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 v2:
- Do not grab mm->mmap_sem.
Signed-off-by: Javier Martin <javier.mar...@vista-silicon.com>
---
drivers/media/video/videobuf2-vmalloc.c | 71 +++++++++++++++++++++----------
1 files changed, 48 insertions(+), 23 deletions(-)
diff --git a/drivers/media/video/videobuf2-vmalloc.c
b/drivers/media/video/videobuf2-vmalloc.c
index 03aa62f..e621db6 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 +73,9 @@ 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;
+ struct vm_area_struct *res_vma;
+ dma_addr_t physp;
buf = kzalloc(sizeof(*buf), GFP_KERNEL);
if (!buf)
@@ -80,23 +85,37 @@ 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, &res_vma, &physp))
+ goto fail_pages_array_alloc;
+ buf->vma = res_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 +139,20 @@ 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);
}
--
1.7.0.4
--
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