drm/udl: add support to export a handle to a FD on UDL.

Only importing an FD to a handle is currently supported on UDL,
but the exporting functionality is equally useful.

Signed-off-by: Haixia Shi <hshi@chromium.org>
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

5 files changed, 278 insertions, 72 deletions

diff --git a/drivers/gpu/drm/udl/Makefile b/drivers/gpu/drm/udl/Makefile
index 05c7481bfd40..195bcac0b6c8 100644
--- a/drivers/gpu/drm/udl/Makefile
+++ b/drivers/gpu/drm/udl/Makefile
@@ -1,6 +1,6 @@
 
 ccflags-y := -Iinclude/drm
 
-udl-y := udl_drv.o udl_modeset.o udl_connector.o udl_encoder.o udl_main.o udl_fb.o udl_transfer.o udl_gem.o
+udl-y := udl_drv.o udl_modeset.o udl_connector.o udl_encoder.o udl_main.o udl_fb.o udl_transfer.o udl_gem.o udl_dmabuf.o
 
 obj-$(CONFIG_DRM_UDL) := udl.o
diff --git a/drivers/gpu/drm/udl/udl_dmabuf.c b/drivers/gpu/drm/udl/udl_dmabuf.c
new file mode 100644
index 000000000000..1d85c3a9151d
--- /dev/null
+++ b/drivers/gpu/drm/udl/udl_dmabuf.c
@@ -0,0 +1,273 @@
+/*
+ * udl_dmabuf.c
+ *
+ * Copyright (c) 2014 The Chromium OS Authors
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that 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 "udl_drv.h"
+#include <linux/shmem_fs.h>
+#include <linux/dma-buf.h>
+
+struct udl_drm_dmabuf_attachment {
+        struct sg_table sgt;
+        enum dma_data_direction dir;
+        bool is_mapped;
+};
+
+static int udl_attach_dma_buf(struct dma_buf *dmabuf,
+                              struct device *dev,
+                              struct dma_buf_attachment *attach)
+{
+        struct udl_drm_dmabuf_attachment *udl_attach;
+
+        DRM_DEBUG_PRIME("[DEV:%s] size:%zd\n", dev_name(attach->dev),
+                        attach->dmabuf->size);
+
+        udl_attach = kzalloc(sizeof(*udl_attach), GFP_KERNEL);
+        if (!udl_attach)
+                return -ENOMEM;
+
+        udl_attach->dir = DMA_NONE;
+        attach->priv = udl_attach;
+
+        return 0;
+}
+
+static void udl_detach_dma_buf(struct dma_buf *dmabuf,
+                               struct dma_buf_attachment *attach)
+{
+        struct udl_drm_dmabuf_attachment *udl_attach = attach->priv;
+        struct sg_table *sgt;
+
+        if (!udl_attach)
+                return;
+
+        DRM_DEBUG_PRIME("[DEV:%s] size:%zd\n", dev_name(attach->dev),
+                        attach->dmabuf->size);
+
+        sgt = &udl_attach->sgt;
+
+        if (udl_attach->dir != DMA_NONE)
+                dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
+                                udl_attach->dir);
+
+        sg_free_table(sgt);
+        kfree(udl_attach);
+        attach->priv = NULL;
+}
+
+static struct sg_table *udl_map_dma_buf(struct dma_buf_attachment *attach,
+                                        enum dma_data_direction dir)
+{
+        struct udl_drm_dmabuf_attachment *udl_attach = attach->priv;
+        struct udl_gem_object *obj = to_udl_bo(attach->dmabuf->priv);
+        struct drm_device *dev = obj->base.dev;
+        struct scatterlist *rd, *wr;
+        struct sg_table *sgt = NULL;
+        unsigned int i;
+        int page_count;
+        int nents, ret;
+
+        DRM_DEBUG_PRIME("[DEV:%s] size:%zd dir=%d\n", dev_name(attach->dev),
+                        attach->dmabuf->size, dir);
+
+        /* just return current sgt if already requested. */
+        if (udl_attach->dir == dir && udl_attach->is_mapped)
+                return &udl_attach->sgt;
+
+        if (!obj->pages) {
+                DRM_ERROR("pages is null.\n");
+                return ERR_PTR(-ENOMEM);
+        }
+
+        page_count = obj->base.size / PAGE_SIZE;
+        obj->sg = drm_prime_pages_to_sg(obj->pages, page_count);
+        if (!obj->sg) {
+                DRM_ERROR("sg is null.\n");
+                return ERR_PTR(-ENOMEM);
+        }
+
+        sgt = &udl_attach->sgt;
+
+        ret = sg_alloc_table(sgt, obj->sg->orig_nents, GFP_KERNEL);
+        if (ret) {
+                DRM_ERROR("failed to alloc sgt.\n");
+                return ERR_PTR(-ENOMEM);
+        }
+
+        mutex_lock(&dev->struct_mutex);
+
+        rd = obj->sg->sgl;
+        wr = sgt->sgl;
+        for (i = 0; i < sgt->orig_nents; ++i) {
+                sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
+                rd = sg_next(rd);
+                wr = sg_next(wr);
+        }
+
+        if (dir != DMA_NONE) {
+                nents = dma_map_sg(attach->dev, sgt->sgl, sgt->orig_nents, dir);
+                if (!nents) {
+                        DRM_ERROR("failed to map sgl with iommu.\n");
+                        sg_free_table(sgt);
