drivers/media/video/videobuf-vmalloc.c - linux/kernel/git/mellanox/linux - Git at Google

 /*
  * helper functions for vmalloc video4linux capture buffers
  *
  * The functions expect the hardware being able to scatter gatter
  * (i.e. the buffers are not linear in physical memory, but fragmented
  * into PAGE_SIZE chunks).  They also assume the driver does not need
  * to touch the video data.
  *
  * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
  *
  * 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
  */

 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>

 #include <linux/pci.h>
 #include <linux/vmalloc.h>
 #include <linux/pagemap.h>
 #include <asm/page.h>
 #include <asm/pgtable.h>

 #include <media/videobuf-vmalloc.h>

 #define MAGIC_DMABUF   0x17760309
 #define MAGIC_VMAL_MEM 0x18221223

 #define MAGIC_CHECK(is,should)	if (unlikely((is) != (should))) \
 	{ printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }

 static int debug = 0;
 module_param(debug, int, 0644);

 MODULE_DESCRIPTION("helper module to manage video4linux vmalloc buffers");
 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
 MODULE_LICENSE("GPL");

 #define dprintk(level, fmt, arg...)	if (debug >= level) \
 	printk(KERN_DEBUG "vbuf-sg: " fmt , ## arg)


 /***************************************************************************/

 static void
 videobuf_vm_open(struct vm_area_struct *vma)
 {
 	struct videobuf_mapping *map = vma->vm_private_data;

 	dprintk(2,"vm_open %p [count=%u,vma=%08lx-%08lx]\n",map,
 		map->count,vma->vm_start,vma->vm_end);

 	map->count++;
 }

 static void
 videobuf_vm_close(struct vm_area_struct *vma)
 {
 	struct videobuf_mapping *map = vma->vm_private_data;
 	struct videobuf_queue *q = map->q;
 	int i;

 	dprintk(2,"vm_close %p [count=%u,vma=%08lx-%08lx]\n",map,
 		map->count,vma->vm_start,vma->vm_end);

 	map->count--;
 	if (0 == map->count) {
 		dprintk(1,"munmap %p q=%p\n",map,q);
 		mutex_lock(&q->lock);
 		for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 			if (NULL == q->bufs[i])
 				continue;

 			if (q->bufs[i]->map != map)
 				continue;

 			q->ops->buf_release(q,q->bufs[i]);

 			q->bufs[i]->map   = NULL;
 			q->bufs[i]->baddr = 0;
 		}
 		mutex_unlock(&q->lock);
 		kfree(map);
 	}
 	return;
 }

 static struct vm_operations_struct videobuf_vm_ops =
 {
 	.open     = videobuf_vm_open,
 	.close    = videobuf_vm_close,
 };

 /* ---------------------------------------------------------------------
  * vmalloc handlers for the generic methods
  */

 /* Allocated area consists on 3 parts:
 	struct video_buffer
 	struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
 	struct videobuf_pci_sg_memory
  */

 static void *__videobuf_alloc(size_t size)
 {
 	struct videbuf_vmalloc_memory *mem;
 	struct videobuf_buffer *vb;

 	vb = kzalloc(size+sizeof(*mem),GFP_KERNEL);

 	mem = vb->priv = ((char *)vb)+size;
 	mem->magic=MAGIC_VMAL_MEM;

 	dprintk(1,"%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
 		__FUNCTION__,vb,(long)sizeof(*vb),(long)size-sizeof(*vb),
 		mem,(long)sizeof(*mem));

 	return vb;
 }

 static int __videobuf_iolock (struct videobuf_queue* q,
 			      struct videobuf_buffer *vb,
 			      struct v4l2_framebuffer *fbuf)
 {
 	int pages;

 	struct videbuf_vmalloc_memory *mem=vb->priv;


 	BUG_ON(!mem);

 	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

 	pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;

 	/* Currently, doesn't support V4L2_MEMORY_OVERLAY */
 	if ((vb->memory != V4L2_MEMORY_MMAP) &&
 				(vb->memory != V4L2_MEMORY_USERPTR) ) {
 		printk(KERN_ERR "Method currently unsupported.\n");
 		return -EINVAL;
 	}

