diff options
Diffstat (limited to 'drivers/media/v4l2-core/videobuf2-vmalloc.c')
| -rw-r--r-- | drivers/media/v4l2-core/videobuf2-vmalloc.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-vmalloc.c b/drivers/media/v4l2-core/videobuf2-vmalloc.c new file mode 100644 index 000000000000..94efa04d8d55 --- /dev/null +++ b/drivers/media/v4l2-core/videobuf2-vmalloc.c @@ -0,0 +1,223 @@ +/* + * videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2 + * + * Copyright (C) 2010 Samsung Electronics + * + * Author: Pawel Osciak <pawel@osciak.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/io.h> +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> + +#include <media/videobuf2-core.h> +#include <media/videobuf2-vmalloc.h> +#include <media/videobuf2-memops.h> + +struct vb2_vmalloc_buf { + void *vaddr; + struct page **pages; + struct vm_area_struct *vma; + int write; + unsigned long size; + unsigned int n_pages; + atomic_t refcount; + struct vb2_vmarea_handler handler; +}; + +static void vb2_vmalloc_put(void *buf_priv); + +static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size) +{ + struct vb2_vmalloc_buf *buf; + + buf = kzalloc(sizeof(*buf), GFP_KERNEL); + if (!buf) + return NULL; + + buf->size = size; + buf->vaddr = vmalloc_user(buf->size); + buf->handler.refcount = &buf->refcount; + buf->handler.put = vb2_vmalloc_put; + buf->handler.arg = buf; + + if (!buf->vaddr) { + pr_debug("vmalloc of size %ld failed\n", buf->size); + kfree(buf); + return NULL; + } + + atomic_inc(&buf->refcount); + return buf; +} + +static void vb2_vmalloc_put(void *buf_priv) +{ + struct vb2_vmalloc_buf *buf = buf_priv; + + if (atomic_dec_and_test(&buf->refcount)) { + vfree(buf->vaddr); + kfree(buf); + } +} + +static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr, + unsigned long size, int write) +{ + struct vb2_vmalloc_buf *buf; + unsigned long first, last; + int n_pages, offset; + struct vm_area_struct *vma; + dma_addr_t physp; + + buf = kzalloc(sizeof(*buf), GFP_KERNEL); + if (!buf) + return NULL; + + buf->write = write; + offset = vaddr & ~PAGE_MASK; + buf->size = size; + + + vma = find_vma(current->mm, vaddr); + if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) { + if (vb2_get_contig_userptr(vaddr, size, &vma, &physp)) + goto fail_pages_array_alloc; + buf->vma = vma; + buf->vaddr = ioremap_nocache(physp, size); + if (!buf->vaddr) + goto fail_pages_array_alloc; + } else { + first = vaddr >> PAGE_SHIFT; + last = (vaddr + size - 1) >> PAGE_SHIFT; + buf->n_pages = last - first + 1; + buf->pages = kzalloc(buf->n_pages * sizeof(struct page *), + GFP_KERNEL); + if (!buf->pages) + goto fail_pages_array_alloc; + + /* current->mm->mmap_sem is taken by videobuf2 core */ + n_pages = get_user_pages(current, current->mm, + vaddr & PAGE_MASK, buf->n_pages, + write, 1, /* force */ + buf->pages, NULL); + if (n_pages != buf->n_pages) + goto fail_get_user_pages; + + buf->vaddr = vm_map_ram(buf->pages, buf->n_pages, -1, + PAGE_KERNEL); + if (!buf->vaddr) + goto fail_get_user_pages; + } + + buf->vaddr += offset; + return buf; + +fail_get_user_pages: + pr_debug("get_user_pages requested/got: %d/%d]\n", n_pages, + buf->n_pages); + while (--n_pages >= 0) + put_page(buf->pages[n_pages]); + kfree(buf->pages); + +fail_pages_array_alloc: + kfree(buf); + + return NULL; +} + +static void vb2_vmalloc_put_userptr(void *buf_priv) +{ + struct vb2_vmalloc_buf *buf = buf_priv; + unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK; + unsigned int i; + + if (buf->pages) { + if (vaddr) + vm_unmap_ram((void *)vaddr, buf->n_pages); + for (i = 0; i < buf->n_pages; ++i) { + if (buf->write) + set_page_dirty_lock(buf->pages[i]); + put_page(buf->pages[i]); + } + kfree(buf->pages); + } else { + if (buf->vma) + vb2_put_vma(buf->vma); + iounmap(buf->vaddr); + } + kfree(buf); +} + +static void *vb2_vmalloc_vaddr(void *buf_priv) +{ + struct vb2_vmalloc_buf *buf = buf_priv; + + if (!buf->vaddr) { + pr_err("Address of an unallocated plane requested " + "or cannot map user pointer\n"); + return NULL; + } + + return buf->vaddr; +} + +static unsigned int vb2_vmalloc_num_users(void *buf_priv) +{ + struct vb2_vmalloc_buf *buf = buf_priv; + return atomic_read(&buf->refcount); +} + +static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma) +{ + struct vb2_vmalloc_buf *buf = buf_priv; + int ret; + + if (!buf) { + pr_err("No memory to map\n"); + return -EINVAL; + } + + ret = remap_vmalloc_range(vma, buf->vaddr, 0); + if (ret) { + pr_err("Remapping vmalloc memory, error: %d\n", ret); + return ret; + } + + /* + * Make sure that vm_areas for 2 buffers won't be merged together + */ + vma->vm_flags |= VM_DONTEXPAND; + + /* + * 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; +} + +const struct vb2_mem_ops vb2_vmalloc_memops = { + .alloc = vb2_vmalloc_alloc, + .put = vb2_vmalloc_put, + .get_userptr = vb2_vmalloc_get_userptr, + .put_userptr = vb2_vmalloc_put_userptr, + .vaddr = vb2_vmalloc_vaddr, + .mmap = vb2_vmalloc_mmap, + .num_users = vb2_vmalloc_num_users, +}; +EXPORT_SYMBOL_GPL(vb2_vmalloc_memops); + +MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2"); +MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); +MODULE_LICENSE("GPL"); |