[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / ieee1394 / dma.c

/*
 * DMA region bookkeeping routines
 *
 * Copyright (C) 2002 Maas Digital LLC
 *
 * This code is licensed under the GPL.  See the file COPYING in the root
 * directory of the kernel sources for details.
 */

#include <linux/mm.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <asm/scatterlist.h>

#include "dma.h"

/* dma_prog_region */

void dma_prog_region_init(struct dma_prog_region *prog)
{
	prog->kvirt = NULL;
	prog->dev = NULL;
	prog->n_pages = 0;
	prog->bus_addr = 0;
}

int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes,
			  struct pci_dev *dev)
{
	/* round up to page size */
	n_bytes = PAGE_ALIGN(n_bytes);

	prog->n_pages = n_bytes >> PAGE_SHIFT;

	prog->kvirt = pci_alloc_consistent(dev, n_bytes, &prog->bus_addr);
	if (!prog->kvirt) {
		printk(KERN_ERR
		       "dma_prog_region_alloc: pci_alloc_consistent() failed\n");
		dma_prog_region_free(prog);
		return -ENOMEM;
	}

	prog->dev = dev;

	return 0;
}

void dma_prog_region_free(struct dma_prog_region *prog)
{
	if (prog->kvirt) {
		pci_free_consistent(prog->dev, prog->n_pages << PAGE_SHIFT,
				    prog->kvirt, prog->bus_addr);
	}

	prog->kvirt = NULL;
	prog->dev = NULL;
	prog->n_pages = 0;
	prog->bus_addr = 0;
}

/* dma_region */

/**
 * dma_region_init - clear out all fields but do not allocate anything
 */
void dma_region_init(struct dma_region *dma)
{
	dma->kvirt = NULL;
	dma->dev = NULL;
	dma->n_pages = 0;
	dma->n_dma_pages = 0;
	dma->sglist = NULL;
}

/**
 * dma_region_alloc - allocate the buffer and map it to the IOMMU
 */
int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes,
		     struct pci_dev *dev, int direction)
{
	unsigned int i;

	/* round up to page size */
	n_bytes = PAGE_ALIGN(n_bytes);

	dma->n_pages = n_bytes >> PAGE_SHIFT;

	dma->kvirt = vmalloc_32(n_bytes);
	if (!dma->kvirt) {
		printk(KERN_ERR "dma_region_alloc: vmalloc_32() failed\n");
		goto err;
	}

	/* Clear the ram out, no junk to the user */
	memset(dma->kvirt, 0, n_bytes);

	/* allocate scatter/gather list */
	dma->sglist = vmalloc(dma->n_pages * sizeof(*dma->sglist));
	if (!dma->sglist) {
		printk(KERN_ERR "dma_region_alloc: vmalloc(sglist) failed\n");
		goto err;
	}

	/* just to be safe - this will become unnecessary once sglist->address goes away */
	memset(dma->sglist, 0, dma->n_pages * sizeof(*dma->sglist));

	/* fill scatter/gather list with pages */
	for (i = 0; i < dma->n_pages; i++) {
		unsigned long va =
		    (unsigned long)dma->kvirt + (i << PAGE_SHIFT);

		dma->sglist[i].page = vmalloc_to_page((void *)va);
		dma->sglist[i].length = PAGE_SIZE;
	}

	/* map sglist to the IOMMU */
	dma->n_dma_pages =
	    pci_map_sg(dev, dma->sglist, dma->n_pages, direction);

	if (dma->n_dma_pages == 0) {
		printk(KERN_ERR "dma_region_alloc: pci_map_sg() failed\n");
		goto err;
	}

	dma->dev = dev;
	dma->direction = direction;

	return 0;

      err:
	dma_region_free(dma);
	return -ENOMEM;
}

/**
 * dma_region_free - unmap and free the buffer
 */
void dma_region_free(struct dma_region *dma)
{
	if (dma->n_dma_pages) {
		pci_unmap_sg(dma->dev, dma->sglist, dma->n_pages,
			     dma->direction);
		dma->n_dma_pages = 0;
		dma->dev = NULL;
	}

