diff options
| -rw-r--r-- | drivers/media/video/Kconfig | 6 | ||||
| -rw-r--r-- | drivers/media/video/Makefile | 1 | ||||
| -rw-r--r-- | drivers/media/video/videobuf2-dma-sg.c | 292 | ||||
| -rw-r--r-- | include/media/videobuf2-dma-sg.h | 32 |
4 files changed, 331 insertions, 0 deletions
diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig index b64183e0634..8710d90f9e1 100644 --- a/drivers/media/video/Kconfig +++ b/drivers/media/video/Kconfig @@ -60,6 +60,12 @@ config VIDEOBUF2_VMALLOC select VIDEOBUF2_MEMOPS tristate + +config VIDEOBUF2_DMA_SG + #depends on HAS_DMA + select VIDEOBUF2_CORE + select VIDEOBUF2_MEMOPS + tristate # # Multimedia Video device configuration # diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile index 106d40bbe72..40833fec34d 100644 --- a/drivers/media/video/Makefile +++ b/drivers/media/video/Makefile @@ -115,6 +115,7 @@ obj-$(CONFIG_VIDEOBUF2_CORE) += videobuf2-core.o obj-$(CONFIG_VIDEOBUF2_MEMOPS) += videobuf2-memops.o obj-$(CONFIG_VIDEOBUF2_VMALLOC) += videobuf2-vmalloc.o obj-$(CONFIG_VIDEOBUF2_DMA_CONTIG) += videobuf2-dma-contig.o +obj-$(CONFIG_VIDEOBUF2_DMA_SG) += videobuf2-dma-sg.o obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o diff --git a/drivers/media/video/videobuf2-dma-sg.c b/drivers/media/video/videobuf2-dma-sg.c new file mode 100644 index 00000000000..20b5c5dcc0e --- /dev/null +++ b/drivers/media/video/videobuf2-dma-sg.c @@ -0,0 +1,292 @@ +/* + * videobuf2-dma-sg.c - dma scatter/gather memory allocator for videobuf2 + * + * Copyright (C) 2010 Samsung Electronics + * + * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com> + * + * 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. + */ + +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/scatterlist.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> + +#include <media/videobuf2-core.h> +#include <media/videobuf2-memops.h> +#include <media/videobuf2-dma-sg.h> + +struct vb2_dma_sg_buf { + void *vaddr; + struct page **pages; + int write; + int offset; + struct vb2_dma_sg_desc sg_desc; + atomic_t refcount; + struct vb2_vmarea_handler handler; +}; + +static void vb2_dma_sg_put(void *buf_priv); + +static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size) +{ + struct vb2_dma_sg_buf *buf; + int i; + + buf = kzalloc(sizeof *buf, GFP_KERNEL); + if (!buf) + return NULL; + + buf->vaddr = NULL; + buf->write = 0; + buf->offset = 0; + buf->sg_desc.size = size; + buf->sg_desc.num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; + + buf->sg_desc.sglist = vmalloc(buf->sg_desc.num_pages * + sizeof(*buf->sg_desc.sglist)); + if (!buf->sg_desc.sglist) + goto fail_sglist_alloc; + memset(buf->sg_desc.sglist, 0, buf->sg_desc.num_pages * + sizeof(*buf->sg_desc.sglist)); + sg_init_table(buf->sg_desc.sglist, buf->sg_desc.num_pages); + + buf->pages = kzalloc(buf->sg_desc.num_pages * sizeof(struct page *), + GFP_KERNEL); + if (!buf->pages) + goto fail_pages_array_alloc; + + for (i = 0; i < buf->sg_desc.num_pages; ++i) { + buf->pages[i] = alloc_page(GFP_KERNEL); + if (NULL == buf->pages[i]) + goto fail_pages_alloc; + sg_set_page(&buf->sg_desc.sglist[i], + buf->pages[i], PAGE_SIZE, 