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author | Mauro Carvalho Chehab <mchehab@redhat.com> | 2012-06-14 16:35:52 -0300 |
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committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2012-08-13 23:02:38 -0300 |
commit | 5bc3cb743bbab408792c1b4ef31adf6268aa4b7e (patch) | |
tree | 94faf3260c80a9626b450a6472780828cdf03b26 /drivers/media/v4l2-core/videobuf2-dma-sg.c | |
parent | 2ea4b442589b30210a166b9630c2547ebbe2cb82 (diff) | |
download | linux-stable-5bc3cb743bbab408792c1b4ef31adf6268aa4b7e.tar.gz linux-stable-5bc3cb743bbab408792c1b4ef31adf6268aa4b7e.tar.bz2 linux-stable-5bc3cb743bbab408792c1b4ef31adf6268aa4b7e.zip |
[media] v4l: move v4l2 core into a separate directory
Currently, the v4l2 core is mixed together with other non-core drivers.
Move them into a separate directory.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/v4l2-core/videobuf2-dma-sg.c')
-rw-r--r-- | drivers/media/v4l2-core/videobuf2-dma-sg.c | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c new file mode 100644 index 000000000000..25c3b360e1ad --- /dev/null +++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c @@ -0,0 +1,283 @@ +/* + * 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 = vzalloc(buf->sg_desc.num_pages * + sizeof(*buf->sg_desc.sglist)); + if (!buf->sg_desc.sglist) + goto fail_sglist_alloc; + 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 | __GFP_ZERO | __GFP_NOWARN); + 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); + return buf; + +fail_pages_alloc: + while (--i >= 0) + __free_page(buf->pages[i]); + kfree(buf->pages); + +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 = vzalloc( + buf->sg_desc.num_pages * sizeof(*buf->sg_desc.sglist)); + if (!buf->sg_desc.sglist) + goto userptr_fail_sglist_alloc; + + 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; + + num_pages_from_user = get_user_pages(current, current->mm, + vaddr & PAGE_MASK, + buf->sg_desc.num_pages, + write, + 1, /* force */ + buf->pages, + NULL); + + 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]); + kfree(buf->pages); + +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"); |