+                        sgt = ERR_PTR(-EIO);
+                        goto err_unlock;
+                }
+        }
+
+        udl_attach->is_mapped = true;
+        udl_attach->dir = dir;
+        attach->priv = udl_attach;
+
+err_unlock:
+        mutex_unlock(&dev->struct_mutex);
+        return sgt;
+}
+
+static void udl_unmap_dma_buf(struct dma_buf_attachment *attach,
+                              struct sg_table *sgt,
+                              enum dma_data_direction dir)
+{
+        /* Nothing to do. */
+        DRM_DEBUG_PRIME("[DEV:%s] size:%zd dir:%d\n", dev_name(attach->dev),
+                        attach->dmabuf->size, dir);
+}
+
+static void *udl_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
+{
+        /* TODO */
+
+        return NULL;
+}
+
+static void *udl_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
+                                    unsigned long page_num)
+{
+        /* TODO */
+
+        return NULL;
+}
+
+static void udl_dmabuf_kunmap(struct dma_buf *dma_buf,
+                              unsigned long page_num, void *addr)
+{
+        /* TODO */
+}
+
+static void udl_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
+                                     unsigned long page_num,
+                                     void *addr)
+{
+        /* TODO */
+}
+
+static int udl_dmabuf_mmap(struct dma_buf *dma_buf,
+                           struct vm_area_struct *vma)
+{
+        /* TODO */
+
+        return -EINVAL;
+}
+
+static struct dma_buf_ops udl_dmabuf_ops = {
+        .attach                 = udl_attach_dma_buf,
+        .detach                 = udl_detach_dma_buf,
+        .map_dma_buf            = udl_map_dma_buf,
+        .unmap_dma_buf          = udl_unmap_dma_buf,
+        .kmap                   = udl_dmabuf_kmap,
+        .kmap_atomic            = udl_dmabuf_kmap_atomic,
+        .kunmap                 = udl_dmabuf_kunmap,
+        .kunmap_atomic          = udl_dmabuf_kunmap_atomic,
+        .mmap                   = udl_dmabuf_mmap,
+        .release                = drm_gem_dmabuf_release,
+};
+
+struct dma_buf *udl_gem_prime_export(struct drm_device *dev,
+                                     struct drm_gem_object *obj, int flags)
+{
+        return dma_buf_export(obj, &udl_dmabuf_ops, obj->size, flags, NULL);
+}
+
+static int udl_prime_create(struct drm_device *dev,
+                            size_t size,
+                            struct sg_table *sg,
+                            struct udl_gem_object **obj_p)
+{
+        struct udl_gem_object *obj;
+        int npages;
+
+        npages = size / PAGE_SIZE;
+
+        *obj_p = NULL;
+        obj = udl_gem_alloc_object(dev, npages * PAGE_SIZE);
+        if (!obj)
+                return -ENOMEM;
+
+        obj->sg = sg;
+        obj->pages = drm_malloc_ab(npages, sizeof(struct page *));
+        if (obj->pages == NULL) {
+                DRM_ERROR("obj pages is NULL %d\n", npages);
+                return -ENOMEM;
+        }
+
+        drm_prime_sg_to_page_addr_arrays(sg, obj->pages, NULL, npages);
+
+        *obj_p = obj;
+        return 0;
+}
+
+struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev,
+                                struct dma_buf *dma_buf)
+{
+        struct dma_buf_attachment *attach;
+        struct sg_table *sg;
+        struct udl_gem_object *uobj;
+        int ret;
+
+        /* need to attach */
+        get_device(dev->dev);
+        attach = dma_buf_attach(dma_buf, dev->dev);
+        if (IS_ERR(attach)) {
+                put_device(dev->dev);
+                return ERR_CAST(attach);
+        }
+
+        get_dma_buf(dma_buf);
+
+        sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
+        if (IS_ERR(sg)) {
+                ret = PTR_ERR(sg);
+                goto fail_detach;
+        }
+
+        ret = udl_prime_create(dev, dma_buf->size, sg, &uobj);
+        if (ret)
+                goto fail_unmap;
+
+        uobj->base.import_attach = attach;
+        uobj->flags = UDL_BO_WC;
+
+        return &uobj->base;
+
+fail_unmap:
+        dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
+fail_detach:
+        dma_buf_detach(dma_buf, attach);
+        dma_buf_put(dma_buf);
+        put_device(dev->dev);
+        return ERR_PTR(ret);
+}
diff --git a/drivers/gpu/drm/udl/udl_drv.c b/drivers/gpu/drm/udl/udl_drv.c
index 8607e9e513db..d5728ec85254 100644
--- a/drivers/gpu/drm/udl/udl_drv.c
+++ b/drivers/gpu/drm/udl/udl_drv.c
@@ -51,7 +51,9 @@ static struct drm_driver driver = {
         .dumb_destroy = drm_gem_dumb_destroy,
         .fops = &udl_driver_fops,
 
