media: drivers/media/common/videobuf2: rename from videobuf

This directory contains the videobuf2 framework, so name the
directory accordingly.

The name 'videobuf' typically refers to the old and deprecated
videobuf version 1 framework so that was confusing.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

1 files changed, 669 insertions, 0 deletions

diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
new file mode 100644
index 000000000000..753ed3138dcc
--- /dev/null
+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
@@ -0,0 +1,669 @@
+/*
+ * videobuf2-dma-sg.c - dma scatter/gather memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Andrzej Pietrasiewicz <andrzej.p@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/mm.h>
+#include <linux/refcount.h>
+#include <linux/scatterlist.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include <media/videobuf2-v4l2.h>
+#include <media/videobuf2-memops.h>
+#include <media/videobuf2-dma-sg.h>
+
+static int debug;
+module_param(debug, int, 0644);
+
+#define dprintk(level, fmt, arg...)					\
+	do {								\
+		if (debug >= level)					\
+			printk(KERN_DEBUG "vb2-dma-sg: " fmt, ## arg);	\
+	} while (0)
+
+struct vb2_dma_sg_buf {
+	struct device			*dev;
+	void				*vaddr;
+	struct page			**pages;
+	struct frame_vector		*vec;
+	int				offset;
+	enum dma_data_direction		dma_dir;
+	struct sg_table			sg_table;
+	/*
+	 * This will point to sg_table when used with the MMAP or USERPTR
+	 * memory model, and to the dma_buf sglist when used with the
+	 * DMABUF memory model.
+	 */
+	struct sg_table			*dma_sgt;
+	size_t				size;
+	unsigned int			num_pages;
+	refcount_t			refcount;
+	struct vb2_vmarea_handler	handler;
+
+	struct dma_buf_attachment	*db_attach;
+};
+
+static void vb2_dma_sg_put(void *buf_priv);
+
+static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf,
+		gfp_t gfp_flags)
+{
+	unsigned int last_page = 0;
+	int size = buf->size;
+
+	while (size > 0) {
+		struct page *pages;
+		int order;
+		int i;
+
+		order = get_order(size);
+		/* Dont over allocate*/
+		if ((PAGE_SIZE << order) > size)
+			order--;
+
+		pages = NULL;
+		while (!pages) {
+			pages = alloc_pages(GFP_KERNEL | __GFP_ZERO |
+					__GFP_NOWARN | gfp_flags, order);
+			if (pages)
+				break;
+
+			if (order == 0) {
+				while (last_page--)
+					__free_page(buf->pages[last_page]);
+				return -ENOMEM;
+			}
+			order--;
+		}
+
+		split_page(pages, order);
+		for (i = 0; i < (1 << order); i++)
+			buf->pages[last_page++] = &pages[i];
+
+		size -= PAGE_SIZE << order;
+	}
+
+	return 0;
+}
+
+static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs,
+			      unsigned long size, enum dma_data_direction dma_dir,
+			      gfp_t gfp_flags)
+{
+	struct vb2_dma_sg_buf *buf;
+	struct sg_table *sgt;
+	int ret;
+	int num_pages;
+
+	if (WARN_ON(!dev))
+		return ERR_PTR(-EINVAL);
+
+	buf = kzalloc(sizeof *buf, GFP_KERNEL);
+	if (!buf)
+		return ERR_PTR(-ENOMEM);
+
+	buf->vaddr = NULL;
+	buf->dma_dir = dma_dir;
+	buf->offset = 0;
+	buf->size = size;
+	/* size is already page aligned */
+	buf->num_pages = size >> PAGE_SHIFT;
+	buf->dma_sgt = &buf->sg_table;
+
+	buf->pages = kvmalloc_array(buf->num_pages, sizeof(struct page *),
+				    GFP_KERNEL | __GFP_ZERO);
+	if (!buf->pages)
+		goto fail_pages_array_alloc;
+
+	ret = vb2_dma_sg_alloc_compacted(buf, gfp_flags);
+	if (ret)
+		goto fail_pages_alloc;
+
+	ret = sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
+			buf->num_pages, 0, size, GFP_KERNEL);
+	if (ret)
+		goto fail_table_alloc;
+
+	/* Prevent the device from being released while the buffer is used */
+	buf->dev = get_device(dev);
+
+	sgt = &buf->sg_table;
+	/*
+	 * No need to sync to the device, this will happen later when the
+	 * prepare() memop is called.
