[PATCH] gma500: enable GEM mmap

From: Alan Cox
Date: Tue May 10 2011 - 16:46:42 EST


Support mapping of GEM objects. This ought to be a small plumbing change but
instead we have to cut and paste a pile of stuff into the driver. This
really wants to be handled *IN* GEM

You can now allocate, mmap and munmap GEM objects in the driver. You can't
yet map them into the GART or display them however.

Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
---

drivers/staging/gma500/psb_drv.c | 4 +-
drivers/staging/gma500/psb_gem.c | 86 ++++++++++++++++++++++++++++++++++++--
2 files changed, 84 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/gma500/psb_drv.c b/drivers/staging/gma500/psb_drv.c
index 360d582..4da0b18 100644
--- a/drivers/staging/gma500/psb_drv.c
+++ b/drivers/staging/gma500/psb_drv.c
@@ -1422,11 +1422,11 @@ static struct drm_driver driver = {
.open = drm_open,
.release = drm_release,
.unlocked_ioctl = psb_unlocked_ioctl,
- .mmap = drm_mmap,
+ .mmap = drm_gem_mmap,
.poll = drm_poll,
.fasync = drm_fasync,
.read = drm_read,
- },
+ },
.name = DRIVER_NAME,
.desc = DRIVER_DESC,
.date = PSB_DRM_DRIVER_DATE,
diff --git a/drivers/staging/gma500/psb_gem.c b/drivers/staging/gma500/psb_gem.c
index 518f8c1..2132fe9 100644
--- a/drivers/staging/gma500/psb_gem.c
+++ b/drivers/staging/gma500/psb_gem.c
@@ -41,6 +41,15 @@ void psb_gem_free_object(struct drm_gem_object *obj)
{
struct gtt_range *gtt = container_of(obj, struct gtt_range, gem);
psb_gtt_free_range(obj->dev, gtt);
+ if (obj->map_list.map) {
+ /* Do things GEM should do for us */
+ struct drm_gem_mm *mm = obj->dev->mm_private;
+ struct drm_map_list *list = &obj->map_list;
+ drm_ht_remove_item(&mm->offset_hash, &list->hash);
+ drm_mm_put_block(list->file_offset_node);
+ kfree(list->map);
+ list->map = NULL;
+ }
drm_gem_object_release(obj);
}

@@ -51,6 +60,59 @@ int psb_gem_get_aperture(struct drm_device *dev, void *data,
}

/**
+ * psb_gem_create_mmap_offset - invent an mmap offset
+ * @obj: our object
+ *
+ * This is basically doing by hand a pile of ugly crap which should
+ * be done automatically by the GEM library code but isn't
+ */
+static int psb_gem_create_mmap_offset(struct drm_gem_object *obj)
+{
+ struct drm_device *dev = obj->dev;
+ struct drm_gem_mm *mm = dev->mm_private;
+ struct drm_map_list *list;
+ struct drm_local_map *map;
+ int ret;
+
+ list = &obj->map_list;
+ list->map = kzalloc(sizeof(struct drm_map_list), GFP_KERNEL);
+ if (list->map == NULL)
+ return -ENOMEM;
+ map = list->map;
+ map->type = _DRM_GEM;
+ map->size = obj->size;
+ map->handle =obj;
+
+ list->file_offset_node = drm_mm_search_free(&mm->offset_manager,
+ obj->size / PAGE_SIZE, 0, 0);
+ if (!list->file_offset_node) {
+ DRM_ERROR("failed to allocate offset for bo %d\n", obj->name);
+ ret = -ENOSPC;
+ goto free_it;
+ }
+ list->file_offset_node = drm_mm_get_block(list->file_offset_node,
+ obj->size / PAGE_SIZE, 0);
+ if (!list->file_offset_node) {
+ ret = -ENOMEM;
+ goto free_it;
+ }
+ list->hash.key = list->file_offset_node->start;
+ ret = drm_ht_insert_item(&mm->offset_hash, &list->hash);
+ if (ret) {
+ DRM_ERROR("failed to add to map hash\n");
+ goto free_mm;
+ }
+ return 0;
+
+free_mm:
+ drm_mm_put_block(list->file_offset_node);
+free_it:
+ kfree(list->map);
+ list->map = NULL;
+ return ret;
+}
+
+/**
* psb_gem_dumb_map_gtt - buffer mapping for dumb interface
* @file: our drm client file
* @dev: drm device
@@ -62,19 +124,35 @@ int psb_gem_get_aperture(struct drm_device *dev, void *data,
int psb_gem_dumb_map_gtt(struct drm_file *file, struct drm_device *dev,
uint32_t handle, uint64_t *offset)
{
+ int ret = 0;
struct drm_gem_object *obj;
+
if (!(dev->driver->driver_features & DRIVER_GEM))
return -ENODEV;
+
+ mutex_lock(&dev->struct_mutex);
+
/* GEM does all our handle to object mapping */
obj = drm_gem_object_lookup(dev, file, handle);
- if (obj == NULL)
- return -ENOENT;
+ if (obj == NULL) {
+ ret = -ENOENT;
+ goto unlock;
+ }
/* What validation is needed here ? */

- /* GEM works out the hash offsets for us */
+ /* Make it mmapable */
+ if (!obj->map_list.map) {
+ ret = psb_gem_create_mmap_offset(obj);
+ if (ret)
+ goto out;
+ }
+ /* GEM should really work out the hash offsets for us */
*offset = (u64)obj->map_list.hash.key << PAGE_SHIFT;
+out:
drm_gem_object_unreference(obj);
- return 0;
+unlock:
+ mutex_unlock(&dev->struct_mutex);
+ return ret;
}

/**

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