+        .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
         .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
+        .gem_prime_export = udl_gem_prime_export,
         .gem_prime_import = udl_gem_prime_import,
 
         .name = DRIVER_NAME,
diff --git a/drivers/gpu/drm/udl/udl_drv.h b/drivers/gpu/drm/udl/udl_drv.h
index 308278086c72..1b132d779621 100644
--- a/drivers/gpu/drm/udl/udl_drv.h
+++ b/drivers/gpu/drm/udl/udl_drv.h
@@ -124,6 +124,8 @@ int udl_gem_mmap(struct drm_file *file_priv, struct drm_device *dev,
 void udl_gem_free_object(struct drm_gem_object *gem_obj);
 struct udl_gem_object *udl_gem_alloc_object(struct drm_device *dev,
                                             size_t size);
+struct dma_buf *udl_gem_prime_export(struct drm_device *dev,
+                                     struct drm_gem_object *obj, int flags);
 struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev,
                                 struct dma_buf *dma_buf);
 
diff --git a/drivers/gpu/drm/udl/udl_gem.c b/drivers/gpu/drm/udl/udl_gem.c
index e00459d38dcb..692d6f21f1bc 100644
--- a/drivers/gpu/drm/udl/udl_gem.c
+++ b/drivers/gpu/drm/udl/udl_gem.c
@@ -240,74 +240,3 @@ unlock:
         mutex_unlock(&dev->struct_mutex);
         return ret;
 }
-
-static int udl_prime_create(struct drm_device *dev,
-                            size_t size,
-                            struct sg_table *sg,
-                            struct udl_gem_object **obj_p)
-{
-        struct udl_gem_object *obj;
-        int npages;
-
-        npages = size / PAGE_SIZE;
-
-        *obj_p = NULL;
-        obj = udl_gem_alloc_object(dev, npages * PAGE_SIZE);
-        if (!obj)
-                return -ENOMEM;
-
-        obj->sg = sg;
-        obj->pages = drm_malloc_ab(npages, sizeof(struct page *));
-        if (obj->pages == NULL) {
-                DRM_ERROR("obj pages is NULL %d\n", npages);
-                return -ENOMEM;
-        }
-
-        drm_prime_sg_to_page_addr_arrays(sg, obj->pages, NULL, npages);
-
-        *obj_p = obj;
-        return 0;
-}
-
-struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev,
-                                struct dma_buf *dma_buf)
-{
-        struct dma_buf_attachment *attach;
-        struct sg_table *sg;
-        struct udl_gem_object *uobj;
-        int ret;
-
-        /* need to attach */
-        get_device(dev->dev);
-        attach = dma_buf_attach(dma_buf, dev->dev);
-        if (IS_ERR(attach)) {
-                put_device(dev->dev);
-                return ERR_CAST(attach);
-        }
-
-        get_dma_buf(dma_buf);
-
-        sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
-        if (IS_ERR(sg)) {
-                ret = PTR_ERR(sg);
-                goto fail_detach;
-        }
-
-        ret = udl_prime_create(dev, dma_buf->size, sg, &uobj);
-        if (ret) {
-                goto fail_unmap;
-        }
-
-        uobj->base.import_attach = attach;
-        uobj->flags = UDL_BO_WC;
-
-        return &uobj->base;
-
-fail_unmap:
-        dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
-fail_detach:
-        dma_buf_detach(dma_buf, attach);
-        dma_buf_put(dma_buf);
-        put_device(dev->dev);
-        return ERR_PTR(ret);
-}