drm: GEM CMA: Add DRM PRIME support
authorLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Sun, 17 Feb 2013 00:57:30 +0000 (01:57 +0100)
committerLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Sat, 8 Jun 2013 07:14:05 +0000 (09:14 +0200)
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
drivers/gpu/drm/drm_gem_cma_helper.c
include/drm/drm_gem_cma_helper.h

index 7a4db4e..f94fcd7 100644 (file)
@@ -21,6 +21,7 @@
 #include <linux/slab.h>
 #include <linux/mutex.h>
 #include <linux/export.h>
+#include <linux/dma-buf.h>
 #include <linux/dma-mapping.h>
 
 #include <drm/drmP.h>
@@ -82,6 +83,8 @@ struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,
                unsigned int size)
 {
        struct drm_gem_cma_object *cma_obj;
+       struct sg_table *sgt = NULL;
+       int ret;
 
        size = round_up(size, PAGE_SIZE);
 
@@ -94,11 +97,29 @@ struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,
        if (!cma_obj->vaddr) {
                dev_err(drm->dev, "failed to allocate buffer with size %d\n",
                        size);
-               drm_gem_cma_free_object(&cma_obj->base);
-               return ERR_PTR(-ENOMEM);
+               ret = -ENOMEM;
+               goto error;
+       }
+
+       sgt = kzalloc(sizeof(*cma_obj->sgt), GFP_KERNEL);
+       if (sgt == NULL) {
+               ret = -ENOMEM;
+               goto error;
        }
 
+       ret = dma_get_sgtable(drm->dev, sgt, cma_obj->vaddr,
+                             cma_obj->paddr, size);
+       if (ret < 0)
+               goto error;
+
+       cma_obj->sgt = sgt;
+
        return cma_obj;
+
+error:
+       kfree(sgt);
+       drm_gem_cma_free_object(&cma_obj->base);
+       return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(drm_gem_cma_create);
 
@@ -156,9 +177,16 @@ void drm_gem_cma_free_object(struct drm_gem_object *gem_obj)
 
        cma_obj = to_drm_gem_cma_obj(gem_obj);
 
-       if (cma_obj->vaddr)
+       if (cma_obj->vaddr) {
                dma_free_writecombine(gem_obj->dev->dev, cma_obj->base.size,
                                      cma_obj->vaddr, cma_obj->paddr);
+               if (cma_obj->sgt) {
+                       sg_free_table(cma_obj->sgt);
+                       kfree(cma_obj->sgt);
+               }
+       } else if (gem_obj->import_attach) {
+               drm_prime_gem_destroy(gem_obj, cma_obj->sgt);
+       }
 
        drm_gem_object_release(gem_obj);
 
