staging: comedi: separate out comedi_buf_* functions

Create a new file, comedi_buf.c, to hold all the comedi_async buffer
functions. Currently they are all in drivers.c and really don't have
any association with that source file.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 0 insertions, 398 deletions

diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
index b67a0c9b149e..dca26f521fd0 100644
--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -430,404 +430,6 @@ static int insn_rw_emulate_bits(struct comedi_device *dev,
 	return 1;
 }
 
-int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
-		     unsigned long new_size)
-{
-	struct comedi_async *async = s->async;
-
-	/* Round up new_size to multiple of PAGE_SIZE */
-	new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK;
-
-	/* if no change is required, do nothing */
-	if (async->prealloc_buf && async->prealloc_bufsz == new_size)
-		return 0;
-
-	/*  deallocate old buffer */
-	if (async->prealloc_buf) {
-		vunmap(async->prealloc_buf);
-		async->prealloc_buf = NULL;
-		async->prealloc_bufsz = 0;
-	}
-	if (async->buf_page_list) {
-		unsigned i;
-		for (i = 0; i < async->n_buf_pages; ++i) {
-			if (async->buf_page_list[i].virt_addr) {
-				clear_bit(PG_reserved,
-					&(virt_to_page(async->buf_page_list[i].
-							virt_addr)->flags));
-				if (s->async_dma_dir != DMA_NONE) {
-					dma_free_coherent(dev->hw_dev,
-							  PAGE_SIZE,
-							  async->
-							  buf_page_list
-							  [i].virt_addr,
-							  async->
-							  buf_page_list
-							  [i].dma_addr);
-				} else {
-					free_page((unsigned long)
-						  async->buf_page_list[i].
-						  virt_addr);
-				}
-			}
-		}
-		vfree(async->buf_page_list);
-		async->buf_page_list = NULL;
-		async->n_buf_pages = 0;
-	}
-	/*  allocate new buffer */
-	if (new_size) {
-		unsigned i = 0;
-		unsigned n_pages = new_size >> PAGE_SHIFT;
-		struct page **pages = NULL;
-
-		async->buf_page_list =
-		    vzalloc(sizeof(struct comedi_buf_page) * n_pages);
-		if (async->buf_page_list)
-			pages = vmalloc(sizeof(struct page *) * n_pages);
-
-		if (pages) {
-			for (i = 0; i < n_pages; i++) {
-				if (s->async_dma_dir != DMA_NONE) {
-					async->buf_page_list[i].virt_addr =
-					    dma_alloc_coherent(dev->hw_dev,
-							       PAGE_SIZE,
-							       &async->
-							       buf_page_list
-							       [i].dma_addr,
-							       GFP_KERNEL |
-							       __GFP_COMP);
-				} else {
-					async->buf_page_list[i].virt_addr =
-					    (void *)
-					    get_zeroed_page(GFP_KERNEL);
-				}
-				if (async->buf_page_list[i].virt_addr == NULL)
-					break;
-
-				set_bit(PG_reserved,
-					&(virt_to_page(async->buf_page_list[i].
-							virt_addr)->flags));
-				pages[i] = virt_to_page(async->buf_page_list[i].
-								virt_addr);
-			}
-		}
-		if (i == n_pages) {
-			async->prealloc_buf =
-#ifdef PAGE_KERNEL_NOCACHE
-			    vmap(pages, n_pages, VM_MAP, PAGE_KERNEL_NOCACHE);
-#else
-			    vmap(pages, n_pages, VM_MAP, PAGE_KERNEL);
-#endif
-		}
-		vfree(pages);
-
-		if (async->prealloc_buf == NULL) {
-			/* Some allocation failed above. */
-			if (async->buf_page_list) {
-				for (i = 0; i < n_pages; i++) {
-					if (async->buf_page_list[i].virt_addr ==
-					    NULL) {
-						break;
-					}
-					clear_bit(PG_reserved,
-						&(virt_to_page(async->
-							buf_page_list[i].
