[PATCH 23/30] drm/i915: Take reservation lock around i915_vma_pin.

[Maarten Lankhorst]

We previously complained when ww == NULL.

This function is now only used in selftests to pin an object,
and ww locking is now fixed.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_gem.c |  6 +++++-
 drivers/gpu/drm/i915/i915_vma.c |  4 +---
 drivers/gpu/drm/i915/i915_vma.h | 20 ++++++++++++++++----
 3 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index d349c0b796ec..929a8f20cca4 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1036,7 +1036,11 @@ i915_gem_object_ggtt_pin_ww(struct drm_i915_gem_object *obj,
 			return ERR_PTR(ret);
 	}
 
-	ret = i915_vma_pin_ww(vma, ww, size, alignment, flags | PIN_GLOBAL);
+	if (ww)
+		ret = i915_vma_pin_ww(vma, ww, size, alignment, flags | PIN_GLOBAL);
+	else
+		ret = i915_vma_pin(vma, size, alignment, flags | PIN_GLOBAL);
+
 	if (ret)
 		return ERR_PTR(ret);
 
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 88bffe60ddd3..a566d20a1782 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -861,9 +861,7 @@ int i915_vma_pin_ww(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,
 	int err;
 
 #ifdef CONFIG_PROVE_LOCKING
-	if (debug_locks && lockdep_is_held(&vma->vm->i915->drm.struct_mutex))
-		WARN_ON(!ww);
-	if (debug_locks && ww && vma->resv)
+	if (debug_locks && !WARN_ON(!ww) && vma->resv)
 		assert_vma_held(vma);
 #endif
 
diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
index 3c951d5428cf..cea6e7b8611b 100644
--- a/drivers/gpu/drm/i915/i915_vma.h
+++ b/drivers/gpu/drm/i915/i915_vma.h
@@ -246,10 +246,22 @@ i915_vma_pin_ww(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,
 static inline int __must_check
 i915_vma_pin(struct i915_vma *vma, u64 size, u64 alignment, u64 flags)
 {
-#ifdef CONFIG_LOCKDEP
-	WARN_ON_ONCE(vma->resv && dma_resv_held(vma->resv));
-#endif
-	return i915_vma_pin_ww(vma, NULL, size, alignment, flags);
+	struct i915_gem_ww_ctx ww;
+	int err;
+
+	i915_gem_ww_ctx_init(&ww, true);
+retry:
+	err = i915_gem_object_lock(vma->obj, &ww);
+	if (!err)
+		err = i915_vma_pin_ww(vma, &ww, size, alignment, flags);
+	if (err == -EDEADLK) {
+		err = i915_gem_ww_ctx_backoff(&ww);
+		if (!err)
+			goto retry;
+	}
+	i915_gem_ww_ctx_fini(&ww);
+
+	return err;
 }
 
 int i915_ggtt_pin(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,
-- 
2.28.0