drm/exynos: added drm prime feature.

this patch adds exynos specific codes for DRM Prime feature.
with this patch, user application can get file descriptor
from gem handle through DRM_IOCTL_PRIME_HANDLE_TO_FD ioctl
command(export) and also gem handle from file descriptor
through DRM_IOCTL_PRIME_FD_TO_HANLDE(import) ioctl command.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

8 files changed, 353 insertions, 9 deletions

diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig
index 3343ac437fe5..135b61801e83 100644
--- a/drivers/gpu/drm/exynos/Kconfig
+++ b/drivers/gpu/drm/exynos/Kconfig
@@ -10,6 +10,12 @@ config DRM_EXYNOS
           Choose this option if you have a Samsung SoC EXYNOS chipset.
           If M is selected the module will be called exynosdrm.
 
+config DRM_EXYNOS_DMABUF
+        bool "EXYNOS DRM DMABUF"
+        depends on DRM_EXYNOS
+        help
+          Choose this option if you want to use DMABUF feature for DRM.
+
 config DRM_EXYNOS_FIMD
         bool "Exynos DRM FIMD"
         depends on DRM_EXYNOS && !FB_S3C
diff --git a/drivers/gpu/drm/exynos/Makefile b/drivers/gpu/drm/exynos/Makefile
index 9e0bff8badf9..353e1b7c2e3c 100644
--- a/drivers/gpu/drm/exynos/Makefile
+++ b/drivers/gpu/drm/exynos/Makefile
@@ -8,6 +8,7 @@ exynosdrm-y := exynos_drm_drv.o exynos_drm_encoder.o exynos_drm_connector.o \
                 exynos_drm_buf.o exynos_drm_gem.o exynos_drm_core.o \
                 exynos_drm_plane.o
 
+exynosdrm-$(CONFIG_DRM_EXYNOS_DMABUF) += exynos_drm_dmabuf.o
 exynosdrm-$(CONFIG_DRM_EXYNOS_FIMD)     += exynos_drm_fimd.o
 exynosdrm-$(CONFIG_DRM_EXYNOS_HDMI)     += exynos_hdmi.o exynos_mixer.o \
                                            exynos_ddc.o exynos_hdmiphy.o \
diff --git a/drivers/gpu/drm/exynos/exynos_drm_buf.c b/drivers/gpu/drm/exynos/exynos_drm_buf.c
index de8d2090bce3..b3cb0a69fbf2 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_buf.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_buf.c
@@ -35,7 +35,7 @@ static int lowlevel_buffer_allocate(struct drm_device *dev,
                 unsigned int flags, struct exynos_drm_gem_buf *buf)
 {
         dma_addr_t start_addr;
-        unsigned int npages, page_size, i = 0;
+        unsigned int npages, i = 0;
         struct scatterlist *sgl;
         int ret = 0;
 
@@ -53,13 +53,13 @@ static int lowlevel_buffer_allocate(struct drm_device *dev,
 
         if (buf->size >= SZ_1M) {
                 npages = buf->size >> SECTION_SHIFT;
-                page_size = SECTION_SIZE;
+                buf->page_size = SECTION_SIZE;
         } else if (buf->size >= SZ_64K) {
                 npages = buf->size >> 16;
-                page_size = SZ_64K;
+                buf->page_size = SZ_64K;
         } else {
                 npages = buf->size >> PAGE_SHIFT;
-                page_size = PAGE_SIZE;
+                buf->page_size = PAGE_SIZE;
         }
 
         buf->sgt = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
@@ -96,9 +96,9 @@ static int lowlevel_buffer_allocate(struct drm_device *dev,
 
