1 files changed, 0 insertions, 692 deletions

diff --git a/drivers/staging/comedi/comedi_buf.c b/drivers/staging/comedi/comedi_buf.c
deleted file mode 100644
index 06bfc859ab31..000000000000
--- a/drivers/staging/comedi/comedi_buf.c
+++ /dev/null
@@ -1,692 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * comedi_buf.c
- *
- * COMEDI - Linux Control and Measurement Device Interface
- * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
- * Copyright (C) 2002 Frank Mori Hess <fmhess@users.sourceforge.net>
- */
-
-#include <linux/vmalloc.h>
-#include <linux/slab.h>
-
-#include "comedidev.h"
-#include "comedi_internal.h"
-
-#ifdef PAGE_KERNEL_NOCACHE
-#define COMEDI_PAGE_PROTECTION		PAGE_KERNEL_NOCACHE
-#else
-#define COMEDI_PAGE_PROTECTION		PAGE_KERNEL
-#endif
-
-static void comedi_buf_map_kref_release(struct kref *kref)
-{
-	struct comedi_buf_map *bm =
-		container_of(kref, struct comedi_buf_map, refcount);
-	struct comedi_buf_page *buf;
-	unsigned int i;
-
-	if (bm->page_list) {
-		if (bm->dma_dir != DMA_NONE) {
-			/*
-			 * DMA buffer was allocated as a single block.
-			 * Address is in page_list[0].
-			 */
-			buf = &bm->page_list[0];
-			dma_free_coherent(bm->dma_hw_dev,
-					  PAGE_SIZE * bm->n_pages,
-					  buf->virt_addr, buf->dma_addr);
-		} else {
-			for (i = 0; i < bm->n_pages; i++) {
-				buf = &bm->page_list[i];
-				ClearPageReserved(virt_to_page(buf->virt_addr));
-				free_page((unsigned long)buf->virt_addr);
-			}
-		}
-		vfree(bm->page_list);
-	}
-	if (bm->dma_dir != DMA_NONE)
-		put_device(bm->dma_hw_dev);
-	kfree(bm);
-}
-
-static void __comedi_buf_free(struct comedi_device *dev,
-			      struct comedi_subdevice *s)
-{
-	struct comedi_async *async = s->async;
-	struct comedi_buf_map *bm;
-	unsigned long flags;
-
-	if (async->prealloc_buf) {
-		if (s->async_dma_dir == DMA_NONE)
-			vunmap(async->prealloc_buf);
-		async->prealloc_buf = NULL;
-		async->prealloc_bufsz = 0;
-	}
-
-	spin_lock_irqsave(&s->spin_lock, flags);
-	bm = async->buf_map;
-	async->buf_map = NULL;
-	spin_unlock_irqrestore(&s->spin_lock, flags);
-	comedi_buf_map_put(bm);
-}
-
-static struct comedi_buf_map *
-comedi_buf_map_alloc(struct comedi_device *dev, enum dma_data_direction dma_dir,
-		     unsigned int n_pages)
-{
-	struct comedi_buf_map *bm;
-	struct comedi_buf_page *buf;
-	unsigned int i;
-
-	bm = kzalloc(sizeof(*bm), GFP_KERNEL);
-	if (!bm)
-		return NULL;
-
-	kref_init(&bm->refcount);
-	bm->dma_dir = dma_dir;
-	if (bm->dma_dir != DMA_NONE) {
-		/* Need ref to hardware device to free buffer later. */
-		bm->dma_hw_dev = get_device(dev->hw_dev);
-	}
-
-	bm->page_list = vzalloc(sizeof(*buf) * n_pages);
-	if (!bm->page_list)
-		goto err;
-
-	if (bm->dma_dir != DMA_NONE) {
-		void *virt_addr;
-		dma_addr_t dma_addr;
-
-		/*
-		 * Currently, the DMA buffer needs to be allocated as a
-		 * single block so that it can be mmap()'ed.
