From 033908aed5a596f6202c848c6bbc8a40fb1a8490 Mon Sep 17 00:00:00 2001 From: Dave Gordon Date: Thu, 10 Dec 2015 18:51:23 +0000 Subject: drm/i915: mark GEM object pages dirty when mapped & written by the CPU In various places, a single page of a (regular) GEM object is mapped into CPU address space and updated. In each such case, either the page or the the object should be marked dirty, to ensure that the modifications are not discarded if the object is evicted under memory pressure. The typical sequence is: va = kmap_atomic(i915_gem_object_get_page(obj, pageno)); *(va+offset) = ... kunmap_atomic(va); Here we introduce i915_gem_object_get_dirty_page(), which performs the same operation as i915_gem_object_get_page() but with the side-effect of marking the returned page dirty in the pagecache. This will ensure that if the object is subsequently evicted (due to memory pressure), the changes are written to backing store rather than discarded. Note that it works only for regular (shmfs-backed) GEM objects, but (at least for now) those are the only ones that are updated in this way -- the objects in question are contexts and batchbuffers, which are always shmfs-backed. Separate patches deal with the cases where whole objects are (or may be) dirtied. v3: Mark two more pages dirty in the page-boundary-crossing cases of the execbuffer relocation code [Chris Wilson] Signed-off-by: Dave Gordon Cc: Chris Wilson Link: http://patchwork.freedesktop.org/patch/msgid/1449773486-30822-2-git-send-email-david.s.gordon@intel.com Reviewed-by: Chris Wilson Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gem_render_state.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/gpu/drm/i915/i915_gem_render_state.c') diff --git a/drivers/gpu/drm/i915/i915_gem_render_state.c b/drivers/gpu/drm/i915/i915_gem_render_state.c index 5026a6267a88..fc7e6d5c6251 100644 --- a/drivers/gpu/drm/i915/i915_gem_render_state.c +++ b/drivers/gpu/drm/i915/i915_gem_render_state.c @@ -103,7 +103,7 @@ static int render_state_setup(struct render_state *so) if (ret) return ret; - page = sg_page(so->obj->pages->sgl); + page = i915_gem_object_get_dirty_page(so->obj, 0); d = kmap(page); while (i < rodata->batch_items) { -- cgit v1.2.3