From: Chris Wilson Date: Tue, 13 Jan 2015 13:32:52 +0000 (+0000) Subject: drm/i915: Performed deferred clflush inside set-cache-level X-Git-Tag: firefly_0821_release~176^2~1915^2~35^2~141 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0f71979ab7fbd0c71c41c2798de3d33937915434;p=firefly-linux-kernel-4.4.55.git drm/i915: Performed deferred clflush inside set-cache-level Currently we are hitting the WARN inside i915_gem_object_set_cache_level() as we can now have an unbound object in the GTT write domain (due to 43566dedde54f9 "drm/i915: Broaden application of set-domain(GTT)"). To avoid the warning, we need to track when we elided the clflush on a cacheable object and then evict the cache for the object when we move the object out of a cacheable domain. Reported-by: Jani Nikula Signed-off-by: Chris Wilson Cc: Jani Nikula Cc: Ville Syrjälä Tested-by: Jani Nikula Testcase: igt/gem_mmap_wc/set-cache-level Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88607 Tested-by: huax.lu@intel.com [danvet: Split if into nested if as discussion on the m-l.] Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index de304d78e2bf..0ad8dbf896c0 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2055,6 +2055,7 @@ struct drm_i915_gem_object { */ unsigned long gt_ro:1; unsigned int cache_level:3; + unsigned int cache_dirty:1; unsigned int has_dma_mapping:1; diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 2a4d1f01118d..a0264aa5cf51 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3637,11 +3637,14 @@ i915_gem_clflush_object(struct drm_i915_gem_object *obj, * snooping behaviour occurs naturally as the result of our domain * tracking. */ - if (!force && cpu_cache_is_coherent(obj->base.dev, obj->cache_level)) + if (!force && cpu_cache_is_coherent(obj->base.dev, obj->cache_level)) { + obj->cache_dirty = true; return false; + } trace_i915_gem_object_clflush(obj); drm_clflush_sg(obj->pages); + obj->cache_dirty = false; return true; } @@ -3824,27 +3827,11 @@ int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj, vma->node.color = cache_level; obj->cache_level = cache_level; - if (cpu_write_needs_clflush(obj)) { - u32 old_read_domains, old_write_domain; - - /* If we're coming from LLC cached, then we haven't - * actually been tracking whether the data is in the - * CPU cache or not, since we only allow one bit set - * in obj->write_domain and have been skipping the clflushes. - * Just set it to the CPU cache for now. - */ - i915_gem_object_retire(obj); - WARN_ON(obj->base.write_domain & ~I915_GEM_DOMAIN_CPU); - - old_read_domains = obj->base.read_domains; - old_write_domain = obj->base.write_domain; - - obj->base.read_domains = I915_GEM_DOMAIN_CPU; - obj->base.write_domain = I915_GEM_DOMAIN_CPU; - - trace_i915_gem_object_change_domain(obj, - old_read_domains, - old_write_domain); + if (obj->cache_dirty && + obj->base.write_domain != I915_GEM_DOMAIN_CPU && + cpu_write_needs_clflush(obj)) { + if (i915_gem_clflush_object(obj, true)) + i915_gem_chipset_flush(obj->base.dev); } return 0;