drm/i915: Install fence register for tiled scanout on i915
With the work by Jesse Barnes to eliminate allocation of fences during
execbuffer, it becomes possible to write to the scan-out buffer with it
never acquiring a fence (simply by only ever writing to the object using
tiled GPU commands and never writing to it via the GTT). So for pre-i965
chipsets which require fenced access for tiled scan-out buffers, we need
to obtain a fence register.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 8ef6bce..451b547 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -646,6 +646,7 @@
int i915_gem_object_unbind(struct drm_gem_object *obj);
void i915_gem_lastclose(struct drm_device *dev);
uint32_t i915_get_gem_seqno(struct drm_device *dev);
+int i915_gem_object_get_fence_reg(struct drm_gem_object *obj);
void i915_gem_retire_requests(struct drm_device *dev);
void i915_gem_retire_work_handler(struct work_struct *work);
void i915_gem_clflush_object(struct drm_gem_object *obj);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index a5f95ad..4f34541 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -46,7 +46,6 @@
static int i915_gem_object_wait_rendering(struct drm_gem_object *obj);
static int i915_gem_object_bind_to_gtt(struct drm_gem_object *obj,
unsigned alignment);
-static int i915_gem_object_get_fence_reg(struct drm_gem_object *obj, bool write);
static void i915_gem_clear_fence_reg(struct drm_gem_object *obj);
static int i915_gem_evict_something(struct drm_device *dev);
static int i915_gem_phys_pwrite(struct drm_device *dev, struct drm_gem_object *obj,
@@ -1158,7 +1157,7 @@
/* Need a new fence register? */
if (obj_priv->fence_reg == I915_FENCE_REG_NONE &&
obj_priv->tiling_mode != I915_TILING_NONE) {
- ret = i915_gem_object_get_fence_reg(obj, write);
+ ret = i915_gem_object_get_fence_reg(obj);
if (ret) {
mutex_unlock(&dev->struct_mutex);
return VM_FAULT_SIGBUS;
@@ -2169,7 +2168,6 @@
/**
* i915_gem_object_get_fence_reg - set up a fence reg for an object
* @obj: object to map through a fence reg
- * @write: object is about to be written
*
* When mapping objects through the GTT, userspace wants to be able to write
* to them without having to worry about swizzling if the object is tiled.
@@ -2180,8 +2178,8 @@
* It then sets up the reg based on the object's properties: address, pitch
* and tiling format.
*/
-static int
-i915_gem_object_get_fence_reg(struct drm_gem_object *obj, bool write)
+int
+i915_gem_object_get_fence_reg(struct drm_gem_object *obj)
{
struct drm_device *dev = obj->dev;
struct drm_i915_private *dev_priv = dev->dev_private;
@@ -3550,7 +3548,7 @@
if (!IS_I965G(dev) &&
obj_priv->fence_reg == I915_FENCE_REG_NONE &&
obj_priv->tiling_mode != I915_TILING_NONE) {
- ret = i915_gem_object_get_fence_reg(obj, true);
+ ret = i915_gem_object_get_fence_reg(obj);
if (ret != 0) {
if (ret != -EBUSY && ret != -ERESTARTSYS)
DRM_ERROR("Failure to install fence: %d\n",
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 028f5b6..3e1c781 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -828,19 +828,31 @@
}
mutex_lock(&dev->struct_mutex);
- ret = i915_gem_object_pin(intel_fb->obj, alignment);
+ ret = i915_gem_object_pin(obj, alignment);
if (ret != 0) {
mutex_unlock(&dev->struct_mutex);
return ret;
}
- ret = i915_gem_object_set_to_gtt_domain(intel_fb->obj, 1);
+ ret = i915_gem_object_set_to_gtt_domain(obj, 1);
if (ret != 0) {
- i915_gem_object_unpin(intel_fb->obj);
+ i915_gem_object_unpin(obj);
mutex_unlock(&dev->struct_mutex);
return ret;
}
+ /* Pre-i965 needs to install a fence for tiled scan-out */
+ if (!IS_I965G(dev) &&
+ obj_priv->fence_reg == I915_FENCE_REG_NONE &&
+ obj_priv->tiling_mode != I915_TILING_NONE) {
+ ret = i915_gem_object_get_fence_reg(obj);
+ if (ret != 0) {
+ i915_gem_object_unpin(obj);
+ mutex_unlock(&dev->struct_mutex);
+ return ret;
+ }
+ }
+
dspcntr = I915_READ(dspcntr_reg);
/* Mask out pixel format bits in case we change it */
dspcntr &= ~DISPPLANE_PIXFORMAT_MASK;
@@ -860,7 +872,7 @@
break;
default:
DRM_ERROR("Unknown color depth\n");
- i915_gem_object_unpin(intel_fb->obj);
+ i915_gem_object_unpin(obj);
mutex_unlock(&dev->struct_mutex);
return -EINVAL;
}