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@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
drivers/media/video/Kconfig | 5 +
drivers/media/video/Makefile | 4 +
drivers/media/video/videobuf2-dma-coherent.c | 208 ++++++++++++++++++++++++++
include/media/videobuf2-dma-coherent.h | 16 ++
4 files changed, 233 insertions(+), 0 deletions(-)
create mode 100644 drivers/media/video/videobuf2-dma-coherent.c
create mode 100644 include/media/videobuf2-dma-coherent.h
diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index aae7a30..5286b2f 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -55,6 +55,11 @@ config VIDEOBUF2_CORE
config VIDEOBUF2_MEMOPS
tristate
+config VIDEOBUF2_DMA_COHERENT
+ select VIDEOBUF2_CORE
+ select VIDEOBUF2_GEN_MEMOPS
+ tristate
+
config VIDEOBUF2_VMALLOC
select VIDEOBUF2_CORE
select VIDEOBUF2_GEN_MEMOPS
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index b7c15ae..20d359d 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -120,6 +120,10 @@ obj-$(CONFIG_VIDEO_BTCX) += btcx-risc.o
obj-$(CONFIG_VIDEOBUF2_CORE) += videobuf2-core.o
obj-$(CONFIG_VIDEOBUF2_MEMOPS) += videobuf2-memops.o
+obj-$(CONFIG_VIDEOBUF2_DMA_COHERENT) += videobuf2_dma_coherent.o
+videobuf2_dma_coherent-y := videobuf2-dma-coherent.o \
+ videobuf2-memops.o
+
obj-$(CONFIG_VIDEOBUF2_VMALLOC) += videobuf2_vmalloc.o
videobuf2_vmalloc-y := videobuf2-vmalloc.o \
videobuf2-memops.o
diff --git a/drivers/media/video/videobuf2-dma-coherent.c b/drivers/media/video/videobuf2-dma-coherent.c
new file mode 100644
index 0000000..8c77f9d
--- /dev/null
+++ b/drivers/media/video/videobuf2-dma-coherent.c
@@ -0,0 +1,208 @@
+/*
+ * videobuf2-dma-coherent.c - DMA coherent memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <p.osciak@xxxxxxxxxxx>
+ *
+ * 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/dma-mapping.h>
+
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-memops.h>
+
+struct vb2_dc_conf {
+ struct vb2_alloc_ctx alloc_ctx;
+ struct device *dev;
+};
+
+struct vb2_dc_buf {
+ struct vb2_dc_conf *conf;
+ void *vaddr;
+ dma_addr_t paddr;
+ unsigned long size;
+ unsigned int refcount;
+ struct vm_area_struct *vma;
+};
+
+struct vb2_alloc_ctx *vb2_dma_coherent_init(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->alloc_ctx;
+}
+EXPORT_SYMBOL_GPL(vb2_dma_coherent_init);
+
+void vb2_dma_coherent_cleanup(struct vb2_alloc_ctx *alloc_ctx)
+{
+ struct vb2_dc_conf *conf =
+ container_of(alloc_ctx, struct vb2_dc_conf, alloc_ctx);
+
+ kfree(conf);
+}
+EXPORT_SYMBOL_GPL(vb2_dma_coherent_cleanup);
+
+static void *vb2_dma_coherent_alloc(const struct vb2_alloc_ctx *alloc_ctx,
+ unsigned long size)
+{
+ struct vb2_dc_conf *conf =
+ container_of(alloc_ctx, struct vb2_dc_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, buf->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;
+
+ return buf;
+}
+
+static void vb2_dma_coherent_put(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ buf->refcount--;
+
+ if (0 == buf->refcount) {
+ dma_free_coherent(buf->conf->dev, buf->size, buf->vaddr,
+ buf->paddr);
+ kfree(buf);
+ }
+}
+
