[RFC v2 7/8] gpu: drm: tegra: Prime support
Terje Bergstrom
tbergstrom at nvidia.com
Mon Nov 26 05:19:13 PST 2012
From: Arto Merilainen <amerilainen at nvidia.com>
This patch introduces support for exporting allocated memory as
dmabuf objects. Exported buffers are used for delivering data to
nvhost driver.
Signed-off-by: Arto Merilainen <amerilainen at nvidia.com>
Signed-off-by: Terje Bergstrom <tbergstrom at nvidia.com>
---
drivers/gpu/drm/tegra/Makefile | 2 +-
drivers/gpu/drm/tegra/dmabuf.c | 150 ++++++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/tegra/drm.c | 9 ++-
drivers/gpu/drm/tegra/drm.h | 6 ++
4 files changed, 165 insertions(+), 2 deletions(-)
create mode 100644 drivers/gpu/drm/tegra/dmabuf.c
diff --git a/drivers/gpu/drm/tegra/Makefile b/drivers/gpu/drm/tegra/Makefile
index 57a334d..53ea383 100644
--- a/drivers/gpu/drm/tegra/Makefile
+++ b/drivers/gpu/drm/tegra/Makefile
@@ -3,6 +3,6 @@ ccflags-$(CONFIG_DRM_TEGRA_DEBUG) += -DDEBUG
tegra-drm-y := drm.o fb.o dc.o
tegra-drm-y += output.o rgb.o hdmi.o tvo.o dsi.o
-tegra-drm-y += plane.o
+tegra-drm-y += plane.o dmabuf.o
obj-$(CONFIG_DRM_TEGRA) += tegra-drm.o
diff --git a/drivers/gpu/drm/tegra/dmabuf.c b/drivers/gpu/drm/tegra/dmabuf.c
new file mode 100644
index 0000000..e81db12
--- /dev/null
+++ b/drivers/gpu/drm/tegra/dmabuf.c
@@ -0,0 +1,150 @@
+/*
+ * drivers/gpu/drm/tegra/dmabuf.c
+ *
+ * dmabuf exporter for cma allocations
+ *
+ * Copyright (c) 2012, NVIDIA Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm.h>
+#include <drm/drm_gem_cma_helper.h>
+
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/scatterlist.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/dma-buf.h>
+
+#include <asm/page.h>
+#include <asm/dma-iommu.h>
+
+static struct sg_table *tegra_dmabuf_map(struct dma_buf_attachment *attach,
+ enum dma_data_direction dir)
+{
+ struct drm_gem_cma_object *obj = attach->dmabuf->priv;
+ struct page **pages;
+ int npages = obj->base.size / PAGE_SIZE;
+ struct sg_table *sgt;
+ struct scatterlist *sg;
+ int i, page_num = 0;
+
+ /* create a list of used pages */
+ pages = kzalloc(sizeof(*pages) * npages, GFP_KERNEL);
+ if (!pages)
+ goto err_alloc_pages;
+ for (i = 0; i < npages; i++)
+ pages[i] = virt_to_page(obj->vaddr + i * PAGE_SIZE);
+
+ /* generate sgt using the page list */
+ sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+ if (!sgt)
+ goto err_alloc_sgt;
+ if (sg_alloc_table_from_pages(sgt, pages, npages, 0, obj->base.size,
+ GFP_KERNEL))
+ goto err_generate_sgt;
+ for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+ sg->dma_address = page_to_phys(pages[page_num]);
+ page_num += sg->length >> PAGE_SHIFT;
+ }
+
+ /* only the sgt is interesting */
+ kfree(pages);
+
+ return sgt;
+
+err_generate_sgt:
+ kfree(sgt);
+err_alloc_sgt:
+ kfree(pages);
+err_alloc_pages:
+ return NULL;
+}
+
+static void tegra_dmabuf_unmap(struct dma_buf_attachment *attach,
+ struct sg_table *sgt,
+ enum dma_data_direction dir)
+{
+ sg_free_table(sgt);
+ kfree(sgt);
+}
+
+static void tegra_dmabuf_release(struct dma_buf *dmabuf)
+{