	vfree(dma->sglist);
	dma->sglist = NULL;

	vfree(dma->kvirt);
	dma->kvirt = NULL;
	dma->n_pages = 0;
}

/* find the scatterlist index and remaining offset corresponding to a
   given offset from the beginning of the buffer */
static inline int dma_region_find(struct dma_region *dma, unsigned long offset,
				  unsigned int start, unsigned long *rem)
{
	int i;
	unsigned long off = offset;

	for (i = start; i < dma->n_dma_pages; i++) {
		if (off < sg_dma_len(&dma->sglist[i])) {
			*rem = off;
			break;
		}

		off -= sg_dma_len(&dma->sglist[i]);
	}

	BUG_ON(i >= dma->n_dma_pages);

	return i;
}

/**
 * dma_region_offset_to_bus - get bus address of an offset within a DMA region
 *
 * Returns the DMA bus address of the byte with the given @offset relative to
 * the beginning of the @dma.
 */
dma_addr_t dma_region_offset_to_bus(struct dma_region * dma,
				    unsigned long offset)
{
	unsigned long rem = 0;

	struct scatterlist *sg =
	    &dma->sglist[dma_region_find(dma, offset, 0, &rem)];
	return sg_dma_address(sg) + rem;
}

/**
 * dma_region_sync_for_cpu - sync the CPU's view of the buffer
 */
void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset,
			     unsigned long len)
{
	int first, last;
	unsigned long rem = 0;

	if (!len)
		len = 1;

	first = dma_region_find(dma, offset, 0, &rem);
	last = dma_region_find(dma, rem + len - 1, first, &rem);

	pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1,
				dma->direction);
}

/**
 * dma_region_sync_for_device - sync the IO bus' view of the buffer
 */
void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset,
				unsigned long len)
{
	int first, last;
	unsigned long rem = 0;

	if (!len)
		len = 1;

	first = dma_region_find(dma, offset, 0, &rem);
	last = dma_region_find(dma, rem + len - 1, first, &rem);

	pci_dma_sync_sg_for_device(dma->dev, &dma->sglist[first],
				   last - first + 1, dma->direction);
}

#ifdef CONFIG_MMU

/* nopage() handler for mmap access */

static struct page *dma_region_pagefault(struct vm_area_struct *area,
					 unsigned long address, int *type)
{
	unsigned long offset;
	unsigned long kernel_virt_addr;
	struct page *ret = NOPAGE_SIGBUS;

	struct dma_region *dma = (struct dma_region *)area->vm_private_data;

	if (!dma->kvirt)
		goto out;

	if ((address < (unsigned long)area->vm_start) ||
	    (address >
	     (unsigned long)area->vm_start + (dma->n_pages << PAGE_SHIFT)))
		goto out;

	if (type)
		*type = VM_FAULT_MINOR;
	offset = address - area->vm_start;
	kernel_virt_addr = (unsigned long)dma->kvirt + offset;
	ret = vmalloc_to_page((void *)kernel_virt_addr);
	get_page(ret);
      out:
	return ret;
}

static struct vm_operations_struct dma_region_vm_ops = {
	.nopage = dma_region_pagefault,
};

/**
 * dma_region_mmap - map the buffer into a user space process
 */
int dma_region_mmap(struct dma_region *dma, struct file *file,
		    struct vm_area_struct *vma)
{
	unsigned long size;

	if (!dma->kvirt)
		return -EINVAL;

	/* must be page-aligned */
	if (vma->vm_pgoff != 0)
		return -EINVAL;

	/* check the length */
	size = vma->vm_end - vma->vm_start;
	if (size > (dma->n_pages << PAGE_SHIFT))
		return -EINVAL;

	vma->vm_ops = &dma_region_vm_ops;
	vma->vm_private_data = dma;
	vma->vm_file = file;
	vma->vm_flags |= VM_RESERVED;

	return 0;
}

#else				/* CONFIG_MMU */

int dma_region_mmap(struct dma_region *dma, struct file *file,
		    struct vm_area_struct *vma)
{
	return -EINVAL;
}