+static unsigned long vb2_dma_coherent_paddr(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ return buf->paddr;
+}
+
+static unsigned int vb2_dma_coherent_num_users(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ return buf->refcount;
+}
+
+static void vb2_dma_coherent_vm_open(struct vm_area_struct *vma)
+{
+ struct vb2_dc_buf *buf = vma->vm_private_data;
+
+ printk(KERN_DEBUG "%s cma_priv: %p, refcount: %d, "
+ "vma: %08lx-%08lx\n", __func__, buf, buf->refcount,
+ vma->vm_start, vma->vm_end);
+
+ buf->refcount++;
+}
+
+static void vb2_dma_coherent_vm_close(struct vm_area_struct *vma)
+{
+ struct vb2_dc_buf *buf = vma->vm_private_data;
+
+ printk(KERN_DEBUG "%s cma_priv: %p, refcount: %d, "
+ "vma: %08lx-%08lx\n", __func__, buf, buf->refcount,
+ vma->vm_start, vma->vm_end);
+
+ vb2_dma_coherent_put(buf);
+}
+
+static const struct vm_operations_struct vb2_dma_coherent_vm_ops = {
+ .open = vb2_dma_coherent_vm_open,
+ .close = vb2_dma_coherent_vm_close,
+};
+
+static int vb2_dma_coherent_mmap(void *buf_priv, struct vm_area_struct *vma)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ if (!buf) {
+ printk(KERN_ERR "No memory to map\n");
+ return -EINVAL;
+ }
+
+ return vb2_mmap_pfn_range(vma, buf->paddr, buf->size,
+ &vb2_dma_coherent_vm_ops, buf);
+}
+
+static void *vb2_dma_coherent_get_userptr(unsigned long vaddr,
+ unsigned long size)
+{
+ struct vb2_dc_buf *buf;
+ unsigned long paddr = 0;
+ int ret;
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ buf->vma = vb2_get_userptr(vaddr);
+ if (!buf->vma) {
+ printk(KERN_ERR "Failed acquiring VMA for vaddr 0x%08lx\n",
+ vaddr);
+ ret = -EINVAL;
+ goto done;
+ }
+
+ ret = vb2_contig_verify_userptr(buf->vma, vaddr, size, &paddr);
+ if (ret) {
+ vb2_put_userptr(buf->vma);
+ goto done;
+ }
+
+ buf->size = size;
+ buf->paddr = paddr;
+
+ return buf;
+
+done:
+ kfree(buf);
+ return ERR_PTR(ret);
+}
+
+static void vb2_dma_coherent_put_userptr(void *mem_priv)
+{
+ struct vb2_dc_buf *buf = mem_priv;
+
+ if (!buf)
+ return;
+
+ vb2_put_userptr(buf->vma);
+ kfree(buf);
+}
+
+const struct vb2_mem_ops vb2_dma_coherent_ops = {
+ .alloc = vb2_dma_coherent_alloc,
+ .put = vb2_dma_coherent_put,
+ .paddr = vb2_dma_coherent_paddr,
+ .mmap = vb2_dma_coherent_mmap,
+ .get_userptr = vb2_dma_coherent_get_userptr,
+ .put_userptr = vb2_dma_coherent_put_userptr,
+ .num_users = vb2_dma_coherent_num_users,
+};
+
+MODULE_DESCRIPTION("DMA-coherent memory handling routines for videobuf2");
+MODULE_AUTHOR("Pawel Osciak");
+MODULE_LICENSE("GPL");
+
diff --git a/include/media/videobuf2-dma-coherent.h b/include/media/videobuf2-dma-coherent.h
new file mode 100644
index 0000000..c7fce51
--- /dev/null
+++ b/include/media/videobuf2-dma-coherent.h
@@ -0,0 +1,16 @@
+/*
+ * videobuf2-dma-coherent.h - DMA coherent memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <p.osciak@xxxxxxxxxxx>
+ *
+ * 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 <media/videobuf2-core.h>
+
+void *vb2_dma_coherent_init(struct device *dev);
+void vb2_dma_coherent_cleanup(struct vb2_alloc_ctx *alloc_ctx);
--
1.7.2.1.97.g3235b.dirty
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