linux/sound/core/memalloc.c
Yacine Belkadi eb7c06e8e9 ALSA: add/change some comments describing function return values
script/kernel-doc reports the following type of warnings (when run in verbose
mode):

Warning(sound/core/init.c:152): No description found for return value of
'snd_card_create'

To fix that:
- add missing descriptions of function return values
- use "Return:" sections to describe those return values

Along the way:
- complete some descriptions
- fix some typos

Signed-off-by: Yacine Belkadi <yacine.belkadi.1@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2013-03-12 08:32:53 +01:00

548 lines
13 KiB
C

/*
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
* Takashi Iwai <tiwai@suse.de>
*
* Generic memory allocators
*
*
* 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/module.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <asm/uaccess.h>
#include <linux/dma-mapping.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <sound/memalloc.h>
MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>, Jaroslav Kysela <perex@perex.cz>");
MODULE_DESCRIPTION("Memory allocator for ALSA system.");
MODULE_LICENSE("GPL");
/*
*/
static DEFINE_MUTEX(list_mutex);
static LIST_HEAD(mem_list_head);
/* buffer preservation list */
struct snd_mem_list {
struct snd_dma_buffer buffer;
unsigned int id;
struct list_head list;
};
/* id for pre-allocated buffers */
#define SNDRV_DMA_DEVICE_UNUSED (unsigned int)-1
/*
*
* Generic memory allocators
*
*/
static long snd_allocated_pages; /* holding the number of allocated pages */
static inline void inc_snd_pages(int order)
{
snd_allocated_pages += 1 << order;
}
static inline void dec_snd_pages(int order)
{
snd_allocated_pages -= 1 << order;
}
/**
* snd_malloc_pages - allocate pages with the given size
* @size: the size to allocate in bytes
* @gfp_flags: the allocation conditions, GFP_XXX
*
* Allocates the physically contiguous pages with the given size.
*
* Return: The pointer of the buffer, or %NULL if no enough memory.
*/
void *snd_malloc_pages(size_t size, gfp_t gfp_flags)
{
int pg;
void *res;
if (WARN_ON(!size))
return NULL;
if (WARN_ON(!gfp_flags))
return NULL;
gfp_flags |= __GFP_COMP; /* compound page lets parts be mapped */
pg = get_order(size);
if ((res = (void *) __get_free_pages(gfp_flags, pg)) != NULL)
inc_snd_pages(pg);
return res;
}
/**
* snd_free_pages - release the pages
* @ptr: the buffer pointer to release
* @size: the allocated buffer size
*
* Releases the buffer allocated via snd_malloc_pages().
*/
void snd_free_pages(void *ptr, size_t size)
{
int pg;
if (ptr == NULL)
return;
pg = get_order(size);
dec_snd_pages(pg);
free_pages((unsigned long) ptr, pg);
}
/*
*
* Bus-specific memory allocators
*
*/
#ifdef CONFIG_HAS_DMA
/* allocate the coherent DMA pages */
static void *snd_malloc_dev_pages(struct device *dev, size_t size, dma_addr_t *dma)
{
int pg;
void *res;
gfp_t gfp_flags;
if (WARN_ON(!dma))
return NULL;
pg = get_order(size);
gfp_flags = GFP_KERNEL
| __GFP_COMP /* compound page lets parts be mapped */
| __GFP_NORETRY /* don't trigger OOM-killer */
| __GFP_NOWARN; /* no stack trace print - this call is non-critical */
res = dma_alloc_coherent(dev, PAGE_SIZE << pg, dma, gfp_flags);
if (res != NULL)
inc_snd_pages(pg);
return res;
}
/* free the coherent DMA pages */
static void snd_free_dev_pages(struct device *dev, size_t size, void *ptr,
dma_addr_t dma)
{
int pg;
if (ptr == NULL)
return;
pg = get_order(size);
dec_snd_pages(pg);
dma_free_coherent(dev, PAGE_SIZE << pg, ptr, dma);
}
#endif /* CONFIG_HAS_DMA */
/*
*
* ALSA generic memory management
*
*/
/**
* snd_dma_alloc_pages - allocate the buffer area according to the given type
* @type: the DMA buffer type
* @device: the device pointer
* @size: the buffer size to allocate
* @dmab: buffer allocation record to store the allocated data
*
* Calls the memory-allocator function for the corresponding
* buffer type.
