diff options
Diffstat (limited to 'drivers/video/adf/adf_memblock.c')
| -rw-r--r-- | drivers/video/adf/adf_memblock.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/drivers/video/adf/adf_memblock.c b/drivers/video/adf/adf_memblock.c new file mode 100644 index 000000000000..e73a7d59f1e6 --- /dev/null +++ b/drivers/video/adf/adf_memblock.c @@ -0,0 +1,160 @@ +/* + * Copyright (C) 2013 Google, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * 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. + * + */ + +#include <linux/dma-buf.h> +#include <linux/highmem.h> +#include <linux/memblock.h> +#include <linux/slab.h> + +struct adf_memblock_pdata { + phys_addr_t base; +}; + +static struct sg_table *adf_memblock_map(struct dma_buf_attachment *attach, + enum dma_data_direction direction) +{ + struct adf_memblock_pdata *pdata = attach->dmabuf->priv; + unsigned long pfn = PFN_DOWN(pdata->base); + struct page *page = pfn_to_page(pfn); + struct sg_table *table; + int nents, ret; + + table = kzalloc(sizeof(*table), GFP_KERNEL); + if (!table) + return ERR_PTR(-ENOMEM); + + ret = sg_alloc_table(table, 1, GFP_KERNEL); + if (ret < 0) + goto err_alloc; + + sg_set_page(table->sgl, page, attach->dmabuf->size, 0); + + nents = dma_map_sg(attach->dev, table->sgl, 1, direction); + if (!nents) { + ret = -EINVAL; + goto err_map; + } + + return table; + +err_map: + sg_free_table(table); +err_alloc: + kfree(table); + return ERR_PTR(ret); +} + +static void adf_memblock_unmap(struct dma_buf_attachment *attach, + struct sg_table *table, enum dma_data_direction direction) +{ + dma_unmap_sg(attach->dev, table->sgl, 1, direction); + sg_free_table(table); +} + +static void __init_memblock adf_memblock_release(struct dma_buf *buf) +{ + struct adf_memblock_pdata *pdata = buf->priv; + int err = memblock_free(pdata->base, buf->size); + + if (err < 0) + pr_warn("%s: freeing memblock failed: %d\n", __func__, err); + kfree(pdata); +} + +static void *adf_memblock_do_kmap(struct dma_buf *buf, unsigned long pgoffset, + bool atomic) +{ + struct adf_memblock_pdata *pdata = buf->priv; + unsigned long pfn = PFN_DOWN(pdata->base) + pgoffset; + struct page *page = pfn_to_page(pfn); + + if (atomic) + return kmap_atomic(page); + else + return kmap(page); +} + +static void *adf_memblock_kmap_atomic(struct dma_buf *buf, + unsigned long pgoffset) +{ + return adf_memblock_do_kmap(buf, pgoffset, true); +} + +static void adf_memblock_kunmap_atomic(struct dma_buf *buf, + unsigned long pgoffset, void *vaddr) +{ + kunmap_atomic(vaddr); +} + +static void *adf_memblock_kmap(struct dma_buf *buf, unsigned long pgoffset) +{ + return adf_memblock_do_kmap(buf, pgoffset, false); +} + +static void adf_memblock_kunmap(struct dma_buf *buf, unsigned long pgoffset, + void *vaddr) +{ + kunmap(vaddr); +} + +static int adf_memblock_mmap(struct dma_buf *buf, struct vm_area_struct *vma) +{ + struct adf_memblock_pdata *pdata = buf->priv; + + return remap_pfn_range(vma, vma->vm_start, PFN_DOWN(pdata->base), + vma->vm_end - vma->vm_start, vma->vm_page_prot); +} + +struct dma_buf_ops adf_memblock_ops = { + .map_dma_buf = adf_memblock_map, + .unmap_dma_buf = adf_memblock_unmap, + .release = adf_memblock_release, + .kmap_atomic = adf_memblock_kmap_atomic, + .kunmap_atomic = adf_memblock_kunmap_atomic, + .kmap = adf_memblock_kmap, + .kunmap = adf_memblock_kunmap, + .mmap = adf_memblock_mmap, +}; + +/** + * adf_memblock_export - export a memblock reserved area as a dma-buf + * + * @base: base physical address + * @size: memblock size + * @flags: mode flags for the dma-buf's file + * + * @base and @size must be page-aligned. + * + * Returns a dma-buf on success or ERR_PTR(-errno) on failure. + */ +struct dma_buf *adf_memblock_export(phys_addr_t base, size_t size, int flags) +{ + struct adf_memblock_pdata *pdata; + struct dma_buf *buf; + + if (PAGE_ALIGN(base) != base || PAGE_ALIGN(size) != size) + return ERR_PTR(-EINVAL); + + pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return ERR_PTR(-ENOMEM); + + pdata->base = base; + buf = dma_buf_export(pdata, &adf_memblock_ops, size, flags); + if (IS_ERR(buf)) + kfree(pdata); + + return buf; +} +EXPORT_SYMBOL(adf_memblock_export); |