+	 */
+	sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
+				      buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+	if (!sgt->nents)
+		goto fail_map;
+
+	buf->handler.refcount = &buf->refcount;
+	buf->handler.put = vb2_dma_sg_put;
+	buf->handler.arg = buf;
+
+	refcount_set(&buf->refcount, 1);
+
+	dprintk(1, "%s: Allocated buffer of %d pages\n",
+		__func__, buf->num_pages);
+	return buf;
+
+fail_map:
+	put_device(buf->dev);
+	sg_free_table(buf->dma_sgt);
+fail_table_alloc:
+	num_pages = buf->num_pages;
+	while (num_pages--)
+		__free_page(buf->pages[num_pages]);
+fail_pages_alloc:
+	kvfree(buf->pages);
+fail_pages_array_alloc:
+	kfree(buf);
+	return ERR_PTR(-ENOMEM);
+}
+
+static void vb2_dma_sg_put(void *buf_priv)
+{
+	struct vb2_dma_sg_buf *buf = buf_priv;
+	struct sg_table *sgt = &buf->sg_table;
+	int i = buf->num_pages;
+
+	if (refcount_dec_and_test(&buf->refcount)) {
+		dprintk(1, "%s: Freeing buffer of %d pages\n", __func__,
+			buf->num_pages);
+		dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
+				   buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+		if (buf->vaddr)
+			vm_unmap_ram(buf->vaddr, buf->num_pages);
+		sg_free_table(buf->dma_sgt);
+		while (--i >= 0)
+			__free_page(buf->pages[i]);
+		kvfree(buf->pages);
+		put_device(buf->dev);
+		kfree(buf);
+	}
+}
+
+static void vb2_dma_sg_prepare(void *buf_priv)
+{
+	struct vb2_dma_sg_buf *buf = buf_priv;
+	struct sg_table *sgt = buf->dma_sgt;
+
+	/* DMABUF exporter will flush the cache for us */
+	if (buf->db_attach)
+		return;
+
+	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
+			       buf->dma_dir);
+}
+
+static void vb2_dma_sg_finish(void *buf_priv)
+{
+	struct vb2_dma_sg_buf *buf = buf_priv;
+	struct sg_table *sgt = buf->dma_sgt;
+
+	/* DMABUF exporter will flush the cache for us */
+	if (buf->db_attach)
+		return;
+
+	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
+}
+
+static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr,
+				    unsigned long size,
+				    enum dma_data_direction dma_dir)
+{
+	struct vb2_dma_sg_buf *buf;
+	struct sg_table *sgt;
+	struct frame_vector *vec;
+
+	if (WARN_ON(!dev))
+		return ERR_PTR(-EINVAL);
+
+	buf = kzalloc(sizeof *buf, GFP_KERNEL);
+	if (!buf)
+		return ERR_PTR(-ENOMEM);
+
+	buf->vaddr = NULL;
+	buf->dev = dev;
+	buf->dma_dir = dma_dir;
+	buf->offset = vaddr & ~PAGE_MASK;
+	buf->size = size;
+	buf->dma_sgt = &buf->sg_table;
+	vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE ||
+					       dma_dir == DMA_BIDIRECTIONAL);
+	if (IS_ERR(vec))
+		goto userptr_fail_pfnvec;
+	buf->vec = vec;
+
+	buf->pages = frame_vector_pages(vec);
+	if (IS_ERR(buf->pages))
+		goto userptr_fail_sgtable;
+	buf->num_pages = frame_vector_count(vec);
+
+	if (sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
+			buf->num_pages, buf->offset, size, 0))
+		goto userptr_fail_sgtable;
+
+	sgt = &buf->sg_table;
+	/*
+	 * No need to sync to the device, this will happen later when the
+	 * prepare() memop is called.
