[deliverable/linux.git] / drivers / media / v4l2-core / videobuf2-vmalloc.c

/*
 * videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2
 *
 * Copyright (C) 2010 Samsung Electronics
 *
 * Author: Pawel Osciak <pawel@osciak.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/io.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>

#include <media/videobuf2-core.h>
#include <media/videobuf2-vmalloc.h>
#include <media/videobuf2-memops.h>

struct vb2_vmalloc_buf {
	void				*vaddr;
	struct page			**pages;
	struct vm_area_struct		*vma;
	int				write;
	unsigned long			size;
	unsigned int			n_pages;
	atomic_t			refcount;
	struct vb2_vmarea_handler	handler;
};

static void vb2_vmalloc_put(void *buf_priv);

static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size)
{
	struct vb2_vmalloc_buf *buf;

	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
	if (!buf)
		return NULL;

	buf->size = size;
	buf->vaddr = vmalloc_user(buf->size);
	buf->handler.refcount = &buf->refcount;
	buf->handler.put = vb2_vmalloc_put;
	buf->handler.arg = buf;

	if (!buf->vaddr) {
		pr_debug("vmalloc of size %ld failed\n", buf->size);
		kfree(buf);
		return NULL;
	}

	atomic_inc(&buf->refcount);
	return buf;
}

static void vb2_vmalloc_put(void *buf_priv)
{
	struct vb2_vmalloc_buf *buf = buf_priv;

	if (atomic_dec_and_test(&buf->refcount)) {
		vfree(buf->vaddr);
		kfree(buf);
	}
}

static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
				     unsigned long size, int write)
{
	struct vb2_vmalloc_buf *buf;
	unsigned long first, last;
	int n_pages, offset;
	struct vm_area_struct *vma;
	dma_addr_t physp;

	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
	if (!buf)
		return NULL;

	buf->write = write;
	offset = vaddr & ~PAGE_MASK;
	buf->size = size;


	vma = find_vma(current->mm, vaddr);
	if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) {
		if (vb2_get_contig_userptr(vaddr, size, &vma, &physp))
			goto fail_pages_array_alloc;
		buf->vma = vma;
		buf->vaddr = ioremap_nocache(physp, size);
		if (!buf->vaddr)
			goto fail_pages_array_alloc;
	} else {
		first = vaddr >> PAGE_SHIFT;
		last  = (vaddr + size - 1) >> PAGE_SHIFT;
		buf->n_pages = last - first + 1;
		buf->pages = kzalloc(buf->n_pages * sizeof(struct page *),
				     GFP_KERNEL);
		if (!buf->pages)
			goto fail_pages_array_alloc;

		/* current->mm->mmap_sem is taken by videobuf2 core */
		n_pages = get_user_pages(current, current->mm,
					 vaddr & PAGE_MASK, buf->n_pages,
					 write, 1, /* force */
					 buf->pages, NULL);
		if (n_pages != buf->n_pages)
			goto fail_get_user_pages;

		buf->vaddr = vm_map_ram(buf->pages, buf->n_pages, -1,
					PAGE_KERNEL);
		if (!buf->vaddr)
			goto fail_get_user_pages;
	}

	buf->vaddr += offset;
	return buf;

fail_get_user_pages:
	pr_debug("get_user_pages requested/got: %d/%d]\n", n_pages,
		 buf->n_pages);
	while (--n_pages >= 0)
		put_page(buf->pages[n_pages]);
	kfree(buf->pages);

fail_pages_array_alloc:
	kfree(buf);

	return NULL;
}

static void vb2_vmalloc_put_userptr(void *buf_priv)
{
	struct vb2_vmalloc_buf *buf = buf_priv;
	unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
	unsigned int i;

	if (buf->pages) {
		if (vaddr)
			vm_unmap_ram((void *)vaddr, buf->n_pages);
		for (i = 0; i < buf->n_pages; ++i) {
			if (buf->write)
				set_page_dirty_lock(buf->pages[i]);
			put_page(buf->pages[i]);
		}
		kfree(buf->pages);
	} else {
		if (buf->vma)
			vb2_put_vma(buf->vma);
		iounmap(buf->vaddr);
	}
	kfree(buf);
}

static void *vb2_vmalloc_vaddr(void *buf_priv)
{
	struct vb2_vmalloc_buf *buf = buf_priv;

	if (!buf->vaddr) {
		pr_err("Address of an unallocated plane requested "
		       "or cannot map user pointer\n");
		return NULL;
	}

	return buf->vaddr;
}

static unsigned int vb2_vmalloc_num_users(void *buf_priv)
{
	struct vb2_vmalloc_buf *buf = buf_priv;
	return atomic_read(&buf->refcount);
}

static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
{
	struct vb2_vmalloc_buf *buf = buf_priv;
	int ret;

	if (!buf) {
		pr_err("No memory to map\n");
		return -EINVAL;
	}

	ret = remap_vmalloc_range(vma, buf->vaddr, 0);
	if (ret) {
		pr_err("Remapping vmalloc memory, error: %d\n", ret);
		return ret;
	}

