On 09/15/2015 09:33 AM, ankitprasad.r.sha...@intel.com wrote:
From: Ankitprasad Sharma <ankitprasad.r.sha...@intel.com>This patch adds support for clearing buffer objects via CPU/GTT. This is particularly useful for clearing out the non shmem backed objects. Currently intend to use this only for buffers allocated from stolen region. v2: Added kernel doc for i915_gem_clear_object(), corrected/removed variable assignments (Tvrtko) Testcase: igt/gem_stolen Signed-off-by: Ankitprasad Sharma <ankitprasad.r.sha...@intel.com> --- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/i915_gem.c | 39 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index e0f3f05..8db905a 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2820,6 +2820,7 @@ int i915_gem_obj_prepare_shmem_read(struct drm_i915_gem_object *obj, int *needs_clflush); int __must_check i915_gem_object_get_pages(struct drm_i915_gem_object *obj); +int i915_gem_clear_object(struct drm_i915_gem_object *obj); static inline int __sg_page_count(struct scatterlist *sg) { diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 1ac57ec..94533bf 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -5139,3 +5139,42 @@ fail: drm_gem_object_unreference(&obj->base); return ERR_PTR(ret); } + +/** + * i915_gem_clear_object() - Clear buffer object via CPU/GTT + * @obj: Buffer object to be cleared + * + * Return: 0 - success, non-zero - failure + */ +int i915_gem_clear_object(struct drm_i915_gem_object *obj) +{ + int ret; + char __iomem *base; + size_t size = obj->base.size; + struct drm_i915_private *dev_priv = to_i915(obj->base.dev); + + WARN_ON(!mutex_is_locked(&obj->base.dev->struct_mutex)); + ret = i915_gem_obj_ggtt_pin(obj, 0, PIN_MAPPABLE); + if (ret) + return ret; + + ret = i915_gem_object_put_fence(obj); + if (ret) + goto unpin; + + /* Get the CPU virtual address of the buffer */ + base = ioremap_wc(dev_priv->gtt.mappable_base + + i915_gem_obj_ggtt_offset(obj), size); + if (base == NULL) { + DRM_ERROR("Mapping of gem object to CPU failed!\n"); + ret = -ENOSPC; + goto unpin; + } + + memset_io(base, 0, size); + + iounmap(base); +unpin: + i915_gem_object_ggtt_unpin(obj); + return ret; +}
Reviewed-by: Tvrtko Ursulin <tvrtko.ursu...@intel.com> Regards, Tvrtko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
