memory.c

linux2.6.16版本

}

/*
 * page allocation for DMA
 */
struct snd_util_memblk *
snd_emu10k1_alloc_pages(struct snd_emu10k1 *emu, struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
	struct snd_util_memhdr *hdr;
	struct snd_emu10k1_memblk *blk;
	int page, err, idx;

	snd_assert(emu, return NULL);
	snd_assert(runtime->dma_bytes > 0 && runtime->dma_bytes < MAXPAGES * EMUPAGESIZE, return NULL);
	hdr = emu->memhdr;
	snd_assert(hdr, return NULL);

	down(&hdr->block_mutex);
	blk = search_empty(emu, runtime->dma_bytes);
	if (blk == NULL) {
		up(&hdr->block_mutex);
		return NULL;
	}
	/* fill buffer addresses but pointers are not stored so that
	 * snd_free_pci_page() is not called in in synth_free()
	 */
	idx = 0;
	for (page = blk->first_page; page <= blk->last_page; page++, idx++) {
		dma_addr_t addr;
#ifdef CONFIG_SND_DEBUG
		if (idx >= sgbuf->pages) {
			printk(KERN_ERR "emu: pages overflow! (%d-%d) for %d\n",
			       blk->first_page, blk->last_page, sgbuf->pages);
			up(&hdr->block_mutex);
			return NULL;
		}
#endif
		addr = sgbuf->table[idx].addr;
		if (! is_valid_page(emu, addr)) {
			printk(KERN_ERR "emu: failure page = %d\n", idx);
			up(&hdr->block_mutex);
			return NULL;
		}
		emu->page_addr_table[page] = addr;
		emu->page_ptr_table[page] = NULL;
	}

	/* set PTB entries */
	blk->map_locked = 1; /* do not unmap this block! */
	err = snd_emu10k1_memblk_map(emu, blk);
	if (err < 0) {
		__snd_util_mem_free(hdr, (struct snd_util_memblk *)blk);
		up(&hdr->block_mutex);
		return NULL;
	}
	up(&hdr->block_mutex);
	return (struct snd_util_memblk *)blk;
}


/*
 * release DMA buffer from page table
 */
int snd_emu10k1_free_pages(struct snd_emu10k1 *emu, struct snd_util_memblk *blk)
{
	snd_assert(emu && blk, return -EINVAL);
	return snd_emu10k1_synth_free(emu, blk);
}


/*
 * memory allocation using multiple pages (for synth)
 * Unlike the DMA allocation above, non-contiguous pages are assined.
 */

/*
 * allocate a synth sample area
 */
struct snd_util_memblk *
snd_emu10k1_synth_alloc(struct snd_emu10k1 *hw, unsigned int size)
{
	struct snd_emu10k1_memblk *blk;
	struct snd_util_memhdr *hdr = hw->memhdr; 

	down(&hdr->block_mutex);
	blk = (struct snd_emu10k1_memblk *)__snd_util_mem_alloc(hdr, size);
	if (blk == NULL) {
		up(&hdr->block_mutex);
		return NULL;
	}
	if (synth_alloc_pages(hw, blk)) {
		__snd_util_mem_free(hdr, (struct snd_util_memblk *)blk);
		up(&hdr->block_mutex);
		return NULL;
	}
	snd_emu10k1_memblk_map(hw, blk);
	up(&hdr->block_mutex);
	return (struct snd_util_memblk *)blk;
}


/*
 * free a synth sample area
 */
int
snd_emu10k1_synth_free(struct snd_emu10k1 *emu, struct snd_util_memblk *memblk)
{
	struct snd_util_memhdr *hdr = emu->memhdr; 
	struct snd_emu10k1_memblk *blk = (struct snd_emu10k1_memblk *)memblk;
	unsigned long flags;

	down(&hdr->block_mutex);
	spin_lock_irqsave(&emu->memblk_lock, flags);
	if (blk->mapped_page >= 0)
		unmap_memblk(emu, blk);
	spin_unlock_irqrestore(&emu->memblk_lock, flags);
	synth_free_pages(emu, blk);
	 __snd_util_mem_free(hdr, memblk);
	up(&hdr->block_mutex);
	return 0;
}


/* check new allocation range */
static void get_single_page_range(struct snd_util_memhdr *hdr,
				  struct snd_emu10k1_memblk *blk,
				  int *first_page_ret, int *last_page_ret)
{
	struct list_head *p;
	struct snd_emu10k1_memblk *q;
	int first_page, last_page;
	first_page = blk->first_page;
	if ((p = blk->mem.list.prev) != &hdr->block) {
		q = get_emu10k1_memblk(p, mem.list);
		if (q->last_page == first_page)
			first_page++;  /* first page was already allocated */
	}
	last_page = blk->last_page;
	if ((p = blk->mem.list.next) != &hdr->block) {
		q = get_emu10k1_memblk(p, mem.list);
		if (q->first_page == last_page)
			last_page--; /* last page was already allocated */
	}
	*first_page_ret = first_page;
	*last_page_ret = last_page;
}

