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path: root/drivers/iio/kfifo_buf.c
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Diffstat (limited to 'drivers/iio/kfifo_buf.c')
-rw-r--r--drivers/iio/kfifo_buf.c49
1 files changed, 36 insertions, 13 deletions
diff --git a/drivers/iio/kfifo_buf.c b/drivers/iio/kfifo_buf.c
index a923c78d5cb4..95c6fc81c2c7 100644
--- a/drivers/iio/kfifo_buf.c
+++ b/drivers/iio/kfifo_buf.c
@@ -7,10 +7,12 @@
#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;
};
@@ -31,13 +33,18 @@ static int iio_request_update_kfifo(struct iio_buffer *r)
int ret = 0;
struct iio_kfifo *buf = iio_to_kfifo(r);
- if (!buf->update_needed)
- goto error_ret;
- kfifo_free(&buf->kf);
- ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
+ 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);
+ buf->update_needed = false;
+ } else {
+ kfifo_reset_out(&buf->kf);
+ }
r->stufftoread = false;
-error_ret:
+ mutex_unlock(&buf->user_lock);
+
return ret;
}
@@ -94,7 +101,7 @@ static int iio_set_length_kfifo(struct iio_buffer *r, int length)
}
static int iio_store_to_kfifo(struct iio_buffer *r,
- u8 *data)
+ const void *data)
{
int ret;
struct iio_kfifo *kf = iio_to_kfifo(r);
@@ -102,7 +109,7 @@ static int iio_store_to_kfifo(struct iio_buffer *r,
if (ret != 1)
return -EBUSY;
r->stufftoread = true;
- wake_up_interruptible(&r->pollq);
+ wake_up_interruptible_poll(&r->pollq, POLLIN | POLLRDNORM);
return 0;
}
@@ -113,12 +120,13 @@ static int iio_read_first_n_kfifo(struct iio_buffer *r,
int ret, copied;
struct iio_kfifo *kf = iio_to_kfifo(r);
- if (n < r->bytes_per_datum || r->bytes_per_datum == 0)
- return -EINVAL;
+ if (mutex_lock_interruptible(&kf->user_lock))
+ return -ERESTARTSYS;
- ret = kfifo_to_user(&kf->kf, buf, n, &copied);
- if (ret < 0)
- return ret;
+ if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf))
+ ret = -EINVAL;
+ else
+ ret = kfifo_to_user(&kf->kf, buf, n, &copied);
if (kfifo_is_empty(&kf->kf))
r->stufftoread = false;
@@ -126,9 +134,22 @@ static int iio_read_first_n_kfifo(struct iio_buffer *r,
if (!kfifo_is_empty(&kf->kf))
r->stufftoread = true;
+ mutex_unlock(&kf->user_lock);
+ if (ret < 0)
+ return ret;
+
return copied;
}
+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,
@@ -137,6 +158,7 @@ static const struct iio_buffer_access_funcs kfifo_access_funcs = {
.set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo,
.get_length = &iio_get_length_kfifo,
.set_length = &iio_set_length_kfifo,
+ .release = &iio_kfifo_buffer_release,
};
struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev)
@@ -151,13 +173,14 @@ struct iio_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev)
kf->buffer.attrs = &iio_kfifo_attribute_group;
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)
{
- kfree(iio_to_kfifo(r));
+ iio_buffer_put(r);
}
EXPORT_SYMBOL(iio_kfifo_free);