From 70001cd256548391add796cce40bd2e2394d4297 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 16 Feb 2017 09:46:21 +0000 Subject: [PATCH] drm/i915: Remove struct_mutex for destroying framebuffers We do not need to hold struct_mutex for destroying drm_i915_gem_objects any longer, and with a little care taken over tracking obj->framebuffer_references, we can relinquish BKL locking around the destroy of intel_framebuffer. v2: Use atomic check for WARN_ON framebuffer miscounting Signed-off-by: Chris Wilson Cc: Joonas Lahtinen Link: http://patchwork.freedesktop.org/patch/msgid/20170216094621.3426-1-chris@chris-wilson.co.uk Reviewed-by: Joonas Lahtinen --- drivers/gpu/drm/i915/i915_gem_object.h | 2 +- drivers/gpu/drm/i915/i915_gem_shrinker.c | 2 +- drivers/gpu/drm/i915/i915_gem_tiling.c | 2 +- drivers/gpu/drm/i915/intel_display.c | 9 ++++----- 4 files changed, 7 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_object.h b/drivers/gpu/drm/i915/i915_gem_object.h index 02365a5f7c80..ef4893a4f08c 100644 --- a/drivers/gpu/drm/i915/i915_gem_object.h +++ b/drivers/gpu/drm/i915/i915_gem_object.h @@ -165,7 +165,7 @@ struct drm_i915_gem_object { struct reservation_object *resv; /** References from framebuffers, locks out tiling changes. */ - unsigned long framebuffer_references; + atomic_t framebuffer_references; /** Record of address bit 17 of each page at last unbind. */ unsigned long *bit_17; diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c index f249a1eb46ac..8bc515e8b2a2 100644 --- a/drivers/gpu/drm/i915/i915_gem_shrinker.c +++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c @@ -207,7 +207,7 @@ i915_gem_shrink(struct drm_i915_private *dev_priv, if (!(flags & I915_SHRINK_ACTIVE) && (i915_gem_object_is_active(obj) || - obj->framebuffer_references)) + atomic_read(&obj->framebuffer_references))) continue; if (!can_release_pages(obj)) diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c index 8b2b507bdf7e..46ade36dcee6 100644 --- a/drivers/gpu/drm/i915/i915_gem_tiling.c +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c @@ -238,7 +238,7 @@ i915_gem_object_set_tiling(struct drm_i915_gem_object *obj, if ((tiling | stride) == obj->tiling_and_stride) return 0; - if (obj->framebuffer_references) + if (atomic_read(&obj->framebuffer_references)) return -EBUSY; /* We need to rebind the object if its current allocation diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 660581fb329a..e483540d2439 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -14265,14 +14265,13 @@ static void intel_setup_outputs(struct drm_i915_private *dev_priv) static void intel_user_framebuffer_destroy(struct drm_framebuffer *fb) { - struct drm_device *dev = fb->dev; struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb); drm_framebuffer_cleanup(fb); - mutex_lock(&dev->struct_mutex); - WARN_ON(!intel_fb->obj->framebuffer_references--); + + WARN_ON(atomic_dec_return(&intel_fb->obj->framebuffer_references) < 0); i915_gem_object_put(intel_fb->obj); - mutex_unlock(&dev->struct_mutex); + kfree(intel_fb); } @@ -14509,7 +14508,7 @@ static int intel_framebuffer_init(struct drm_device *dev, return ret; } - intel_fb->obj->framebuffer_references++; + atomic_inc(&intel_fb->obj->framebuffer_references); return 0; } -- 2.20.1