kernel-ark/sound/firewire/iso-resources.h
Clemens Ladisch 5b2599a07e ALSA: firewire-lib: allocate DMA buffer separately
For correct cache coherency on some architectures, DMA buffers must be
allocated in a different cache line than data that is concurrently used
by the CPU.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-03-15 08:42:28 +01:00

40 lines
1.2 KiB
C

#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;
__be32 *buffer;
};
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