linux/arch/s390/include/asm/sigp.h
Gerald Schaefer 59b6978745 [S390] spinlock: check virtual cpu running status
This patch introduces a new function that checks the running status
of a cpu in a hypervisor. This status is not virtualized, so the check
is only correct if running in an LPAR. On acquiring a spinlock, if the
cpu holding the lock is scheduled by the hypervisor, we do a busy wait
on the lock. If it is not scheduled, we yield over to that cpu.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26 22:37:31 +01:00

132 lines
2.5 KiB
C

/*
* Routines and structures for signalling other processors.
*
* Copyright IBM Corp. 1999,2010
* Author(s): Denis Joseph Barrow,
* Martin Schwidefsky <schwidefsky@de.ibm.com>,
* Heiko Carstens <heiko.carstens@de.ibm.com>,
*/
#ifndef __ASM_SIGP_H
#define __ASM_SIGP_H
#include <asm/system.h>
/* Get real cpu address from logical cpu number. */
extern unsigned short __cpu_logical_map[];
static inline int cpu_logical_map(int cpu)
{
#ifdef CONFIG_SMP
return __cpu_logical_map[cpu];
#else
return stap();
#endif
}
enum {
sigp_sense = 1,
sigp_external_call = 2,
sigp_emergency_signal = 3,
sigp_start = 4,
sigp_stop = 5,
sigp_restart = 6,
sigp_stop_and_store_status = 9,
sigp_initial_cpu_reset = 11,
sigp_cpu_reset = 12,
sigp_set_prefix = 13,
sigp_store_status_at_address = 14,
sigp_store_extended_status_at_address = 15,
sigp_set_architecture = 18,
sigp_conditional_emergency_signal = 19,
sigp_sense_running = 21,
};
enum {
sigp_order_code_accepted = 0,
sigp_status_stored = 1,
sigp_busy = 2,
sigp_not_operational = 3,
};
/*
* Definitions for external call.
*/
enum {
ec_schedule = 0,
ec_call_function,
ec_call_function_single,
};
/*
* Signal processor.
*/
static inline int raw_sigp(u16 cpu, int order)
{
register unsigned long reg1 asm ("1") = 0;
int ccode;
asm volatile(
" sigp %1,%2,0(%3)\n"
" ipm %0\n"
" srl %0,28\n"
: "=d" (ccode)
: "d" (reg1), "d" (cpu),
"a" (order) : "cc" , "memory");
return ccode;
}
/*
* Signal processor with parameter.
*/
static inline int raw_sigp_p(u32 parameter, u16 cpu, int order)
{
register unsigned int reg1 asm ("1") = parameter;
int ccode;
asm volatile(
" sigp %1,%2,0(%3)\n"
" ipm %0\n"
" srl %0,28\n"
: "=d" (ccode)
: "d" (reg1), "d" (cpu),
"a" (order) : "cc" , "memory");
return ccode;
}
/*
* Signal processor with parameter and return status.
*/
static inline int raw_sigp_ps(u32 *status, u32 parm, u16 cpu, int order)
{
register unsigned int reg1 asm ("1") = parm;
int ccode;
asm volatile(
" sigp %1,%2,0(%3)\n"
" ipm %0\n"
" srl %0,28\n"
: "=d" (ccode), "+d" (reg1)
: "d" (cpu), "a" (order)
: "cc" , "memory");
*status = reg1;
return ccode;
}
static inline int sigp(int cpu, int order)
{
return raw_sigp(cpu_logical_map(cpu), order);
}
static inline int sigp_p(u32 parameter, int cpu, int order)
{
return raw_sigp_p(parameter, cpu_logical_map(cpu), order);
}
static inline int sigp_ps(u32 *status, u32 parm, int cpu, int order)
{
return raw_sigp_ps(status, parm, cpu_logical_map(cpu), order);
}
#endif /* __ASM_SIGP_H */