-		 */
-		virt_addr = dma_alloc_coherent(bm->dma_hw_dev,
-					       PAGE_SIZE * n_pages, &dma_addr,
-					       GFP_KERNEL);
-		if (!virt_addr)
-			goto err;
-
-		for (i = 0; i < n_pages; i++) {
-			buf = &bm->page_list[i];
-			buf->virt_addr = virt_addr + (i << PAGE_SHIFT);
-			buf->dma_addr = dma_addr + (i << PAGE_SHIFT);
-		}
-
-		bm->n_pages = i;
-	} else {
-		for (i = 0; i < n_pages; i++) {
-			buf = &bm->page_list[i];
-			buf->virt_addr = (void *)get_zeroed_page(GFP_KERNEL);
-			if (!buf->virt_addr)
-				break;
-
-			SetPageReserved(virt_to_page(buf->virt_addr));
-		}
-
-		bm->n_pages = i;
-		if (i < n_pages)
-			goto err;
-	}
-
-	return bm;
-
-err:
-	comedi_buf_map_put(bm);
-	return NULL;
-}
-
-static void __comedi_buf_alloc(struct comedi_device *dev,
-			       struct comedi_subdevice *s,
-			       unsigned int n_pages)
-{
-	struct comedi_async *async = s->async;
-	struct page **pages = NULL;
-	struct comedi_buf_map *bm;
-	struct comedi_buf_page *buf;
-	unsigned long flags;
-	unsigned int i;
-
-	if (!IS_ENABLED(CONFIG_HAS_DMA) && s->async_dma_dir != DMA_NONE) {
-		dev_err(dev->class_dev,
-			"dma buffer allocation not supported\n");
-		return;
-	}
-
-	bm = comedi_buf_map_alloc(dev, s->async_dma_dir, n_pages);
-	if (!bm)
-		return;
-
-	spin_lock_irqsave(&s->spin_lock, flags);
-	async->buf_map = bm;
-	spin_unlock_irqrestore(&s->spin_lock, flags);
-
-	if (bm->dma_dir != DMA_NONE) {
-		/*
-		 * DMA buffer was allocated as a single block.
-		 * Address is in page_list[0].
-		 */
-		buf = &bm->page_list[0];
-		async->prealloc_buf = buf->virt_addr;
-	} else {
-		pages = vmalloc(sizeof(struct page *) * n_pages);
-		if (!pages)
-			return;
-
-		for (i = 0; i < n_pages; i++) {
-			buf = &bm->page_list[i];
-			pages[i] = virt_to_page(buf->virt_addr);
-		}
-
-		/* vmap the pages to prealloc_buf */
-		async->prealloc_buf = vmap(pages, n_pages, VM_MAP,
-					   COMEDI_PAGE_PROTECTION);
-
-		vfree(pages);
-	}
-}
-
-void comedi_buf_map_get(struct comedi_buf_map *bm)
-{
-	if (bm)
-		kref_get(&bm->refcount);
-}
-
-int comedi_buf_map_put(struct comedi_buf_map *bm)
-{
-	if (bm)
-		return kref_put(&bm->refcount, comedi_buf_map_kref_release);
-	return 1;
-}
-
-/* helper for "access" vm operation */
-int comedi_buf_map_access(struct comedi_buf_map *bm, unsigned long offset,
-			  void *buf, int len, int write)
-{
-	unsigned int pgoff = offset_in_page(offset);
-	unsigned long pg = offset >> PAGE_SHIFT;
-	int done = 0;
-
-	while (done < len && pg < bm->n_pages) {
-		int l = min_t(int, len - done, PAGE_SIZE - pgoff);
-		void *b = bm->page_list[pg].virt_addr + pgoff;
-
-		if (write)
-			memcpy(b, buf, l);
-		else
-			memcpy(buf, b, l);
-		buf += l;
-		done += l;
-		pg++;
-		pgoff = 0;
-	}
-	return done;
-}
-
-/* returns s->async->buf_map and increments its kref refcount */
-struct comedi_buf_map *
-comedi_buf_map_from_subdev_get(struct comedi_subdevice *s)
-{
-	struct comedi_async *async = s->async;
-	struct comedi_buf_map *bm = NULL;
-	unsigned long flags;
-
-	if (!async)
-		return NULL;
-
-	spin_lock_irqsave(&s->spin_lock, flags);
-	bm = async->buf_map;
-	/* only want it if buffer pages allocated */
-	if (bm && bm->n_pages)
-		comedi_buf_map_get(bm);
-	else
-		bm = NULL;
-	spin_unlock_irqrestore(&s->spin_lock, flags);
-
-	return bm;
-}
-
-bool comedi_buf_is_mmapped(struct comedi_subdevice *s)
-{
-	struct comedi_buf_map *bm = s->async->buf_map;
-
-	return bm && (kref_read(&bm->refcount) > 1);
-}
-
-int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
-		     unsigned long new_size)
