drm/tegra: Add PRIME support
Implement very basic PRIME support. This currently only works with
buffers that are contiguous in memory and will refuse to import any
physically non-contiguous buffers.
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index eec8d2e..88a5290 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -580,7 +580,7 @@
#endif
static struct drm_driver tegra_drm_driver = {
- .driver_features = DRIVER_MODESET | DRIVER_GEM,
+ .driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME,
.load = tegra_drm_load,
.unload = tegra_drm_unload,
.open = tegra_drm_open,
@@ -598,6 +598,12 @@
.gem_free_object = tegra_bo_free_object,
.gem_vm_ops = &tegra_bo_vm_ops,
+
+ .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
+ .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
+ .gem_prime_export = tegra_gem_prime_export,
+ .gem_prime_import = tegra_gem_prime_import,
+
.dumb_create = tegra_bo_dumb_create,
.dumb_map_offset = tegra_bo_dumb_map_offset,
.dumb_destroy = drm_gem_dumb_destroy,
diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index 7741e33..ef853e5 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -18,6 +18,7 @@
* GNU General Public License for more details.
*/
+#include <linux/dma-buf.h>
#include <drm/tegra_drm.h>
#include "gem.h"
@@ -173,13 +174,87 @@
return ERR_PTR(ret);
}
+struct tegra_bo *tegra_bo_import(struct drm_device *drm, struct dma_buf *buf)
+{
+ struct dma_buf_attachment *attach;
+ struct tegra_bo *bo;
+ ssize_t size;
+ int err;
+
+ bo = kzalloc(sizeof(*bo), GFP_KERNEL);
+ if (!bo)
+ return ERR_PTR(-ENOMEM);
+
+ host1x_bo_init(&bo->base, &tegra_bo_ops);
+ size = round_up(buf->size, PAGE_SIZE);
+
+ err = drm_gem_object_init(drm, &bo->gem, size);
+ if (err < 0)
+ goto free;
+
+ err = drm_gem_create_mmap_offset(&bo->gem);
+ if (err < 0)
+ goto release;
+
+ attach = dma_buf_attach(buf, drm->dev);
+ if (IS_ERR(attach)) {
+ err = PTR_ERR(attach);
+ goto free_mmap;
+ }
+
+ get_dma_buf(buf);
+
+ bo->sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
+ if (!bo->sgt) {
+ err = -ENOMEM;
+ goto detach;
+ }
+
+ if (IS_ERR(bo->sgt)) {
+ err = PTR_ERR(bo->sgt);
+ goto detach;
+ }
+
+ if (bo->sgt->nents > 1) {
+ err = -EINVAL;
+ goto detach;
+ }
+
+ bo->paddr = sg_dma_address(bo->sgt->sgl);
+ bo->gem.import_attach = attach;
+
+ return bo;
+
+detach:
+ if (!IS_ERR_OR_NULL(bo->sgt))
+ dma_buf_unmap_attachment(attach, bo->sgt, DMA_TO_DEVICE);
+
+ dma_buf_detach(buf, attach);
+ dma_buf_put(buf);
+free_mmap:
+ drm_gem_free_mmap_offset(&bo->gem);
+release:
+ drm_gem_object_release(&bo->gem);
+free:
+ kfree(bo);
+
+ return ERR_PTR(err);
+}
+
void tegra_bo_free_object(struct drm_gem_object *gem)
{
struct tegra_bo *bo = to_tegra_bo(gem);
+ if (gem->import_attach) {
+ dma_buf_unmap_attachment(gem->import_attach, bo->sgt,
+ DMA_TO_DEVICE);
+ drm_prime_gem_destroy(gem, NULL);
+ } else {
+ tegra_bo_destroy(gem->dev, bo);
+ }
+
drm_gem_free_mmap_offset(gem);
drm_gem_object_release(gem);