*
* Return: Zero if the buffer with the given size is allocated successfully,
* otherwise a negative value on error.
*/
int snd_dma_alloc_pages(int type, struct device *device, size_t size,
struct snd_dma_buffer *dmab)
{
if (WARN_ON(!size))
return -ENXIO;
if (WARN_ON(!dmab))
return -ENXIO;
dmab->dev.type = type;
dmab->dev.dev = device;
dmab->bytes = 0;
switch (type) {
case SNDRV_DMA_TYPE_CONTINUOUS:
dmab->area = snd_malloc_pages(size,
(__force gfp_t)(unsigned long)device);
dmab->addr = 0;
break;
#ifdef CONFIG_HAS_DMA
case SNDRV_DMA_TYPE_DEV:
dmab->area = snd_malloc_dev_pages(device, size, &dmab->addr);
break;
#endif
#ifdef CONFIG_SND_DMA_SGBUF
case SNDRV_DMA_TYPE_DEV_SG:
snd_malloc_sgbuf_pages(device, size, dmab, NULL);
break;
#endif
default:
printk(KERN_ERR "snd-malloc: invalid device type %d\n", type);
dmab->area = NULL;
dmab->addr = 0;
return -ENXIO;
}
if (! dmab->area)
return -ENOMEM;
dmab->bytes = size;
return 0;
}
/**
* snd_dma_alloc_pages_fallback - allocate the buffer area according to the given type with fallback
* @type: the DMA buffer type
* @device: the device pointer
* @size: the buffer size to allocate
* @dmab: buffer allocation record to store the allocated data
*
* Calls the memory-allocator function for the corresponding
* buffer type. When no space is left, this function reduces the size and
* tries to allocate again. The size actually allocated is stored in
* res_size argument.
*
* Return: Zero if the buffer with the given size is allocated successfully,
* otherwise a negative value on error.
*/
int snd_dma_alloc_pages_fallback(int type, struct device *device, size_t size,
struct snd_dma_buffer *dmab)
{
int err;
while ((err = snd_dma_alloc_pages(type, device, size, dmab)) < 0) {
size_t aligned_size;
if (err != -ENOMEM)
return err;
if (size <= PAGE_SIZE)
return -ENOMEM;
aligned_size = PAGE_SIZE << get_order(size);
if (size != aligned_size)
size = aligned_size;
else
size >>= 1;
}
if (! dmab->area)
return -ENOMEM;
return 0;
}
/**
* snd_dma_free_pages - release the allocated buffer
* @dmab: the buffer allocation record to release
*
* Releases the allocated buffer via snd_dma_alloc_pages().
*/
void snd_dma_free_pages(struct snd_dma_buffer *dmab)
{
switch (dmab->dev.type) {
case SNDRV_DMA_TYPE_CONTINUOUS:
snd_free_pages(dmab->area, dmab->bytes);
break;
#ifdef CONFIG_HAS_DMA
case SNDRV_DMA_TYPE_DEV:
snd_free_dev_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
break;
#endif
#ifdef CONFIG_SND_DMA_SGBUF
case SNDRV_DMA_TYPE_DEV_SG:
snd_free_sgbuf_pages(dmab);
break;
#endif
default:
printk(KERN_ERR "snd-malloc: invalid device type %d\n", dmab->dev.type);
}
}
/**
* snd_dma_get_reserved - get the reserved buffer for the given device
* @dmab: the buffer allocation record to store
* @id: the buffer id
*
* Looks for the reserved-buffer list and re-uses if the same buffer
* is found in the list. When the buffer is found, it's removed from the free list.
*
* Return: The size of buffer if the buffer is found, or zero if not found.