/*
 * allocate kernel pages
 */
static int synth_alloc_pages(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
{
	int page, first_page, last_page;
	struct snd_dma_buffer dmab;

	emu10k1_memblk_init(blk);
	get_single_page_range(emu->memhdr, blk, &first_page, &last_page);
	/* allocate kernel pages */
	for (page = first_page; page <= last_page; page++) {
		if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, snd_dma_pci_data(emu->pci),
					PAGE_SIZE, &dmab) < 0)
			goto __fail;
		if (! is_valid_page(emu, dmab.addr)) {
			snd_dma_free_pages(&dmab);
			goto __fail;
		}
		emu->page_addr_table[page] = dmab.addr;
		emu->page_ptr_table[page] = dmab.area;
	}
	return 0;

__fail:
	/* release allocated pages */
	last_page = page - 1;
	for (page = first_page; page <= last_page; page++) {
		dmab.area = emu->page_ptr_table[page];
		dmab.addr = emu->page_addr_table[page];
		dmab.bytes = PAGE_SIZE;
		snd_dma_free_pages(&dmab);
		emu->page_addr_table[page] = 0;
		emu->page_ptr_table[page] = NULL;
	}

	return -ENOMEM;
}

/*
 * free pages
 */
static int synth_free_pages(struct snd_emu10k1 *emu, struct snd_emu10k1_memblk *blk)
{
	int page, first_page, last_page;
	struct snd_dma_buffer dmab;

	get_single_page_range(emu->memhdr, blk, &first_page, &last_page);
	dmab.dev.type = SNDRV_DMA_TYPE_DEV;
	dmab.dev.dev = snd_dma_pci_data(emu->pci);
	for (page = first_page; page <= last_page; page++) {
		if (emu->page_ptr_table[page] == NULL)
			continue;
		dmab.area = emu->page_ptr_table[page];
		dmab.addr = emu->page_addr_table[page];
		dmab.bytes = PAGE_SIZE;
		snd_dma_free_pages(&dmab);
		emu->page_addr_table[page] = 0;
		emu->page_ptr_table[page] = NULL;
	}

	return 0;
}

/* calculate buffer pointer from offset address */
static inline void *offset_ptr(struct snd_emu10k1 *emu, int page, int offset)
{
	char *ptr;
	snd_assert(page >= 0 && page < emu->max_cache_pages, return NULL);
	ptr = emu->page_ptr_table[page];
	if (! ptr) {
		printk(KERN_ERR "emu10k1: access to NULL ptr: page = %d\n", page);
		return NULL;
	}
	ptr += offset & (PAGE_SIZE - 1);
	return (void*)ptr;
}

/*
 * bzero(blk + offset, size)
 */
int snd_emu10k1_synth_bzero(struct snd_emu10k1 *emu, struct snd_util_memblk *blk,
			    int offset, int size)
{
	int page, nextofs, end_offset, temp, temp1;
	void *ptr;
	struct snd_emu10k1_memblk *p = (struct snd_emu10k1_memblk *)blk;

	offset += blk->offset & (PAGE_SIZE - 1);
	end_offset = offset + size;
	page = get_aligned_page(offset);
	do {
		nextofs = aligned_page_offset(page + 1);
		temp = nextofs - offset;
		temp1 = end_offset - offset;
		if (temp1 < temp)
			temp = temp1;
		ptr = offset_ptr(emu, page + p->first_page, offset);
		if (ptr)
			memset(ptr, 0, temp);
		offset = nextofs;
		page++;
	} while (offset < end_offset);
	return 0;
}

/*
 * copy_from_user(blk + offset, data, size)
 */
int snd_emu10k1_synth_copy_from_user(struct snd_emu10k1 *emu, struct snd_util_memblk *blk,
				     int offset, const char __user *data, int size)
{
	int page, nextofs, end_offset, temp, temp1;
	void *ptr;
	struct snd_emu10k1_memblk *p = (struct snd_emu10k1_memblk *)blk;

	offset += blk->offset & (PAGE_SIZE - 1);
	end_offset = offset + size;
	page = get_aligned_page(offset);
	do {
		nextofs = aligned_page_offset(page + 1);
		temp = nextofs - offset;
		temp1 = end_offset - offset;
		if (temp1 < temp)
			temp = temp1;
		ptr = offset_ptr(emu, page + p->first_page, offset);
		if (ptr && copy_from_user(ptr, data, temp))
			return -EFAULT;
		offset = nextofs;
		data += temp;
		page++;
	} while (offset < end_offset);
	return 0;
}