-{
-	struct comedi_async *async = s->async;
-
-	lockdep_assert_held(&dev->mutex);
-
-	/* 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 */
-	__comedi_buf_free(dev, s);
-
-	/* allocate new buffer */
-	if (new_size) {
-		unsigned int n_pages = new_size >> PAGE_SHIFT;
-
-		__comedi_buf_alloc(dev, s, n_pages);
-
-		if (!async->prealloc_buf) {
-			/* allocation failed */
-			__comedi_buf_free(dev, s);
-			return -ENOMEM;
-		}
-	}
-	async->prealloc_bufsz = new_size;
-
-	return 0;
-}
-
-void comedi_buf_reset(struct comedi_subdevice *s)
-{
-	struct comedi_async *async = s->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->scans_done = 0;
-	async->scan_progress = 0;
-	async->munge_chan = 0;
-	async->munge_count = 0;
-	async->munge_ptr = 0;
-
-	async->events = 0;
-}
-
-static unsigned int comedi_buf_write_n_unalloc(struct comedi_subdevice *s)
-{
-	struct comedi_async *async = s->async;
-	unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
-
-	return free_end - async->buf_write_alloc_count;
-}
-
-unsigned int comedi_buf_write_n_available(struct comedi_subdevice *s)
-{
-	struct comedi_async *async = s->async;
-	unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
-
-	return free_end - async->buf_write_count;
-}
-
-/**
- * comedi_buf_write_alloc() - Reserve buffer space for writing
- * @s: COMEDI subdevice.
- * @nbytes: Maximum space to reserve in bytes.
- *
- * Reserve up to @nbytes bytes of space to be written in the COMEDI acquisition
- * data buffer associated with the subdevice.  The amount reserved is limited
- * by the space available.
- *
- * Return: The amount of space reserved in bytes.
- */
-unsigned int comedi_buf_write_alloc(struct comedi_subdevice *s,
-				    unsigned int nbytes)
-{
-	struct comedi_async *async = s->async;
-	unsigned int unalloc = comedi_buf_write_n_unalloc(s);
-
-	if (nbytes > unalloc)
-		nbytes = unalloc;
-
-	async->buf_write_alloc_count += nbytes;
-
-	/*
-	 * ensure the async buffer 'counts' are read and updated
-	 * before we write data to the write-alloc'ed buffer space
-	 */
-	smp_mb();
-
-	return nbytes;
-}
-EXPORT_SYMBOL_GPL(comedi_buf_write_alloc);
-
-/*
- * munging is applied to data by core as it passes between user
- * and kernel space
- */
-static unsigned int comedi_buf_munge(struct comedi_subdevice *s,
-				     unsigned int num_bytes)
-{
-	struct comedi_async *async = s->async;
-	unsigned int count = 0;
-	const unsigned int num_sample_bytes = comedi_bytes_per_sample(s);
-
-	if (!s->munge || (async->cmd.flags & CMDF_RAWDATA)) {
-		async->munge_count += num_bytes;
-		return num_bytes;
-	}
-
-	/* don't munge partial samples */
-	num_bytes -= num_bytes % num_sample_bytes;
-	while (count < num_bytes) {
-		int block_size = num_bytes - count;
-		unsigned int buf_end;
-
-		buf_end = async->prealloc_bufsz - async->munge_ptr;
-		if (block_size > buf_end)
-			block_size = buf_end;
-
-		s->munge(s->device, s,
-			 async->prealloc_buf + async->munge_ptr,
-			 block_size, async->munge_chan);
-
-		/*
-		 * ensure data is munged in buffer before the
-		 * async buffer munge_count is incremented
-		 */
-		smp_wmb();
-
-		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;
-	}
-
-	return count;
-}
-
-unsigned int comedi_buf_write_n_allocated(struct comedi_subdevice *s)
-{
-	struct comedi_async *async = s->async;
-
-	return async->buf_write_alloc_count - async->buf_write_count;
-}
-
-/**
- * comedi_buf_write_free() - Free buffer space after it is written
- * @s: COMEDI subdevice.
- * @nbytes: Maximum space to free in bytes.