-							virt_addr)->flags));
-					if (s->async_dma_dir != DMA_NONE) {
-						dma_free_coherent(dev->hw_dev,
-								  PAGE_SIZE,
-								  async->
-								  buf_page_list
-								  [i].virt_addr,
-								  async->
-								  buf_page_list
-								  [i].dma_addr);
-					} else {
-						free_page((unsigned long)
-							  async->buf_page_list
-							  [i].virt_addr);
-					}
-				}
-				vfree(async->buf_page_list);
-				async->buf_page_list = NULL;
-			}
-			return -ENOMEM;
-		}
-		async->n_buf_pages = n_pages;
-	}
-	async->prealloc_bufsz = new_size;
-
-	return 0;
-}
-
-/* munging is applied to data by core as it passes between user
- * and kernel space */
-static unsigned int comedi_buf_munge(struct comedi_async *async,
-				     unsigned int num_bytes)
-{
-	struct comedi_subdevice *s = async->subdevice;
-	unsigned int count = 0;
-	const unsigned num_sample_bytes = bytes_per_sample(s);
-
-	if (s->munge == NULL || (async->cmd.flags & CMDF_RAWDATA)) {
-		async->munge_count += num_bytes;
-		BUG_ON((int)(async->munge_count - async->buf_write_count) > 0);
-		return num_bytes;
-	}
-	/* don't munge partial samples */
-	num_bytes -= num_bytes % num_sample_bytes;
-	while (count < num_bytes) {
-		int block_size;
-
-		block_size = num_bytes - count;
-		if (block_size < 0) {
-			dev_warn(s->device->class_dev,
-				 "%s: %s: bug! block_size is negative\n",
-				 __FILE__, __func__);
-			break;
-		}
-		if ((int)(async->munge_ptr + block_size -
-			  async->prealloc_bufsz) > 0)
-			block_size = async->prealloc_bufsz - async->munge_ptr;
-
-		s->munge(s->device, s, async->prealloc_buf + async->munge_ptr,
-			 block_size, async->munge_chan);
-
-		smp_wmb();	/* barrier insures data is munged in buffer
-				 * before munge_count is incremented */
-
-		async->munge_chan += block_size / num_sample_bytes;
-		async->munge_chan %= async->cmd.chanlist_len;
-		async->munge_count += block_size;
-		async->munge_ptr += block_size;
-		async->munge_ptr %= async->prealloc_bufsz;
-		count += block_size;
-	}
-	BUG_ON((int)(async->munge_count - async->buf_write_count) > 0);
-	return count;
-}
-
-unsigned int comedi_buf_write_n_available(struct comedi_async *async)
-{
-	unsigned int free_end;
-	unsigned int nbytes;
-
-	if (async == NULL)
-		return 0;
-
-	free_end = async->buf_read_count + async->prealloc_bufsz;
-	nbytes = free_end - async->buf_write_alloc_count;
-	nbytes -= nbytes % bytes_per_sample(async->subdevice);
-	/* barrier insures the read of buf_read_count in this
-	   query occurs before any following writes to the buffer which
-	   might be based on the return value from this query.
-	 */
-	smp_mb();
-	return nbytes;
-}
-
-/* allocates chunk for the writer from free buffer space */
-unsigned int comedi_buf_write_alloc(struct comedi_async *async,
-				    unsigned int nbytes)
-{
-	unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
-
-	if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0)
-		nbytes = free_end - async->buf_write_alloc_count;
-
-	async->buf_write_alloc_count += nbytes;
-	/* barrier insures the read of buf_read_count above occurs before
-	   we write data to the write-alloc'ed buffer space */
-	smp_mb();
-	return nbytes;
-}
-EXPORT_SYMBOL(comedi_buf_write_alloc);
-
-/* allocates nothing unless it can completely fulfill the request */
-unsigned int comedi_buf_write_alloc_strict(struct comedi_async *async,
-					   unsigned int nbytes)
-{
-	unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
-
-	if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0)
-		nbytes = 0;
-
-	async->buf_write_alloc_count += nbytes;
-	/* barrier insures the read of buf_read_count above occurs before
-	   we write data to the write-alloc'ed buffer space */
-	smp_mb();
-	return nbytes;
-}
-
-/* transfers a chunk from writer to filled buffer space */
-unsigned comedi_buf_write_free(struct comedi_async *async, unsigned int nbytes)
-{
-	if ((int)(async->buf_write_count + nbytes -
-		  async->buf_write_alloc_count) > 0) {
-		dev_info(async->subdevice->device->class_dev,
-			 "attempted to write-free more bytes than have been write-allocated.\n");
-		nbytes = async->buf_write_alloc_count - async->buf_write_count;
-	}
-	async->buf_write_count += nbytes;
-	async->buf_write_ptr += nbytes;
-	comedi_buf_munge(async, async->buf_write_count - async->munge_count);
-	if (async->buf_write_ptr >= async->prealloc_bufsz)