	/*
	 * Make sure that vm_areas for 2 buffers won't be merged together
	 */
	vma->vm_flags		|= VM_DONTEXPAND;

	/*
	 * 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;
}

const struct vb2_mem_ops vb2_vmalloc_memops = {
	.alloc		= vb2_vmalloc_alloc,
	.put		= vb2_vmalloc_put,
	.get_userptr	= vb2_vmalloc_get_userptr,
	.put_userptr	= vb2_vmalloc_put_userptr,
	.vaddr		= vb2_vmalloc_vaddr,
	.mmap		= vb2_vmalloc_mmap,
	.num_users	= vb2_vmalloc_num_users,
};
EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);

MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
MODULE_LICENSE("GPL");
Commit	Line	Data
3c18ff06 PO	1	/*
	2	* videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2
	3	*
	4	* Copyright (C) 2010 Samsung Electronics
	5	*
95072084	6	* Author: Pawel Osciak <pawel@osciak.com>
3c18ff06 PO	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation.
	11	*/
	12
570d2a48	13	#include <linux/io.h>
3c18ff06 PO	14	#include <linux/module.h>
3c18ff06 PO	15	#include <linux/mm.h>
4419b8ac	16	#include <linux/sched.h>
3c18ff06 PO	17	#include <linux/slab.h>
	18	#include <linux/vmalloc.h>
	19
	20	#include <media/videobuf2-core.h>
ddb9fa25	21	#include <media/videobuf2-vmalloc.h>
3c18ff06 PO	22	#include <media/videobuf2-memops.h>
	23
	24	struct vb2_vmalloc_buf {
	25	void *vaddr;
4419b8ac	26	struct page **pages;
570d2a48	27	struct vm_area_struct *vma;
4419b8ac	28	int write;
3c18ff06	29	unsigned long size;
4419b8ac	30	unsigned int n_pages;
3c18ff06 PO	31	atomic_t refcount;
	32	struct vb2_vmarea_handler handler;
	33	};
	34
	35	static void vb2_vmalloc_put(void *buf_priv);
	36
	37	static void vb2_vmalloc_alloc(void alloc_ctx, unsigned long size)
	38	{
	39	struct vb2_vmalloc_buf *buf;
	40
4419b8ac	41	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
3c18ff06 PO	42	if (!buf)
	43	return NULL;
	44
	45	buf->size = size;
	46	buf->vaddr = vmalloc_user(buf->size);
	47	buf->handler.refcount = &buf->refcount;
	48	buf->handler.put = vb2_vmalloc_put;
	49	buf->handler.arg = buf;
	50
	51	if (!buf->vaddr) {
4419b8ac	52	pr_debug("vmalloc of size %ld failed\n", buf->size);
3c18ff06 PO	53	kfree(buf);
	54	return NULL;
	55	}
	56
	57	atomic_inc(&buf->refcount);
3c18ff06 PO	58	return buf;
	59	}
	60
	61	static void vb2_vmalloc_put(void *buf_priv)
	62	{
	63	struct vb2_vmalloc_buf *buf = buf_priv;
	64
	65	if (atomic_dec_and_test(&buf->refcount)) {
3c18ff06 PO	66	vfree(buf->vaddr);
	67	kfree(buf);
	68	}
	69	}
	70
4419b8ac AP	71	static void vb2_vmalloc_get_userptr(void alloc_ctx, unsigned long vaddr,
	72	unsigned long size, int write)
	73	{
	74	struct vb2_vmalloc_buf *buf;
	75	unsigned long first, last;
	76	int n_pages, offset;
570d2a48 JM	77	struct vm_area_struct *vma;
570d2a48 JM	78	dma_addr_t physp;
4419b8ac AP	79
	80	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
	81	if (!buf)
	82	return NULL;
	83
	84	buf->write = write;
	85	offset = vaddr & ~PAGE_MASK;
	86	buf->size = size;
	87
4419b8ac	88
570d2a48 JM	89	vma = find_vma(current->mm, vaddr);
	90	if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) {
	91	if (vb2_get_contig_userptr(vaddr, size, &vma, &physp))
	92	goto fail_pages_array_alloc;
	93	buf->vma = vma;
	94	buf->vaddr = ioremap_nocache(physp, size);
	95	if (!buf->vaddr)
	96	goto fail_pages_array_alloc;
	97	} else {
	98	first = vaddr >> PAGE_SHIFT;
	99	last = (vaddr + size - 1) >> PAGE_SHIFT;
	100	buf->n_pages = last - first + 1;
