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authorPawel Osciak <p.osciak@samsung.com>2010-10-11 17:59:36 +0400
committerMauro Carvalho Chehab <mchehab@redhat.com>2011-03-22 02:31:34 +0300
commit1a758d4e847f7743ac1b5aa79fde3ba2d8b5132b (patch)
treeb5f37565157d7dd16af460b00b19cafa1b01c966 /drivers/media/video/videobuf2-dma-contig.c
parent3c18ff06d811f743d380e6436fac0143ffcf1266 (diff)
downloadlinux-1a758d4e847f7743ac1b5aa79fde3ba2d8b5132b.tar.xz
[media] v4l: videobuf2: add DMA coherent allocator
Add an implementation of DMA coherent memory allocator and handling routines for videobuf2, implemented on top of dma_alloc_coherent() call. Signed-off-by: Pawel Osciak <p.osciak@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> Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/video/videobuf2-dma-contig.c')
-rw-r--r--drivers/media/video/videobuf2-dma-contig.c185
1 files changed, 185 insertions, 0 deletions
diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c
new file mode 100644
index 000000000000..bb6a5602cf94
--- /dev/null
+++ b/drivers/media/video/videobuf2-dma-contig.c
@@ -0,0 +1,185 @@
+/*
+ * videobuf2-dma-contig.c - DMA contig memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <p.osciak@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-memops.h>
+
+struct vb2_dc_conf {
+ struct device *dev;
+};
+
+struct vb2_dc_buf {
+ struct vb2_dc_conf *conf;
+ void *vaddr;
+ dma_addr_t paddr;
+ unsigned long size;
+ struct vm_area_struct *vma;
+ atomic_t refcount;
+ struct vb2_vmarea_handler handler;
+};
+
+static void vb2_dma_contig_put(void *buf_priv);
+
+static void *vb2_dma_contig_alloc(void *alloc_ctx, unsigned long size)
+{
+ struct vb2_dc_conf *conf = alloc_ctx;
+ struct vb2_dc_buf *buf;
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ buf->vaddr = dma_alloc_coherent(conf->dev, size, &buf->paddr,
+ GFP_KERNEL);
+ if (!buf->vaddr) {
+ dev_err(conf->dev, "dma_alloc_coherent of size %ld failed\n",
+ buf->size);
+ kfree(buf);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ buf->conf = conf;
+ buf->size = size;
+
+ buf->handler.refcount = &buf->refcount;
+ buf->handler.put = vb2_dma_contig_put;
+ buf->handler.arg = buf;
+
+ atomic_inc(&buf->refcount);
+
+ return buf;
+}
+
+static void vb2_dma_contig_put(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ if (atomic_dec_and_test(&buf->refcount)) {
+ dma_free_coherent(buf->conf->dev, buf->size, buf->vaddr,
+ buf->paddr);
+ kfree(buf);
+ }
+}
+
+static void *vb2_dma_contig_cookie(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ return (void *)buf->paddr;
+}
+
+static void *vb2_dma_contig_vaddr(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+ if (!buf)
+ return 0;
+
+ return buf->vaddr;
+}
+
+static unsigned int vb2_dma_contig_num_users(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ return atomic_read(&buf->refcount);
+}
+
+static int vb2_dma_contig_mmap(void *buf_priv, struct vm_area_struct *vma)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ if (!buf) {
+ printk(KERN_ERR "No buffer to map\n");
+ return -EINVAL;
+ }
+
+ return vb2_mmap_pfn_range(vma, buf->paddr, buf->size,
+ &vb2_common_vm_ops, &buf->handler);
+}
+
+static void *vb2_dma_contig_get_userptr(void *alloc_ctx, unsigned long vaddr,
+ unsigned long size, int write)
+{
+ struct vb2_dc_buf *buf;
+ struct vm_area_struct *vma;
+ dma_addr_t paddr = 0;
+ int ret;
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ ret = vb2_get_contig_userptr(vaddr, size, &vma, &paddr);
+ if (ret) {
+ printk(KERN_ERR "Failed acquiring VMA for vaddr 0x%08lx\n",
+ vaddr);
+ kfree(buf);
+ return ERR_PTR(ret);
+ }
+
+ buf->size = size;
+ buf->paddr = paddr;
+ buf->vma = vma;
+
+ return buf;
+}
+
+static void vb2_dma_contig_put_userptr(void *mem_priv)
+{
+ struct vb2_dc_buf *buf = mem_priv;
+
+ if (!buf)
+ return;
+
+ vb2_put_vma(buf->vma);
+ kfree(buf);
+}
+
+const struct vb2_mem_ops vb2_dma_contig_memops = {
+ .alloc = vb2_dma_contig_alloc,
+ .put = vb2_dma_contig_put,
+ .cookie = vb2_dma_contig_cookie,
+ .vaddr = vb2_dma_contig_vaddr,
+ .mmap = vb2_dma_contig_mmap,
+ .get_userptr = vb2_dma_contig_get_userptr,
+ .put_userptr = vb2_dma_contig_put_userptr,
+ .num_users = vb2_dma_contig_num_users,
+};
+EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);
+
+void *vb2_dma_contig_init_ctx(struct device *dev)
+{
+ struct vb2_dc_conf *conf;
+
+ conf = kzalloc(sizeof *conf, GFP_KERNEL);
+ if (!conf)
+ return ERR_PTR(-ENOMEM);
+
+ conf->dev = dev;
+
+ return conf;
+}
+EXPORT_SYMBOL_GPL(vb2_dma_contig_init_ctx);
+
+void vb2_dma_contig_cleanup_ctx(void *alloc_ctx)
+{
+ kfree(alloc_ctx);
+}
+EXPORT_SYMBOL_GPL(vb2_dma_contig_cleanup_ctx);
+
+MODULE_DESCRIPTION("DMA-contig memory handling routines for videobuf2");
+MODULE_AUTHOR("Pawel Osciak");
+MODULE_LICENSE("GPL");