- *
- * Free up to @nbytes bytes of space previously reserved for writing in the
- * COMEDI acquisition data buffer associated with the subdevice.  The amount of
- * space freed is limited to the amount that was reserved.  The freed space is
- * assumed to have been filled with sample data by the writer.
- *
- * If the samples in the freed space need to be "munged", do so here.  The
- * freed space becomes available for allocation by the reader.
- *
- * Return: The amount of space freed in bytes.
- */
-unsigned int comedi_buf_write_free(struct comedi_subdevice *s,
-				   unsigned int nbytes)
-{
-	struct comedi_async *async = s->async;
-	unsigned int allocated = comedi_buf_write_n_allocated(s);
-
-	if (nbytes > allocated)
-		nbytes = allocated;
-
-	async->buf_write_count += nbytes;
-	async->buf_write_ptr += nbytes;
-	comedi_buf_munge(s, 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_GPL(comedi_buf_write_free);
-
-/**
- * comedi_buf_read_n_available() - Determine amount of readable buffer space
- * @s: COMEDI subdevice.
- *
- * Determine the amount of readable buffer space in the COMEDI acquisition data
- * buffer associated with the subdevice.  The readable buffer space is that
- * which has been freed by the writer and "munged" to the sample data format
- * expected by COMEDI if necessary.
- *
- * Return: The amount of readable buffer space.
- */
-unsigned int comedi_buf_read_n_available(struct comedi_subdevice *s)
-{
-	struct comedi_async *async = s->async;
-	unsigned int num_bytes;
-
-	if (!async)
-		return 0;
-
-	num_bytes = async->munge_count - async->buf_read_count;
-
-	/*
-	 * ensure the async buffer 'counts' are read before we
-	 * attempt to read data from the buffer
-	 */
-	smp_rmb();
-
-	return num_bytes;
-}
-EXPORT_SYMBOL_GPL(comedi_buf_read_n_available);
-
-/**
- * comedi_buf_read_alloc() - Reserve buffer space for reading
- * @s: COMEDI subdevice.
- * @nbytes: Maximum space to reserve in bytes.
- *
- * Reserve up to @nbytes bytes of previously written and "munged" buffer space
- * for reading in the COMEDI acquisition data buffer associated with the
- * subdevice.  The amount reserved is limited to the space available.  The
- * reader can read from the reserved space and then free it.  A reader is also
- * allowed to read from the space before reserving it as long as it determines
- * the amount of readable data available, but the space needs to be marked as
- * reserved before it can be freed.
- *
- * Return: The amount of space reserved in bytes.
- */
-unsigned int comedi_buf_read_alloc(struct comedi_subdevice *s,
-				   unsigned int nbytes)
-{
-	struct comedi_async *async = s->async;
-	unsigned int available;
-
-	available = async->munge_count - async->buf_read_alloc_count;
-	if (nbytes > available)
-		nbytes = available;
-
-	async->buf_read_alloc_count += nbytes;
-
-	/*
-	 * ensure the async buffer 'counts' are read before we
-	 * attempt to read data from the read-alloc'ed buffer space
-	 */
-	smp_rmb();
-
-	return nbytes;
-}
-EXPORT_SYMBOL_GPL(comedi_buf_read_alloc);
-
-static unsigned int comedi_buf_read_n_allocated(struct comedi_async *async)
-{
-	return async->buf_read_alloc_count - async->buf_read_count;
-}
-
-/**
- * comedi_buf_read_free() - Free buffer space after it has been read
- * @s: COMEDI subdevice.
- * @nbytes: Maximum space to free in bytes.
- *
- * Free up to @nbytes bytes of buffer space previously reserved for reading in
- * the COMEDI acquisition data buffer associated with the subdevice.  The
- * amount of space freed is limited to the amount that was reserved.
- *
- * The freed space becomes available for allocation by the writer.
- *
- * Return: The amount of space freed in bytes.
