#ifndef __NET_NCSI_H
#define __NET_NCSI_H
/*
* The NCSI device states seen from external. More NCSI device states are
* only visible internally (in net/ncsi/internal.h). When the NCSI device
* is registered, it's in ncsi_dev_state_registered state. The state
* ncsi_dev_state_start is used to drive to choose active package and
* channel. After that, its state is changed to ncsi_dev_state_functional.
*
* The state ncsi_dev_state_stop helps to shut down the currently active
* package and channel while ncsi_dev_state_config helps to reconfigure
* them.
*/
enum {
ncsi_dev_state_registered = 0x0000,
ncsi_dev_state_functional = 0x0100,
ncsi_dev_state_probe = 0x0200,
ncsi_dev_state_config = 0x0300,
ncsi_dev_state_suspend = 0x0400,
};
struct ncsi_dev {
int state;
int link_up;
struct net_device *dev;
void (*handler)(struct ncsi_dev *ndev);
};
#ifdef CONFIG_NET_NCSI
struct ncsi_dev *ncsi_register_dev(struct net_device *dev,
void (*notifier)(struct ncsi_dev *nd));
int ncsi_start_dev(struct ncsi_dev *nd);
void ncsi_stop_dev(struct ncsi_dev *nd);
void ncsi_unregister_dev(struct ncsi_dev *nd);
#else /* !CONFIG_NET_NCSI */
static inline struct ncsi_dev *ncsi_register_dev(struct net_device *dev,
void (*notifier)(struct ncsi_dev *nd))
{
return NULL;
}
static inline int ncsi_start_dev(struct ncsi_dev *nd)
{
return -ENOTTY;
}
static void ncsi_stop_dev(struct ncsi_dev *nd)
{
}
static inline void ncsi_unregister_dev(struct ncsi_dev *nd)
{
}
#endif /* CONFIG_NET_NCSI */
#endif /* __NET_NCSI_H */
href='/cgit.cgi/linux/net-next.git/?h=nds-private-remove'>summaryrefslogtreecommitdiff
dmaengine: pl330: fix double lock
The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the
following double-lock bug:
Double lock:
1. spin_lock_irqsave(pch->lock, flags) at pl330_free_chan_resources:2236;
2. call to function `pl330_release_channel' immediately after;
3. call to function `dma_pl330_rqcb' in line 1753;
4. spin_lock_irqsave(pch->lock, flags) at dma_pl330_rqcb:1505.
I have fixed it as suggested by Marek Szyprowski.
First, I have replaced `pch->lock' with `pl330->lock' in functions
`pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids
the double-lock by acquiring a different lock than `dma_pl330_rqcb'.
NOTE that, as a result, `pl330_free_chan_resources' executes
`list_splice_tail_init' on `pch->work_list' under lock `pl330->lock',
whereas in the rest of the code `pch->work_list' is protected by
`pch->lock'. I don't know if this may cause race conditions. Similarly
`pch->cyclic' is written by `pl330_alloc_chan_resources' under
`pl330->lock' but read by `pl330_tx_submit' under `pch->lock'.
Second, I have removed locking from `pl330_request_channel' and
`pl330_release_channel' functions. Function `pl330_request_channel' is
only called from `pl330_alloc_chan_resources', so the lock is already
held. Function `pl330_release_channel' is called from
`pl330_free_chan_resources', which already holds the lock, and from
`pl330_del'. Function `pl330_del' is called in an error path of
`pl330_probe' and at the end of `pl330_remove', but I assume that there
cannot be concurrent accesses to the protected data at those points.
Signed-off-by: Iago Abal <mail@iagoabal.eu>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>