 	/* FIXME: should be tested with kernel mmap mem */
 	mem->vmalloc=vmalloc_user (PAGE_ALIGN(vb->size));
 	if (NULL == mem->vmalloc) {
 		printk(KERN_ERR "vmalloc (%d pages) failed\n",pages);
 		return -ENOMEM;
 	}

 	dprintk(1,"vmalloc is at addr 0x%08lx, size=%d\n",
 				(unsigned long)mem->vmalloc,
 				pages << PAGE_SHIFT);

 	/* It seems that some kernel versions need to do remap *after*
 	   the mmap() call
 	 */
 	if (mem->vma) {
 		int retval=remap_vmalloc_range(mem->vma, mem->vmalloc,0);
 		kfree(mem->vma);
 		mem->vma=NULL;
 		if (retval<0) {
 			dprintk(1,"mmap app bug: remap_vmalloc_range area %p error %d\n",
 				mem->vmalloc,retval);
 			return retval;
 		}
 	}

 	return 0;
 }

 static int __videobuf_sync(struct videobuf_queue *q,
 			   struct videobuf_buffer *buf)
 {
 	return 0;
 }

 static int __videobuf_mmap_free(struct videobuf_queue *q)
 {
 	unsigned int i;

 	for (i = 0; i < VIDEO_MAX_FRAME; i++) {
 		if (q->bufs[i]) {
 			if (q->bufs[i]->map)
 				return -EBUSY;
 		}
 	}

 	return 0;
 }

 static int __videobuf_mmap_mapper(struct videobuf_queue *q,
 			 struct vm_area_struct *vma)
 {
 	struct videbuf_vmalloc_memory *mem;
 	struct videobuf_mapping *map;
 	unsigned int first;
 	int retval;
 	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;

 	if (! (vma->vm_flags & VM_WRITE) || ! (vma->vm_flags & VM_SHARED))
 		return -EINVAL;

 	/* look for first buffer to map */
 	for (first = 0; first < VIDEO_MAX_FRAME; first++) {
 		if (NULL == q->bufs[first])
 			continue;

 		if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
 			continue;
 		if (q->bufs[first]->boff == offset)
 			break;
 	}
 	if (VIDEO_MAX_FRAME == first) {
 		dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
 			(vma->vm_pgoff << PAGE_SHIFT));
 		return -EINVAL;
 	}

 	/* create mapping + update buffer list */
 	map = q->bufs[first]->map = kzalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
 	if (NULL == map)
 		return -ENOMEM;

 	map->start = vma->vm_start;
 	map->end   = vma->vm_end;
 	map->q     = q;

 	q->bufs[first]->baddr = vma->vm_start;

 	vma->vm_ops          = &videobuf_vm_ops;
 	vma->vm_flags       |= VM_DONTEXPAND | VM_RESERVED;
 	vma->vm_private_data = map;

 	mem=q->bufs[first]->priv;
 	BUG_ON (!mem);
 	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

 	/* Try to remap memory */
 	retval=remap_vmalloc_range(vma, mem->vmalloc,0);
 	if (retval<0) {
 		dprintk(1,"mmap: postponing remap_vmalloc_range\n");

 		mem->vma=kmalloc(sizeof(*vma),GFP_KERNEL);
 		if (!mem->vma) {
 			kfree(map);
 			q->bufs[first]->map=NULL;
 			return -ENOMEM;
 		}
 		memcpy(mem->vma,vma,sizeof(*vma));
 	}

 	dprintk(1,"mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n",
 		map,q,vma->vm_start,vma->vm_end,
 		(long int) q->bufs[first]->bsize,
 		vma->vm_pgoff,first);

 	videobuf_vm_open(vma);

 	return (0);
 }

 static int __videobuf_copy_to_user ( struct videobuf_queue *q,
 				char __user *data, size_t count,
 				int nonblocking )
 {
 	struct videbuf_vmalloc_memory *mem=q->read_buf->priv;
 	BUG_ON (!mem);
 	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

 	BUG_ON (!mem->vmalloc);

 	/* copy to userspace */
 	if (count > q->read_buf->size - q->read_off)
 		count = q->read_buf->size - q->read_off;

 	if (copy_to_user(data, mem->vmalloc+q->read_off, count))
 		return -EFAULT;

 	return count;
 }

 static int __videobuf_copy_stream ( struct videobuf_queue *q,
 				char __user *data, size_t count, size_t pos,
 				int vbihack, int nonblocking )
 {
 	unsigned int  *fc;
 	struct videbuf_vmalloc_memory *mem=q->read_buf->priv;
 	BUG_ON (!mem);
 	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

 	if (vbihack) {
 		/* dirty, undocumented hack -- pass the frame counter
 			* within the last four bytes of each vbi data block.
 			* We need that one to maintain backward compatibility
 			* to all vbi decoding software out there ... */
 		fc  = (unsigned int*)mem->vmalloc;
 		fc += (q->read_buf->size>>2) -1;
 		*fc = q->read_buf->field_count >> 1;
 		dprintk(1,"vbihack: %d\n",*fc);
 	}

