+++ /dev/null
-#include <linux/slab.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/device.h>
-#include <linux/workqueue.h>
-#include <linux/kfifo.h>
-#include <linux/mutex.h>
-#include <linux/iio/kfifo_buf.h>
-#include <linux/sched.h>
-#include <linux/poll.h>
-
-struct iio_kfifo {
- struct iio_buffer buffer;
- struct kfifo kf;
- struct mutex user_lock;
- int update_needed;
-};
-
-#define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer)
-
-static inline int __iio_allocate_kfifo(struct iio_kfifo *buf,
- int bytes_per_datum, int length)
-{
- if ((length == 0) || (bytes_per_datum == 0))
- return -EINVAL;
-
- return __kfifo_alloc((struct __kfifo *)&buf->kf, length,
- bytes_per_datum, GFP_KERNEL);
-}
-
-static int iio_request_update_kfifo(struct iio_buffer *r)
-{
- int ret = 0;
- struct iio_kfifo *buf = iio_to_kfifo(r);
-
- mutex_lock(&buf->user_lock);
- if (buf->update_needed) {
- kfifo_free(&buf->kf);
- ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
- buf->buffer.length);
- if (ret >= 0)
- buf->update_needed = false;
- } else {
- kfifo_reset_out(&buf->kf);
- }
- mutex_unlock(&buf->user_lock);
-
- return ret;
-}
-
-static int iio_mark_update_needed_kfifo(struct iio_buffer *r)
-{
- struct iio_kfifo *kf = iio_to_kfifo(r);
- kf->update_needed = true;
- return 0;
-}
-
-static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd)
-{
- if (r->bytes_per_datum != bpd) {
- r->bytes_per_datum = bpd;
- iio_mark_update_needed_kfifo(r);
- }
- return 0;
-}
-
-static int iio_set_length_kfifo(struct iio_buffer *r, int length)
-{
- /* Avoid an invalid state */
- if (length < 2)
- length = 2;
- if (r->length != length) {
- r->length = length;
- iio_mark_update_needed_kfifo(r);
- }
- return 0;
-}
-
-static int iio_store_to_kfifo(struct iio_buffer *r,
- const void *data)
-{
- int ret;
- struct iio_kfifo *kf = iio_to_kfifo(r);
- ret = kfifo_in(&kf->kf, data, 1);
- if (ret != 1)
- return -EBUSY;
- return 0;
-}
-
-static int iio_read_first_n_kfifo(struct iio_buffer *r,
- size_t n, char __user *buf)
-{
- int ret, copied;
- struct iio_kfifo *kf = iio_to_kfifo(r);
-
- if (mutex_lock_interruptible(&kf->user_lock))
- return -ERESTARTSYS;
-
- if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf))
- ret = -EINVAL;
- else
- ret = kfifo_to_user(&kf->kf, buf, n, &copied);
- mutex_unlock(&kf->user_lock);
- if (ret < 0)
- return ret;
-
- return copied;
-}
-
-static size_t iio_kfifo_buf_data_available(struct iio_buffer *r)
-{
- struct iio_kfifo *kf = iio_to_kfifo(r);
- size_t samples;
-
- mutex_lock(&kf->user_lock);
- samples = kfifo_len(&kf->kf);
- mutex_unlock(&kf->user_lock);
-
- return samples;
-}
-
-static void iio_kfifo_buffer_release(struct iio_buffer *buffer)
-{
- struct iio_kfifo *kf = iio_to_kfifo(buffer);
-
- mutex_destroy(&kf->user_lock);
- kfifo_free(&kf->kf);
- kfree(kf);
-}
-
-static const struct iio_buffer_access_funcs kfifo_access_funcs = {
- .store_to = &iio_store_to_kfifo,
- .read_first_n = &iio_read_first_n_kfifo,
- .data_available = iio_kfifo_buf_data_available,
- .request_update = &iio_request_update_kfifo,
- .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo,
- .set_length = &iio_set_length_kfifo,
- .release = &iio_kfifo_buffer_release,
-};
-
-struct iio_buffer *iio_kfifo_allocate(void)
-{
- struct iio_kfifo *kf;
-
- kf = kzalloc(sizeof(*kf), GFP_KERNEL);
- if (!kf)
- return NULL;
-
- kf->update_needed = true;
- iio_buffer_init(&kf->buffer);
- kf->buffer.access = &kfifo_access_funcs;
- kf->buffer.length = 2;
- mutex_init(&kf->user_lock);
-
- return &kf->buffer;
-}
-EXPORT_SYMBOL(iio_kfifo_allocate);
-
-void iio_kfifo_free(struct iio_buffer *r)
-{
- iio_buffer_put(r);
-}
-EXPORT_SYMBOL(iio_kfifo_free);
-
-static void devm_iio_kfifo_release(struct device *dev, void *res)
-{
- iio_kfifo_free(*(struct iio_buffer **)res);
-}
-
-static int devm_iio_kfifo_match(struct device *dev, void *res, void *data)
-{
- struct iio_buffer **r = res;
-
- if (WARN_ON(!r || !*r))
- return 0;
-
- return *r == data;
-}
-
-/**
- * devm_iio_fifo_allocate - Resource-managed iio_kfifo_allocate()
- * @dev: Device to allocate kfifo buffer for
- *
- * RETURNS:
- * Pointer to allocated iio_buffer on success, NULL on failure.
- */
-struct iio_buffer *devm_iio_kfifo_allocate(struct device *dev)
-{
- struct iio_buffer **ptr, *r;
-
- ptr = devres_alloc(devm_iio_kfifo_release, sizeof(*ptr), GFP_KERNEL);
- if (!ptr)
- return NULL;
-
- r = iio_kfifo_allocate();
- if (r) {
- *ptr = r;
- devres_add(dev, ptr);
- } else {
- devres_free(ptr);
- }
-
- return r;
-}
-EXPORT_SYMBOL(devm_iio_kfifo_allocate);
-
-/**
- * devm_iio_fifo_free - Resource-managed iio_kfifo_free()
- * @dev: Device the buffer belongs to
- * @r: The buffer associated with the device
- */
-void devm_iio_kfifo_free(struct device *dev, struct iio_buffer *r)
-{
- WARN_ON(devres_release(dev, devm_iio_kfifo_release,
- devm_iio_kfifo_match, r));
-}
-EXPORT_SYMBOL(devm_iio_kfifo_free);
-
-MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff