The newly-introduced function i915_gem_object_pin_map() returns an
ERR_PTR (not NULL) if the pin-and-map opertaion fails, so that's what we
must check for. And it's nicer not to assign such a pointer-or-error to
a structure being filled in until after it's been validated, so we
should keep it local and avoid exporting a bogus pointer. Also, for
clarity and symmetry, we should clear 'virtual_start' along with 'vma'
when unmapping a ringbuffer.
Signed-off-by: Dave Gordon <david.s.gor...@intel.com>
Cc: Chris Wilson <ch...@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursu...@linux.intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 6 ++++--
drivers/gpu/drm/i915/intel_ringbuffer.c | 15 +++++++++------
2 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index a9c8211..bc8f0a3 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3000,9 +3000,11 @@ static inline void i915_gem_object_unpin_pages(struct
drm_i915_gem_object *obj)
* pages and then returns a contiguous mapping of the backing storage into
* the kernel address space.
*
- * The caller must hold the struct_mutex.
+ * The caller must hold the struct_mutex, and is responsible for calling
+ * i915_gem_object_unpin_map() when the mapping is no longer required.
*
- * Returns the pointer through which to access the backing storage.
+ * Returns the pointer through which to access the mapped object, or an
+ * ERR_PTR() on error.
*/
void *__must_check i915_gem_object_pin_map(struct drm_i915_gem_object *obj);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c
b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 41b604e..35231ff 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2086,6 +2086,7 @@ void intel_unpin_ringbuffer_obj(struct intel_ringbuffer
*ringbuf)
i915_gem_object_unpin_map(ringbuf->obj);
else
iounmap(ringbuf->virtual_start);
+ ringbuf->virtual_start = NULL;
ringbuf->vma = NULL;
i915_gem_object_ggtt_unpin(ringbuf->obj);
}
@@ -2096,6 +2097,7 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device
*dev,
struct drm_i915_private *dev_priv = to_i915(dev);
struct i915_ggtt *ggtt = &dev_priv->ggtt;
struct drm_i915_gem_object *obj = ringbuf->obj;
+ void *addr;
int ret;
if (HAS_LLC(dev_priv) && !obj->stolen) {
@@ -2107,9 +2109,9 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device
*dev,
if (ret)
goto err_unpin;
- ringbuf->virtual_start = i915_gem_object_pin_map(obj);
- if (ringbuf->virtual_start == NULL) {
- ret = -ENOMEM;
+ addr = i915_gem_object_pin_map(obj);
+ if (IS_ERR(addr)) {
+ ret = PTR_ERR(addr);
goto err_unpin;
}
} else {
@@ -2124,14 +2126,15 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device
*dev,
/* Access through the GTT requires the device to be awake. */
assert_rpm_wakelock_held(dev_priv);
- ringbuf->virtual_start = ioremap_wc(ggtt->mappable_base +
-
i915_gem_obj_ggtt_offset(obj), ringbuf->size);
- if (ringbuf->virtual_start == NULL) {
+ addr = ioremap_wc(ggtt->mappable_base +
+ i915_gem_obj_ggtt_offset(obj), ringbuf->size);
+ if (addr == NULL) {
ret = -ENOMEM;
goto err_unpin;
}
}
+ ringbuf->virtual_start = addr;
ringbuf->vma = i915_gem_obj_to_ggtt(obj);
return 0;
--
1.9.1
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