 	/* copy stuff using the common method */
 	count = __videobuf_copy_to_user (q,data,count,nonblocking);

 	if ( (count==-EFAULT) && (0 == pos) )
 		return -EFAULT;

 	return count;
 }

 static struct videobuf_qtype_ops qops = {
 	.magic        = MAGIC_QTYPE_OPS,

 	.alloc        = __videobuf_alloc,
 	.iolock       = __videobuf_iolock,
 	.sync         = __videobuf_sync,
 	.mmap_free    = __videobuf_mmap_free,
 	.mmap_mapper  = __videobuf_mmap_mapper,
 	.video_copy_to_user = __videobuf_copy_to_user,
 	.copy_stream  = __videobuf_copy_stream,
 };

 void videobuf_queue_vmalloc_init(struct videobuf_queue* q,
 			 struct videobuf_queue_ops *ops,
 			 void *dev,
 			 spinlock_t *irqlock,
 			 enum v4l2_buf_type type,
 			 enum v4l2_field field,
 			 unsigned int msize,
 			 void *priv)
 {
 	videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
 				 priv, &qops);
 }

 EXPORT_SYMBOL_GPL(videobuf_queue_vmalloc_init);

 void *videobuf_to_vmalloc (struct videobuf_buffer *buf)
 {
 	struct videbuf_vmalloc_memory *mem=buf->priv;
 	BUG_ON (!mem);
 	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

 	return mem->vmalloc;
 }
 EXPORT_SYMBOL_GPL(videobuf_to_vmalloc);

 void videobuf_vmalloc_free (struct videobuf_buffer *buf)
 {
 	struct videbuf_vmalloc_memory *mem=buf->priv;
 	BUG_ON (!mem);

 	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

 	vfree(mem->vmalloc);
 	mem->vmalloc=NULL;

 	return;
 }
 EXPORT_SYMBOL_GPL(videobuf_vmalloc_free);

 /*
  * Local variables:
  * c-basic-offset: 8
  * End:
  */
	/*
	* helper functions for vmalloc video4linux capture buffers
	*
	* The functions expect the hardware being able to scatter gatter
	* (i.e. the buffers are not linear in physical memory, but fragmented
	* into PAGE_SIZE chunks). They also assume the driver does not need
	* to touch the video data.
	*
	* (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
	*
	* 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
	*/

	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/slab.h>
	#include <linux/interrupt.h>

	#include <linux/pci.h>
	#include <linux/vmalloc.h>
	#include <linux/pagemap.h>
	#include <asm/page.h>
	#include <asm/pgtable.h>

	#include <media/videobuf-vmalloc.h>

	#define MAGIC_DMABUF 0x17760309
	#define MAGIC_VMAL_MEM 0x18221223

	#define MAGIC_CHECK(is,should) if (unlikely((is) != (should))) \
	{ printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }

	static int debug = 0;
	module_param(debug, int, 0644);

	MODULE_DESCRIPTION("helper module to manage video4linux vmalloc buffers");
	MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
	MODULE_LICENSE("GPL");

	#define dprintk(level, fmt, arg...) if (debug >= level) \
	printk(KERN_DEBUG "vbuf-sg: " fmt , ## arg)


	/***************************************************************************/

	static void
	videobuf_vm_open(struct vm_area_struct *vma)
	{
	struct videobuf_mapping *map = vma->vm_private_data;

	dprintk(2,"vm_open %p [count=%u,vma=%08lx-%08lx]\n",map,
	map->count,vma->vm_start,vma->vm_end);

	map->count++;
	}

	static void
	videobuf_vm_close(struct vm_area_struct *vma)
	{
	struct videobuf_mapping *map = vma->vm_private_data;
	struct videobuf_queue *q = map->q;
	int i;

	dprintk(2,"vm_close %p [count=%u,vma=%08lx-%08lx]\n",map,
	map->count,vma->vm_start,vma->vm_end);

