intel-gem: Don't do the GTT-pwrite shortcut on tiled buffers.

These will be covered by the fence, while pread/pwrite are supposed to be
CPU-perspective writes, with manual detiling done by the client.

diff --git a/linux-core/i915_gem.c b/linux-core/i915_gem.c
index c5c68af..ca2dd19 100644 (file)
--- a/linux-core/i915_gem.c
+++ b/linux-core/i915_gem.c
@@ -165,18 +165,12 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data,
 
 #include "drm_compat.h"
 
-/**
- * Writes data to the object referenced by handle.
- *
- * On error, the contents of the buffer that were to be modified are undefined.
- */
-int
-i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
-                     struct drm_file *file_priv)
+static int
+i915_gem_gtt_pwrite(struct drm_device *dev, struct drm_gem_object *obj,
+                   struct drm_i915_gem_pwrite *args,
+                   struct drm_file *file_priv)
 {
-       struct drm_i915_gem_pwrite *args = data;
-       struct drm_gem_object *obj;
-       struct drm_i915_gem_object *obj_priv;
+       struct drm_i915_gem_object *obj_priv = obj->driver_private;
        ssize_t remain;
        loff_t offset;
        char __user *user_data;
@@ -186,18 +180,6 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
        unsigned long pfn;
        unsigned long unwritten;
 
-       obj = drm_gem_object_lookup(dev, file_priv, args->handle);
-       if (obj == NULL)
-               return -EINVAL;
-
-       /** Bounds check destination.
-        *
-        * XXX: This could use review for overflow issues...
-        */
-       if (args->offset > obj->size || args->size > obj->size || 
-           args->offset + args->size > obj->size)
-               return -EFAULT;
-
        user_data = (char __user *) (uintptr_t) args->data_ptr;
        remain = args->size;
        if (!access_ok(VERIFY_READ, user_data, remain))
@@ -207,7 +189,6 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
        mutex_lock(&dev->struct_mutex);
        ret = i915_gem_object_pin(obj, 0);
        if (ret) {
-               drm_gem_object_unreference(obj);
                mutex_unlock(&dev->struct_mutex);
                return ret;
        }
@@ -283,13 +264,92 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
 
 fail:
        i915_gem_object_unpin (obj);
-       drm_gem_object_unreference(obj);
        mutex_unlock(&dev->struct_mutex);
 
+       return ret;
+}
+
+int
+i915_gem_shmem_pwrite(struct drm_device *dev, struct drm_gem_object *obj,
+                     struct drm_i915_gem_pwrite *args,
+                     struct drm_file *file_priv)
+{
+       int ret;
+       loff_t offset;
+       ssize_t written;
+
+       mutex_lock(&dev->struct_mutex);
+
+       ret = i915_gem_set_domain(obj, file_priv,
+                                 I915_GEM_DOMAIN_CPU, I915_GEM_DOMAIN_CPU);
+       if (ret) {
+               mutex_unlock(&dev->struct_mutex);
+               return ret;
+       }
+
+       offset = args->offset;
+
+       written = vfs_write(obj->filp,
+                           (char __user *)(uintptr_t) args->data_ptr,
+                           args->size, &offset);
+       if (written != args->size) {
+               mutex_unlock(&dev->struct_mutex);
+               if (written < 0)
+                       return written;
+               else
+                       return -EINVAL;
+       }
+
+       mutex_unlock(&dev->struct_mutex);
+
+       return 0;
+}
+
+/**
+ * Writes data to the object referenced by handle.
+ *
+ * On error, the contents of the buffer that were to be modified are undefined.
+ */
+int
+i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
+                     struct drm_file *file_priv)
+{
+       struct drm_i915_gem_pwrite *args = data;
+       struct drm_gem_object *obj;
+       struct drm_i915_gem_object *obj_priv;
+       int ret = 0;
+
+       obj = drm_gem_object_lookup(dev, file_priv, args->handle);
+       if (obj == NULL)
+               return -EINVAL;
+       obj_priv = obj->driver_private;
+
+       /** Bounds check destination.
+        *
+        * XXX: This could use review for overflow issues...
+        */
+       if (args->offset > obj->size || args->size > obj->size || 
+           args->offset + args->size > obj->size)
+               return -EFAULT;
+
+       /* We can only do the GTT pwrite on untiled buffers, as otherwise
+        * it would end up going through the fenced access, and we'll get
+        * different detiling behavior between reading and writing.
+        * pread/pwrite currently are reading and writing from the CPU
+        * perspective, requiring manual detiling by the client.
+        */
+       if (obj_priv->tiling_mode == I915_TILING_NONE)
+               ret = i915_gem_gtt_pwrite(dev, obj, args, file_priv);
+       else
+               ret = i915_gem_shmem_pwrite(dev, obj, args, file_priv);
+
 #if WATCH_PWRITE
        if (ret)
                DRM_INFO("pwrite failed %d\n", ret);
 #endif
+
+       drm_gem_object_unreference(obj);
+
        return ret;
 }