Hello,
On Wednesday, January 04, 2012 5:19 PM Javier Martin wrote:
> Some video devices need to use contiguous memory
> which is not backed by pages as it happens with
> vmalloc. This patch provides userptr handling for
> those devices.
>
> ---
> Changes since v3:
> - Remove vma_res variable.
>
> Signed-off-by: Javier Martin <javier.martin@xxxxxxxxxxxxxxxxx>
Acked-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Do you plan to put a git tree with all your patches and send a pull request
to Mauro? If not I will take this patch and put it on my vb2 branch.
> ---
> drivers/media/video/videobuf2-vmalloc.c | 70 +++++++++++++++++++++----------
> 1 files changed, 47 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/media/video/videobuf2-vmalloc.c b/drivers/media/video/videobuf2-vmalloc.c
> index 03aa62f..f9ff15f 100644
> --- a/drivers/media/video/videobuf2-vmalloc.c
> +++ b/drivers/media/video/videobuf2-vmalloc.c
> @@ -10,6 +10,7 @@
> * the Free Software Foundation.
> */
>
> +#include <linux/io.h>
> #include <linux/module.h>
> #include <linux/mm.h>
> #include <linux/sched.h>
> @@ -22,6 +23,7 @@
> struct vb2_vmalloc_buf {
> void *vaddr;
> struct page **pages;
> + struct vm_area_struct *vma;
> int write;
> unsigned long size;
> unsigned int n_pages;
> @@ -71,6 +73,8 @@ static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
> 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)
> @@ -80,23 +84,37 @@ static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
> offset = vaddr & ~PAGE_MASK;
> buf->size = size;
>
> - 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;
> + 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;
> @@ -120,14 +138,20 @@ static void vb2_vmalloc_put_userptr(void *buf_priv)
> unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
> unsigned int i;
>
> - 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]);
> + 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->pages);
> kfree(buf);
> }
>
> --
Best regards
--
Marek Szyprowski
Samsung Poland R&D Center
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