memalloc.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 665 行 · 第 1/2 页

{
	snd_assert(size > 0, return -ENXIO);
	snd_assert(dmab != NULL, 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, (unsigned long)device);
		dmab->addr = 0;
		break;
#ifdef CONFIG_SBUS
	case SNDRV_DMA_TYPE_SBUS:
		dmab->area = snd_malloc_sbus_pages(device, size, &dmab->addr);
		break;
#endif
	case SNDRV_DMA_TYPE_DEV:
		dmab->area = snd_malloc_dev_pages(device, size, &dmab->addr);
		break;
	case SNDRV_DMA_TYPE_DEV_SG:
		snd_malloc_sgbuf_pages(device, size, dmab, NULL);
		break;
	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.
 * 
 * Returns zero if the buffer with the given size is allocated successfuly,
 * other a negative value at error.
 */
int snd_dma_alloc_pages_fallback(int type, struct device *device, size_t size,
				 struct snd_dma_buffer *dmab)
{
	int err;

	snd_assert(size > 0, return -ENXIO);
	snd_assert(dmab != NULL, return -ENXIO);

	while ((err = snd_dma_alloc_pages(type, device, size, dmab)) < 0) {
		if (err != -ENOMEM)
			return err;
		size >>= 1;
		if (size <= PAGE_SIZE)
			return -ENOMEM;
	}
	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_SBUS
	case SNDRV_DMA_TYPE_SBUS:
		snd_free_sbus_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
		break;
#endif
	case SNDRV_DMA_TYPE_DEV:
		snd_free_dev_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
		break;
	case SNDRV_DMA_TYPE_DEV_SG:
		snd_free_sgbuf_pages(dmab);
		break;
	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.
 *
 * Returns 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 list_head *p;
	struct snd_mem_list *mem;

	snd_assert(dmab, return 0);

	down(&list_mutex);
	list_for_each(p, &mem_list_head) {
		mem = list_entry(p, struct snd_mem_list, list);
		if (mem->id == id &&
		    ! memcmp(&mem->buffer.dev, &dmab->dev, sizeof(dmab->dev))) {
			list_del(p);
			*dmab = mem->buffer;
			kfree(mem);
			up(&list_mutex);
			return dmab->bytes;
		}
	}
	up(&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.
 * 
 * Returns zero if successful, or a negative code at error.
 */
int snd_dma_reserve_buf(struct snd_dma_buffer *dmab, unsigned int id)
{
	struct snd_mem_list *mem;

	snd_assert(dmab, return -EINVAL);
	mem = kmalloc(sizeof(*mem), GFP_KERNEL);
	if (! mem)
		return -ENOMEM;
	down(&list_mutex);
	mem->buffer = *dmab;
	mem->id = id;
	list_add_tail(&mem->list, &mem_list_head);
	up(&list_mutex);
	return 0;
}

/*
 * purge all reserved buffers
 */
static void free_all_reserved_pages(void)
{
	struct list_head *p;
	struct snd_mem_list *mem;

	down(&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);
	}
	up(&list_mutex);
}



/*
 * allocation of buffers for pre-defined devices
 */

#ifdef CONFIG_PCI
/* FIXME: for pci only - other bus? */
struct prealloc_dev {
	unsigned short vendor;
	unsigned short device;
	unsigned long dma_mask;
	unsigned int size;
	unsigned int buffers;
};

#define HAMMERFALL_BUFFER_SIZE    (16*1024*4*(26+1)+0x10000)

static struct prealloc_dev prealloc_devices[] __initdata = {
	{
		/* hammerfall */
		.vendor = 0x10ee,
		.device = 0x3fc4,
		.dma_mask = 0xffffffff,
		.size = HAMMERFALL_BUFFER_SIZE,
		.buffers = 2
	},
	{
		/* HDSP */
		.vendor = 0x10ee,
		.device = 0x3fc5,
		.dma_mask = 0xffffffff,
		.size = HAMMERFALL_BUFFER_SIZE,
		.buffers = 2
	},
	{ }, /* terminator */
};

static void __init preallocate_cards(void)
{
	struct pci_dev *pci = NULL;
	int card;

	card = 0;

	while ((pci = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, pci)) != NULL) {
		struct prealloc_dev *dev;
		unsigned int i;
		if (card >= SNDRV_CARDS)
			break;
		for (dev = prealloc_devices; dev->vendor; dev++) {
			if (dev->vendor == pci->vendor && dev->device == pci->device)
				break;
		}
		if (! dev->vendor)
			continue;
		if (! enable[card++]) {
			printk(KERN_DEBUG "snd-page-alloc: skipping card %d, device %04x:%04x\n", card, pci->vendor, pci->device);
			continue;
		}
			
		if (pci_set_dma_mask(pci, dev->dma_mask) < 0 ||
		    pci_set_consistent_dma_mask(pci, dev->dma_mask) < 0) {
			printk(KERN_ERR "snd-page-alloc: cannot set DMA mask %lx for pci %04x:%04x\n", dev->dma_mask, dev->vendor, dev->device);
			continue;
		}
		for (i = 0; i < dev->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),
						dev->size, &dmab) < 0)
				printk(KERN_WARNING "snd-page-alloc: cannot allocate buffer pages (size = %d)\n", dev->size);
			else
				snd_dma_reserve_buf(&dmab, snd_dma_pci_buf_id(pci));
		}
	}
}
#else
#define preallocate_cards()	/* NOP */
#endif


#ifdef CONFIG_PROC_FS
/*
 * proc file interface
 */
static int snd_mem_proc_read(char *page, char **start, off_t off,
			     int count, int *eof, void *data)
{
	int len = 0;
	long pages = snd_allocated_pages >> (PAGE_SHIFT-12);
	struct list_head *p;
	struct snd_mem_list *mem;
	int devno;
	static char *types[] = { "UNKNOWN", "CONT", "DEV", "DEV-SG", "SBUS" };

	down(&list_mutex);
	len += snprintf(page + len, count - len,
			"pages  : %li bytes (%li pages per %likB)\n",
			pages * PAGE_SIZE, pages, PAGE_SIZE / 1024);
	devno = 0;
	list_for_each(p, &mem_list_head) {
		mem = list_entry(p, struct snd_mem_list, list);
		devno++;
		len += snprintf(page + len, count - len,
				"buffer %d : ID %08x : type %s\n",
				devno, mem->id, types[mem->buffer.dev.type]);
		len += snprintf(page + len, count - len,
				"  addr = 0x%lx, size = %d bytes\n",
				(unsigned long)mem->buffer.addr, (int)mem->buffer.bytes);
	}
	up(&list_mutex);
	return len;
}
#endif /* CONFIG_PROC_FS */

/*
 * module entry
 */

static int __init snd_mem_init(void)
{
#ifdef CONFIG_PROC_FS
	create_proc_read_entry("driver/snd-page-alloc", 0, NULL, snd_mem_proc_read, NULL);
#endif
	preallocate_cards();
	return 0;
}

static void __exit snd_mem_exit(void)
{
	remove_proc_entry("driver/snd-page-alloc", 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);