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Commit 570d2a48 authored by Javier Martin's avatar Javier Martin Committed by Mauro Carvalho Chehab
Browse files

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



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: default avatarJavier Martin <javier.martin@vista-silicon.com>
Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: default avatarSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent a1212162

drivers/media/video/videobuf2-vmalloc.c

+47 −23
Original line number Diff line number Diff line
@@ -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;





	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);

		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 */

		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);

		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;
@@ -120,6 +138,7 @@ static void vb2_vmalloc_put_userptr(void *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) {
@@ -128,6 +147,11 @@ static void vb2_vmalloc_put_userptr(void *buf_priv) 
			put_page(buf->pages[i]);

		}

		kfree(buf->pages);

	} else {

		if (buf->vma)

			vb2_put_vma(buf->vma);

		iounmap(buf->vaddr);

	}

	kfree(buf);

}