@@ -17,6 +17,7 @@
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
+#include <linux/pagemap.h>
#include <linux/dma-mapping.h>
#include <media/videobuf-dma-contig.h>
@@ -25,6 +26,7 @@ struct videobuf_dma_contig_memory {
void *vaddr;
dma_addr_t dma_handle;
unsigned long size;
+ int is_userptr;
};
#define MAGIC_DC_MEM 0x0733ac61
@@ -108,6 +110,70 @@ static struct vm_operations_struct video
.close = videobuf_vm_close,
};
+static void videobuf_dma_contig_user_put(struct videobuf_dma_contig_memory *mem)
+{
+ mem->is_userptr = 0;
+ mem->dma_handle = 0;
+ mem->size = 0;
+}
+
+static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem,
+ struct videobuf_buffer *vb)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ unsigned long prev_pfn, this_pfn;
+ unsigned long pages_done, user_address;
+ unsigned long prot;
+ resource_size_t phys;
+ int ret;
+
+ mem->size = PAGE_ALIGN(vb->size);
+ mem->is_userptr = 0;
+ ret = -EINVAL;
+
+ down_read(&mm->mmap_sem);
+
+ vma = find_vma(mm, vb->baddr);
+ if (!vma)
+ goto out_up;
+
+ if ((vb->baddr + mem->size) > vma->vm_end)
+ goto out_up;
+
+ pages_done = 0;
+ prev_pfn = 0; /* kill warning */
+ user_address = vb->baddr;
+
+ while (pages_done < (mem->size >> PAGE_SHIFT)) {
+ ret = follow_phys(vma, user_address, 0, &prot, &phys);
+ if (ret)
+ break;
+
+ this_pfn = phys >> PAGE_SHIFT;
+
+ if (pages_done == 0)
+ mem->dma_handle = phys;
+ else if (this_pfn != (prev_pfn + 1))
+ ret = -EFAULT;
+
+ if (ret)
+ break;
+
+ prev_pfn = this_pfn;
+ user_address += PAGE_SIZE;
+ pages_done++;
+ }
+
+ if (!ret)
+ mem->is_userptr = 1;
+
+ out_up:
+ up_read(¤t->mm->mmap_sem);
+
+ return ret;
+}
+
static void *__videobuf_alloc(size_t size)
{
struct videobuf_dma_contig_memory *mem;
@@ -154,12 +220,11 @@ static int __videobuf_iolock(struct vide
case V4L2_MEMORY_USERPTR:
dev_dbg(q->dev, "%s memory method USERPTR\n", __func__);
- /* The only USERPTR currently supported is the one needed for
- read() method.
- */
+ /* handle pointer from user space */
if (vb->baddr)
- return -EINVAL;
+ return videobuf_dma_contig_user_get(mem, vb);
+ /* allocate memory for the read() method */
mem->size = PAGE_ALIGN(vb->size);
mem->vaddr = dma_alloc_coherent(q->dev, mem->size,
&mem->dma_handle, GFP_KERNEL);
@@ -386,7 +451,7 @@ void videobuf_dma_contig_free(struct vid
So, it should free memory only if the memory were allocated for
read() operation.
*/
- if ((buf->memory != V4L2_MEMORY_USERPTR) || buf->baddr)
+ if (buf->memory != V4L2_MEMORY_USERPTR)
return;
if (!mem)
@@ -394,6 +459,13 @@ void videobuf_dma_contig_free(struct vid
MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
+ /* handle user space pointer case */
+ if (buf->baddr) {
+ videobuf_dma_contig_user_put(mem);
+ return;
+ }
+
+ /* read() method */
dma_free_coherent(q->dev, mem->size, mem->vaddr, mem->dma_handle);
mem->vaddr = NULL;
}
@@ -3009,7 +3009,6 @@ int in_gate_area_no_task(unsigned long a
#endif /* __HAVE_ARCH_GATE_AREA */
-#ifdef CONFIG_HAVE_IOREMAP_PROT
int follow_phys(struct vm_area_struct *vma,
unsigned long address, unsigned int flags,
unsigned long *prot, resource_size_t *phys)
@@ -3063,7 +3062,9 @@ unlock:
out:
return ret;
}
+EXPORT_SYMBOL(follow_phys);
+#ifdef CONFIG_HAVE_IOREMAP_PROT
int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
void *buf, int len, int write)
{