[mirror_ubuntu-eoan-kernel.git] / sound / core / sgbuf.c

/*
 * Scatter-Gather buffer
 *
 *  Copyright (c) by Takashi Iwai <tiwai@suse.de>
 *
 *   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.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/export.h>
#include <asm/pgtable.h>
#include <sound/memalloc.h>


/* table entries are align to 32 */
#define SGBUF_TBL_ALIGN		32
#define sgbuf_align_table(tbl)	ALIGN((tbl), SGBUF_TBL_ALIGN)

int snd_free_sgbuf_pages(struct snd_dma_buffer *dmab)
{
	struct snd_sg_buf *sgbuf = dmab->private_data;
	struct snd_dma_buffer tmpb;
	int i;

	if (! sgbuf)
		return -EINVAL;

	vunmap(dmab->area);
	dmab->area = NULL;

	tmpb.dev.type = SNDRV_DMA_TYPE_DEV;
	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_UC_SG)
		tmpb.dev.type = SNDRV_DMA_TYPE_DEV_UC;
	tmpb.dev.dev = sgbuf->dev;
	for (i = 0; i < sgbuf->pages; i++) {
		if (!(sgbuf->table[i].addr & ~PAGE_MASK))
			continue; /* continuous pages */
		tmpb.area = sgbuf->table[i].buf;
		tmpb.addr = sgbuf->table[i].addr & PAGE_MASK;
		tmpb.bytes = (sgbuf->table[i].addr & ~PAGE_MASK) << PAGE_SHIFT;
		snd_dma_free_pages(&tmpb);
	}

	kfree(sgbuf->table);
	kfree(sgbuf->page_table);
	kfree(sgbuf);
	dmab->private_data = NULL;
	
	return 0;
}

#define MAX_ALLOC_PAGES		32

void *snd_malloc_sgbuf_pages(struct device *device,
			     size_t size, struct snd_dma_buffer *dmab,
			     size_t *res_size)
{
	struct snd_sg_buf *sgbuf;
	unsigned int i, pages, chunk, maxpages;
	struct snd_dma_buffer tmpb;
	struct snd_sg_page *table;
	struct page **pgtable;
	int type = SNDRV_DMA_TYPE_DEV;
	pgprot_t prot = PAGE_KERNEL;

	dmab->area = NULL;
	dmab->addr = 0;
	dmab->private_data = sgbuf = kzalloc(sizeof(*sgbuf), GFP_KERNEL);
	if (! sgbuf)
		return NULL;
	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_UC_SG) {
		type = SNDRV_DMA_TYPE_DEV_UC;
#ifdef pgprot_noncached
		prot = pgprot_noncached(PAGE_KERNEL);
#endif
	}
	sgbuf->dev = device;
	pages = snd_sgbuf_aligned_pages(size);
	sgbuf->tblsize = sgbuf_align_table(pages);
	table = kcalloc(sgbuf->tblsize, sizeof(*table), GFP_KERNEL);
	if (!table)
		goto _failed;
	sgbuf->table = table;
	pgtable = kcalloc(sgbuf->tblsize, sizeof(*pgtable), GFP_KERNEL);
	if (!pgtable)
		goto _failed;
	sgbuf->page_table = pgtable;

	/* allocate pages */
	maxpages = MAX_ALLOC_PAGES;
	while (pages > 0) {
		chunk = pages;
		/* don't be too eager to take a huge chunk */
		if (chunk > maxpages)
			chunk = maxpages;
		chunk <<= PAGE_SHIFT;
		if (snd_dma_alloc_pages_fallback(type, device,
						 chunk, &tmpb) < 0) {
			if (!sgbuf->pages)
				goto _failed;
			if (!res_size)
				goto _failed;
			size = sgbuf->pages * PAGE_SIZE;
			break;
		}
		chunk = tmpb.bytes >> PAGE_SHIFT;
		for (i = 0; i < chunk; i++) {
			table->buf = tmpb.area;
			table->addr = tmpb.addr;
			if (!i)
				table->addr |= chunk; /* mark head */
			table++;
			*pgtable++ = virt_to_page(tmpb.area);
			tmpb.area += PAGE_SIZE;
			tmpb.addr += PAGE_SIZE;
		}
		sgbuf->pages += chunk;
		pages -= chunk;
		if (chunk < maxpages)
			maxpages = chunk;
	}

	sgbuf->size = size;
	dmab->area = vmap(sgbuf->page_table, sgbuf->pages, VM_MAP, prot);
	if (! dmab->area)
		goto _failed;
	if (res_size)
		*res_size = sgbuf->size;
	return dmab->area;

