[PATCH 1/4] drm: add prime helpers
Aaron Plattner
aplattner at nvidia.com
Thu Dec 6 10:07:48 PST 2012
Instead of reimplementing all of the dma_buf functionality in every driver,
create helpers drm_prime_import and drm_prime_export that implement them in
terms of new, lower-level hook functions:
gem_prime_pin: callback when a buffer is created, used to pin buffers into GTT
gem_prime_get_pages: convert a drm_gem_object to an sg_table for export
gem_prime_import_sg: convert an sg_table into a drm_gem_object
gem_prime_vmap, gem_prime_vunmap: map and unmap an object
These hooks are optional; drivers can opt in by using drm_gem_prime_import and
drm_gem_prime_export as the .gem_prime_import and .gem_prime_export fields of
struct drm_driver.
Signed-off-by: Aaron Plattner <aplattner at nvidia.com>
---
drivers/gpu/drm/drm_prime.c | 190 +++++++++++++++++++++++++++++++++++++++++++-
include/drm/drmP.h | 15 ++++
2 files changed, 204 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 7f12573..566c2ac 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -53,7 +53,8 @@
* Self-importing: if userspace is using PRIME as a replacement for flink
* then it will get a fd->handle request for a GEM object that it created.
* Drivers should detect this situation and return back the gem object
- * from the dma-buf private.
+ * from the dma-buf private. Prime will do this automatically for drivers that
+ * use the drm_gem_prime_{import,export} helpers.
*/
struct drm_prime_member {
@@ -62,6 +63,146 @@ struct drm_prime_member {
uint32_t handle;
};
+static struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
+ enum dma_data_direction dir)
+{
+ struct drm_gem_object *obj = attach->dmabuf->priv;
+ struct sg_table *st;
+
+ mutex_lock_interruptible(&obj->dev->struct_mutex);
+
+ st = obj->dev->driver->gem_prime_get_pages(obj);
+
+ if (!IS_ERR_OR_NULL(st))
+ dma_map_sg(attach->dev, st->sgl, st->nents, dir);
+
+ mutex_unlock(&obj->dev->struct_mutex);
+ return st;
+}
+
+static void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
+ struct sg_table *sg, enum dma_data_direction dir)
+{
+ dma_unmap_sg(attach->dev, sg->sgl, sg->nents, dir);
+ sg_free_table(sg);
+ kfree(sg);
+}
+
+static void drm_gem_dmabuf_release(struct dma_buf *dma_buf)
+{
+ struct drm_gem_object *obj = dma_buf->priv;
+
+ if (obj->export_dma_buf == dma_buf) {
+ /* drop the reference on the export fd holds */
+ obj->export_dma_buf = NULL;
+ drm_gem_object_unreference_unlocked(obj);
+ }
+}
+
+static void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
+{
+ struct drm_gem_object *obj = dma_buf->priv;
+ struct drm_device *dev = obj->dev;
+ void *virtual = ERR_PTR(-EINVAL);
+
+ if (!dev->driver->gem_prime_vmap)
+ return ERR_PTR(-EINVAL);
+
+ mutex_lock(&dev->struct_mutex);
+ if (obj->vmapping_count) {
+ obj->vmapping_count++;
+ virtual = obj->vmapping_ptr;
+ goto out_unlock;
+ }
+
+ virtual = dev->driver->gem_prime_vmap(obj);
+ if (IS_ERR(virtual)) {
+ mutex_unlock(&dev->struct_mutex);
+ return virtual;
+ }
+ obj->vmapping_count = 1;
+ obj->vmapping_ptr = virtual;
+out_unlock:
+ mutex_unlock(&dev->struct_mutex);
+ return obj->vmapping_ptr;
+}
+
+static void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
+{
+ struct drm_gem_object *obj = dma_buf->priv;
+ struct drm_device *dev = obj->dev;
+
+ mutex_lock(&dev->struct_mutex);
+ obj->vmapping_count--;
+ if (obj->vmapping_count == 0) {
+ dev->driver->gem_prime_vunmap(obj);
+ obj->vmapping_ptr = NULL;
+ }
+ mutex_unlock(&dev->struct_mutex);
+}
+
+static void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
+ unsigned long page_num)
+{
+ return NULL;
+}
+
+static void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
+ unsigned long page_num, void *addr)
+{
+
+}
+static void *drm_gem_dmabuf_kmap(struct dma_buf *dma_buf,
+ unsigned long page_num)
+{
+ return NULL;
+}
+
+static void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
+ unsigned long page_num, void *addr)
+{
+
+}
+
+static int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf,
+ struct vm_area_struct *vma)
+{
+ return -EINVAL;
+}
+