+	 */
+	sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
+				      buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+	if (!sgt->nents)
+		goto userptr_fail_map;
+
+	return buf;
+
+userptr_fail_map:
+	sg_free_table(&buf->sg_table);
+userptr_fail_sgtable:
+	vb2_destroy_framevec(vec);
+userptr_fail_pfnvec:
+	kfree(buf);
+	return ERR_PTR(-ENOMEM);
+}
+
+/*
+ * @put_userptr: inform the allocator that a USERPTR buffer will no longer
+ *		 be used
+ */
+static void vb2_dma_sg_put_userptr(void *buf_priv)
+{
+	struct vb2_dma_sg_buf *buf = buf_priv;
+	struct sg_table *sgt = &buf->sg_table;
+	int i = buf->num_pages;
+
+	dprintk(1, "%s: Releasing userspace buffer of %d pages\n",
+	       __func__, buf->num_pages);
+	dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir,
+			   DMA_ATTR_SKIP_CPU_SYNC);
+	if (buf->vaddr)
+		vm_unmap_ram(buf->vaddr, buf->num_pages);
+	sg_free_table(buf->dma_sgt);
+	if (buf->dma_dir == DMA_FROM_DEVICE ||
+	    buf->dma_dir == DMA_BIDIRECTIONAL)
+		while (--i >= 0)
+			set_page_dirty_lock(buf->pages[i]);
+	vb2_destroy_framevec(buf->vec);
+	kfree(buf);
+}
+
+static void *vb2_dma_sg_vaddr(void *buf_priv)
+{
+	struct vb2_dma_sg_buf *buf = buf_priv;
+
+	BUG_ON(!buf);
+
+	if (!buf->vaddr) {
+		if (buf->db_attach)
+			buf->vaddr = dma_buf_vmap(buf->db_attach->dmabuf);
+		else
+			buf->vaddr = vm_map_ram(buf->pages,
+					buf->num_pages, -1, PAGE_KERNEL);
+	}
+
+	/* add offset in case userptr is not page-aligned */
+	return buf->vaddr ? buf->vaddr + buf->offset : NULL;
+}
+
+static unsigned int vb2_dma_sg_num_users(void *buf_priv)
+{
+	struct vb2_dma_sg_buf *buf = buf_priv;
+
+	return refcount_read(&buf->refcount);
+}
+
+static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma)
+{
+	struct vb2_dma_sg_buf *buf = buf_priv;
+	unsigned long uaddr = vma->vm_start;
+	unsigned long usize = vma->vm_end - vma->vm_start;
+	int i = 0;
+
+	if (!buf) {
+		printk(KERN_ERR "No memory to map\n");
+		return -EINVAL;
+	}
+
+	do {
+		int ret;
+
+		ret = vm_insert_page(vma, uaddr, buf->pages[i++]);
+		if (ret) {
+			printk(KERN_ERR "Remapping memory, error: %d\n", ret);
+			return ret;
+		}
+
+		uaddr += PAGE_SIZE;
+		usize -= PAGE_SIZE;
+	} while (usize > 0);
+
+
+	/*
+	 * Use common vm_area operations to track buffer refcount.
+	 */
+	vma->vm_private_data	= &buf->handler;
+	vma->vm_ops		= &vb2_common_vm_ops;
+
+	vma->vm_ops->open(vma);
+
+	return 0;
+}
+
+/*********************************************/
+/*         DMABUF ops for exporters          */
+/*********************************************/
+
+struct vb2_dma_sg_attachment {
+	struct sg_table sgt;
+	enum dma_data_direction dma_dir;
+};
+
+static int vb2_dma_sg_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev,
+	struct dma_buf_attachment *dbuf_attach)
+{
+	struct vb2_dma_sg_attachment *attach;
+	unsigned int i;
+	struct scatterlist *rd, *wr;
+	struct sg_table *sgt;
+	struct vb2_dma_sg_buf *buf = dbuf->priv;
+	int ret;
+
+	attach = kzalloc(sizeof(*attach), GFP_KERNEL);
+	if (!attach)
+		return -ENOMEM;
+
+	sgt = &attach->sgt;
+	/* Copy the buf->base_sgt scatter list to the attachment, as we can't
+	 * map the same scatter list to multiple attachments at the same time.