 _failed:
	snd_free_sgbuf_pages(dmab); /* free the table */
	return NULL;
}

/*
 * compute the max chunk size with continuous pages on sg-buffer
 */
unsigned int snd_sgbuf_get_chunk_size(struct snd_dma_buffer *dmab,
				      unsigned int ofs, unsigned int size)
{
	struct snd_sg_buf *sg = dmab->private_data;
	unsigned int start, end, pg;

	start = ofs >> PAGE_SHIFT;
	end = (ofs + size - 1) >> PAGE_SHIFT;
	/* check page continuity */
	pg = sg->table[start].addr >> PAGE_SHIFT;
	for (;;) {
		start++;
		if (start > end)
			break;
		pg++;
		if ((sg->table[start].addr >> PAGE_SHIFT) != pg)
			return (start << PAGE_SHIFT) - ofs;
	}
	/* ok, all on continuous pages */
	return size;
}
EXPORT_SYMBOL(snd_sgbuf_get_chunk_size);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Scatter-Gather buffer
	3	*
	4	* Copyright (c) by Takashi Iwai <tiwai@suse.de>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*
	20	*/
	21
1da177e4 LT	22	#include <linux/slab.h>
	23	#include <linux/mm.h>
	24	#include <linux/vmalloc.h>
9d069dc0	25	#include <linux/export.h>
42e748a0	26	#include <asm/pgtable.h>
1da177e4 LT	27	#include <sound/memalloc.h>
	28
	29
	30	/* table entries are align to 32 */
	31	#define SGBUF_TBL_ALIGN 32
7ab39926	32	#define sgbuf_align_table(tbl) ALIGN((tbl), SGBUF_TBL_ALIGN)
1da177e4 LT	33
	34	int snd_free_sgbuf_pages(struct snd_dma_buffer *dmab)
	35	{
	36	struct snd_sg_buf *sgbuf = dmab->private_data;
	37	struct snd_dma_buffer tmpb;
	38	int i;
	39
	40	if (! sgbuf)
	41	return -EINVAL;
	42
d712eaf2	43	vunmap(dmab->area);
6af845e4 TI	44	dmab->area = NULL;
6af845e4 TI	45
1da177e4	46	tmpb.dev.type = SNDRV_DMA_TYPE_DEV;
42e748a0 TI	47	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_UC_SG)
42e748a0 TI	48	tmpb.dev.type = SNDRV_DMA_TYPE_DEV_UC;
1da177e4 LT	49	tmpb.dev.dev = sgbuf->dev;
1da177e4 LT	50	for (i = 0; i < sgbuf->pages; i++) {
51e9f2e6 TI	51	if (!(sgbuf->table[i].addr & ~PAGE_MASK))
51e9f2e6 TI	52	continue; /* continuous pages */
1da177e4	53	tmpb.area = sgbuf->table[i].buf;
51e9f2e6 TI	54	tmpb.addr = sgbuf->table[i].addr & PAGE_MASK;
51e9f2e6 TI	55	tmpb.bytes = (sgbuf->table[i].addr & ~PAGE_MASK) << PAGE_SHIFT;
1da177e4 LT	56	snd_dma_free_pages(&tmpb);
1da177e4 LT	57	}
1da177e4 LT	58
	59	kfree(sgbuf->table);
	60	kfree(sgbuf->page_table);
	61	kfree(sgbuf);
	62	dmab->private_data = NULL;
	63
	64	return 0;
	65	}
	66
51e9f2e6 TI	67	#define MAX_ALLOC_PAGES 32
51e9f2e6 TI	68
1da177e4 LT	69	void snd_malloc_sgbuf_pages(struct device device,
	70	size_t size, struct snd_dma_buffer *dmab,
	71	size_t *res_size)
	72	{
	73	struct snd_sg_buf *sgbuf;
51e9f2e6	74	unsigned int i, pages, chunk, maxpages;
1da177e4	75	struct snd_dma_buffer tmpb;
51e9f2e6 TI	76	struct snd_sg_page *table;
51e9f2e6 TI	77	struct page **pgtable;
42e748a0 TI	78	int type = SNDRV_DMA_TYPE_DEV;
42e748a0 TI	79	pgprot_t prot = PAGE_KERNEL;
1da177e4 LT	80
	81	dmab->area = NULL;
	82	dmab->addr = 0;