	map->count--;
	if (0 == map->count) {
	dprintk(1,"munmap %p q=%p\n",map,q);
	mutex_lock(&q->lock);
	for (i = 0; i < VIDEO_MAX_FRAME; i++) {
	if (NULL == q->bufs[i])
	continue;

	if (q->bufs[i]->map != map)
	continue;

	q->ops->buf_release(q,q->bufs[i]);

	q->bufs[i]->map = NULL;
	q->bufs[i]->baddr = 0;
	}
	mutex_unlock(&q->lock);
	kfree(map);
	}
	return;
	}

	static struct vm_operations_struct videobuf_vm_ops =
	{
	.open = videobuf_vm_open,
	.close = videobuf_vm_close,
	};

	/* ---------------------------------------------------------------------
	* vmalloc handlers for the generic methods
	*/

	/* Allocated area consists on 3 parts:
	struct video_buffer
	struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
	struct videobuf_pci_sg_memory
	*/

	static void *__videobuf_alloc(size_t size)
	{
	struct videbuf_vmalloc_memory *mem;
	struct videobuf_buffer *vb;

	vb = kzalloc(size+sizeof(*mem),GFP_KERNEL);

	mem = vb->priv = ((char *)vb)+size;
	mem->magic=MAGIC_VMAL_MEM;

	dprintk(1,"%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
	__FUNCTION__,vb,(long)sizeof(vb),(long)size-sizeof(vb),
	mem,(long)sizeof(*mem));

	return vb;
	}

	static int __videobuf_iolock (struct videobuf_queue* q,
	struct videobuf_buffer *vb,
	struct v4l2_framebuffer *fbuf)
	{
	int pages;

	struct videbuf_vmalloc_memory *mem=vb->priv;


	BUG_ON(!mem);

	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

	pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;

	/* Currently, doesn't support V4L2_MEMORY_OVERLAY */
	if ((vb->memory != V4L2_MEMORY_MMAP) &&
	(vb->memory != V4L2_MEMORY_USERPTR) ) {
	printk(KERN_ERR "Method currently unsupported.\n");
	return -EINVAL;
	}

	/* FIXME: should be tested with kernel mmap mem */
	mem->vmalloc=vmalloc_user (PAGE_ALIGN(vb->size));
	if (NULL == mem->vmalloc) {
	printk(KERN_ERR "vmalloc (%d pages) failed\n",pages);
	return -ENOMEM;
	}

	dprintk(1,"vmalloc is at addr 0x%08lx, size=%d\n",
	(unsigned long)mem->vmalloc,
	pages << PAGE_SHIFT);

	/* It seems that some kernel versions need to do remap after
	the mmap() call
	*/
	if (mem->vma) {
	int retval=remap_vmalloc_range(mem->vma, mem->vmalloc,0);
	kfree(mem->vma);
	mem->vma=NULL;
	if (retval<0) {
	dprintk(1,"mmap app bug: remap_vmalloc_range area %p error %d\n",
	mem->vmalloc,retval);
	return retval;
	}
	}

	return 0;
	}

	static int __videobuf_sync(struct videobuf_queue *q,
	struct videobuf_buffer *buf)
	{
	return 0;
	}

	static int __videobuf_mmap_free(struct videobuf_queue *q)
	{
	unsigned int i;

	for (i = 0; i < VIDEO_MAX_FRAME; i++) {
	if (q->bufs[i]) {
	if (q->bufs[i]->map)
	return -EBUSY;
	}
	}

	return 0;
	}

	static int __videobuf_mmap_mapper(struct videobuf_queue *q,
	struct vm_area_struct *vma)
	{
	struct videbuf_vmalloc_memory *mem;
	struct videobuf_mapping *map;
	unsigned int first;
	int retval;
	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;

	if (! (vma->vm_flags & VM_WRITE) \|\| ! (vma->vm_flags & VM_SHARED))
	return -EINVAL;

	/* look for first buffer to map */
	for (first = 0; first < VIDEO_MAX_FRAME; first++) {
	if (NULL == q->bufs[first])
	continue;

	if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
	continue;
	if (q->bufs[first]->boff == offset)
	break;
	}
	if (VIDEO_MAX_FRAME == first) {
	dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
	(vma->vm_pgoff << PAGE_SHIFT));
	return -EINVAL;
	}