0); + } + + buf->handler.refcount = &buf->refcount; + buf->handler.put = vb2_dma_sg_put; + buf->handler.arg = buf; + + atomic_inc(&buf->refcount); + + printk(KERN_DEBUG "%s: Allocated buffer of %d pages\n", + __func__, buf->sg_desc.num_pages); + + if (!buf->vaddr) + buf->vaddr = vm_map_ram(buf->pages, + buf->sg_desc.num_pages, + -1, + PAGE_KERNEL); + return buf; + +fail_pages_alloc: + while (--i >= 0) + __free_page(buf->pages[i]); + +fail_pages_array_alloc: + vfree(buf->sg_desc.sglist); + +fail_sglist_alloc: + kfree(buf); + return NULL; +} + +static void vb2_dma_sg_put(void *buf_priv) +{ + struct vb2_dma_sg_buf *buf = buf_priv; + int i = buf->sg_desc.num_pages; + + if (atomic_dec_and_test(&buf->refcount)) { + printk(KERN_DEBUG "%s: Freeing buffer of %d pages\n", __func__, + buf->sg_desc.num_pages); + if (buf->vaddr) + vm_unmap_ram(buf->vaddr, buf->sg_desc.num_pages); + vfree(buf->sg_desc.sglist); + while (--i >= 0) + __free_page(buf->pages[i]); + kfree(buf->pages); + kfree(buf); + } +} + +static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, + unsigned long size, int write) +{ + struct vb2_dma_sg_buf *buf; + unsigned long first, last; + int num_pages_from_user, i; + + buf = kzalloc(sizeof *buf, GFP_KERNEL); + if (!buf) + return NULL; + + buf->vaddr = NULL; + buf->write = write; + buf->offset = vaddr & ~PAGE_MASK; + buf->sg_desc.size = size; + + first = (vaddr & PAGE_MASK) >> PAGE_SHIFT; + last = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT; + buf->sg_desc.num_pages = last - first + 1; + + buf->sg_desc.sglist = vmalloc( + buf->sg_desc.num_pages * sizeof(*buf->sg_desc.sglist)); + if (!buf->sg_desc.sglist) + goto userptr_fail_sglist_alloc; + + memset(buf->sg_desc.sglist, 0, + buf->sg_desc.num_pages * sizeof(*buf->sg_desc.sglist)); + sg_init_table(buf->sg_desc.sglist, buf->sg_desc.num_pages); + + buf->pages = kzalloc(buf->sg_desc.num_pages * sizeof(struct page *), + GFP_KERNEL); + if (!buf->pages) + goto userptr_fail_pages_array_alloc; + + down_read(¤t->mm->mmap_sem); + num_pages_from_user = get_user_pages(current, current->mm, + vaddr & PAGE_MASK, + buf->sg_desc.num_pages, + write, + 1, /* force */ + buf->pages, + NULL); + up_read(¤t->mm->mmap_sem); + if (num_pages_from_user != buf->sg_desc.num_pages) + goto userptr_fail_get_user_pages; + + sg_set_page(&buf->sg_desc.sglist[0], buf->pages[0], + PAGE_SIZE - buf->offset, buf->offset); + size -= PAGE_SIZE - buf->offset; + for (i = 1; i < buf->sg_desc.num_pages; ++i) { + sg_set_page(&buf->sg_desc.sglist[i], buf->pages[i], + min_t(size_t, PAGE_SIZE, size), 0); + size -= min_t(size_t, PAGE_SIZE, size); + } + return buf; + +userptr_fail_get_user_pages: + printk(KERN_DEBUG "get_user_pages requested/got: %d/%d]\n", + num_pages_from_user, buf->sg_desc.num_pages); + while (--num_pages_from_user >= 0) + put_page(buf->pages[num_pages_from_user]); + +userptr_fail_pages_array_alloc: + vfree(buf->sg_desc.sglist); + +userptr_fail_sglist_alloc: + kfree(buf); + return NULL; +} + +/* + * @put_userptr: inform the allocator that a USERPTR buffer will no longer + * be used + */ +static void vb2_dma_sg_put_userptr(void *buf_priv) +{ + struct vb2_dma_sg_buf *buf = buf_priv; + int i = buf->sg_desc.num_pages; + + printk(KERN_DEBUG "%s: Releasing userspace buffer of %d pages\n", + __func__, buf->sg_desc.num_pages); + if (buf->vaddr) + vm_unmap_ram(buf->vaddr, buf->sg_desc.num_pages); + while (--i >= 0) { + if (buf->write) + set_page_dirty_lock(buf->pages[i]); + put_page(buf->pages[i]); + } + vfree(buf->sg_desc.sglist); + kfree(buf->pages); + kfree(buf); +} + +static void *vb2_dma_sg_vaddr(void *buf_priv) +{ + struct vb2_dma_sg_buf *buf = buf_priv; + + BUG_ON(!buf); + + if (!buf->vaddr) + buf->vaddr = vm_map_ram(buf->pages, + buf->sg_desc.num_pages, + -1, + PAGE_KERNEL); + + /* add offset in case userptr is not page-aligned */ + return buf->vaddr + buf->offset; +} + +static unsigned int vb2_dma_sg_num_users(void *buf_priv) +{ + struct vb2_dma_sg_buf *buf = buf_priv; + + return atomic_read(&buf->refcount); +} + +static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma) +{ + struct vb2_dma_sg_buf *buf = buf_priv; + unsigned long uaddr = vma->vm_start; + unsigned long usize = vma->vm_end - vma->vm_start; + int i = 0; + + if (!buf) { + printk(KERN_ERR "No memory to map\n"); + return -EINVAL; + } + + do { + int ret; + + ret = vm_insert_page(vma, uaddr, buf->pages[i++]); + if (ret) { + printk(KERN_ERR "Remapping memory, error: %d\n", ret); + return ret; + } + + uaddr += PAGE_SIZE; + usize -= PAGE_SIZE; + } while (usize > 0); + + + /* + * Use common vm_area operations to track buffer refcount. + */ + vma->vm_private_data = &buf->handler; + vma->vm_ops = &vb2_common_vm_ops; + + vma->vm_ops->open(vma); + + return 0; +} + +static void *vb2_dma_sg_cookie(void *buf_priv) +{ + struct vb2_dma_sg_buf *buf = buf_priv; + + return &buf->sg_desc; +} + +const struct vb2_mem_ops vb2_dma_sg_memops = { + .alloc = vb2_dma_sg_alloc, + .put = vb2_dma_sg_put, + .get_userptr = vb2_dma_sg_get_userptr, + .put_userptr = vb2_dma_sg_put_userptr, + .vaddr = vb2_dma_sg_vaddr, + .mmap = vb2_dma_sg_mmap, + .num_users = vb2_dma_sg_num_users, + .cookie = vb2_dma_sg_cookie, +}; +EXPORT_SYMBOL_GPL(vb2_dma_sg_memops); + +MODULE_DESCRIPTION("dma scatter/gather memory handling routines for videobuf2"); +MODULE_AUTHOR("Andrzej Pietrasiewicz"); +MODULE_LICENSE("GPL"); diff --git a/include/media/videobuf2-dma-sg.h b/include/media/videobuf2-dma-sg.h new file mode 100644 index 00000000000..0038526b8ef --- /dev/null +++ b/include/media/videobuf2-dma-sg.h @@ -0,0 +1,32 @@ +/* + * videobuf2-dma-sg.h - DMA scatter/gather memory allocator for videobuf2 + * + * Copyright (C) 2010 Samsung Electronics + * + * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com> + * + * 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. + */ + +#ifndef _MEDIA_VIDEOBUF2_DMA_SG_H +#define _MEDIA_VIDEOBUF2_DMA_SG_H + +#include <media/videobuf2-core.h> + +struct vb2_dma_sg_desc { + unsigned long size; + unsigned int num_pages; + struct scatterlist *sglist; +}; + +static inline struct vb2_dma_sg_desc *vb2_dma_sg_plane_desc( + struct vb2_buffer *vb, unsigned int plane_no) +{ + return (struct vb2_dma_sg_desc *)vb2_plane_cookie(vb, plane_no); +} + +extern const struct vb2_mem_ops vb2_dma_sg_memops; + +#endif |