drm: GEM mmap support
Add core support for mapping of GEM objects. Drivers should provide a
vm_operations_struct if they want to support page faulting of objects.
The code for handling GEM object offsets was taken from TTM, which was
written by Thomas Hellström.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index dc3ce3e0a..7fb690b 100644
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -262,6 +262,9 @@
DRM_DEBUG("AGP offset = 0x%08lx, size = 0x%08lx\n", map->offset, map->size);
break;
+ case _DRM_GEM:
+ DRM_ERROR("tried to rmmap GEM object\n");
+ break;
}
case _DRM_SCATTER_GATHER:
if (!dev->sg) {
@@ -429,6 +432,9 @@
dmah.size = map->size;
__drm_pci_free(dev, &dmah);
break;
+ case _DRM_GEM:
+ DRM_ERROR("tried to rmmap GEM object\n");
+ break;
}
drm_free(map, sizeof(*map), DRM_MEM_MAPS);
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 9f04ca3..98a7813 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -209,6 +209,7 @@
if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
drm_dma_takedown(dev);
+ dev->dev_mapping = NULL;
mutex_unlock(&dev->struct_mutex);
DRM_DEBUG("lastclose completed\n");
@@ -273,6 +274,8 @@
*/
static void drm_cleanup(struct drm_device * dev)
{
+ struct drm_driver *driver = dev->driver;
+
DRM_DEBUG("\n");
if (!dev) {
@@ -304,6 +307,9 @@
drm_ht_remove(&dev->map_hash);
drm_ctxbitmap_cleanup(dev);
+ if (driver->driver_features & DRIVER_GEM)
+ drm_gem_destroy(dev);
+
drm_put_minor(&dev->primary);
if (drm_put_dev(dev))
DRM_ERROR("Cannot unload module\n");
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index f228523..3a6c439 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -133,11 +133,21 @@
spin_lock(&dev->count_lock);
if (!dev->open_count++) {
spin_unlock(&dev->count_lock);
- return drm_setup(dev);
+ retcode = drm_setup(dev);
+ goto out;
}
spin_unlock(&dev->count_lock);
}
+out:
+ mutex_lock(&dev->struct_mutex);
+ if (dev->dev_mapping == NULL)
+ dev->dev_mapping = inode->i_mapping;
+ else if (dev->dev_mapping != inode->i_mapping)
+ WARN(1, "dev->dev_mapping not inode mapping (%p expected %p)\n",
+ dev->dev_mapping, inode->i_mapping);
+ mutex_unlock(&dev->struct_mutex);
+
return retcode;
}
EXPORT_SYMBOL(drm_open);
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index ccd1afd..b3939de 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -64,6 +64,13 @@
* up at a later date, and as our interface with shmfs for memory allocation.
*/
+/*
+ * We make up offsets for buffer objects so we can recognize them at
+ * mmap time.
+ */
+#define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1)
+#define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16)
+
/**
* Initialize the GEM device fields
*/
@@ -71,6 +78,8 @@
int
drm_gem_init(struct drm_device *dev)
{
+ struct drm_gem_mm *mm;
+
spin_lock_init(&dev->object_name_lock);
idr_init(&dev->object_name_idr);
atomic_set(&dev->object_count, 0);
@@ -79,9 +88,41 @@
atomic_set(&dev->pin_memory, 0);
atomic_set(&dev->gtt_count, 0);
atomic_set(&dev->gtt_memory, 0);
+
+ mm = drm_calloc(1, sizeof(struct drm_gem_mm), DRM_MEM_MM);
+ if (!mm) {
+ DRM_ERROR("out of memory\n");
+ return -ENOMEM;
+ }
+
+ dev->mm_private = mm;
+
+ if (drm_ht_create(&mm->offset_hash, 19)) {
+ drm_free(mm, sizeof(struct drm_gem_mm), DRM_MEM_MM);
+ return -ENOMEM;
+ }
+
+ if (drm_mm_init(&mm->offset_manager, DRM_FILE_PAGE_OFFSET_START,
+ DRM_FILE_PAGE_OFFSET_SIZE)) {
+ drm_free(mm, sizeof(struct drm_gem_mm), DRM_MEM_MM);
+ drm_ht_remove(&mm->offset_hash);
+ return -ENOMEM;
+ }
+
return 0;
}
+void
+drm_gem_destroy(struct drm_device *dev)
+{
+ struct drm_gem_mm *mm = dev->mm_private;
+
+ drm_mm_takedown(&mm->offset_manager);
+ drm_ht_remove(&mm->offset_hash);
+ drm_free(mm, sizeof(struct drm_gem_mm), DRM_MEM_MM);
+ dev->mm_private = NULL;
+}
+
/**
* Allocate a GEM object of the specified size with shmfs backing store
*/
@@ -419,3 +460,71 @@
}
EXPORT_SYMBOL(drm_gem_object_handle_free);
+/**
+ * drm_gem_mmap - memory map routine for GEM objects
+ * @filp: DRM file pointer
+ * @vma: VMA for the area to be mapped
+ *
+ * If a driver supports GEM object mapping, mmap calls on the DRM file
+ * descriptor will end up here.