+	 */
+	ret = sg_alloc_table(sgt, buf->dma_sgt->orig_nents, GFP_KERNEL);
+	if (ret) {
+		kfree(attach);
+		return -ENOMEM;
+	}
+
+	rd = buf->dma_sgt->sgl;
+	wr = sgt->sgl;
+	for (i = 0; i < sgt->orig_nents; ++i) {
+		sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
+		rd = sg_next(rd);
+		wr = sg_next(wr);
+	}
+
+	attach->dma_dir = DMA_NONE;
+	dbuf_attach->priv = attach;
+
+	return 0;
+}
+
+static void vb2_dma_sg_dmabuf_ops_detach(struct dma_buf *dbuf,
+	struct dma_buf_attachment *db_attach)
+{
+	struct vb2_dma_sg_attachment *attach = db_attach->priv;
+	struct sg_table *sgt;
+
+	if (!attach)
+		return;
+
+	sgt = &attach->sgt;
+
+	/* release the scatterlist cache */
+	if (attach->dma_dir != DMA_NONE)
+		dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
+			attach->dma_dir);
+	sg_free_table(sgt);
+	kfree(attach);
+	db_attach->priv = NULL;
+}
+
+static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
+	struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
+{
+	struct vb2_dma_sg_attachment *attach = db_attach->priv;
+	/* stealing dmabuf mutex to serialize map/unmap operations */
+	struct mutex *lock = &db_attach->dmabuf->lock;
+	struct sg_table *sgt;
+
+	mutex_lock(lock);
+
+	sgt = &attach->sgt;
+	/* return previously mapped sg table */
+	if (attach->dma_dir == dma_dir) {
+		mutex_unlock(lock);
+		return sgt;
+	}
+
+	/* release any previous cache */
+	if (attach->dma_dir != DMA_NONE) {
+		dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
+			attach->dma_dir);
+		attach->dma_dir = DMA_NONE;
+	}
+
+	/* mapping to the client with new direction */
+	sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
+				dma_dir);
+	if (!sgt->nents) {
+		pr_err("failed to map scatterlist\n");
+		mutex_unlock(lock);
+		return ERR_PTR(-EIO);
+	}
+
+	attach->dma_dir = dma_dir;
+
+	mutex_unlock(lock);
+
+	return sgt;
+}
+
+static void vb2_dma_sg_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
+	struct sg_table *sgt, enum dma_data_direction dma_dir)
+{
+	/* nothing to be done here */
+}
+
+static void vb2_dma_sg_dmabuf_ops_release(struct dma_buf *dbuf)
+{
+	/* drop reference obtained in vb2_dma_sg_get_dmabuf */
+	vb2_dma_sg_put(dbuf->priv);
+}
+
+static void *vb2_dma_sg_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum)
+{
+	struct vb2_dma_sg_buf *buf = dbuf->priv;
+
+	return buf->vaddr ? buf->vaddr + pgnum * PAGE_SIZE : NULL;
+}
+
+static void *vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf *dbuf)
+{
+	struct vb2_dma_sg_buf *buf = dbuf->priv;
+
+	return vb2_dma_sg_vaddr(buf);
+}
+
+static int vb2_dma_sg_dmabuf_ops_mmap(struct dma_buf *dbuf,
+	struct vm_area_struct *vma)
+{
+	return vb2_dma_sg_mmap(dbuf->priv, vma);
+}
+
+static const struct dma_buf_ops vb2_dma_sg_dmabuf_ops = {
+	.attach = vb2_dma_sg_dmabuf_ops_attach,
+	.detach = vb2_dma_sg_dmabuf_ops_detach,
+	.map_dma_buf = vb2_dma_sg_dmabuf_ops_map,
+	.unmap_dma_buf = vb2_dma_sg_dmabuf_ops_unmap,
+	.map = vb2_dma_sg_dmabuf_ops_kmap,
+	.map_atomic = vb2_dma_sg_dmabuf_ops_kmap,
+	.vmap = vb2_dma_sg_dmabuf_ops_vmap,
+	.mmap = vb2_dma_sg_dmabuf_ops_mmap,
+	.release = vb2_dma_sg_dmabuf_ops_release,
+};
+
+static struct dma_buf *vb2_dma_sg_get_dmabuf(void *buf_priv, unsigned long flags)
+{
+	struct vb2_dma_sg_buf *buf = buf_priv;
+	struct dma_buf *dbuf;
+	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+	exp_info.ops = &vb2_dma_sg_dmabuf_ops;
+	exp_info.size = buf->size;
+	exp_info.flags = flags;
+	exp_info.priv = buf;
