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#ifndef SOUND_FIREWIRE_ISO_RESOURCES_H_INCLUDED
#define SOUND_FIREWIRE_ISO_RESOURCES_H_INCLUDED

#include <linux/mutex.h>
#include <linux/types.h>

struct fw_unit;

/**
 * struct fw_iso_resources - manages channel/bandwidth allocation
 * @channels_mask: if the device does not support all channel numbers, set this
 *                 bit mask to something else than the default (all ones)
 *
 * This structure manages (de)allocation of isochronous resources (channel and
 * bandwidth) for one isochronous stream.
 */
struct fw_iso_resources {
	u64 channels_mask;
	/* private: */
	struct fw_unit *unit;
	struct mutex mutex;
	unsigned int channel;
	unsigned int bandwidth; /* in bandwidth units, without overhead */
	unsigned int bandwidth_overhead;
	int generation; /* in which allocation is valid */
	bool allocated;
};

int fw_iso_resources_init(struct fw_iso_resources *r,
			  struct fw_unit *unit);
void fw_iso_resources_destroy(struct fw_iso_resources *r);

int fw_iso_resources_allocate(struct fw_iso_resources *r,
			      unsigned int max_payload_bytes, int speed);
int fw_iso_resources_update(struct fw_iso_resources *r);
void fw_iso_resources_free(struct fw_iso_resources *r);

#endif
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>
Diffstat (limited to 'net/switchdev')