Signed-off-by: Laurent Pinchart laurent.pinchart+renesas@ideasonboard.com --- drivers/gpu/drm/drm_gem_cma_helper.c | 321 ++++++++++++++++++++++++++++++++++- include/drm/drm_gem_cma_helper.h | 9 + 2 files changed, 327 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c index 7a4db4e..1dc2157 100644 --- a/drivers/gpu/drm/drm_gem_cma_helper.c +++ b/drivers/gpu/drm/drm_gem_cma_helper.c @@ -21,6 +21,9 @@ #include <linux/slab.h> #include <linux/mutex.h> #include <linux/export.h> +#if CONFIG_DMA_SHARED_BUFFER +#include <linux/dma-buf.h> +#endif #include <linux/dma-mapping.h>
#include <drm/drmP.h> @@ -82,6 +85,8 @@ 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 +99,29 @@ 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 +179,16 @@ 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 +321,288 @@ 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 + */ + +#if CONFIG_DMA_SHARED_BUFFER +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); +#endif diff --git a/include/drm/drm_gem_cma_helper.h b/include/drm/drm_gem_cma_helper.h index 63397ce..6e17251 100644 --- a/include/drm/drm_gem_cma_helper.h +++ b/include/drm/drm_gem_cma_helper.h @@ -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__ */