-		async->buf_write_ptr %= async->prealloc_bufsz;
-
-	return nbytes;
-}
-EXPORT_SYMBOL(comedi_buf_write_free);
-
-/* allocates a chunk for the reader from filled (and munged) buffer space */
-unsigned comedi_buf_read_alloc(struct comedi_async *async, unsigned nbytes)
-{
-	if ((int)(async->buf_read_alloc_count + nbytes - async->munge_count) >
-	    0) {
-		nbytes = async->munge_count - async->buf_read_alloc_count;
-	}
-	async->buf_read_alloc_count += nbytes;
-	/* barrier insures read of munge_count occurs before we actually read
-	   data out of buffer */
-	smp_rmb();
-	return nbytes;
-}
-EXPORT_SYMBOL(comedi_buf_read_alloc);
-
-/* transfers control of a chunk from reader to free buffer space */
-unsigned comedi_buf_read_free(struct comedi_async *async, unsigned int nbytes)
-{
-	/* barrier insures data has been read out of
-	 * buffer before read count is incremented */
-	smp_mb();
-	if ((int)(async->buf_read_count + nbytes -
-		  async->buf_read_alloc_count) > 0) {
-		dev_info(async->subdevice->device->class_dev,
-			 "attempted to read-free more bytes than have been read-allocated.\n");
-		nbytes = async->buf_read_alloc_count - async->buf_read_count;
-	}
-	async->buf_read_count += nbytes;
-	async->buf_read_ptr += nbytes;
-	async->buf_read_ptr %= async->prealloc_bufsz;
-	return nbytes;
-}
-EXPORT_SYMBOL(comedi_buf_read_free);
-
-void comedi_buf_memcpy_to(struct comedi_async *async, unsigned int offset,
-			  const void *data, unsigned int num_bytes)
-{
-	unsigned int write_ptr = async->buf_write_ptr + offset;
-
-	if (write_ptr >= async->prealloc_bufsz)
-		write_ptr %= async->prealloc_bufsz;
-
-	while (num_bytes) {
-		unsigned int block_size;
-
-		if (write_ptr + num_bytes > async->prealloc_bufsz)
-			block_size = async->prealloc_bufsz - write_ptr;
-		else
-			block_size = num_bytes;
-
-		memcpy(async->prealloc_buf + write_ptr, data, block_size);
-
-		data += block_size;
-		num_bytes -= block_size;
-
-		write_ptr = 0;
-	}
-}
-EXPORT_SYMBOL(comedi_buf_memcpy_to);
-
-void comedi_buf_memcpy_from(struct comedi_async *async, unsigned int offset,
-			    void *dest, unsigned int nbytes)
-{
-	void *src;
-	unsigned int read_ptr = async->buf_read_ptr + offset;
-
-	if (read_ptr >= async->prealloc_bufsz)
-		read_ptr %= async->prealloc_bufsz;
-
-	while (nbytes) {
-		unsigned int block_size;
-
-		src = async->prealloc_buf + read_ptr;
-
-		if (nbytes >= async->prealloc_bufsz - read_ptr)
-			block_size = async->prealloc_bufsz - read_ptr;
-		else
-			block_size = nbytes;
-
-		memcpy(dest, src, block_size);
-		nbytes -= block_size;
-		dest += block_size;
-		read_ptr = 0;
-	}
-}
-EXPORT_SYMBOL(comedi_buf_memcpy_from);
-
-unsigned int comedi_buf_read_n_available(struct comedi_async *async)
-{
-	unsigned num_bytes;
-
-	if (async == NULL)
-		return 0;
-	num_bytes = async->munge_count - async->buf_read_count;
-	/* barrier insures the read of munge_count in this
-	   query occurs before any following reads of the buffer which
-	   might be based on the return value from this query.
-	 */
-	smp_rmb();
-	return num_bytes;
-}
-EXPORT_SYMBOL(comedi_buf_read_n_available);
-
-int comedi_buf_get(struct comedi_async *async, short *x)
-{
-	unsigned int n = comedi_buf_read_n_available(async);
-
-	if (n < sizeof(short))
-		return 0;
-	comedi_buf_read_alloc(async, sizeof(short));
-	*x = *(short *)(async->prealloc_buf + async->buf_read_ptr);
-	comedi_buf_read_free(async, sizeof(short));
-	return 1;
-}
-EXPORT_SYMBOL(comedi_buf_get);
-
-int comedi_buf_put(struct comedi_async *async, short x)
-{
-	unsigned int n = comedi_buf_write_alloc_strict(async, sizeof(short));
-
-	if (n < sizeof(short)) {
-		async->events |= COMEDI_CB_ERROR;
-		return 0;
-	}
-	*(short *)(async->prealloc_buf + async->buf_write_ptr) = x;
-	comedi_buf_write_free(async, sizeof(short));
-	return 1;
-}
-EXPORT_SYMBOL(comedi_buf_put);
-
-void comedi_reset_async_buf(struct comedi_async *async)
-{
-	async->buf_write_alloc_count = 0;
-	async->buf_write_count = 0;
-	async->buf_read_alloc_count = 0;
-	async->buf_read_count = 0;
-
-	async->buf_write_ptr = 0;
-	async->buf_read_ptr = 0;
-
-	async->cur_chan = 0;
-	async->scan_progress = 0;
-	async->munge_chan = 0;
-	async->munge_count = 0;
-	async->munge_ptr = 0;
-
-	async->events = 0;
-}
-
 int comedi_auto_config(struct device *hardware_device,
 		       struct comedi_driver *driver, unsigned long context)
 {