#endif				/* CONFIG_MMU */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* DMA region bookkeeping routines
	3	*
	4	* Copyright (C) 2002 Maas Digital LLC
	5	*
	6	* This code is licensed under the GPL. See the file COPYING in the root
	7	* directory of the kernel sources for details.
	8	*/
	9
de4394f1	10	#include <linux/mm.h>
1da177e4	11	#include <linux/module.h>
de4394f1	12	#include <linux/pci.h>
1da177e4	13	#include <linux/slab.h>
de4394f1 SR	14	#include <linux/vmalloc.h>
	15	#include <asm/scatterlist.h>
	16
1da177e4 LT	17	#include "dma.h"
	18
	19	/* dma_prog_region */
	20
	21	void dma_prog_region_init(struct dma_prog_region *prog)
	22	{
	23	prog->kvirt = NULL;
	24	prog->dev = NULL;
	25	prog->n_pages = 0;
	26	prog->bus_addr = 0;
	27	}
	28
6649e92d JMH	29	int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes,
6649e92d JMH	30	struct pci_dev *dev)
1da177e4 LT	31	{
	32	/* round up to page size */
	33	n_bytes = PAGE_ALIGN(n_bytes);
	34
	35	prog->n_pages = n_bytes >> PAGE_SHIFT;
	36
	37	prog->kvirt = pci_alloc_consistent(dev, n_bytes, &prog->bus_addr);
	38	if (!prog->kvirt) {
6649e92d JMH	39	printk(KERN_ERR
6649e92d JMH	40	"dma_prog_region_alloc: pci_alloc_consistent() failed\n");
1da177e4 LT	41	dma_prog_region_free(prog);
	42	return -ENOMEM;
	43	}
	44
	45	prog->dev = dev;
	46
	47	return 0;
	48	}
	49
	50	void dma_prog_region_free(struct dma_prog_region *prog)
	51	{
	52	if (prog->kvirt) {
6649e92d JMH	53	pci_free_consistent(prog->dev, prog->n_pages << PAGE_SHIFT,
6649e92d JMH	54	prog->kvirt, prog->bus_addr);
1da177e4 LT	55	}
	56
	57	prog->kvirt = NULL;
	58	prog->dev = NULL;
	59	prog->n_pages = 0;
	60	prog->bus_addr = 0;
	61	}
	62
	63	/* dma_region */
	64
afd6546d SR	65	/**
	66	* dma_region_init - clear out all fields but do not allocate anything
	67	*/
1da177e4 LT	68	void dma_region_init(struct dma_region *dma)
	69	{
	70	dma->kvirt = NULL;
	71	dma->dev = NULL;
	72	dma->n_pages = 0;
	73	dma->n_dma_pages = 0;
	74	dma->sglist = NULL;
	75	}
	76
afd6546d SR	77	/**
	78	* dma_region_alloc - allocate the buffer and map it to the IOMMU
	79	*/
6649e92d JMH	80	int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes,
6649e92d JMH	81	struct pci_dev *dev, int direction)
1da177e4 LT	82	{
	83	unsigned int i;
	84
	85	/* round up to page size */
	86	n_bytes = PAGE_ALIGN(n_bytes);
	87
	88	dma->n_pages = n_bytes >> PAGE_SHIFT;
	89
	90	dma->kvirt = vmalloc_32(n_bytes);
	91	if (!dma->kvirt) {
	92	printk(KERN_ERR "dma_region_alloc: vmalloc_32() failed\n");
	93	goto err;
	94	}
	95
	96	/* Clear the ram out, no junk to the user */
	97	memset(dma->kvirt, 0, n_bytes);
	98
	99	/* allocate scatter/gather list */
	100	dma->sglist = vmalloc(dma->n_pages * sizeof(*dma->sglist));
	101	if (!dma->sglist) {
	102	printk(KERN_ERR "dma_region_alloc: vmalloc(sglist) failed\n");
	103	goto err;
	104	}
	105
	106	/* just to be safe - this will become unnecessary once sglist->address goes away */