- tegra_bo_destroy(gem->dev, bo);
kfree(bo);
}
@@ -255,3 +330,106 @@
return ret;
}
+
+static struct sg_table *
+tegra_gem_prime_map_dma_buf(struct dma_buf_attachment *attach,
+ enum dma_data_direction dir)
+{
+ struct drm_gem_object *gem = attach->dmabuf->priv;
+ struct tegra_bo *bo = to_tegra_bo(gem);
+ struct sg_table *sgt;
+
+ sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
+ if (!sgt)
+ return NULL;
+
+ if (sg_alloc_table(sgt, 1, GFP_KERNEL)) {
+ kfree(sgt);
+ return NULL;
+ }
+
+ sg_dma_address(sgt->sgl) = bo->paddr;
+ sg_dma_len(sgt->sgl) = gem->size;
+
+ return sgt;
+}
+
+static void tegra_gem_prime_unmap_dma_buf(struct dma_buf_attachment *attach,
+ struct sg_table *sgt,
+ enum dma_data_direction dir)
+{
+ sg_free_table(sgt);
+ kfree(sgt);
+}
+
+static void tegra_gem_prime_release(struct dma_buf *buf)
+{
+ drm_gem_dmabuf_release(buf);
+}
+
+static void *tegra_gem_prime_kmap_atomic(struct dma_buf *buf,
+ unsigned long page)
+{
+ return NULL;
+}
+
+static void tegra_gem_prime_kunmap_atomic(struct dma_buf *buf,
+ unsigned long page,
+ void *addr)
+{
+}
+
+static void *tegra_gem_prime_kmap(struct dma_buf *buf, unsigned long page)
+{
+ return NULL;
+}
+
+static void tegra_gem_prime_kunmap(struct dma_buf *buf, unsigned long page,
+ void *addr)
+{
+}
+
+static int tegra_gem_prime_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
+{
+ return -EINVAL;
+}
+
+static const struct dma_buf_ops tegra_gem_prime_dmabuf_ops = {
+ .map_dma_buf = tegra_gem_prime_map_dma_buf,
+ .unmap_dma_buf = tegra_gem_prime_unmap_dma_buf,
+ .release = tegra_gem_prime_release,
+ .kmap_atomic = tegra_gem_prime_kmap_atomic,
+ .kunmap_atomic = tegra_gem_prime_kunmap_atomic,
+ .kmap = tegra_gem_prime_kmap,
+ .kunmap = tegra_gem_prime_kunmap,
+ .mmap = tegra_gem_prime_mmap,
+};
+
+struct dma_buf *tegra_gem_prime_export(struct drm_device *drm,
+ struct drm_gem_object *gem,
+ int flags)
+{
+ return dma_buf_export(gem, &tegra_gem_prime_dmabuf_ops, gem->size,
+ flags);
+}
+
+struct drm_gem_object *tegra_gem_prime_import(struct drm_device *drm,
+ struct dma_buf *buf)
+{
+ struct tegra_bo *bo;
+
+ if (buf->ops == &tegra_gem_prime_dmabuf_ops) {
+ struct drm_gem_object *gem = buf->priv;
+
+ if (gem->dev == drm) {
+ drm_gem_object_reference(gem);
+ return gem;
+ }
+ }
+
+ bo = tegra_bo_import(drm, buf);
+ if (IS_ERR(bo))
+ return ERR_CAST(bo);
+
+ return &bo->gem;
+}
diff --git a/drivers/gpu/drm/tegra/gem.h b/drivers/gpu/drm/tegra/gem.h
index 007e0be..ffd4f792 100644
--- a/drivers/gpu/drm/tegra/gem.h
+++ b/drivers/gpu/drm/tegra/gem.h
@@ -31,6 +31,7 @@
struct drm_gem_object gem;
struct host1x_bo base;
unsigned long flags;
+ struct sg_table *sgt;
dma_addr_t paddr;
void *vaddr;
};
@@ -57,4 +58,10 @@
extern const struct vm_operations_struct tegra_bo_vm_ops;
+struct dma_buf *tegra_gem_prime_export(struct drm_device *drm,
+ struct drm_gem_object *gem,
+ int flags);
+struct drm_gem_object *tegra_gem_prime_import(struct drm_device *drm,
+ struct dma_buf *buf);
+
#endif
