drm/xe: Convert xe_dma_buf.c for exhaustive eviction

Convert dma-buf migration to XE_PL_TT and dma-buf import to
support exhaustive eviction, using xe_validation_guard().
It seems unlikely that the import would result in an -ENOMEM,
but convert import anyway for completeness.

The dma-buf map_attachment() functionality unfortunately doesn't
support passing a drm_exec, which means that foreign devices
validating a dma-buf that we exported will not, unless they are
xeKMD devices, participate in the exhaustive eviction scheme.

v2:
- Avoid gotos from within xe_validation_guard(). (Matt Brost)
- Adapt to signature change of xe_validation_guard(). (Matt Brost)
- Remove an unneeded (void)ret. (Matt Brost)
- Fix up an error path.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250908101246.65025-9-thomas.hellstrom@linux.intel.com

diff --git a/drivers/gpu/drm/xe/xe_dma_buf.c b/drivers/gpu/drm/xe/xe_dma_buf.c
index 7c27932655610dded60ad01e6bc5416e80aa1028..2e5b4b37118f1a3dc9562935888afc5ea71b4378 100644 (file)
--- a/drivers/gpu/drm/xe/xe_dma_buf.c
+++ b/drivers/gpu/drm/xe/xe_dma_buf.c
@@ -163,16 +163,26 @@ static int xe_dma_buf_begin_cpu_access(struct dma_buf *dma_buf,
        struct xe_bo *bo = gem_to_xe_bo(obj);
        bool reads =  (direction == DMA_BIDIRECTIONAL ||
                       direction == DMA_FROM_DEVICE);
-       struct drm_exec *exec = XE_VALIDATION_UNIMPLEMENTED;
+       struct xe_validation_ctx ctx;
+       struct drm_exec exec;
+       int ret = 0;
 
        if (!reads)
                return 0;
 
        /* Can we do interruptible lock here? */
-       xe_bo_lock(bo, false);
-       (void)xe_bo_migrate(bo, XE_PL_TT, NULL, exec);
-       xe_bo_unlock(bo);
+       xe_validation_guard(&ctx, &xe_bo_device(bo)->val, &exec, (struct xe_val_flags) {}, ret) {
+               ret = drm_exec_lock_obj(&exec, &bo->ttm.base);
+               drm_exec_retry_on_contention(&exec);
+               if (ret)
+                       break;
+
+               ret = xe_bo_migrate(bo, XE_PL_TT, NULL, &exec);
+               drm_exec_retry_on_contention(&exec);
+               xe_validation_retry_on_oom(&ctx, &ret);
+       }
 
+       /* If we failed, cpu-access takes place in current placement. */
        return 0;
 }
 
@@ -211,25 +221,36 @@ xe_dma_buf_init_obj(struct drm_device *dev, struct xe_bo *storage,
 {
        struct dma_resv *resv = dma_buf->resv;
        struct xe_device *xe = to_xe_device(dev);
-       struct drm_exec *exec = XE_VALIDATION_UNIMPLEMENTED;
+       struct xe_validation_ctx ctx;
+       struct drm_gem_object *dummy_obj;
+       struct drm_exec exec;
        struct xe_bo *bo;
-       int ret;
-
-       dma_resv_lock(resv, NULL);
-       bo = ___xe_bo_create_locked(xe, storage, NULL, resv, NULL, dma_buf->size,
-                                   0, /* Will require 1way or 2way for vm_bind */
-                                   ttm_bo_type_sg, XE_BO_FLAG_SYSTEM, exec);
-       if (IS_ERR(bo)) {
-               ret = PTR_ERR(bo);
-               goto error;
+       int ret = 0;
+
+       dummy_obj = drm_gpuvm_resv_object_alloc(&xe->drm);
+       if (!dummy_obj)
+               return ERR_PTR(-ENOMEM);
+
+       dummy_obj->resv = resv;
+       xe_validation_guard(&ctx, &xe->val, &exec, (struct xe_val_flags) {}, ret) {
+               ret = drm_exec_lock_obj(&exec, dummy_obj);
+               drm_exec_retry_on_contention(&exec);
+               if (ret)
+                       break;
+
+               bo = ___xe_bo_create_locked(xe, storage, NULL, resv, NULL, dma_buf->size,
+                                           0, /* Will require 1way or 2way for vm_bind */
+                                           ttm_bo_type_sg, XE_BO_FLAG_SYSTEM, &exec);
+               drm_exec_retry_on_contention(&exec);
+               if (IS_ERR(bo)) {
+                       ret = PTR_ERR(bo);
+                       xe_validation_retry_on_oom(&ctx, &ret);
+                       break;
+               }
        }
-       dma_resv_unlock(resv);
-
-       return &bo->ttm.base;
+       drm_gem_object_put(dummy_obj);
 
-error:
-       dma_resv_unlock(resv);
-       return ERR_PTR(ret);
+       return ret ? ERR_PTR(ret) : &bo->ttm.base;
 }
 
 static void xe_dma_buf_move_notify(struct dma_buf_attachment *attach)