	107	memset(dma->sglist, 0, dma->n_pages * sizeof(*dma->sglist));
	108
	109	/* fill scatter/gather list with pages */
	110	for (i = 0; i < dma->n_pages; i++) {
6649e92d JMH	111	unsigned long va =
6649e92d JMH	112	(unsigned long)dma->kvirt + (i << PAGE_SHIFT);
1da177e4 LT	113
	114	dma->sglist[i].page = vmalloc_to_page((void *)va);
	115	dma->sglist[i].length = PAGE_SIZE;
	116	}
	117
	118	/* map sglist to the IOMMU */
6649e92d JMH	119	dma->n_dma_pages =
6649e92d JMH	120	pci_map_sg(dev, dma->sglist, dma->n_pages, direction);
1da177e4 LT	121
	122	if (dma->n_dma_pages == 0) {
	123	printk(KERN_ERR "dma_region_alloc: pci_map_sg() failed\n");
	124	goto err;
	125	}
	126
	127	dma->dev = dev;
	128	dma->direction = direction;
	129
	130	return 0;
	131
6649e92d	132	err:
1da177e4 LT	133	dma_region_free(dma);
	134	return -ENOMEM;
	135	}
	136
afd6546d SR	137	/**
	138	* dma_region_free - unmap and free the buffer
	139	*/
1da177e4 LT	140	void dma_region_free(struct dma_region *dma)
	141	{
	142	if (dma->n_dma_pages) {
6649e92d JMH	143	pci_unmap_sg(dma->dev, dma->sglist, dma->n_pages,
6649e92d JMH	144	dma->direction);
1da177e4 LT	145	dma->n_dma_pages = 0;
	146	dma->dev = NULL;
	147	}
	148
	149	vfree(dma->sglist);
	150	dma->sglist = NULL;
	151
	152	vfree(dma->kvirt);
	153	dma->kvirt = NULL;
	154	dma->n_pages = 0;
	155	}
	156
	157	/* find the scatterlist index and remaining offset corresponding to a
	158	given offset from the beginning of the buffer */
6649e92d	159	static inline int dma_region_find(struct dma_region *dma, unsigned long offset,
9bb2bcdb	160	unsigned int start, unsigned long *rem)
1da177e4 LT	161	{
	162	int i;
	163	unsigned long off = offset;
	164
9bb2bcdb	165	for (i = start; i < dma->n_dma_pages; i++) {
1da177e4 LT	166	if (off < sg_dma_len(&dma->sglist[i])) {
	167	*rem = off;
	168	break;
	169	}
	170
	171	off -= sg_dma_len(&dma->sglist[i]);
	172	}
	173
	174	BUG_ON(i >= dma->n_dma_pages);
	175
	176	return i;
	177	}
	178
afd6546d SR	179	/**
	180	* dma_region_offset_to_bus - get bus address of an offset within a DMA region
	181	*
	182	* Returns the DMA bus address of the byte with the given @offset relative to
	183	* the beginning of the @dma.
	184	*/
6649e92d JMH	185	dma_addr_t dma_region_offset_to_bus(struct dma_region * dma,
6649e92d JMH	186	unsigned long offset)
1da177e4	187	{
1934b8b6	188	unsigned long rem = 0;
1da177e4	189
6649e92d	190	struct scatterlist *sg =
9bb2bcdb	191	&dma->sglist[dma_region_find(dma, offset, 0, &rem)];
1da177e4 LT	192	return sg_dma_address(sg) + rem;
	193	}
	194
afd6546d SR	195	/**
	196	* dma_region_sync_for_cpu - sync the CPU's view of the buffer
	197	*/
6649e92d JMH	198	void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset,
6649e92d JMH	199	unsigned long len)
1da177e4 LT	200	{
1da177e4 LT	201	int first, last;
9bb2bcdb	202	unsigned long rem = 0;
1da177e4 LT	203
	204	if (!len)
	205	len = 1;
	206
9bb2bcdb BC	207	first = dma_region_find(dma, offset, 0, &rem);