         while (i < npages) {
                 buf->pages[i] = phys_to_page(start_addr);
-                sg_set_page(sgl, buf->pages[i], page_size, 0);
+                sg_set_page(sgl, buf->pages[i], buf->page_size, 0);
                 sg_dma_address(sgl) = start_addr;
-                start_addr += page_size;
+                start_addr += buf->page_size;
                 sgl = sg_next(sgl);
                 i++;
         }
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
new file mode 100644
index 000000000000..274909271c36
--- /dev/null
+++ b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
@@ -0,0 +1,272 @@
+/* exynos_drm_dmabuf.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ * Author: Inki Dae <inki.dae@samsung.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include "drmP.h"
+#include "drm.h"
+#include "exynos_drm_drv.h"
+#include "exynos_drm_gem.h"
+
+#include <linux/dma-buf.h>
+
+static struct sg_table *exynos_pages_to_sg(struct page **pages, int nr_pages,
+                unsigned int page_size)
+{
+        struct sg_table *sgt = NULL;
+        struct scatterlist *sgl;
+        int i, ret;
+
+        sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+        if (!sgt)
+                goto out;
+
+        ret = sg_alloc_table(sgt, nr_pages, GFP_KERNEL);
+        if (ret)
+                goto err_free_sgt;
+
+        if (page_size < PAGE_SIZE)
+                page_size = PAGE_SIZE;
+
+        for_each_sg(sgt->sgl, sgl, nr_pages, i)
+                sg_set_page(sgl, pages[i], page_size, 0);
+
+        return sgt;
+
+err_free_sgt:
+        kfree(sgt);
+        sgt = NULL;
+out:
+        return NULL;
+}
+
+static struct sg_table *
+                exynos_gem_map_dma_buf(struct dma_buf_attachment *attach,
+                                        enum dma_data_direction dir)
+{
+        struct exynos_drm_gem_obj *gem_obj = attach->dmabuf->priv;
+        struct drm_device *dev = gem_obj->base.dev;
+        struct exynos_drm_gem_buf *buf;
+        struct sg_table *sgt = NULL;
+        unsigned int npages;
+        int nents;
+
+        DRM_DEBUG_PRIME("%s\n", __FILE__);
+
+        mutex_lock(&dev->struct_mutex);
+
+        buf = gem_obj->buffer;
+
+        /* there should always be pages allocated. */
+        if (!buf->pages) {
+                DRM_ERROR("pages is null.\n");
+                goto err_unlock;
+        }
+
+        npages = buf->size / buf->page_size;
+
+        sgt = exynos_pages_to_sg(buf->pages, npages, buf->page_size);
+        nents = dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir);
+
+        DRM_DEBUG_PRIME("npages = %d buffer size = 0x%lx page_size = 0x%lx\n",
+                        npages, buf->size, buf->page_size);
+
+err_unlock:
+        mutex_unlock(&dev->struct_mutex);
+        return sgt;
+}
+
+static void exynos_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
+                                                struct sg_table *sgt,
+                                                enum dma_data_direction dir)
+{
+        dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
+        sg_free_table(sgt);
+        kfree(sgt);
+        sgt = NULL;
+}
+
+static void exynos_dmabuf_release(struct dma_buf *dmabuf)
+{
+        struct exynos_drm_gem_obj *exynos_gem_obj = dmabuf->priv;
+
+        DRM_DEBUG_PRIME("%s\n", __FILE__);
+
+        /*
+         * exynos_dmabuf_release() call means that file object's
+         * f_count is 0 and it calls drm_gem_object_handle_unreference()
+         * to drop the references that these values had been increased
+         * at drm_prime_handle_to_fd()
+         */
+        if (exynos_gem_obj->base.export_dma_buf == dmabuf) {
+                exynos_gem_obj->base.export_dma_buf = NULL;
+
+                /*
+                 * drop this gem object refcount to release allocated buffer
+                 * and resources.
+                 */
+                drm_gem_object_unreference_unlocked(&exynos_gem_obj->base);
+        }
+}
+
+static void *exynos_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
+                                                unsigned long page_num)
+{
+        /* TODO */
+
+        return NULL;
+}
+
+static void exynos_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
+                                                unsigned long page_num,
+                                                void *addr)
+{
+        /* TODO */
+}
+
+static void *exynos_gem_dmabuf_kmap(struct dma_buf *dma_buf,
+                                        unsigned long page_num)
+{
+        /* TODO */
+
+        return NULL;
+}
+
+static void exynos_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
+                                        unsigned long page_num, void *addr)
+{
+        /* TODO */
+}
+
+static struct dma_buf_ops exynos_dmabuf_ops = {
+        .map_dma_buf            = exynos_gem_map_dma_buf,
