drm/i915: Add missing -EDEADLK handling to execbuf pinning, v2.

i915_vma_pin may fail with -EDEADLK when we start locking page tables,
so ensure we handle this correctly.

Changes since v1:
- Drop -EDEADLK todo, this commit handles it.
- Change eb_pin_vma from sort-of-bool + -EDEADLK to a proper int. (Matt)

Cc: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-5-maarten.lankhorst@linux.intel.com

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 8f020b1ca02ccac33f637063731fc16d86970785..c070fd860b51e9ce58c490591d00da84ce395b63 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -420,13 +420,14 @@ static u64 eb_pin_flags(const struct drm_i915_gem_exec_object2 *entry,
        return pin_flags;
 }
 
-static inline bool
+static inline int
 eb_pin_vma(struct i915_execbuffer *eb,
           const struct drm_i915_gem_exec_object2 *entry,
           struct eb_vma *ev)
 {
        struct i915_vma *vma = ev->vma;
        u64 pin_flags;
+       int err;
 
        if (vma->node.size)
                pin_flags = vma->node.start;
@@ -438,24 +439,29 @@ eb_pin_vma(struct i915_execbuffer *eb,
                pin_flags |= PIN_GLOBAL;
 
        /* Attempt to reuse the current location if available */
-       /* TODO: Add -EDEADLK handling here */
-       if (unlikely(i915_vma_pin_ww(vma, &eb->ww, 0, 0, pin_flags))) {
+       err = i915_vma_pin_ww(vma, &eb->ww, 0, 0, pin_flags);
+       if (err == -EDEADLK)
+               return err;
+
+       if (unlikely(err)) {
                if (entry->flags & EXEC_OBJECT_PINNED)
-                       return false;
+                       return err;
 
                /* Failing that pick any _free_ space if suitable */
-               if (unlikely(i915_vma_pin_ww(vma, &eb->ww,
+               err = i915_vma_pin_ww(vma, &eb->ww,
                                             entry->pad_to_size,
                                             entry->alignment,
                                             eb_pin_flags(entry, ev->flags) |
-                                            PIN_USER | PIN_NOEVICT)))
-                       return false;
+                                            PIN_USER | PIN_NOEVICT);
+               if (unlikely(err))
+                       return err;
        }
 
        if (unlikely(ev->flags & EXEC_OBJECT_NEEDS_FENCE)) {
-               if (unlikely(i915_vma_pin_fence(vma))) {
+               err = i915_vma_pin_fence(vma);
+               if (unlikely(err)) {
                        i915_vma_unpin(vma);
-                       return false;
+                       return err;
                }
 
                if (vma->fence)
@@ -463,7 +469,10 @@ eb_pin_vma(struct i915_execbuffer *eb,
        }
 
        ev->flags |= __EXEC_OBJECT_HAS_PIN;
-       return !eb_vma_misplaced(entry, vma, ev->flags);
+       if (eb_vma_misplaced(entry, vma, ev->flags))
+               return -EBADSLT;
+
+       return 0;
 }
 
 static inline void
@@ -906,7 +915,11 @@ static int eb_validate_vmas(struct i915_execbuffer *eb)
                if (err)
                        return err;
 
-               if (eb_pin_vma(eb, entry, ev)) {
+               err = eb_pin_vma(eb, entry, ev);
+               if (err == -EDEADLK)
+                       return err;
+
+               if (!err) {
                        if (entry->offset != vma->node.start) {
                                entry->offset = vma->node.start | UPDATE;
                                eb->args->flags |= __EXEC_HAS_RELOC;