	101	buf->pages = kzalloc(buf->n_pages * sizeof(struct page *),
	102	GFP_KERNEL);
	103	if (!buf->pages)
	104	goto fail_pages_array_alloc;
	105
	106	/* current->mm->mmap_sem is taken by videobuf2 core */
	107	n_pages = get_user_pages(current, current->mm,
	108	vaddr & PAGE_MASK, buf->n_pages,
	109	write, 1, /* force */
	110	buf->pages, NULL);
	111	if (n_pages != buf->n_pages)
	112	goto fail_get_user_pages;
	113
	114	buf->vaddr = vm_map_ram(buf->pages, buf->n_pages, -1,
	115	PAGE_KERNEL);
	116	if (!buf->vaddr)
	117	goto fail_get_user_pages;
	118	}
4419b8ac AP	119
	120	buf->vaddr += offset;
	121	return buf;
	122
	123	fail_get_user_pages:
	124	pr_debug("get_user_pages requested/got: %d/%d]\n", n_pages,
	125	buf->n_pages);
	126	while (--n_pages >= 0)
	127	put_page(buf->pages[n_pages]);
	128	kfree(buf->pages);
	129
	130	fail_pages_array_alloc:
	131	kfree(buf);
	132
	133	return NULL;
	134	}
	135
	136	static void vb2_vmalloc_put_userptr(void *buf_priv)
3c18ff06 PO	137	{
3c18ff06 PO	138	struct vb2_vmalloc_buf *buf = buf_priv;
4419b8ac AP	139	unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
	140	unsigned int i;
	141
570d2a48 JM	142	if (buf->pages) {
	143	if (vaddr)
	144	vm_unmap_ram((void *)vaddr, buf->n_pages);
	145	for (i = 0; i < buf->n_pages; ++i) {
	146	if (buf->write)
	147	set_page_dirty_lock(buf->pages[i]);
	148	put_page(buf->pages[i]);
	149	}
	150	kfree(buf->pages);
	151	} else {
	152	if (buf->vma)
	153	vb2_put_vma(buf->vma);
	154	iounmap(buf->vaddr);
4419b8ac	155	}
4419b8ac AP	156	kfree(buf);
4419b8ac AP	157	}
3c18ff06	158
4419b8ac AP	159	static void vb2_vmalloc_vaddr(void buf_priv)
	160	{
	161	struct vb2_vmalloc_buf *buf = buf_priv;
3c18ff06 PO	162
3c18ff06 PO	163	if (!buf->vaddr) {
4419b8ac AP	164	pr_err("Address of an unallocated plane requested "
4419b8ac AP	165	"or cannot map user pointer\n");
3c18ff06 PO	166	return NULL;
	167	}
	168
	169	return buf->vaddr;
	170	}
	171
	172	static unsigned int vb2_vmalloc_num_users(void *buf_priv)
	173	{
	174	struct vb2_vmalloc_buf *buf = buf_priv;
	175	return atomic_read(&buf->refcount);
	176	}
	177
	178	static int vb2_vmalloc_mmap(void buf_priv, struct vm_area_struct vma)
	179	{
	180	struct vb2_vmalloc_buf *buf = buf_priv;
	181	int ret;
	182
	183	if (!buf) {
4419b8ac	184	pr_err("No memory to map\n");
3c18ff06 PO	185	return -EINVAL;
	186	}
	187
	188	ret = remap_vmalloc_range(vma, buf->vaddr, 0);
	189	if (ret) {
4419b8ac	190	pr_err("Remapping vmalloc memory, error: %d\n", ret);
3c18ff06 PO	191	return ret;
	192	}
	193
	194	/*
	195	* Make sure that vm_areas for 2 buffers won't be merged together
	196	*/
	197	vma->vm_flags \|= VM_DONTEXPAND;
	198
	199	/*
	200	* Use common vm_area operations to track buffer refcount.
	201	*/
	202	vma->vm_private_data = &buf->handler;
	203	vma->vm_ops = &vb2_common_vm_ops;
	204
	205	vma->vm_ops->open(vma);
	206
	207	return 0;
	208	}
	209
	210	const struct vb2_mem_ops vb2_vmalloc_memops = {
	211	.alloc = vb2_vmalloc_alloc,
	212	.put = vb2_vmalloc_put,
4419b8ac AP	213	.get_userptr = vb2_vmalloc_get_userptr,
4419b8ac AP	214	.put_userptr = vb2_vmalloc_put_userptr,
3c18ff06 PO	215	.vaddr = vb2_vmalloc_vaddr,
	216	.mmap = vb2_vmalloc_mmap,
	217	.num_users = vb2_vmalloc_num_users,
	218	};
	219	EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);
	220
	221	MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
95072084	222	MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
3c18ff06	223	MODULE_LICENSE("GPL");