+ *
+ * If we find the object based on the offset passed in (vma->vm_pgoff will
+ * contain the fake offset we created when the GTT map ioctl was called on
+ * the object), we set up the driver fault handler so that any accesses
+ * to the object can be trapped, to perform migration, GTT binding, surface
+ * register allocation, or performance monitoring.
+ */
+int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+ struct drm_file *priv = filp->private_data;
+ struct drm_device *dev = priv->minor->dev;
+ struct drm_gem_mm *mm = dev->mm_private;
+ struct drm_map *map = NULL;
+ struct drm_gem_object *obj;
+ struct drm_hash_item *hash;
+ unsigned long prot;
+ int ret = 0;
+
+ mutex_lock(&dev->struct_mutex);
+
+ if (drm_ht_find_item(&mm->offset_hash, vma->vm_pgoff, &hash)) {
+ mutex_unlock(&dev->struct_mutex);
+ return drm_mmap(filp, vma);
+ }
+
+ map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
+ if (!map ||
+ ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN))) {
+ ret = -EPERM;
+ goto out_unlock;
+ }
+
+ /* Check for valid size. */
+ if (map->size < vma->vm_end - vma->vm_start) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ obj = map->handle;
+ if (!obj->dev->driver->gem_vm_ops) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ vma->vm_flags |= VM_RESERVED | VM_IO | VM_PFNMAP | VM_DONTEXPAND;
+ vma->vm_ops = obj->dev->driver->gem_vm_ops;
+ vma->vm_private_data = map->handle;
+ /* FIXME: use pgprot_writecombine when available */
+ prot = pgprot_val(vma->vm_page_prot);
+ prot |= _PAGE_CACHE_WC;
+ vma->vm_page_prot = __pgprot(prot);
+
+ vma->vm_file = filp; /* Needed for drm_vm_open() */
+ drm_vm_open_locked(vma);
+
+out_unlock:
+ mutex_unlock(&dev->struct_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_gem_mmap);
diff --git a/drivers/gpu/drm/drm_hashtab.c b/drivers/gpu/drm/drm_hashtab.c
index 3316067..af539f7 100644
--- a/drivers/gpu/drm/drm_hashtab.c
+++ b/drivers/gpu/drm/drm_hashtab.c
@@ -127,6 +127,7 @@
}
return 0;
}
+EXPORT_SYMBOL(drm_ht_insert_item);
/*
* Just insert an item and return any "bits" bit key that hasn't been
@@ -188,6 +189,7 @@
ht->fill--;
return 0;
}
+EXPORT_SYMBOL(drm_ht_remove_item);
void drm_ht_remove(struct drm_open_hash *ht)
{
diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c
index c234c6f..3ffae02 100644
--- a/drivers/gpu/drm/drm_vm.c
+++ b/drivers/gpu/drm/drm_vm.c
@@ -267,6 +267,9 @@
dmah.size = map->size;
__drm_pci_free(dev, &dmah);
break;
+ case _DRM_GEM:
+ DRM_ERROR("tried to rmmap GEM object\n");
+ break;
}
drm_free(map, sizeof(*map), DRM_MEM_MAPS);
}
@@ -399,7 +402,7 @@
* Create a new drm_vma_entry structure as the \p vma private data entry and
* add it to drm_device::vmalist.
*/
-static void drm_vm_open_locked(struct vm_area_struct *vma)
+void drm_vm_open_locked(struct vm_area_struct *vma)
{
struct drm_file *priv = vma->vm_file->private_data;
struct drm_device *dev = priv->minor->dev;
@@ -540,7 +543,7 @@
* according to the mapping type and remaps the pages. Finally sets the file
* pointer and calls vm_open().
*/
-static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
+int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
{
struct drm_file *priv = filp->private_data;
struct drm_device *dev = priv->minor->dev;
