From: Andrzej Pietrasiewicz <andrze...@samsung.com>
This patch adds support for user pointer memory buffers to vmalloc
videobuf2 allocator.
Signed-off-by: Andrzej Pietrasiewicz <andrze...@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.p...@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprow...@samsung.com>
---
drivers/media/video/videobuf2-vmalloc.c | 97 ++++++++++++++++++++++++++++---
1 files changed, 89 insertions(+), 8 deletions(-)
diff --git a/drivers/media/video/videobuf2-vmalloc.c
b/drivers/media/video/videobuf2-vmalloc.c
index a3a8842..8843ad0 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;
};
@@ -42,14 +46,14 @@ static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned
long size)
buf->handler.arg = buf;
if (!buf->vaddr) {
- printk(KERN_ERR "vmalloc of size %ld failed\n", buf->size);
+ pr_err("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);
+ pr_err("Allocated vmalloc buffer of size %ld at vaddr=%p\n", buf->size,
+ buf->vaddr);
return buf;
}
@@ -59,13 +63,87 @@ static void vb2_vmalloc_put(void *buf_priv)
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);
+ pr_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_from_user, offset;
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return NULL;
+
+ buf->write = write;
+ offset = vaddr & ~PAGE_MASK;
+ buf->size = size;
+
+ first = (vaddr & PAGE_MASK) >> PAGE_SHIFT;
+ last = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT;
+ buf->n_pages = last - first + 1;
+ buf->pages = kzalloc(buf->n_pages * sizeof(struct page *), GFP_KERNEL);
+ if (!buf->pages)
+ goto userptr_fail_pages_array_alloc;
+
+ /* current->mm->mmap_sem is taken by videobuf core */
+ n_pages_from_user = get_user_pages(current, current->mm,
+ vaddr & PAGE_MASK,
+ buf->n_pages,
+ write,
+ 1, /* force */
+ buf->pages,
+ NULL);
+ if (n_pages_from_user != buf->n_pages)
+ goto userptr_fail_get_user_pages;
+
+ buf->vaddr = vm_map_ram(buf->pages, buf->n_pages, -1, PAGE_KERNEL);
+
+ if (!buf->vaddr)
+ goto userptr_fail_get_user_pages;
+
+ buf->vaddr += offset;
+ return buf;
+
+userptr_fail_get_user_pages:
+ pr_debug("get_user_pages requested/got: %d/%d]\n", n_pages_from_user,
+ buf->n_pages);
+ while (--n_pages_from_user >= 0)
+ put_page(buf->pages[n_pages_from_user]);
+ kfree(buf->pages);
+
+userptr_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 int i;
+ int offset = (unsigned long)buf->vaddr & ~PAGE_MASK;
+
+ if (buf->vaddr)
+ vm_unmap_ram((const void *)((unsigned long)buf->vaddr - offset),
+ 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;
@@ -73,7 +151,8 @@ static void *vb2_vmalloc_vaddr(void *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 +171,13 @@ static int vb2_vmalloc_mmap(void *buf_priv, struct
vm_area_struct *vma)
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 +200,8 @@ static int vb2_vmalloc_mmap(void *buf_priv, struct
vm_area_struct *vma)
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,
--
1.7.1.569.g6f426
--
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