historical/gems-kernel.git/source/THIRDPARTY/linux-old/drivers/scsi/sg.h

33 lines
1.1 KiB
C

/*
History:
Started: Aug 9 by Lawrence Foard (entropy@world.std.com), to allow user
process control of SCSI devices.
Development Sponsored by Killy Corp. NY NY
*/
/*
An SG device is accessed by writting "packets" to it, the replies
are then read using the read call. The same header is used for
reply, just ignore reply_len field.
*/
struct sg_header
{
int pack_len; /* length of incoming packet <4096 (including header) */
int reply_len; /* maximum length <4096 of expected reply */
int pack_id; /* id number of packet */
int result; /* 0==ok, otherwise refer to errno codes */
/* command follows then data for command */
};
/* ioctl's */
#define SG_SET_TIMEOUT 0x2201 /* set timeout *(int *)arg==timeout */
#define SG_GET_TIMEOUT 0x2202 /* get timeout return timeout */
#define SG_DEFAULT_TIMEOUT 6000 /* 1 minute timeout */
#define SG_DEFAULT_RETRIES 1
#define SG_MAX_QUEUE 4 /* maximum outstanding request, arbitrary, may be
changed if sufficient DMA buffer room available */
#define SG_BIG_BUFF 32768