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[1/1] v4l: videobuf2: Add DMA pool allocator

Message ID 1293684907-7272-2-git-send-email-jtp.park@samsung.com (mailing list archive)
State RFC
Headers show

Commit Message

Jeongtae Park Dec. 30, 2010, 4:55 a.m. UTC
None
diff mbox

Patch

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index a1b2412..cee5b0a 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -71,6 +71,13 @@  config VIDEOBUF2_DMA_SG
 	select VIDEOBUF2_CORE
 	select VIDEOBUF2_MEMOPS
 	tristate
+
+config VIDEOBUF2_DMA_POOL
+	select VIDEOBUF2_CORE
+	select VIDEOBUF2_MEMOPS
+	select GENERIC_ALLOCATOR
+	tristate
+
 #
 # Multimedia Video device configuration
 #
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index af33c30..eb53da3 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -120,6 +120,7 @@  obj-$(CONFIG_VIDEOBUF2_MEMOPS)		+= videobuf2-memops.o
 obj-$(CONFIG_VIDEOBUF2_VMALLOC)		+= videobuf2-vmalloc.o
 obj-$(CONFIG_VIDEOBUF2_DMA_CONTIG)	+= videobuf2-dma-contig.o
 obj-$(CONFIG_VIDEOBUF2_DMA_SG)		+= videobuf2-dma-sg.o
+obj-$(CONFIG_VIDEOBUF2_DMA_POOL)	+= videobuf2-dma-pool.o
 
 obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o
 
diff --git a/drivers/media/video/videobuf2-dma-pool.c b/drivers/media/video/videobuf2-dma-pool.c
new file mode 100644
index 0000000..59f4cba
--- /dev/null
+++ b/drivers/media/video/videobuf2-dma-pool.c
@@ -0,0 +1,310 @@ 
+/*
+ * videobuf2-dma-pool.c - DMA pool memory allocator for videobuf2
+ *
+ * Copyright (c) 2010 Samsung Electronics Co., Ltd.
+ *		http://www.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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+#include <linux/genalloc.h>
+
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-memops.h>
+
+#define DMA_POOL_MAGIC	0x706F6F6C
+#define MAGIC_CHECK(is, should)					\
+	if (unlikely((is) != (should))) {			\
+		pr_err("magic mismatch: %x (expected %x)\n",	\
+				(is), (should));		\
+		BUG();						\
+	}
+
+static int debug;
+module_param(debug, int, 0644);
+
+#define dprintk(level, fmt, arg...)					\
+	do {								\
+		if (debug >= level)					\
+			printk(KERN_DEBUG "vb2_dp: " fmt, ## arg);	\
+	} while (0)
+
+struct vb2_dma_pool_conf {
+	struct device		*dev;
+	struct gen_pool		*pool;
+	dma_addr_t		paddr;
+	void			*vaddr;
+	unsigned long		size;
+	u32			magic;
+};
+
+struct vb2_dma_pool_buf {
+	struct vb2_dma_pool_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_pool_put(void *buf_priv);
+
+static void *vb2_dma_pool_alloc(void *alloc_ctx, unsigned long size)
+{
+	struct vb2_dma_pool_conf *conf = alloc_ctx;
+	struct vb2_dma_pool_buf *buf;
+
+	BUG_ON(!conf);
+	MAGIC_CHECK(conf->magic, DMA_POOL_MAGIC);
+
+	buf = kzalloc(sizeof *buf, GFP_KERNEL);
+	if (!buf)
+		return ERR_PTR(-ENOMEM);
+
+	buf->paddr = gen_pool_alloc(conf->pool, size);
+	if (!buf->paddr) {
+		dev_err(conf->dev, "failed to get buffer from pool: %ld\n",
+			size);
+		kfree(buf);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	buf->conf = conf;
+	buf->vaddr = conf->vaddr + (buf->paddr - conf->paddr);
+	buf->size = size;
+
+	buf->handler.refcount = &buf->refcount;
+	buf->handler.put = vb2_dma_pool_put;
+	buf->handler.arg = buf;
+
+	atomic_inc(&buf->refcount);
+
+	dprintk(2, "alloc-> vaddr: %p, paddr: 0x%08x, size: %ld\n",
+		buf->vaddr, buf->paddr, size);
+
+	return buf;
+}
+
+static void vb2_dma_pool_put(void *buf_priv)
+{
+	struct vb2_dma_pool_buf *buf = buf_priv;
+
+	dprintk(3, "put-> refcount: %d\n", atomic_read(&buf->refcount));
+
+	if (atomic_dec_and_test(&buf->refcount)) {
+		dprintk(2, "put-> paddr: 0x%08x, size: %ld\n",
+			buf->paddr, buf->size);
+
+		gen_pool_free(buf->conf->pool, buf->paddr, buf->size);
+		kfree(buf);
+	}
+}
+
+static void *vb2_dma_pool_cookie(void *buf_priv)
+{
+	struct vb2_dma_pool_buf *buf = buf_priv;
+
+	if (!buf) {
+		pr_err("failed to get buffer\n");
+		return NULL;
+	}
+
+	return (void *)buf->paddr;
+}
+
+static void *vb2_dma_pool_vaddr(void *buf_priv)
+{
+	struct vb2_dma_pool_buf *buf = buf_priv;
+
+	if (!buf) {
+		pr_err("failed to get buffer\n");
+		return NULL;
+	}
+
+	return buf->vaddr;
+}
+
+static unsigned int vb2_dma_pool_num_users(void *buf_priv)
+{
+	struct vb2_dma_pool_buf *buf = buf_priv;
+
+	if (!buf) {
+		pr_err("failed to get buffer\n");
+		return 0;
+	}
+
+	return atomic_read(&buf->refcount);
+}
+
+static int vb2_dma_pool_mmap(void *buf_priv, struct vm_area_struct *vma)
+{
+	struct vb2_dma_pool_buf *buf = buf_priv;
+
+	if (!buf) {
+		pr_err("no buffer to map\n");
+		return -EINVAL;
+	}
+
+	return vb2_mmap_pfn_range(vma, buf->paddr, buf->size,
+				  &vb2_common_vm_ops, &buf->handler);
+}
+
+const struct vb2_mem_ops vb2_dma_pool_memops = {
+	.alloc		= vb2_dma_pool_alloc,
+	.put		= vb2_dma_pool_put,
+	.cookie		= vb2_dma_pool_cookie,
+	.vaddr		= vb2_dma_pool_vaddr,
+	.mmap		= vb2_dma_pool_mmap,
+	.num_users	= vb2_dma_pool_num_users,
+};
+EXPORT_SYMBOL_GPL(vb2_dma_pool_memops);
+
+void *vb2_dma_pool_init(struct device *dev, unsigned long base_order,
+			unsigned long alloc_order, unsigned long size)
+{
+	struct vb2_dma_pool_conf *conf;
+	int ret;
+	unsigned long margin, margin_order;
+
+	if (!(size >> alloc_order))
+		return ERR_PTR(-EINVAL);
+
+	conf = kzalloc(sizeof *conf, GFP_KERNEL);
+	if (!conf)
+		return ERR_PTR(-ENOMEM);
+
+	conf->magic = DMA_POOL_MAGIC;
+	conf->dev = dev;
+	conf->size = size;
+
+	conf->vaddr = dma_alloc_coherent(conf->dev, conf->size,
