddev->filelist_mutex);
+ list_for_each_entry(file, &ddev->filelist, lhead) {
+ spin_lock(&file->table_lock);
+ idr_for_each_entry(&file->object_idr, gobj, handle) {
+ if (gobj == &bo->base) {
+ dummy_page = file->dummy_page;
+ break;
+ }
+ }
+ spin_unlock(&file->table_lock);
+ }
+ mutex_unlock(&ddev->filelist_mutex);
+ }
+
+ if (dummy_page) {
+ /*
+ * Let do_fault complete the PTE install e.t.c using vmf->page
+ *
+ * TODO - should i call free_page somewhere ?
+ */
+ get_page(dummy_page);
+ vmf->page = dummy_page;
+ return 0;
+ } else {
+ return VM_FAULT_SIGSEGV;
+ }
+ }
}
EXPORT_SYMBOL(ttm_bo_vm_fault);
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