diff options
Diffstat (limited to 'drivers/staging/omapdrm/omap_gem_dmabuf.c')
| -rw-r--r-- | drivers/staging/omapdrm/omap_gem_dmabuf.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/staging/omapdrm/omap_gem_dmabuf.c b/drivers/staging/omapdrm/omap_gem_dmabuf.c new file mode 100644 index 000000000000..42728e0cc194 --- /dev/null +++ b/drivers/staging/omapdrm/omap_gem_dmabuf.c @@ -0,0 +1,220 @@ +/* + * drivers/staging/omapdrm/omap_gem_dmabuf.c + * + * Copyright (C) 2011 Texas Instruments + * Author: Rob Clark <rob.clark@linaro.org> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * 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 "omap_drv.h" + +#include <linux/dma-buf.h> + +static struct sg_table *omap_gem_map_dma_buf( + struct dma_buf_attachment *attachment, + enum dma_data_direction dir) +{ + struct drm_gem_object *obj = attachment->dmabuf->priv; + struct sg_table *sg; + dma_addr_t paddr; + int ret; + + sg = kzalloc(sizeof(*sg), GFP_KERNEL); + if (!sg) + return ERR_PTR(-ENOMEM); + + /* camera, etc, need physically contiguous.. but we need a + * better way to know this.. + */ + ret = omap_gem_get_paddr(obj, &paddr, true); + if (ret) + goto out; + + ret = sg_alloc_table(sg, 1, GFP_KERNEL); + if (ret) + goto out; + + sg_init_table(sg->sgl, 1); + sg_dma_len(sg->sgl) = obj->size; + sg_set_page(sg->sgl, pfn_to_page(PFN_DOWN(paddr)), obj->size, 0); + sg_dma_address(sg->sgl) = paddr; + + /* this should be after _get_paddr() to ensure we have pages attached */ + omap_gem_dma_sync(obj, dir); + +out: + if (ret) + return ERR_PTR(ret); + return sg; +} + +static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment, + struct sg_table *sg, enum dma_data_direction dir) +{ + struct drm_gem_object *obj = attachment->dmabuf->priv; + omap_gem_put_paddr(obj); + sg_free_table(sg); + kfree(sg); +} + +static void omap_gem_dmabuf_release(struct dma_buf *buffer) +{ + struct drm_gem_object *obj = buffer->priv; + /* release reference that was taken when dmabuf was exported + * in omap_gem_prime_set().. + */ + drm_gem_object_unreference_unlocked(obj); +} + + +static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer, + size_t start, size_t len, enum dma_data_direction dir) +{ + struct drm_gem_object *obj = buffer->priv; + struct page **pages; + if (omap_gem_flags(obj) & OMAP_BO_TILED) { + /* TODO we would need to pin at least part of the buffer to + * get de-tiled view. For now just reject it. + */ + return -ENOMEM; + } + /* make sure we have the pages: */ + return omap_gem_get_pages(obj, &pages, true); +} + +static void omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer, + size_t start, size_t len, enum dma_data_direction dir) +{ + struct drm_gem_object *obj = buffer->priv; + omap_gem_put_pages(obj); +} + + +static void *omap_gem_dmabuf_kmap_atomic(struct dma_buf *buffer, + unsigned long page_num) +{ + struct drm_gem_object *obj = buffer->priv; + struct page **pages; + omap_gem_get_pages(obj, &pages, false); + omap_gem_cpu_sync(obj, page_num); + return kmap_atomic(pages[page_num]); +} + +static void omap_gem_dmabuf_kunmap_atomic(struct dma_buf *buffer, + unsigned long page_num, void *addr) +{ + kunmap_atomic(addr); +} + +static void *omap_gem_dmabuf_kmap(struct dma_buf *buffer, + unsigned long page_num) +{ + struct drm_gem_object *obj = buffer->priv; + struct page **pages; + omap_gem_get_pages(obj, &pages, false); + omap_gem_cpu_sync(obj, page_num); + return kmap(pages[page_num]); +} + +static void omap_gem_dmabuf_kunmap(struct dma_buf *buffer, + unsigned long page_num, void *addr) +{ + struct drm_gem_object *obj = buffer->priv; + struct page **pages; + omap_gem_get_pages(obj, &pages, false); + kunmap(pages[page_num]); +} + +/* + * TODO maybe we can split up drm_gem_mmap to avoid duplicating + * some here.. or at least have a drm_dmabuf_mmap helper. + */ +static int omap_gem_dmabuf_mmap(struct dma_buf *buffer, + struct vm_area_struct *vma) +{ + struct drm_gem_object *obj = buffer->priv; + int ret = 0; + + if (WARN_ON(!obj->filp)) + return -EINVAL; + + /* Check for valid size. */ + if (omap_gem_mmap_size(obj) < vma->vm_end - vma->vm_start) { + ret = -EINVAL; + goto out_unlock; + } + + if (!obj->dev->driver->gem_vm_ops) { + ret = -EINVAL; + goto out_unlock; + } + + vma->vm_flags |= VM_RESERVED | VM_IO | VM_PFNMAP | VM_DONTEXPAND; + vma->vm_ops = obj->dev->driver->gem_vm_ops; + vma->vm_private_data = obj; + vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); + + /* Take a ref for this mapping of the object, so that the fault + * handler can dereference the mmap offset's pointer to the object. + * This reference is cleaned up by the corresponding vm_close + * (which should happen whether the vma was created by this call, or + * by a vm_open due to mremap or partial unmap or whatever). + */ + vma->vm_ops->open(vma); + +out_unlock: + + return omap_gem_mmap_obj(obj, vma); +} + +struct dma_buf_ops omap_dmabuf_ops = { + .map_dma_buf = omap_gem_map_dma_buf, + .unmap_dma_buf = omap_gem_unmap_dma_buf, + .release = omap_gem_dmabuf_release, + .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access, + .end_cpu_access = omap_gem_dmabuf_end_cpu_access, + .kmap_atomic = omap_gem_dmabuf_kmap_atomic, + .kunmap_atomic = omap_gem_dmabuf_kunmap_atomic, + .kmap = omap_gem_dmabuf_kmap, + .kunmap = omap_gem_dmabuf_kunmap, + .mmap = omap_gem_dmabuf_mmap, +}; + +struct dma_buf * omap_gem_prime_export(struct drm_device *dev, + struct drm_gem_object *obj, int flags) +{ + return dma_buf_export(obj, &omap_dmabuf_ops, obj->size, 0600); +} + +struct drm_gem_object * omap_gem_prime_import(struct drm_device *dev, + struct dma_buf *buffer) +{ + struct drm_gem_object *obj; + + /* is this one of own objects? */ + if (buffer->ops == &omap_dmabuf_ops) { + obj = buffer->priv; + /* is it from our device? */ + if (obj->dev == dev) { + drm_gem_object_reference(obj); + return obj; + } + } + + /* + * TODO add support for importing buffers from other devices.. + * for now we don't need this but would be nice to add eventually + */ + return ERR_PTR(-EINVAL); +} |