*/
size_t snd_dma_get_reserved_buf(struct snd_dma_buffer *dmab, unsigned int id)
{
struct snd_mem_list *mem;
if (WARN_ON(!dmab))
return 0;
mutex_lock(&list_mutex);
list_for_each_entry(mem, &mem_list_head, list) {
if (mem->id == id &&
(mem->buffer.dev.dev == NULL || dmab->dev.dev == NULL ||
! memcmp(&mem->buffer.dev, &dmab->dev, sizeof(dmab->dev)))) {
struct device *dev = dmab->dev.dev;
list_del(&mem->list);
*dmab = mem->buffer;
if (dmab->dev.dev == NULL)
dmab->dev.dev = dev;
kfree(mem);
mutex_unlock(&list_mutex);
return dmab->bytes;
}
}
mutex_unlock(&list_mutex);
return 0;
}
/**
* snd_dma_reserve_buf - reserve the buffer
* @dmab: the buffer to reserve
* @id: the buffer id
*
* Reserves the given buffer as a reserved buffer.
*
* Return: Zero if successful, or a negative code on error.
*/
int snd_dma_reserve_buf(struct snd_dma_buffer *dmab, unsigned int id)
{
struct snd_mem_list *mem;
if (WARN_ON(!dmab))
return -EINVAL;
mem = kmalloc(sizeof(*mem), GFP_KERNEL);
if (! mem)
return -ENOMEM;
mutex_lock(&list_mutex);
mem->buffer = *dmab;
mem->id = id;
list_add_tail(&mem->list, &mem_list_head);
mutex_unlock(&list_mutex);
return 0;
}
/*
* purge all reserved buffers
*/
static void free_all_reserved_pages(void)
{
struct list_head *p;
struct snd_mem_list *mem;
mutex_lock(&list_mutex);
while (! list_empty(&mem_list_head)) {
p = mem_list_head.next;
mem = list_entry(p, struct snd_mem_list, list);
list_del(p);
snd_dma_free_pages(&mem->buffer);
kfree(mem);
}
mutex_unlock(&list_mutex);
}
#ifdef CONFIG_PROC_FS
/*
* proc file interface
*/
#define SND_MEM_PROC_FILE "driver/snd-page-alloc"
static struct proc_dir_entry *snd_mem_proc;
static int snd_mem_proc_read(struct seq_file *seq, void *offset)
{
long pages = snd_allocated_pages >> (PAGE_SHIFT-12);
struct snd_mem_list *mem;
int devno;
static char *types[] = { "UNKNOWN", "CONT", "DEV", "DEV-SG" };
mutex_lock(&list_mutex);
seq_printf(seq, "pages : %li bytes (%li pages per %likB)\n",
pages * PAGE_SIZE, pages, PAGE_SIZE / 1024);
devno = 0;
list_for_each_entry(mem, &mem_list_head, list) {
devno++;
seq_printf(seq, "buffer %d : ID %08x : type %s\n",
devno, mem->id, types[mem->buffer.dev.type]);
seq_printf(seq, " addr = 0x%lx, size = %d bytes\n",
(unsigned long)mem->buffer.addr,
(int)mem->buffer.bytes);
}
mutex_unlock(&list_mutex);
return 0;
}
static int snd_mem_proc_open(struct inode *inode, struct file *file)
{
return single_open(file, snd_mem_proc_read, NULL);
}
/* FIXME: for pci only - other bus? */
#ifdef CONFIG_PCI
#define gettoken(bufp) strsep(bufp, " \t\n")
static ssize_t snd_mem_proc_write(struct file *file, const char __user * buffer,
size_t count, loff_t * ppos)
{
char buf[128];
char *token, *p;
if (count > sizeof(buf) - 1)
return -EINVAL;
if (copy_from_user(buf, buffer, count))
return -EFAULT;
buf[count] = '\0';
p = buf;
token = gettoken(&p);
if (! token || *token == '#')
return count;
if (strcmp(token, "add") == 0) {
char *endp;
int vendor, device, size, buffers;
long mask;
int i, alloced;