+        .unmap_dma_buf          = exynos_gem_unmap_dma_buf,
+        .kmap                   = exynos_gem_dmabuf_kmap,
+        .kmap_atomic            = exynos_gem_dmabuf_kmap_atomic,
+        .kunmap                 = exynos_gem_dmabuf_kunmap,
+        .kunmap_atomic          = exynos_gem_dmabuf_kunmap_atomic,
+        .release                = exynos_dmabuf_release,
+};
+
+struct dma_buf *exynos_dmabuf_prime_export(struct drm_device *drm_dev,
+                                struct drm_gem_object *obj, int flags)
+{
+        struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
+
+        return dma_buf_export(exynos_gem_obj, &exynos_dmabuf_ops,
+                                exynos_gem_obj->base.size, 0600);
+}
+
+struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
+                                struct dma_buf *dma_buf)
+{
+        struct dma_buf_attachment *attach;
+        struct sg_table *sgt;
+        struct scatterlist *sgl;
+        struct exynos_drm_gem_obj *exynos_gem_obj;
+        struct exynos_drm_gem_buf *buffer;
+        struct page *page;
+        int ret, i = 0;
+
+        DRM_DEBUG_PRIME("%s\n", __FILE__);
+
+        /* is this one of own objects? */
+        if (dma_buf->ops == &exynos_dmabuf_ops) {
+                struct drm_gem_object *obj;
+
+                exynos_gem_obj = dma_buf->priv;
+                obj = &exynos_gem_obj->base;
+
+                /* is it from our device? */
+                if (obj->dev == drm_dev) {
+                        drm_gem_object_reference(obj);
+                        return obj;
+                }
+        }
+
+        attach = dma_buf_attach(dma_buf, drm_dev->dev);
+        if (IS_ERR(attach))
+                return ERR_PTR(-EINVAL);
+
+
+        sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
+        if (IS_ERR(sgt)) {
+                ret = PTR_ERR(sgt);
+                goto err_buf_detach;
+        }
+
+        buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
+        if (!buffer) {
+                DRM_ERROR("failed to allocate exynos_drm_gem_buf.\n");
+                ret = -ENOMEM;
+                goto err_unmap_attach;
+        }
+
+        buffer->pages = kzalloc(sizeof(*page) * sgt->nents, GFP_KERNEL);
+        if (!buffer->pages) {
+                DRM_ERROR("failed to allocate pages.\n");
+                ret = -ENOMEM;
+                goto err_free_buffer;
+        }
+
+        exynos_gem_obj = exynos_drm_gem_init(drm_dev, dma_buf->size);
+        if (!exynos_gem_obj) {
+                ret = -ENOMEM;
+                goto err_free_pages;
+        }
+
+        sgl = sgt->sgl;
+        buffer->dma_addr = sg_dma_address(sgl);
+
+        while (i < sgt->nents) {
+                buffer->pages[i] = sg_page(sgl);
+                buffer->size += sg_dma_len(sgl);
+                sgl = sg_next(sgl);
+                i++;
+        }
+
+        exynos_gem_obj->buffer = buffer;
+        buffer->sgt = sgt;
+        exynos_gem_obj->base.import_attach = attach;
+
+        DRM_DEBUG_PRIME("dma_addr = 0x%x, size = 0x%lx\n", buffer->dma_addr,
+                                                                buffer->size);
+
+        return &exynos_gem_obj->base;
+
+err_free_pages:
+        kfree(buffer->pages);
+        buffer->pages = NULL;
+err_free_buffer:
+        kfree(buffer);
+        buffer = NULL;
+err_unmap_attach:
+        dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
+err_buf_detach:
+        dma_buf_detach(dma_buf, attach);
+        return ERR_PTR(ret);
+}
+
+MODULE_AUTHOR("Inki Dae <inki.dae@samsung.com>");
+MODULE_DESCRIPTION("Samsung SoC DRM DMABUF Module");
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.h b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.h
new file mode 100644
index 000000000000..662a8f98ccdb
--- /dev/null
+++ b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.h
@@ -0,0 +1,39 @@
+/* exynos_drm_dmabuf.h
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ * Author: Inki Dae <inki.dae@samsung.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef _EXYNOS_DRM_DMABUF_H_
+#define _EXYNOS_DRM_DMABUF_H_
+
+#ifdef CONFIG_DRM_EXYNOS_DMABUF
+struct dma_buf *exynos_dmabuf_prime_export(struct drm_device *drm_dev,
+                                struct drm_gem_object *obj, int flags);
+
+struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
+                                                struct dma_buf *dma_buf);
+#else
+#define exynos_dmabuf_prime_export              NULL
+#define exynos_dmabuf_prime_import              NULL
+#endif
+#endif
diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
index a6819b5f8428..f58a487e4425 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
@@ -39,6 +39,7 @@
 #include "exynos_drm_gem.h"
 #include "exynos_drm_plane.h"
 #include "exynos_drm_vidi.h"
+#include "exynos_drm_dmabuf.h"
 