9bb2bcdb BC	208	last = dma_region_find(dma, rem + len - 1, first, &rem);
1da177e4	209
6649e92d JMH	210	pci_dma_sync_sg_for_cpu(dma->dev, &dma->sglist[first], last - first + 1,
6649e92d JMH	211	dma->direction);
1da177e4 LT	212	}
1da177e4 LT	213
afd6546d SR	214	/**
	215	* dma_region_sync_for_device - sync the IO bus' view of the buffer
	216	*/
6649e92d JMH	217	void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset,
6649e92d JMH	218	unsigned long len)
1da177e4 LT	219	{
1da177e4 LT	220	int first, last;
9bb2bcdb	221	unsigned long rem = 0;
1da177e4 LT	222
	223	if (!len)
	224	len = 1;
	225
9bb2bcdb BC	226	first = dma_region_find(dma, offset, 0, &rem);
9bb2bcdb BC	227	last = dma_region_find(dma, rem + len - 1, first, &rem);
1da177e4	228
6649e92d JMH	229	pci_dma_sync_sg_for_device(dma->dev, &dma->sglist[first],
6649e92d JMH	230	last - first + 1, dma->direction);
1da177e4 LT	231	}
	232
	233	#ifdef CONFIG_MMU
	234
	235	/* nopage() handler for mmap access */
	236
6649e92d JMH	237	static struct page dma_region_pagefault(struct vm_area_struct area,
6649e92d JMH	238	unsigned long address, int *type)
1da177e4 LT	239	{
	240	unsigned long offset;
	241	unsigned long kernel_virt_addr;
	242	struct page *ret = NOPAGE_SIGBUS;
	243
6649e92d	244	struct dma_region dma = (struct dma_region )area->vm_private_data;
1da177e4 LT	245
	246	if (!dma->kvirt)
	247	goto out;
	248
6649e92d JMH	249	if ((address < (unsigned long)area->vm_start) \|\|
	250	(address >
	251	(unsigned long)area->vm_start + (dma->n_pages << PAGE_SHIFT)))
1da177e4 LT	252	goto out;
	253
	254	if (type)
	255	*type = VM_FAULT_MINOR;
	256	offset = address - area->vm_start;
6649e92d JMH	257	kernel_virt_addr = (unsigned long)dma->kvirt + offset;
6649e92d JMH	258	ret = vmalloc_to_page((void *)kernel_virt_addr);
1da177e4	259	get_page(ret);
6649e92d	260	out:
1da177e4 LT	261	return ret;
	262	}
	263
	264	static struct vm_operations_struct dma_region_vm_ops = {
6649e92d	265	.nopage = dma_region_pagefault,
1da177e4 LT	266	};
1da177e4 LT	267
afd6546d SR	268	/**
	269	* dma_region_mmap - map the buffer into a user space process
	270	*/
6649e92d JMH	271	int dma_region_mmap(struct dma_region dma, struct file file,
6649e92d JMH	272	struct vm_area_struct *vma)
1da177e4 LT	273	{
	274	unsigned long size;
	275
	276	if (!dma->kvirt)
	277	return -EINVAL;
	278
	279	/* must be page-aligned */
	280	if (vma->vm_pgoff != 0)
	281	return -EINVAL;
	282
	283	/* check the length */
	284	size = vma->vm_end - vma->vm_start;
	285	if (size > (dma->n_pages << PAGE_SHIFT))
	286	return -EINVAL;
	287
	288	vma->vm_ops = &dma_region_vm_ops;
	289	vma->vm_private_data = dma;
	290	vma->vm_file = file;
	291	vma->vm_flags \|= VM_RESERVED;
	292
	293	return 0;
	294	}
	295
6649e92d	296	#else /* CONFIG_MMU */
1da177e4	297
6649e92d JMH	298	int dma_region_mmap(struct dma_region dma, struct file file,
6649e92d JMH	299	struct vm_area_struct *vma)
1da177e4 LT	300	{
	301	return -EINVAL;
	302	}
	303
6649e92d	304	#endif /* CONFIG_MMU */