+
+	if (WARN_ON(!buf->dma_sgt))
+		return NULL;
+
+	dbuf = dma_buf_export(&exp_info);
+	if (IS_ERR(dbuf))
+		return NULL;
+
+	/* dmabuf keeps reference to vb2 buffer */
+	refcount_inc(&buf->refcount);
+
+	return dbuf;
+}
+
+/*********************************************/
+/*       callbacks for DMABUF buffers        */
+/*********************************************/
+
+static int vb2_dma_sg_map_dmabuf(void *mem_priv)
+{
+	struct vb2_dma_sg_buf *buf = mem_priv;
+	struct sg_table *sgt;
+
+	if (WARN_ON(!buf->db_attach)) {
+		pr_err("trying to pin a non attached buffer\n");
+		return -EINVAL;
+	}
+
+	if (WARN_ON(buf->dma_sgt)) {
+		pr_err("dmabuf buffer is already pinned\n");
+		return 0;
+	}
+
+	/* get the associated scatterlist for this buffer */
+	sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir);
+	if (IS_ERR(sgt)) {
+		pr_err("Error getting dmabuf scatterlist\n");
+		return -EINVAL;
+	}
+
+	buf->dma_sgt = sgt;
+	buf->vaddr = NULL;
+
+	return 0;
+}
+
+static void vb2_dma_sg_unmap_dmabuf(void *mem_priv)
+{
+	struct vb2_dma_sg_buf *buf = mem_priv;
+	struct sg_table *sgt = buf->dma_sgt;
+
+	if (WARN_ON(!buf->db_attach)) {
+		pr_err("trying to unpin a not attached buffer\n");
+		return;
+	}
+
+	if (WARN_ON(!sgt)) {
+		pr_err("dmabuf buffer is already unpinned\n");
+		return;
+	}
+
+	if (buf->vaddr) {
+		dma_buf_vunmap(buf->db_attach->dmabuf, buf->vaddr);
+		buf->vaddr = NULL;
+	}
+	dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);
+
+	buf->dma_sgt = NULL;
+}
+
+static void vb2_dma_sg_detach_dmabuf(void *mem_priv)
+{
+	struct vb2_dma_sg_buf *buf = mem_priv;
+
+	/* if vb2 works correctly you should never detach mapped buffer */
+	if (WARN_ON(buf->dma_sgt))
+		vb2_dma_sg_unmap_dmabuf(buf);
+
+	/* detach this attachment */
+	dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach);
+	kfree(buf);
+}
+
+static void *vb2_dma_sg_attach_dmabuf(struct device *dev, struct dma_buf *dbuf,
+	unsigned long size, enum dma_data_direction dma_dir)
+{
+	struct vb2_dma_sg_buf *buf;
+	struct dma_buf_attachment *dba;
+
+	if (WARN_ON(!dev))
+		return ERR_PTR(-EINVAL);
+
+	if (dbuf->size < size)
+		return ERR_PTR(-EFAULT);
+
+	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		return ERR_PTR(-ENOMEM);
+
+	buf->dev = dev;
+	/* create attachment for the dmabuf with the user device */
+	dba = dma_buf_attach(dbuf, buf->dev);
+	if (IS_ERR(dba)) {
+		pr_err("failed to attach dmabuf\n");
+		kfree(buf);
+		return dba;
+	}
+
+	buf->dma_dir = dma_dir;
+	buf->size = size;
+	buf->db_attach = dba;
+
+	return buf;
+}
+
+static void *vb2_dma_sg_cookie(void *buf_priv)
+{
+	struct vb2_dma_sg_buf *buf = buf_priv;
+
+	return buf->dma_sgt;
+}
+
+const struct vb2_mem_ops vb2_dma_sg_memops = {
+	.alloc		= vb2_dma_sg_alloc,
+	.put		= vb2_dma_sg_put,
+	.get_userptr	= vb2_dma_sg_get_userptr,
+	.put_userptr	= vb2_dma_sg_put_userptr,
+	.prepare	= vb2_dma_sg_prepare,
+	.finish		= vb2_dma_sg_finish,
+	.vaddr		= vb2_dma_sg_vaddr,
+	.mmap		= vb2_dma_sg_mmap,
+	.num_users	= vb2_dma_sg_num_users,
+	.get_dmabuf	= vb2_dma_sg_get_dmabuf,
+	.map_dmabuf	= vb2_dma_sg_map_dmabuf,
+	.unmap_dmabuf	= vb2_dma_sg_unmap_dmabuf,
+	.attach_dmabuf	= vb2_dma_sg_attach_dmabuf,
+	.detach_dmabuf	= vb2_dma_sg_detach_dmabuf,
+	.cookie		= vb2_dma_sg_cookie,
+};
+EXPORT_SYMBOL_GPL(vb2_dma_sg_memops);
+
+MODULE_DESCRIPTION("dma scatter/gather memory handling routines for videobuf2");
+MODULE_AUTHOR("Andrzej Pietrasiewicz");
+MODULE_LICENSE("GPL");