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[media] media: vb2: support userptr for PFN mappings

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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.

Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Javier Martin 2012-02-16 12:19:08 -03:00 committed by Mauro Carvalho Chehab
parent a1212162f4
commit 570d2a48b7
1 changed files with 46 additions and 22 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

68
drivers/media/video/videobuf2-vmalloc.c
View file

@ -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;
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;
buf->vaddr = vm_map_ram(buf->pages, buf->n_pages, -1, PAGE_KERNEL);
if (!buf->vaddr)
goto fail_get_user_pages;
/* 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);
}