@@ -291,3 +319,286 @@ void drm_gem_cma_describe(struct drm_gem_cma_object *cma_obj, struct seq_file *m
 }
 EXPORT_SYMBOL_GPL(drm_gem_cma_describe);
 #endif
+
+/* -----------------------------------------------------------------------------
+ * DMA-BUF
+ */
+
+struct drm_gem_cma_dmabuf_attachment {
+       struct sg_table sgt;
+       enum dma_data_direction dir;
+};
+
+static int drm_gem_cma_dmabuf_attach(struct dma_buf *dmabuf, struct device *dev,
+                                    struct dma_buf_attachment *attach)
+{
+       struct drm_gem_cma_dmabuf_attachment *cma_attach;
+
+       cma_attach = kzalloc(sizeof(*cma_attach), GFP_KERNEL);
+       if (!cma_attach)
+               return -ENOMEM;
+
+       cma_attach->dir = DMA_NONE;
+       attach->priv = cma_attach;
+
+       return 0;
+}
+
+static void drm_gem_cma_dmabuf_detach(struct dma_buf *dmabuf,
+                                     struct dma_buf_attachment *attach)
+{
+       struct drm_gem_cma_dmabuf_attachment *cma_attach = attach->priv;
+       struct sg_table *sgt;
+
+       if (cma_attach == NULL)
+               return;
+
+       sgt = &cma_attach->sgt;
+
+       if (cma_attach->dir != DMA_NONE)
+               dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
+                               cma_attach->dir);
+
+       sg_free_table(sgt);
+       kfree(cma_attach);
+       attach->priv = NULL;
+}
+
+static struct sg_table *
+drm_gem_cma_dmabuf_map(struct dma_buf_attachment *attach,
+                      enum dma_data_direction dir)
+{
+       struct drm_gem_cma_dmabuf_attachment *cma_attach = attach->priv;
+       struct drm_gem_cma_object *cma_obj = attach->dmabuf->priv;
+       struct drm_device *drm = cma_obj->base.dev;
+       struct scatterlist *rd, *wr;
+       struct sg_table *sgt;
+       unsigned int i;
+       int nents, ret;
+
+       DRM_DEBUG_PRIME("\n");
+
+       if (WARN_ON(dir == DMA_NONE))
+               return ERR_PTR(-EINVAL);
+
+       /* Return the cached mapping when possible. */
+       if (cma_attach->dir == dir)
+               return &cma_attach->sgt;
+
+       /* Two mappings with different directions for the same attachment are
+        * not allowed.
+        */
+       if (WARN_ON(cma_attach->dir != DMA_NONE))
+               return ERR_PTR(-EBUSY);
+
+       sgt = &cma_attach->sgt;
+
+       ret = sg_alloc_table(sgt, cma_obj->sgt->orig_nents, GFP_KERNEL);
+       if (ret) {
+               DRM_ERROR("failed to alloc sgt.\n");
+               return ERR_PTR(-ENOMEM);
+       }
+
+       mutex_lock(&drm->struct_mutex);
+
+       rd = cma_obj->sgt->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);
+       }
+
+       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 done;
+       }
+
+       cma_attach->dir = dir;
+       attach->priv = cma_attach;
+
+       DRM_DEBUG_PRIME("buffer size = %zu\n", cma_obj->base.size);
+
+done:
+       mutex_unlock(&drm->struct_mutex);
+       return sgt;
+}
+
+static void drm_gem_cma_dmabuf_unmap(struct dma_buf_attachment *attach,
+                                    struct sg_table *sgt,
+                                    enum dma_data_direction dir)
+{
+       /* Nothing to do. */
+}
+
+static void drm_gem_cma_dmabuf_release(struct dma_buf *dmabuf)
+{
+       struct drm_gem_cma_object *cma_obj = dmabuf->priv;
+
+       DRM_DEBUG_PRIME("%s\n", __FILE__);
+
+       /*
+        * drm_gem_cma_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 (cma_obj->base.export_dma_buf == dmabuf) {
+               cma_obj->base.export_dma_buf = NULL;
+
+               /*
+                * drop this gem object refcount to release allocated buffer
+                * and resources.
+                */
+               drm_gem_object_unreference_unlocked(&cma_obj->base);
+       }
+}
+
+static void *drm_gem_cma_dmabuf_kmap_atomic(struct dma_buf *dmabuf,
+                                           unsigned long page_num)
+{
+       /* TODO */
+
+       return NULL;
+}
+
+static void drm_gem_cma_dmabuf_kunmap_atomic(struct dma_buf *dmabuf,
+                                            unsigned long page_num, void *addr)
+{
+       /* TODO */
+}
+
+static void *drm_gem_cma_dmabuf_kmap(struct dma_buf *dmabuf,
+                                    unsigned long page_num)
+{
+       /* TODO */
+
+       return NULL;
+}
+
+static void drm_gem_cma_dmabuf_kunmap(struct dma_buf *dmabuf,
+                                     unsigned long page_num, void *addr)
+{
+       /* TODO */
+}
+
+static int drm_gem_cma_dmabuf_mmap(struct dma_buf *dmabuf,
+                                  struct vm_area_struct *vma)
+{
+       struct drm_gem_cma_object *cma_obj = dmabuf->priv;
+       struct drm_gem_object *gem_obj = &cma_obj->base;