+					 &conf->paddr, GFP_KERNEL);
+	if (!conf->vaddr) {
+		dev_err(dev, "dma_alloc_coherent of size %ld failed\n",
+			size);
+		ret = -ENOMEM;
+		goto fail_dma_alloc;
+	}
+
+	dprintk(1, "init-> vaddr: %p, paddr: 0x%08x, size: %ld\n",
+		conf->vaddr, conf->paddr, conf->size);
+
+	margin_order = (base_order > alloc_order) ? base_order : alloc_order;
+	margin = ALIGN(conf->paddr, (1 << margin_order)) - conf->paddr;
+
+	dprintk(1, "init-> margin_order: %ld, margin: %ld\n",
+		margin_order, margin);
+
+	if (margin >= conf->size) {
+		ret = -ENOMEM;
+		goto fail_base_align;
+	}
+
+	if (!((conf->size - margin) >> alloc_order)) {
+		ret = -ENOMEM;
+		goto fail_base_align;
+	}
+
+	conf->pool = gen_pool_create(alloc_order, -1);
+	if (!conf->pool) {
+		dev_err(conf->dev, "failed to create pool\n");
+		ret = -ENOMEM;
+		goto fail_pool_create;
+	}
+
+	ret = gen_pool_add(conf->pool, (conf->paddr + margin),
+			   (conf->size - margin), -1);
+	if (ret) {
+		dev_err(conf->dev, "could not add buffer to pool");
+		goto fail_pool_add;
+	}
+
+	return conf;
+
+fail_pool_add:
+	gen_pool_destroy(conf->pool);
+fail_base_align:
+fail_pool_create:
+	dma_free_coherent(conf->dev, conf->size, conf->vaddr, conf->paddr);
+fail_dma_alloc:
+	kfree(conf);
+
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(vb2_dma_pool_init);
+
+void vb2_dma_pool_cleanup(void *conf)
+{
+	struct vb2_dma_pool_conf *_conf;
+
+	_conf = (struct vb2_dma_pool_conf *)conf;
+
+	BUG_ON(!_conf);
+	MAGIC_CHECK(_conf->magic, DMA_POOL_MAGIC);
+
+	gen_pool_destroy(_conf->pool);
+	dma_free_coherent(_conf->dev, _conf->size, _conf->vaddr,
+			  _conf->paddr);
+
+	kfree(conf);
+}
+EXPORT_SYMBOL_GPL(vb2_dma_pool_cleanup);
+
+void **vb2_dma_pool_init_multi(struct device *dev, unsigned int num_planes,
+			       unsigned long base_orders[],
+			       unsigned long alloc_orders[],
+			       unsigned long sizes[])
+{
+	struct vb2_dma_pool_conf *conf;
+	void **alloc_ctxes;
+	int i, j;
+
+	alloc_ctxes = kzalloc(sizeof *alloc_ctxes * num_planes, GFP_KERNEL);
+	if (!alloc_ctxes)
+		return ERR_PTR(-ENOMEM);
+
+	conf = (void *)(alloc_ctxes + num_planes);
+
+	for (i = 0; i < num_planes; ++i, ++conf) {
+		dprintk(1, "init_multi-> index: %d, orders: %ld, %ld\n",
+			i, base_orders[i], alloc_orders[i]);
+
+		conf = vb2_dma_pool_init(dev, base_orders[i],
+					 alloc_orders[i], sizes[i]);
+		if (IS_ERR(conf)) {
+			for (j = i - 1; j >= 0; j--)
+				vb2_dma_pool_cleanup(alloc_ctxes[j]);
+
+			kfree(alloc_ctxes);
+			return ERR_PTR(PTR_ERR(conf));
+		}
+
+		alloc_ctxes[i] = conf;
+	}
+
+	return alloc_ctxes;
+}
+EXPORT_SYMBOL_GPL(vb2_dma_pool_init_multi);
+
+void vb2_dma_pool_cleanup_multi(void **alloc_ctxes, unsigned int num_planes)
+{
+	int i;
+
+	for (i = 0; i < num_planes; i++)
+		vb2_dma_pool_cleanup(alloc_ctxes[i]);
+
+	kfree(alloc_ctxes);
+}
+EXPORT_SYMBOL_GPL(vb2_dma_pool_cleanup_multi);
+
+MODULE_DESCRIPTION("DMA-pool handling routines for videobuf2");
+MODULE_AUTHOR("Jeongtae Park");
+MODULE_LICENSE("GPL");
+
diff --git a/include/media/videobuf2-dma-pool.h b/include/media/videobuf2-dma-pool.h
new file mode 100644
index 0000000..3cad846
--- /dev/null
+++ b/include/media/videobuf2-dma-pool.h
@@ -0,0 +1,37 @@ 
+/*
+ * videobuf2-dma-pool.h - DMA pool memory allocator for videobuf2
+ *
+ * Copyright (c) 2010 Samsung Electronics Co., Ltd.
+ *		http://www.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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef _MEDIA_VIDEOBUF2_DMA_POOL_H
+#define _MEDIA_VIDEOBUF2_DMA_POOL_H
+
+#include <media/videobuf2-core.h>
+
+static inline unsigned long vb2_dma_pool_plane_paddr(struct vb2_buffer *vb,
+						     unsigned int plane_no)
+{
+	return (unsigned long)vb2_plane_cookie(vb, plane_no);
+}
+
+void *vb2_dma_pool_init(struct device *dev, unsigned long base_order,
+			unsigned long alloc_order, unsigned long size);
+void vb2_dma_pool_cleanup(struct vb2_alloc_ctx *alloc_ctx);
+
+void **vb2_dma_pool_init_multi(struct device *dev, unsigned int num_planes,
+			       unsigned long base_orders[],
+			       unsigned long alloc_orders[],
+			       unsigned long sizes[]);
+void vb2_dma_pool_cleanup_multi(void **alloc_ctxes,
+				unsigned int num_planes);
+
+extern const struct vb2_mem_ops vb2_dma_pool_memops;
+
+#endif /* _MEDIA_VIDEOBUF2_DMA_POOL_H */