From: Chris Wilson Date: Fri, 23 Dec 2016 14:57:57 +0000 (+0000) Subject: drm/i915: Don't clflush before release phys object X-Git-Tag: v4.10-rc3~19^2~2 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=c3f923b5545306570eff00d11ca051bd67699a23;p=linux.git drm/i915: Don't clflush before release phys object When we teardown the backing storage for the phys object, we copy from the coherent contiguous block back to the shmemfs object, clflushing as we go. Trying to clflush the invalid sg beforehand just oops and would be redundant (due to it already being coherent, and clflushed afterwards). Reported-by: Ville Syrjälä Signed-off-by: Chris Wilson Cc: Joonas Lahtinen Cc: Reviewed-by: Joonas Lahtinen Link: http://patchwork.freedesktop.org/patch/msgid/20161223145804.6605-3-chris@chris-wilson.co.uk (cherry picked from commit e5facdf9644f4490520e0489a0252e8feaba3744) Signed-off-by: Jani Nikula --- diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 4a31b7a891ec..30a1322c8677 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -244,14 +244,16 @@ i915_gem_object_get_pages_phys(struct drm_i915_gem_object *obj) static void __i915_gem_object_release_shmem(struct drm_i915_gem_object *obj, - struct sg_table *pages) + struct sg_table *pages, + bool needs_clflush) { GEM_BUG_ON(obj->mm.madv == __I915_MADV_PURGED); if (obj->mm.madv == I915_MADV_DONTNEED) obj->mm.dirty = false; - if ((obj->base.read_domains & I915_GEM_DOMAIN_CPU) == 0 && + if (needs_clflush && + (obj->base.read_domains & I915_GEM_DOMAIN_CPU) == 0 && !cpu_cache_is_coherent(obj->base.dev, obj->cache_level)) drm_clflush_sg(pages); @@ -263,7 +265,7 @@ static void i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj, struct sg_table *pages) { - __i915_gem_object_release_shmem(obj, pages); + __i915_gem_object_release_shmem(obj, pages, false); if (obj->mm.dirty) { struct address_space *mapping = obj->base.filp->f_mapping; @@ -2231,7 +2233,7 @@ i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj, struct sgt_iter sgt_iter; struct page *page; - __i915_gem_object_release_shmem(obj, pages); + __i915_gem_object_release_shmem(obj, pages, true); i915_gem_gtt_finish_pages(obj, pages);