+       int ret;
+
+       ret = drm_gem_mmap_obj(gem_obj, gem_obj->size, vma);
+       if (ret < 0)
+               return ret;
+
+       return drm_gem_cma_mmap_obj(cma_obj, vma);
+}
+
+static void *drm_gem_cma_dmabuf_vmap(struct dma_buf *dmabuf)
+{
+       struct drm_gem_cma_object *cma_obj = dmabuf->priv;
+
+       return cma_obj->vaddr;
+}
+
+static struct dma_buf_ops drm_gem_cma_dmabuf_ops = {
+       .attach                 = drm_gem_cma_dmabuf_attach,
+       .detach                 = drm_gem_cma_dmabuf_detach,
+       .map_dma_buf            = drm_gem_cma_dmabuf_map,
+       .unmap_dma_buf          = drm_gem_cma_dmabuf_unmap,
+       .kmap                   = drm_gem_cma_dmabuf_kmap,
+       .kmap_atomic            = drm_gem_cma_dmabuf_kmap_atomic,
+       .kunmap                 = drm_gem_cma_dmabuf_kunmap,
+       .kunmap_atomic          = drm_gem_cma_dmabuf_kunmap_atomic,
+       .mmap                   = drm_gem_cma_dmabuf_mmap,
+       .vmap                   = drm_gem_cma_dmabuf_vmap,
+       .release                = drm_gem_cma_dmabuf_release,
+};
+
+struct dma_buf *drm_gem_cma_dmabuf_export(struct drm_device *drm,
+                                         struct drm_gem_object *obj, int flags)
+{
+       struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);
+
+       return dma_buf_export(cma_obj, &drm_gem_cma_dmabuf_ops,
+                             cma_obj->base.size, flags);
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_dmabuf_export);
+
+struct drm_gem_object *drm_gem_cma_dmabuf_import(struct drm_device *drm,
+                                                struct dma_buf *dma_buf)
+{
+       struct drm_gem_cma_object *cma_obj;
+       struct dma_buf_attachment *attach;
+       struct sg_table *sgt;
+       int ret;
+
+       DRM_DEBUG_PRIME("%s\n", __FILE__);
+
+       /* is this one of own objects? */
+       if (dma_buf->ops == &drm_gem_cma_dmabuf_ops) {
+               struct drm_gem_object *obj;
+
+               cma_obj = dma_buf->priv;
+               obj = &cma_obj->base;
+
+               /* is it from our device? */
+               if (obj->dev == drm) {
+                       /*
+                        * Importing dmabuf exported from out own gem increases
+                        * refcount on gem itself instead of f_count of dmabuf.
+                        */
+                       drm_gem_object_reference(obj);
+                       dma_buf_put(dma_buf);
+                       return obj;
+               }
+       }
+
+       /* Create a CMA GEM buffer. */
+       cma_obj = __drm_gem_cma_create(drm, dma_buf->size);
+       if (IS_ERR(cma_obj))
+               return ERR_PTR(PTR_ERR(cma_obj));
+
+       /* Attach to the buffer and map it. Make sure the mapping is contiguous
+        * on the device memory bus, as that's all we support.
+        */
+       attach = dma_buf_attach(dma_buf, drm->dev);
+       if (IS_ERR(attach)) {
+               ret = -EINVAL;
+               goto error_gem_free;
+       }
+
+       sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
+       if (IS_ERR_OR_NULL(sgt)) {
+               ret = sgt ? PTR_ERR(sgt) : -ENOMEM;
+               goto error_buf_detach;
+       }
+
+       if (sgt->nents != 1) {
+               ret = -EINVAL;
+               goto error_buf_unmap;
+       }
+
+       cma_obj->base.import_attach = attach;
+       cma_obj->paddr = sg_dma_address(sgt->sgl);
+       cma_obj->sgt = sgt;
+
+       DRM_DEBUG_PRIME("dma_addr = 0x%x, size = %zu\n", cma_obj->paddr,
+                       dma_buf->size);
+
+       return &cma_obj->base;
+
+error_buf_unmap:
+       dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
+error_buf_detach:
+       dma_buf_detach(dma_buf, attach);
+error_gem_free:
+       drm_gem_cma_free_object(&cma_obj->base);
+       return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_dmabuf_import);
index 63397ce..6e17251 100644 (file)
@@ -4,6 +4,9 @@
 struct drm_gem_cma_object {
        struct drm_gem_object base;
        dma_addr_t paddr;
+       struct sg_table *sgt;
+
+       /* For objects with DMA memory allocated by GEM CMA */
        void *vaddr;
 };
 
@@ -45,4 +48,10 @@ extern const struct vm_operations_struct drm_gem_cma_vm_ops;
 void drm_gem_cma_describe(struct drm_gem_cma_object *obj, struct seq_file *m);
 #endif
 
+struct dma_buf *drm_gem_cma_dmabuf_export(struct drm_device *drm_dev,
+                                         struct drm_gem_object *obj,
+                                         int flags);
+struct drm_gem_object *drm_gem_cma_dmabuf_import(struct drm_device *drm_dev,
+                                                struct dma_buf *dma_buf);
+
 #endif /* __DRM_GEM_CMA_HELPER_H__ */