[PATCH v2 3/4] media: videobuf2-dma-contig: use dma_mmap_coherent if available
From: Hideki EIRAKU <hidden>
Date: 2012-07-26 11:14:18
Also in:
alsa-devel, linux-arm-kernel, linux-media, lkml
Subsystem:
media input infrastructure (v4l/dvb), the rest · Maintainers:
Mauro Carvalho Chehab, Linus Torvalds
Previously the vb2_dma_contig_mmap() function was using a dma_addr_t as a physical address. The two addressses are not necessarily the same. For example, when using the IOMMU funtion on certain platforms, dma_addr_t addresses are not directly mappable physical address. dma_mmap_coherent() maps the address correctly. It is available on ARM platforms. Signed-off-by: Hideki EIRAKU <redacted> --- drivers/media/video/videobuf2-dma-contig.c | 18 ++++++++++++++++++ 1 files changed, 18 insertions(+), 0 deletions(-)
diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c
index 4b71326..4dc85ab 100644
--- a/drivers/media/video/videobuf2-dma-contig.c
+++ b/drivers/media/video/videobuf2-dma-contig.c@@ -101,14 +101,32 @@ static unsigned int vb2_dma_contig_num_users(void *buf_priv) static int vb2_dma_contig_mmap(void *buf_priv, struct vm_area_struct *vma) { struct vb2_dc_buf *buf = buf_priv; +#ifdef ARCH_HAS_DMA_MMAP_COHERENT + int ret; +#endif if (!buf) { printk(KERN_ERR "No buffer to map\n"); return -EINVAL; } +#ifdef ARCH_HAS_DMA_MMAP_COHERENT + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + ret = dma_mmap_coherent(buf->conf->dev, vma, buf->vaddr, buf->dma_addr, + buf->size); + if (ret) { + pr_err("Remapping memory failed, error: %d\n", ret); + return ret; + } + vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED; + vma->vm_private_data = &buf->handler; + vma->vm_ops = &vb2_common_vm_ops; + vma->vm_ops->open(vma); + return 0; +#else return vb2_mmap_pfn_range(vma, buf->dma_addr, buf->size, &vb2_common_vm_ops, &buf->handler); +#endif } static void *vb2_dma_contig_get_userptr(void *alloc_ctx, unsigned long vaddr,
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1.7.0.4