 #define DRIVER_NAME     "exynos"
 #define DRIVER_DESC     "Samsung SoC DRM"
@@ -149,6 +150,8 @@ static int exynos_drm_open(struct drm_device *dev, struct drm_file *file)
 {
         DRM_DEBUG_DRIVER("%s\n", __FILE__);
 
+        drm_prime_init_file_private(&file->prime);
+
         return exynos_drm_subdrv_open(dev, file);
 }
 
@@ -170,6 +173,7 @@ static void exynos_drm_preclose(struct drm_device *dev,
                         e->base.destroy(&e->base);
                 }
         }
+        drm_prime_destroy_file_private(&file->prime);
         spin_unlock_irqrestore(&dev->event_lock, flags);
 
         exynos_drm_subdrv_close(dev, file);
@@ -225,7 +229,7 @@ static const struct file_operations exynos_drm_driver_fops = {
 
 static struct drm_driver exynos_drm_driver = {
         .driver_features        = DRIVER_HAVE_IRQ | DRIVER_BUS_PLATFORM |
-                                  DRIVER_MODESET | DRIVER_GEM,
+                                  DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME,
         .load                   = exynos_drm_load,
         .unload                 = exynos_drm_unload,
         .open                   = exynos_drm_open,
@@ -241,6 +245,10 @@ static struct drm_driver exynos_drm_driver = {
         .dumb_create            = exynos_drm_gem_dumb_create,
         .dumb_map_offset        = exynos_drm_gem_dumb_map_offset,
         .dumb_destroy           = exynos_drm_gem_dumb_destroy,
+        .prime_handle_to_fd     = drm_gem_prime_handle_to_fd,
+        .prime_fd_to_handle     = drm_gem_prime_fd_to_handle,
+        .gem_prime_export       = exynos_dmabuf_prime_export,
+        .gem_prime_import       = exynos_dmabuf_prime_import,
         .ioctls                 = exynos_ioctls,
         .fops                   = &exynos_drm_driver_fops,
         .name   = DRIVER_NAME,
diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index e8ab3beb4510..31bb85f5d274 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -96,7 +96,7 @@ out:
         return roundup(size, PAGE_SIZE);
 }
 
-static struct page **exynos_gem_get_pages(struct drm_gem_object *obj,
+struct page **exynos_gem_get_pages(struct drm_gem_object *obj,
                                                 gfp_t gfpmask)
 {
         struct inode *inode;
@@ -196,6 +196,7 @@ static int exynos_drm_gem_get_pages(struct drm_gem_object *obj)
         }
 
         npages = obj->size >> PAGE_SHIFT;
+        buf->page_size = PAGE_SIZE;
 
         buf->sgt = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
         if (!buf->sgt) {
@@ -308,7 +309,7 @@ void exynos_drm_gem_destroy(struct exynos_drm_gem_obj *exynos_gem_obj)
         exynos_gem_obj = NULL;
 }
 
-static struct exynos_drm_gem_obj *exynos_drm_gem_init(struct drm_device *dev,
+struct exynos_drm_gem_obj *exynos_drm_gem_init(struct drm_device *dev,
                                                       unsigned long size)
 {
         struct exynos_drm_gem_obj *exynos_gem_obj;
@@ -612,8 +613,17 @@ int exynos_drm_gem_init_object(struct drm_gem_object *obj)
 
 void exynos_drm_gem_free_object(struct drm_gem_object *obj)
 {
+        struct exynos_drm_gem_obj *exynos_gem_obj;
+        struct exynos_drm_gem_buf *buf;
+
         DRM_DEBUG_KMS("%s\n", __FILE__);
 
+        exynos_gem_obj = to_exynos_gem_obj(obj);
+        buf = exynos_gem_obj->buffer;
+
+        if (obj->import_attach)
+                drm_prime_gem_destroy(obj, buf->sgt);
+
         exynos_drm_gem_destroy(to_exynos_gem_obj(obj));
 }
 
diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.h b/drivers/gpu/drm/exynos/exynos_drm_gem.h
index 4ed842039505..efc82527b272 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.h
@@ -40,6 +40,7 @@
  *      device address with IOMMU.
  * @sgt: sg table to transfer page data.
  * @pages: contain all pages to allocated memory region.
+ * @page_size: could be 4K, 64K or 1MB.
  * @size: size of allocated memory region.
  */
 struct exynos_drm_gem_buf {
@@ -47,6 +48,7 @@ struct exynos_drm_gem_buf {
         dma_addr_t              dma_addr;
         struct sg_table         *sgt;
         struct page             **pages;
+        unsigned long           page_size;
         unsigned long           size;
 };
 
@@ -74,9 +76,15 @@ struct exynos_drm_gem_obj {
         unsigned int                    flags;
 };
 
+struct page **exynos_gem_get_pages(struct drm_gem_object *obj, gfp_t gfpmask);
+
 /* destroy a buffer with gem object */
 void exynos_drm_gem_destroy(struct exynos_drm_gem_obj *exynos_gem_obj);
 
+/* create a private gem object and initialize it. */
+struct exynos_drm_gem_obj *exynos_drm_gem_init(struct drm_device *dev,
+                                                      unsigned long size);
+
 /* create a new buffer with gem object */
 struct exynos_drm_gem_obj *exynos_drm_gem_create(struct drm_device *dev,
                                                 unsigned int flags,