linux_dsm_epyc7002/arch/s390/include/asm/crw.h
Sebastian Ott b4563e891a [S390] cio: wait for channel report
To fetch a pending channel report word (crw) we use a kernel
thread which triggers stcrw and sleeps on a semaphore. The s390
machine check handler uses crw_handle_channel_report to handle
one crw if needed.

This patch replaces the semaphore with a waitqueue (to block the
kernel thread) and an atomic_t (to count the number of pending
requests).

By this we achieve the ability to force this thread to check for
a pending crw (independent on when it is triggered by the machine
check handler) and wait for this action to finish.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26 22:37:29 +01:00

70 lines
2.0 KiB
C

/*
* Data definitions for channel report processing
* Copyright IBM Corp. 2000,2009
* Author(s): Ingo Adlung <adlung@de.ibm.com>,
* Martin Schwidefsky <schwidefsky@de.ibm.com>,
* Cornelia Huck <cornelia.huck@de.ibm.com>,
* Heiko Carstens <heiko.carstens@de.ibm.com>,
*/
#ifndef _ASM_S390_CRW_H
#define _ASM_S390_CRW_H
#include <linux/types.h>
/*
* Channel Report Word
*/
struct crw {
__u32 res1 : 1; /* reserved zero */
__u32 slct : 1; /* solicited */
__u32 oflw : 1; /* overflow */
__u32 chn : 1; /* chained */
__u32 rsc : 4; /* reporting source code */
__u32 anc : 1; /* ancillary report */
__u32 res2 : 1; /* reserved zero */
__u32 erc : 6; /* error-recovery code */
__u32 rsid : 16; /* reporting-source ID */
} __attribute__ ((packed));
typedef void (*crw_handler_t)(struct crw *, struct crw *, int);
extern int crw_register_handler(int rsc, crw_handler_t handler);
extern void crw_unregister_handler(int rsc);
extern void crw_handle_channel_report(void);
void crw_wait_for_channel_report(void);
#define NR_RSCS 16
#define CRW_RSC_MONITOR 0x2 /* monitoring facility */
#define CRW_RSC_SCH 0x3 /* subchannel */
#define CRW_RSC_CPATH 0x4 /* channel path */
#define CRW_RSC_CONFIG 0x9 /* configuration-alert facility */
#define CRW_RSC_CSS 0xB /* channel subsystem */
#define CRW_ERC_EVENT 0x00 /* event information pending */
#define CRW_ERC_AVAIL 0x01 /* available */
#define CRW_ERC_INIT 0x02 /* initialized */
#define CRW_ERC_TERROR 0x03 /* temporary error */
#define CRW_ERC_IPARM 0x04 /* installed parm initialized */
#define CRW_ERC_TERM 0x05 /* terminal */
#define CRW_ERC_PERRN 0x06 /* perm. error, fac. not init */
#define CRW_ERC_PERRI 0x07 /* perm. error, facility init */
#define CRW_ERC_PMOD 0x08 /* installed parameters modified */
static inline int stcrw(struct crw *pcrw)
{
int ccode;
asm volatile(
" stcrw 0(%2)\n"
" ipm %0\n"
" srl %0,28\n"
: "=d" (ccode), "=m" (*pcrw)
: "a" (pcrw)
: "cc" );
return ccode;
}
#endif /* _ASM_S390_CRW_H */