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authorJames Harper <james.harper@ejbdigital.com.au>2014-06-12 06:53:38 -0300
committerMauro Carvalho Chehab <m.chehab@samsung.com>2014-07-26 11:33:15 -0300
commit7b4eeed174b71c325705ff8c53f333bc79d0ee7a (patch)
tree3f23ad213911ab98dd30694109c6c0bcfe17afd7
parentb601fe5688ae285693c64e833003c14acb38378a (diff)
[media] vmalloc_sg: make sure all pages in vmalloc area are really DMA-ready
Patch originally written by Konrad. Rebased on current linux media tree. Under Xen, vmalloc_32() isn't guaranteed to return pages which are really under 4G in machine physical addresses (only in virtual pseudo-physical addresses). To work around this, implement a vmalloc variant which allocates each page with dma_alloc_coherent() to guarantee that each page is suitable for the device in question. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: James Harper <james.harper@ejbdigital.com.au> Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
-rw-r--r--drivers/media/v4l2-core/videobuf-dma-sg.c62
-rw-r--r--include/media/videobuf-dma-sg.h3
2 files changed, 61 insertions, 4 deletions
diff --git a/drivers/media/v4l2-core/videobuf-dma-sg.c b/drivers/media/v4l2-core/videobuf-dma-sg.c
index 828e7c10bd70..3c8cc023a5a5 100644
--- a/drivers/media/v4l2-core/videobuf-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf-dma-sg.c
@@ -211,13 +211,36 @@ EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
int nr_pages)
{
+ int i;
+
dprintk(1, "init kernel [%d pages]\n", nr_pages);
dma->direction = direction;
- dma->vaddr = vmalloc_32(nr_pages << PAGE_SHIFT);
+ dma->vaddr_pages = kcalloc(nr_pages, sizeof(*dma->vaddr_pages),
+ GFP_KERNEL);
+ if (!dma->vaddr_pages)
+ return -ENOMEM;
+
+ dma->dma_addr = kcalloc(nr_pages, sizeof(*dma->dma_addr), GFP_KERNEL);
+ if (!dma->dma_addr) {
+ kfree(dma->vaddr_pages);
+ return -ENOMEM;
+ }
+ for (i = 0; i < nr_pages; i++) {
+ void *addr;
+
+ addr = dma_alloc_coherent(dma->dev, PAGE_SIZE,
+ &(dma->dma_addr[i]), GFP_KERNEL);
+ if (addr == NULL)
+ goto out_free_pages;
+
+ dma->vaddr_pages[i] = virt_to_page(addr);
+ }
+ dma->vaddr = vmap(dma->vaddr_pages, nr_pages, VM_MAP | VM_IOREMAP,
+ PAGE_KERNEL);
if (NULL == dma->vaddr) {
dprintk(1, "vmalloc_32(%d pages) failed\n", nr_pages);
- return -ENOMEM;
+ goto out_free_pages;
}
dprintk(1, "vmalloc is at addr 0x%08lx, size=%d\n",
@@ -228,6 +251,19 @@ int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
dma->nr_pages = nr_pages;
return 0;
+out_free_pages:
+ while (i > 0) {
+ void *addr = page_address(dma->vaddr_pages[i]);
+ dma_free_coherent(dma->dev, PAGE_SIZE, addr, dma->dma_addr[i]);
+ i--;
+ }
+ kfree(dma->dma_addr);
+ dma->dma_addr = NULL;
+ kfree(dma->vaddr_pages);
+ dma->vaddr_pages = NULL;
+
+ return -ENOMEM;
+
}
EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
@@ -322,8 +358,21 @@ int videobuf_dma_free(struct videobuf_dmabuf *dma)
dma->pages = NULL;
}
- vfree(dma->vaddr);
- dma->vaddr = NULL;
+ if (dma->dma_addr) {
+ for (i = 0; i < dma->nr_pages; i++) {
+ void *addr;
+
+ addr = page_address(dma->vaddr_pages[i]);
+ dma_free_coherent(dma->dev, PAGE_SIZE, addr,
+ dma->dma_addr[i]);
+ }
+ kfree(dma->dma_addr);
+ dma->dma_addr = NULL;
+ kfree(dma->vaddr_pages);
+ dma->vaddr_pages = NULL;
+ vunmap(dma->vaddr);
+ dma->vaddr = NULL;
+ }
if (dma->bus_addr)
dma->bus_addr = 0;
@@ -461,6 +510,11 @@ static int __videobuf_iolock(struct videobuf_queue *q,
MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
+ if (!mem->dma.dev)
+ mem->dma.dev = q->dev;
+ else
+ WARN_ON(mem->dma.dev != q->dev);
+
switch (vb->memory) {
case V4L2_MEMORY_MMAP:
case V4L2_MEMORY_USERPTR:
diff --git a/include/media/videobuf-dma-sg.h b/include/media/videobuf-dma-sg.h
index d8fb6012c10d..fb6fd4d8f4ed 100644
--- a/include/media/videobuf-dma-sg.h
+++ b/include/media/videobuf-dma-sg.h
@@ -53,6 +53,9 @@ struct videobuf_dmabuf {
/* for kernel buffers */
void *vaddr;
+ struct page **vaddr_pages;
+ dma_addr_t *dma_addr;
+ struct device *dev;
/* for overlay buffers (pci-pci dma) */
dma_addr_t bus_addr;

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