struct pci_dev *pci;
if ((token = gettoken(&p)) == NULL ||
(vendor = simple_strtol(token, NULL, 0)) <= 0 ||
(token = gettoken(&p)) == NULL ||
(device = simple_strtol(token, NULL, 0)) <= 0 ||
(token = gettoken(&p)) == NULL ||
(mask = simple_strtol(token, NULL, 0)) < 0 ||
(token = gettoken(&p)) == NULL ||
(size = memparse(token, &endp)) < 64*1024 ||
size > 16*1024*1024 /* too big */ ||
(token = gettoken(&p)) == NULL ||
(buffers = simple_strtol(token, NULL, 0)) <= 0 ||
buffers > 4) {
printk(KERN_ERR "snd-page-alloc: invalid proc write format\n");
return count;
}
vendor &= 0xffff;
device &= 0xffff;
alloced = 0;
pci = NULL;
while ((pci = pci_get_device(vendor, device, pci)) != NULL) {
if (mask > 0 && mask < 0xffffffff) {
if (pci_set_dma_mask(pci, mask) < 0 ||
pci_set_consistent_dma_mask(pci, mask) < 0) {
printk(KERN_ERR "snd-page-alloc: cannot set DMA mask %lx for pci %04x:%04x\n", mask, vendor, device);
pci_dev_put(pci);
return count;
}
}
for (i = 0; i < buffers; i++) {
struct snd_dma_buffer dmab;
memset(&dmab, 0, sizeof(dmab));
if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, snd_dma_pci_data(pci),
size, &dmab) < 0) {
printk(KERN_ERR "snd-page-alloc: cannot allocate buffer pages (size = %d)\n", size);
pci_dev_put(pci);
return count;
}
snd_dma_reserve_buf(&dmab, snd_dma_pci_buf_id(pci));
}
alloced++;
}
if (! alloced) {
for (i = 0; i < buffers; i++) {
struct snd_dma_buffer dmab;
memset(&dmab, 0, sizeof(dmab));
/* FIXME: We can allocate only in ZONE_DMA
* without a device pointer!
*/
if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, NULL,
size, &dmab) < 0) {
printk(KERN_ERR "snd-page-alloc: cannot allocate buffer pages (size = %d)\n", size);
break;
}
snd_dma_reserve_buf(&dmab, (unsigned int)((vendor << 16) | device));
}
}
} else if (strcmp(token, "erase") == 0)
/* FIXME: need for releasing each buffer chunk? */
free_all_reserved_pages();
else
printk(KERN_ERR "snd-page-alloc: invalid proc cmd\n");
return count;
}
#endif /* CONFIG_PCI */
static const struct file_operations snd_mem_proc_fops = {
.owner = THIS_MODULE,
.open = snd_mem_proc_open,
.read = seq_read,
#ifdef CONFIG_PCI
.write = snd_mem_proc_write,
#endif
.llseek = seq_lseek,
.release = single_release,
};
#endif /* CONFIG_PROC_FS */
/*
* module entry
*/
static int __init snd_mem_init(void)
{
#ifdef CONFIG_PROC_FS
snd_mem_proc = proc_create(SND_MEM_PROC_FILE, 0644, NULL,
&snd_mem_proc_fops);
#endif
return 0;
}
static void __exit snd_mem_exit(void)
{
remove_proc_entry(SND_MEM_PROC_FILE, NULL);
free_all_reserved_pages();
if (snd_allocated_pages > 0)
printk(KERN_ERR "snd-malloc: Memory leak? pages not freed = %li\n", snd_allocated_pages);
}
module_init(snd_mem_init)
module_exit(snd_mem_exit)
/*
* exports
*/
EXPORT_SYMBOL(snd_dma_alloc_pages);
EXPORT_SYMBOL(snd_dma_alloc_pages_fallback);
EXPORT_SYMBOL(snd_dma_free_pages);
EXPORT_SYMBOL(snd_dma_get_reserved_buf);
EXPORT_SYMBOL(snd_dma_reserve_buf);
EXPORT_SYMBOL(snd_malloc_pages);
EXPORT_SYMBOL(snd_free_pages);