+ struct drm_gem_cma_object *obj = dmabuf->priv;
+
+ if (obj->base.export_dma_buf == dmabuf) {
+ obj->base.export_dma_buf = NULL;
+ drm_gem_object_unreference_unlocked(&obj->base);
+ }
+}
+
+static void *tegra_dmabuf_kmap_atomic(struct dma_buf *dmabuf,
+ unsigned long page_num)
+{
+ struct drm_gem_cma_object *obj = dmabuf->priv;
+ return obj->vaddr + PAGE_SIZE * page_num;
+}
+
+static void *tegra_dmabuf_kmap(struct dma_buf *dmabuf, unsigned long page_num)
+{
+ return tegra_dmabuf_kmap_atomic(dmabuf, page_num);
+}
+
+static int tegra_dmabuf_mmap(struct dma_buf *dmabuf,
+ struct vm_area_struct *vma)
+{
+ struct drm_gem_cma_object *obj = dmabuf->priv;
+ DEFINE_DMA_ATTRS(attrs);
+
+ vma->vm_private_data = obj;
+
+ return dma_mmap_attrs(obj->base.dev->dev->parent, vma, obj->vaddr,
+ obj->paddr, obj->base.size, &attrs);
+}
+
+static void *tegra_dmabuf_vmap(struct dma_buf *dmabuf)
+{
+ struct drm_gem_cma_object *obj = dmabuf->priv;
+ return obj->vaddr;
+}
+
+static struct dma_buf_ops tegra_dmabuf_ops = {
+ .map_dma_buf = tegra_dmabuf_map,
+ .unmap_dma_buf = tegra_dmabuf_unmap,
+ .release = tegra_dmabuf_release,
+ .kmap_atomic = tegra_dmabuf_kmap_atomic,
+ .kmap = tegra_dmabuf_kmap,
+ .mmap = tegra_dmabuf_mmap,
+ .vmap = tegra_dmabuf_vmap,
+};
+
+struct dma_buf *tegra_dmabuf_export(struct drm_device *drm_dev,
+ struct drm_gem_object *obj, int flags)
+{
+ return dma_buf_export(obj, &tegra_dmabuf_ops, obj->size, O_RDWR);
+}
+
+struct drm_gem_object *tegra_dmabuf_import(struct drm_device *drm_dev,
+ struct dma_buf *dmabuf)
+{
+ return NULL;
+}
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index cba2d1d..f78a31b 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -251,7 +251,8 @@ static const struct file_operations tegra_drm_fops = {
};
struct drm_driver tegra_drm_driver = {
- .driver_features = DRIVER_BUS_PLATFORM | DRIVER_MODESET | DRIVER_GEM,
+ .driver_features = DRIVER_BUS_PLATFORM | DRIVER_MODESET | DRIVER_GEM |
+ DRIVER_PRIME,
.load = tegra_drm_load,
.unload = tegra_drm_unload,
.open = tegra_drm_open,
@@ -267,6 +268,12 @@ struct drm_driver tegra_drm_driver = {
.num_ioctls = ARRAY_SIZE(tegra_drm_ioctls),
.fops = &tegra_drm_fops,
+ .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
+ .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
+
+ .gem_prime_export = tegra_dmabuf_export,
+ .gem_prime_import = tegra_dmabuf_import,
+
.name = DRIVER_NAME,
.desc = DRIVER_DESC,
.date = DRIVER_DATE,
diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
index b2f9f10..1267a38 100644
--- a/drivers/gpu/drm/tegra/drm.h
+++ b/drivers/gpu/drm/tegra/drm.h
@@ -227,4 +227,10 @@ extern struct platform_driver tegra_dsi_driver;
extern struct platform_driver tegra_dc_driver;
extern struct drm_driver tegra_drm_driver;
+/* from dmabuf.c */
+struct dma_buf *tegra_dmabuf_export(struct drm_device *drm_dev,
+ struct drm_gem_object *obj, int flags);
+struct drm_gem_object *tegra_dmabuf_import(struct drm_device *drm_dev,
+ struct dma_buf *dmabuf);
+
#endif /* TEGRA_DRM_H */
--
1.7.9.5
More information about the dri-devel
mailing list