	/* create mapping + update buffer list */
	map = q->bufs[first]->map = kzalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
	if (NULL == map)
	return -ENOMEM;

	map->start = vma->vm_start;
	map->end = vma->vm_end;
	map->q = q;

	q->bufs[first]->baddr = vma->vm_start;

	vma->vm_ops = &videobuf_vm_ops;
	vma->vm_flags \|= VM_DONTEXPAND \| VM_RESERVED;
	vma->vm_private_data = map;

	mem=q->bufs[first]->priv;
	BUG_ON (!mem);
	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

	/* Try to remap memory */
	retval=remap_vmalloc_range(vma, mem->vmalloc,0);
	if (retval<0) {
	dprintk(1,"mmap: postponing remap_vmalloc_range\n");

	mem->vma=kmalloc(sizeof(*vma),GFP_KERNEL);
	if (!mem->vma) {
	kfree(map);
	q->bufs[first]->map=NULL;
	return -ENOMEM;
	}
	memcpy(mem->vma,vma,sizeof(*vma));
	}

	dprintk(1,"mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n",
	map,q,vma->vm_start,vma->vm_end,
	(long int) q->bufs[first]->bsize,
	vma->vm_pgoff,first);

	videobuf_vm_open(vma);

	return (0);
	}

	static int __videobuf_copy_to_user ( struct videobuf_queue *q,
	char __user *data, size_t count,
	int nonblocking )
	{
	struct videbuf_vmalloc_memory *mem=q->read_buf->priv;
	BUG_ON (!mem);
	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

	BUG_ON (!mem->vmalloc);

	/* copy to userspace */
	if (count > q->read_buf->size - q->read_off)
	count = q->read_buf->size - q->read_off;

	if (copy_to_user(data, mem->vmalloc+q->read_off, count))
	return -EFAULT;

	return count;
	}

	static int __videobuf_copy_stream ( struct videobuf_queue *q,
	char __user *data, size_t count, size_t pos,
	int vbihack, int nonblocking )
	{
	unsigned int *fc;
	struct videbuf_vmalloc_memory *mem=q->read_buf->priv;
	BUG_ON (!mem);
	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

	if (vbihack) {
	/* dirty, undocumented hack -- pass the frame counter
	* within the last four bytes of each vbi data block.
	* We need that one to maintain backward compatibility
	* to all vbi decoding software out there ... */
	fc = (unsigned int*)mem->vmalloc;
	fc += (q->read_buf->size>>2) -1;
	*fc = q->read_buf->field_count >> 1;
	dprintk(1,"vbihack: %d\n",*fc);
	}

	/* copy stuff using the common method */
	count = __videobuf_copy_to_user (q,data,count,nonblocking);

	if ( (count==-EFAULT) && (0 == pos) )
	return -EFAULT;

	return count;
	}

	static struct videobuf_qtype_ops qops = {
	.magic = MAGIC_QTYPE_OPS,

	.alloc = __videobuf_alloc,
	.iolock = __videobuf_iolock,
	.sync = __videobuf_sync,
	.mmap_free = __videobuf_mmap_free,
	.mmap_mapper = __videobuf_mmap_mapper,
	.video_copy_to_user = __videobuf_copy_to_user,
	.copy_stream = __videobuf_copy_stream,
	};

	void videobuf_queue_vmalloc_init(struct videobuf_queue* q,
	struct videobuf_queue_ops *ops,
	void *dev,
	spinlock_t *irqlock,
	enum v4l2_buf_type type,
	enum v4l2_field field,
	unsigned int msize,
	void *priv)
	{
	videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
	priv, &qops);
	}

	EXPORT_SYMBOL_GPL(videobuf_queue_vmalloc_init);

	void videobuf_to_vmalloc (struct videobuf_buffer buf)
	{
	struct videbuf_vmalloc_memory *mem=buf->priv;
	BUG_ON (!mem);
	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

	return mem->vmalloc;
	}
	EXPORT_SYMBOL_GPL(videobuf_to_vmalloc);

	void videobuf_vmalloc_free (struct videobuf_buffer *buf)
	{
	struct videbuf_vmalloc_memory *mem=buf->priv;
	BUG_ON (!mem);

	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

	vfree(mem->vmalloc);
	mem->vmalloc=NULL;

	return;
	}
	EXPORT_SYMBOL_GPL(videobuf_vmalloc_free);

	/*
	* Local variables:
	* c-basic-offset: 8
	* End:
	*/