backwards compatibility

This commit is contained in:
Ralph Metzler 2017-12-11 16:10:37 +01:00
parent 04fc90e4d6
commit b42358eaa2
2 changed files with 52 additions and 2 deletions

View File

@ -1382,7 +1382,10 @@ static int dvb_net_add_if(struct dvb_net *dvbnet, u16 pid, u8 feedtype)
return -EINVAL;
net = alloc_netdev(sizeof(struct dvb_net_priv), "dvb",
NET_NAME_UNKNOWN, dvb_net_setup);
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3, 14, 0))
NET_NAME_UNKNOWN,
#endif
dvb_net_setup);
if (!net)
return -ENOMEM;

View File

@ -56,6 +56,9 @@ void dvb_ringbuffer_init(struct dvb_ringbuffer *rbuf, void *data, size_t len)
int dvb_ringbuffer_empty(struct dvb_ringbuffer *rbuf)
{
#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0))
return (rbuf->pread == rbuf->pwrite);
#else
/* smp_load_acquire() to load write pointer on reader side
* this pairs with smp_store_release() in dvb_ringbuffer_write(),
* dvb_ringbuffer_write_user(), or dvb_ringbuffer_reset()
@ -63,6 +66,7 @@ int dvb_ringbuffer_empty(struct dvb_ringbuffer *rbuf)
* for memory barriers also see Documentation/circular-buffers.txt
*/
return (rbuf->pread == smp_load_acquire(&rbuf->pwrite));
#endif
}
@ -88,11 +92,15 @@ ssize_t dvb_ringbuffer_avail(struct dvb_ringbuffer *rbuf)
{
ssize_t avail;
#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0))
avail = rbuf->pwrite - rbuf->pread;
#else
/* smp_load_acquire() to load write pointer on reader side
* this pairs with smp_store_release() in dvb_ringbuffer_write(),
* dvb_ringbuffer_write_user(), or dvb_ringbuffer_reset()
*/
avail = smp_load_acquire(&rbuf->pwrite) - rbuf->pread;
#endif
if (avail < 0)
avail += rbuf->size;
return avail;
@ -102,6 +110,9 @@ ssize_t dvb_ringbuffer_avail(struct dvb_ringbuffer *rbuf)
void dvb_ringbuffer_flush(struct dvb_ringbuffer *rbuf)
{
#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0))
rbuf->pread = smp_load_acquire(&rbuf->pwrite;
#else
/* dvb_ringbuffer_flush() counts as read operation
* smp_load_acquire() to load write pointer
* smp_store_release() to update read pointer, this ensures that the
@ -109,18 +120,23 @@ void dvb_ringbuffer_flush(struct dvb_ringbuffer *rbuf)
* calls on other cpu cores
*/
smp_store_release(&rbuf->pread, smp_load_acquire(&rbuf->pwrite));
#endif
rbuf->error = 0;
}
EXPORT_SYMBOL(dvb_ringbuffer_flush);
void dvb_ringbuffer_reset(struct dvb_ringbuffer *rbuf)
{
#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0))
rbuf->pread = rbuf->pwrite = 0;
#else
/* dvb_ringbuffer_reset() counts as read and write operation
* smp_store_release() to update read pointer
*/
smp_store_release(&rbuf->pread, 0);
/* smp_store_release() to update write pointer */
smp_store_release(&rbuf->pwrite, 0);
#endif
rbuf->error = 0;
}
@ -146,18 +162,25 @@ ssize_t dvb_ringbuffer_read_user(struct dvb_ringbuffer *rbuf, u8 __user *buf, si
return -EFAULT;
buf += split;
todo -= split;
#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0))
rbuf->pread = 0;
#else
/* smp_store_release() for read pointer update to ensure
* that buf is not overwritten until read is complete,
* this pairs with ACCESS_ONCE() in dvb_ringbuffer_free()
*/
smp_store_release(&rbuf->pread, 0);
#endif
}
if (copy_to_user(buf, rbuf->data+rbuf->pread, todo))
return -EFAULT;
#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0))
rbuf->pread = (rbuf->pread + todo) % rbuf->size;
#else
/* smp_store_release() to update read pointer, see above */
smp_store_release(&rbuf->pread, (rbuf->pread + todo) % rbuf->size);
#endif
return len;
}
@ -171,16 +194,24 @@ void dvb_ringbuffer_read(struct dvb_ringbuffer *rbuf, u8 *buf, size_t len)
memcpy(buf, rbuf->data+rbuf->pread, split);
buf += split;
todo -= split;
#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0))
rbuf->pread = 0;
#else
/* smp_store_release() for read pointer update to ensure
* that buf is not overwritten until read is complete,
* this pairs with ACCESS_ONCE() in dvb_ringbuffer_free()
*/
smp_store_release(&rbuf->pread, 0);
#endif
}
memcpy(buf, rbuf->data+rbuf->pread, todo);
#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0))
rbuf->pread = (rbuf->pread + todo) % rbuf->size;
#else
/* smp_store_release() to update read pointer, see above */
smp_store_release(&rbuf->pread, (rbuf->pread + todo) % rbuf->size);
#endif
}
@ -195,16 +226,24 @@ ssize_t dvb_ringbuffer_write(struct dvb_ringbuffer *rbuf, const u8 *buf, size_t
memcpy(rbuf->data+rbuf->pwrite, buf, split);
buf += split;
todo -= split;
#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0))
rbuf->pwrite = 0;
#else
/* smp_store_release() for write pointer update to ensure that
* written data is visible on other cpu cores before the pointer
* update, this pairs with smp_load_acquire() in
* dvb_ringbuffer_empty() or dvb_ringbuffer_avail()
*/
smp_store_release(&rbuf->pwrite, 0);
#endif
}
memcpy(rbuf->data+rbuf->pwrite, buf, todo);
#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0))
rbuf->pwrite = (rbuf->pwrite + todo) % rbuf->size;
#else
/* smp_store_release() for write pointer update, see above */
smp_store_release(&rbuf->pwrite, (rbuf->pwrite + todo) % rbuf->size);
#endif
return len;
}
@ -224,18 +263,26 @@ ssize_t dvb_ringbuffer_write_user(struct dvb_ringbuffer *rbuf,
return len - todo;
buf += split;
todo -= split;
#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0))
rbuf->pwrite = 0;
#else
/* smp_store_release() for write pointer update to ensure that
* written data is visible on other cpu cores before the pointer
* update, this pairs with smp_load_acquire() in
* dvb_ringbuffer_empty() or dvb_ringbuffer_avail()
*/
smp_store_release(&rbuf->pwrite, 0);
#endif
}
status = copy_from_user(rbuf->data+rbuf->pwrite, buf, todo);
if (status)
return len - todo;
#if (LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0))
rbuf->pwrite = (rbuf->pwrite + todo) % rbuf->size;
#else
/* smp_store_release() for write pointer update, see above */
smp_store_release(&rbuf->pwrite, (rbuf->pwrite + todo) % rbuf->size);
#endif
return len;
}