[media] media: vb2: vmalloc-based allocator user pointer handling
This patch adds support for user pointer memory buffers to vmalloc
videobuf2 allocator.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
CC: Pawel Osciak <pawel@osciak.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/videobuf2-vmalloc.c b/drivers/media/video/videobuf2-vmalloc.c
index a3a8842..4e789a1 100644
--- a/drivers/media/video/videobuf2-vmalloc.c
+++ b/drivers/media/video/videobuf2-vmalloc.c
@@ -12,6 +12,7 @@
#include <linux/module.h>
#include <linux/mm.h>
+#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
@@ -20,7 +21,10 @@
struct vb2_vmalloc_buf {
void *vaddr;
+ struct page **pages;
+ int write;
unsigned long size;
+ unsigned int n_pages;
atomic_t refcount;
struct vb2_vmarea_handler handler;
};
@@ -31,7 +35,7 @@
{
struct vb2_vmalloc_buf *buf;
- buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ buf = kzalloc(sizeof(*buf), GFP_KERNEL);
if (!buf)
return NULL;
@@ -42,15 +46,12 @@
buf->handler.arg = buf;
if (!buf->vaddr) {
- printk(KERN_ERR "vmalloc of size %ld failed\n", buf->size);
+ pr_debug("vmalloc of size %ld failed\n", buf->size);
kfree(buf);
return NULL;
}
atomic_inc(&buf->refcount);
- printk(KERN_DEBUG "Allocated vmalloc buffer of size %ld at vaddr=%p\n",
- buf->size, buf->vaddr);
-
return buf;
}
@@ -59,21 +60,84 @@
struct vb2_vmalloc_buf *buf = buf_priv;
if (atomic_dec_and_test(&buf->refcount)) {
- printk(KERN_DEBUG "%s: Freeing vmalloc mem at vaddr=%p\n",
- __func__, buf->vaddr);
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;
+
+ buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+ if (!buf)
+ return NULL;
+
+ buf->write = write;
+ 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;
+
+ 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 (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);
+ kfree(buf);
+}
+
static void *vb2_vmalloc_vaddr(void *buf_priv)
{
struct vb2_vmalloc_buf *buf = buf_priv;
- BUG_ON(!buf);
-
if (!buf->vaddr) {
- printk(KERN_ERR "Address of an unallocated plane requested\n");
+ pr_err("Address of an unallocated plane requested "
+ "or cannot map user pointer\n");
return NULL;
}
@@ -92,13 +156,13 @@
int ret;
if (!buf) {
- printk(KERN_ERR "No memory to map\n");
+ pr_err("No memory to map\n");
return -EINVAL;
}
ret = remap_vmalloc_range(vma, buf->vaddr, 0);
if (ret) {
- printk(KERN_ERR "Remapping vmalloc memory, error: %d\n", ret);
+ pr_err("Remapping vmalloc memory, error: %d\n", ret);
return ret;
}
@@ -121,6 +185,8 @@
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,