+static int drm_gem_begin_cpu_access(struct dma_buf *dma_buf,
+ size_t start, size_t length, enum dma_data_direction direction)
+{
+ return -EINVAL;
+}
+
+static const struct dma_buf_ops drm_gem_prime_dmabuf_ops = {
+ .map_dma_buf = drm_gem_map_dma_buf,
+ .unmap_dma_buf = drm_gem_unmap_dma_buf,
+ .release = drm_gem_dmabuf_release,
+ .kmap = drm_gem_dmabuf_kmap,
+ .kmap_atomic = drm_gem_dmabuf_kmap_atomic,
+ .kunmap = drm_gem_dmabuf_kunmap,
+ .kunmap_atomic = drm_gem_dmabuf_kunmap_atomic,
+ .mmap = drm_gem_dmabuf_mmap,
+ .vmap = drm_gem_dmabuf_vmap,
+ .vunmap = drm_gem_dmabuf_vunmap,
+ .begin_cpu_access = drm_gem_begin_cpu_access,
+};
+
+struct dma_buf *drm_gem_prime_export(struct drm_device *dev,
+ struct drm_gem_object *obj, int flags)
+{
+ if (dev->driver->gem_prime_pin) {
+ int ret = dev->driver->gem_prime_pin(obj);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+ return dma_buf_export(obj, &drm_gem_prime_dmabuf_ops, obj->size,
+ 0600);
+}
+EXPORT_SYMBOL(drm_gem_prime_export);
+
int drm_gem_prime_handle_to_fd(struct drm_device *dev,
struct drm_file *file_priv, uint32_t handle, uint32_t flags,
int *prime_fd)
@@ -117,6 +258,53 @@ int drm_gem_prime_handle_to_fd(struct drm_device *dev,
}
EXPORT_SYMBOL(drm_gem_prime_handle_to_fd);
+struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
+ struct dma_buf *dma_buf)
+{
+ struct dma_buf_attachment *attach;
+ struct sg_table *sg;
+ struct drm_gem_object *obj;
+ int ret;
+
+ if (!dev->driver->gem_prime_import_sg)
+ return ERR_PTR(-EINVAL);
+
+ if (dma_buf->ops == &drm_gem_prime_dmabuf_ops) {
+ obj = dma_buf->priv;
+ if (obj->dev == dev) {
+ drm_gem_object_reference(obj);
+ return obj;
+ }
+ }
+
+ attach = dma_buf_attach(dma_buf, dev->dev);
+ if (IS_ERR(attach))
+ return ERR_PTR(PTR_ERR(attach));
+
+ sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
+ if (IS_ERR_OR_NULL(sg)) {
+ ret = PTR_ERR(sg);
+ goto fail_detach;
+ }
+
+ obj = dev->driver->gem_prime_import_sg(dev, dma_buf->size, sg);
+ if (IS_ERR(obj)) {
+ ret = PTR_ERR(obj);
+ goto fail_unmap;
+ }
+
+ obj->import_attach = attach;
+
+ return obj;
+
+fail_unmap:
+ dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
+fail_detach:
+ dma_buf_detach(dma_buf, attach);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(drm_gem_prime_import);
+
int drm_gem_prime_fd_to_handle(struct drm_device *dev,
struct drm_file *file_priv, int prime_fd, uint32_t *handle)
{
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index fad21c9..f65cae9 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -674,6 +674,10 @@ struct drm_gem_object {
/* dma buf attachment backing this object */
struct dma_buf_attachment *import_attach;
+
+ /* vmap information */
+ int vmapping_count;
+ void *vmapping_ptr;
};
#include <drm/drm_crtc.h>
@@ -919,6 +923,13 @@ struct drm_driver {
/* import dmabuf -> GEM */
struct drm_gem_object * (*gem_prime_import)(struct drm_device *dev,
struct dma_buf *dma_buf);
+ /* low-level interface used by drm_gem_prime_{import,export} */
+ int (*gem_prime_pin)(struct drm_gem_object *obj);
+ struct sg_table *(*gem_prime_get_pages)(struct drm_gem_object *obj);
+ struct drm_gem_object *(*gem_prime_import_sg)(struct drm_device *dev,
+ size_t size, struct sg_table *sg);
+ void *(*gem_prime_vmap)(struct drm_gem_object *obj);
+ void (*gem_prime_vunmap)(struct drm_gem_object *obj);
/* vga arb irq handler */
void (*vgaarb_irq)(struct drm_device *dev, bool state);
@@ -1540,9 +1551,13 @@ extern int drm_clients_info(struct seq_file *m, void* data);
extern int drm_gem_name_info(struct seq_file *m, void *data);
+extern struct dma_buf *drm_gem_prime_export(struct drm_device *dev,
+ struct drm_gem_object *obj, int flags);
extern int drm_gem_prime_handle_to_fd(struct drm_device *dev,
struct drm_file *file_priv, uint32_t handle, uint32_t flags,
int *prime_fd);
+extern struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
+ struct dma_buf *dma_buf);
extern int drm_gem_prime_fd_to_handle(struct drm_device *dev,
struct drm_file *file_priv, int prime_fd, uint32_t *handle);
--
1.8.0.1
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