From 901782b21ecb2af4dde1598b3142bf0e80b20853 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 10 Jul 2009 08:18:50 +0100 Subject: [PATCH] drm/i915: Refactor calls to unmap_mapping_range As we call unmap_mapping_range() twice in identical fashion, refactor and attempt to explain why we need to call unmap_mapping_range(). Signed-off-by: Chris Wilson Signed-off-by: Eric Anholt --- drivers/gpu/drm/i915/i915_gem.c | 36 +++++++++++++++++++++++++++--------- 1 file changed, 27 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 876b65c..08d8e5d 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1252,6 +1252,31 @@ out_free_list: return ret; } +/** + * i915_gem_release_mmap - remove physical page mappings + * @obj: obj in question + * + * Preserve the reservation of the mmaping with the DRM core code, but + * relinquish ownership of the pages back to the system. + * + * It is vital that we remove the page mapping if we have mapped a tiled + * object through the GTT and then lose the fence register due to + * resource pressure. Similarly if the object has been moved out of the + * aperture, than pages mapped into userspace must be revoked. Removing the + * mapping will then trigger a page fault on the next user access, allowing + * fixup by i915_gem_fault(). + */ +static void +i915_gem_release_mmap(struct drm_gem_object *obj) +{ + struct drm_device *dev = obj->dev; + struct drm_i915_gem_object *obj_priv = obj->driver_private; + + if (dev->dev_mapping) + unmap_mapping_range(dev->dev_mapping, + obj_priv->mmap_offset, obj->size, 1); +} + static void i915_gem_free_mmap_offset(struct drm_gem_object *obj) { @@ -1861,7 +1886,6 @@ i915_gem_object_unbind(struct drm_gem_object *obj) { struct drm_device *dev = obj->dev; struct drm_i915_gem_object *obj_priv = obj->driver_private; - loff_t offset; int ret = 0; #if WATCH_BUF @@ -1898,9 +1922,7 @@ i915_gem_object_unbind(struct drm_gem_object *obj) BUG_ON(obj_priv->active); /* blow away mappings if mapped through GTT */ - offset = ((loff_t) obj->map_list.hash.key) << PAGE_SHIFT; - if (dev->dev_mapping) - unmap_mapping_range(dev->dev_mapping, offset, obj->size, 1); + i915_gem_release_mmap(obj); if (obj_priv->fence_reg != I915_FENCE_REG_NONE) i915_gem_clear_fence_reg(obj); @@ -2222,7 +2244,6 @@ try_again: /* None available, try to steal one or wait for a user to finish */ if (i == dev_priv->num_fence_regs) { uint32_t seqno = dev_priv->mm.next_gem_seqno; - loff_t offset; if (avail == 0) return -ENOSPC; @@ -2274,10 +2295,7 @@ try_again: * Zap this virtual mapping so we can set up a fence again * for this object next time we need it. */ - offset = ((loff_t) reg->obj->map_list.hash.key) << PAGE_SHIFT; - if (dev->dev_mapping) - unmap_mapping_range(dev->dev_mapping, offset, - reg->obj->size, 1); + i915_gem_release_mmap(reg->obj); old_obj_priv->fence_reg = I915_FENCE_REG_NONE; } -- 1.8.2.3