On 7/22/2015 8:09 PM, Chris Wilson wrote:
On Wed, Jul 22, 2015 at 07:21:49PM +0530, ankitprasad.r.sharma@xxxxxxxxx wrote:
static int
i915_gem_shmem_pread(struct drm_device *dev,
struct drm_i915_gem_object *obj,
@@ -754,17 +850,20 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data,
goto out;
}
- /* prime objects have no backing filp to GEM pread/pwrite
- * pages from.
- */
- if (!obj->base.filp) {
- ret = -EINVAL;
- goto out;
- }
-
trace_i915_gem_object_pread(obj, args->offset, args->size);
- ret = i915_gem_shmem_pread(dev, obj, args, file);
+ /* pread for non shmem backed objects */
+ if (!obj->base.filp) {
+ if (obj->tiling_mode == I915_TILING_NONE)
pread/pwrite is defined as a cpu linear, the restriction upon tiling is
a simplification of handling swizzling.
+ ret = i915_gem_gtt_pread_pwrite(dev, obj, args->size,
+ args->offset,
+ args->data_ptr,
+ false);
+ else
+ ret = -EINVAL;
+ } else {
+ ret = i915_gem_shmem_pread(dev, obj, args, file);
+ }
out:
drm_gem_object_unreference(&obj->base);
@@ -1105,17 +1204,22 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
goto out;
}
- /* prime objects have no backing filp to GEM pread/pwrite
- * pages from.
- */
- if (!obj->base.filp) {
- ret = -EINVAL;
- goto out;
- }
-
trace_i915_gem_object_pwrite(obj, args->offset, args->size);
ret = -EFAULT;
+
+ /* pwrite for non shmem backed objects */
+ if (!obj->base.filp) {
+ if (obj->tiling_mode == I915_TILING_NONE)
+ ret = i915_gem_gtt_pread_pwrite(dev, obj, args->size,
+ args->offset,
+ args->data_ptr,
+ true);
+ else
+ ret = -EINVAL;
+
+ goto out;
The fast pwrite code always works for obj->base.filp == NULL. To easily
make it generic and handle the cases where we cannot fallback to shem,
undo the PIN_NONBLOCK.
Then you just want something like
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index d3016f37cd4d..f2284a27dd6d 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1114,8 +1114,9 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
* perspective, requiring manual detiling by the client.
*/
if (obj->tiling_mode == I915_TILING_NONE &&
Since the suggestion is to reuse the gtt_pwrite_fast function only for
non-shmem backed objects, can we also relax the Tiling constraint here,
apart from removing the PIN_NONBLOCK flag. As anyways there is a
put_fence already being done in gtt_pwrite_fast function.
Also currently the gtt_pwrite_fast function is non-tolerant to faults,
incurred while accessing the User space buffer, so can that also be
relaxed (at least for the non-shmem backed objects) ??
Best regards
Akash
- obj->base.write_domain != I915_GEM_DOMAIN_CPU &&
- cpu_write_needs_clflush(obj)) {
+ (obj->base.filp == NULL ||
+ (obj->base.write_domain != I915_GEM_DOMAIN_CPU &&
+ cpu_write_needs_clflush(obj)))) {
ret = i915_gem_gtt_pwrite_fast(dev_priv, obj, args, file);
/* Note that the gtt paths might fail with non-page-backed user
* pointers (e.g. gtt mappings when moving data between
@@ -1125,7 +1126,7 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
if (ret == -EFAULT || ret == -ENOSPC) {
if (obj->phys_handle)
ret = i915_gem_phys_pwrite(obj, args, file);
- else
+ else if (obj->filp)
ret = i915_gem_shmem_pwrite(dev, obj, args, file);
}
to enable pwrite access to stolen.
-Chris
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