59feddb2	83	dmab->private_data = sgbuf = kzalloc(sizeof(*sgbuf), GFP_KERNEL);
1da177e4 LT	84	if (! sgbuf)
1da177e4 LT	85	return NULL;
42e748a0 TI	86	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_UC_SG) {
	87	type = SNDRV_DMA_TYPE_DEV_UC;
	88	#ifdef pgprot_noncached
	89	prot = pgprot_noncached(PAGE_KERNEL);
	90	#endif
	91	}
1da177e4 LT	92	sgbuf->dev = device;
	93	pages = snd_sgbuf_aligned_pages(size);
	94	sgbuf->tblsize = sgbuf_align_table(pages);
51e9f2e6 TI	95	table = kcalloc(sgbuf->tblsize, sizeof(*table), GFP_KERNEL);
51e9f2e6 TI	96	if (!table)
1da177e4	97	goto _failed;
51e9f2e6 TI	98	sgbuf->table = table;
	99	pgtable = kcalloc(sgbuf->tblsize, sizeof(*pgtable), GFP_KERNEL);
	100	if (!pgtable)
1da177e4	101	goto _failed;
51e9f2e6	102	sgbuf->page_table = pgtable;
1da177e4	103
51e9f2e6 TI	104	/* allocate pages */
	105	maxpages = MAX_ALLOC_PAGES;
	106	while (pages > 0) {
	107	chunk = pages;
	108	/* don't be too eager to take a huge chunk */
	109	if (chunk > maxpages)
	110	chunk = maxpages;
	111	chunk <<= PAGE_SHIFT;
42e748a0	112	if (snd_dma_alloc_pages_fallback(type, device,
51e9f2e6 TI	113	chunk, &tmpb) < 0) {
51e9f2e6 TI	114	if (!sgbuf->pages)
c810f903	115	goto _failed;
51e9f2e6	116	if (!res_size)
1da177e4	117	goto _failed;
51e9f2e6	118	size = sgbuf->pages * PAGE_SIZE;
1da177e4 LT	119	break;
1da177e4 LT	120	}
51e9f2e6 TI	121	chunk = tmpb.bytes >> PAGE_SHIFT;
	122	for (i = 0; i < chunk; i++) {
	123	table->buf = tmpb.area;
	124	table->addr = tmpb.addr;
	125	if (!i)
	126	table->addr \|= chunk; /* mark head */
	127	table++;
	128	*pgtable++ = virt_to_page(tmpb.area);
	129	tmpb.area += PAGE_SIZE;
	130	tmpb.addr += PAGE_SIZE;
	131	}
	132	sgbuf->pages += chunk;
	133	pages -= chunk;
	134	if (chunk < maxpages)
	135	maxpages = chunk;
1da177e4 LT	136	}
	137
	138	sgbuf->size = size;
42e748a0	139	dmab->area = vmap(sgbuf->page_table, sgbuf->pages, VM_MAP, prot);
1da177e4 LT	140	if (! dmab->area)
1da177e4 LT	141	goto _failed;
51e9f2e6 TI	142	if (res_size)
51e9f2e6 TI	143	*res_size = sgbuf->size;
1da177e4 LT	144	return dmab->area;
	145
	146	_failed:
	147	snd_free_sgbuf_pages(dmab); /* free the table */
	148	return NULL;
	149	}
9d069dc0 TI	150
	151	/*
	152	* compute the max chunk size with continuous pages on sg-buffer
	153	*/
	154	unsigned int snd_sgbuf_get_chunk_size(struct snd_dma_buffer *dmab,
	155	unsigned int ofs, unsigned int size)
	156	{
	157	struct snd_sg_buf *sg = dmab->private_data;
	158	unsigned int start, end, pg;
	159
	160	start = ofs >> PAGE_SHIFT;
	161	end = (ofs + size - 1) >> PAGE_SHIFT;
	162	/* check page continuity */
	163	pg = sg->table[start].addr >> PAGE_SHIFT;
	164	for (;;) {
	165	start++;
	166	if (start > end)
	167	break;
	168	pg++;
	169	if ((sg->table[start].addr >> PAGE_SHIFT) != pg)
	170	return (start << PAGE_SHIFT) - ofs;
	171	}
	172	/* ok, all on continuous pages */
	173	return size;
	174	}
	175	EXPORT_SYMBOL(snd_sgbuf_get_chunk_size);