- */
-unsigned int comedi_buf_read_free(struct comedi_subdevice *s,
-				  unsigned int nbytes)
-{
-	struct comedi_async *async = s->async;
-	unsigned int allocated;
-
-	/*
-	 * ensure data has been read out of buffer before
-	 * the async read count is incremented
-	 */
-	smp_mb();
-
-	allocated = comedi_buf_read_n_allocated(async);
-	if (nbytes > allocated)
-		nbytes = allocated;
-
-	async->buf_read_count += nbytes;
-	async->buf_read_ptr += nbytes;
-	async->buf_read_ptr %= async->prealloc_bufsz;
-	return nbytes;
-}
-EXPORT_SYMBOL_GPL(comedi_buf_read_free);
-
-static void comedi_buf_memcpy_to(struct comedi_subdevice *s,
-				 const void *data, unsigned int num_bytes)
-{
-	struct comedi_async *async = s->async;
-	unsigned int write_ptr = async->buf_write_ptr;
-
-	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;
-	}
-}
-
-static void comedi_buf_memcpy_from(struct comedi_subdevice *s,
-				   void *dest, unsigned int nbytes)
-{
-	void *src;
-	struct comedi_async *async = s->async;
-	unsigned int read_ptr = async->buf_read_ptr;
-
-	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;
-	}
-}
-
-/**
- * comedi_buf_write_samples() - Write sample data to COMEDI buffer
- * @s: COMEDI subdevice.
- * @data: Pointer to source samples.
- * @nsamples: Number of samples to write.
- *
- * Write up to @nsamples samples to the COMEDI acquisition data buffer
- * associated with the subdevice, mark it as written and update the
- * acquisition scan progress.  If there is not enough room for the specified
- * number of samples, the number of samples written is limited to the number
- * that will fit and the %COMEDI_CB_OVERFLOW event flag is set to cause the
- * acquisition to terminate with an overrun error.  Set the %COMEDI_CB_BLOCK
- * event flag if any samples are written to cause waiting tasks to be woken
- * when the event flags are processed.
- *
- * Return: The amount of data written in bytes.
- */
-unsigned int comedi_buf_write_samples(struct comedi_subdevice *s,
-				      const void *data, unsigned int nsamples)
-{
-	unsigned int max_samples;
-	unsigned int nbytes;
-
-	/*
-	 * Make sure there is enough room in the buffer for all the samples.
-	 * If not, clamp the nsamples to the number that will fit, flag the
-	 * buffer overrun and add the samples that fit.
-	 */
-	max_samples = comedi_bytes_to_samples(s, comedi_buf_write_n_unalloc(s));
-	if (nsamples > max_samples) {
-		dev_warn(s->device->class_dev, "buffer overrun\n");
-		s->async->events |= COMEDI_CB_OVERFLOW;
-		nsamples = max_samples;
-	}
-
-	if (nsamples == 0)
-		return 0;
-
-	nbytes = comedi_buf_write_alloc(s,
-					comedi_samples_to_bytes(s, nsamples));
-	comedi_buf_memcpy_to(s, data, nbytes);
-	comedi_buf_write_free(s, nbytes);
-	comedi_inc_scan_progress(s, nbytes);
-	s->async->events |= COMEDI_CB_BLOCK;
-
-	return nbytes;
-}
-EXPORT_SYMBOL_GPL(comedi_buf_write_samples);
-
-/**
- * comedi_buf_read_samples() - Read sample data from COMEDI buffer
- * @s: COMEDI subdevice.
- * @data: Pointer to destination.
- * @nsamples: Maximum number of samples to read.
- *
- * Read up to @nsamples samples from the COMEDI acquisition data buffer
- * associated with the subdevice, mark it as read and update the acquisition
- * scan progress.  Limit the number of samples read to the number available.
- * Set the %COMEDI_CB_BLOCK event flag if any samples are read to cause waiting
- * tasks to be woken when the event flags are processed.
- *
- * Return: The amount of data read in bytes.
- */
-unsigned int comedi_buf_read_samples(struct comedi_subdevice *s,
-				     void *data, unsigned int nsamples)
-{
-	unsigned int max_samples;
-	unsigned int nbytes;
-
-	/* clamp nsamples to the number of full samples available */
-	max_samples = comedi_bytes_to_samples(s,
-					      comedi_buf_read_n_available(s));
-	if (nsamples > max_samples)
-		nsamples = max_samples;
-
-	if (nsamples == 0)
-		return 0;
-
-	nbytes = comedi_buf_read_alloc(s,
-				       comedi_samples_to_bytes(s, nsamples));
-	comedi_buf_memcpy_from(s, data, nbytes);
-	comedi_buf_read_free(s, nbytes);
-	comedi_inc_scan_progress(s, nbytes);
-	s->async->events |= COMEDI_CB_BLOCK;
-
-	return nbytes;
-}
-EXPORT_SYMBOL_GPL(comedi_buf_read_samples);