linux/arch/s390/include/asm/irq.h
Jan Glauber e4b8b3f33f s390: add support for runtime instrumentation
Allow user-space threads to use runtime instrumentation (RI). To enable RI
for a thread there is a new s390 specific system call, sys_s390_runtime_instr,
that takes as parameter a realtime signal number. If the RI facility is
available the system call sets up a control block for the calling thread with
the appropriate permissions for the thread to modify the control block.

The user-space thread can then use the store and modify RI instructions to
alter the control block and start/stop the instrumentation via RION/RIOFF.

If the user specified program buffer runs full RI triggers an external
interrupt. The external interrupt is translated to a real-time signal that
is delivered to the thread that enabled RI on that CPU. The number of
the real-time signal is the number specified in the RI system call. So,
user-space can select any available real-time signal number in case the
application itself uses real-time signals for other purposes.

The kernel saves the RI control blocks on task switch only if the running
thread was enabled for RI. Therefore, the performance impact on task switch
should be negligible if RI is not used.

RI is only enabled for user-space mode and is disabled for the supervisor
state.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-09-26 15:45:02 +02:00

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C

#ifndef _ASM_IRQ_H
#define _ASM_IRQ_H
#include <linux/hardirq.h>
#include <linux/types.h>
enum interruption_class {
EXTERNAL_INTERRUPT,
IO_INTERRUPT,
EXTINT_CLK,
EXTINT_EXC,
EXTINT_EMS,
EXTINT_TMR,
EXTINT_TLA,
EXTINT_PFL,
EXTINT_DSD,
EXTINT_VRT,
EXTINT_SCP,
EXTINT_IUC,
EXTINT_CMS,
EXTINT_CMC,
EXTINT_CMR,
IOINT_CIO,
IOINT_QAI,
IOINT_DAS,
IOINT_C15,
IOINT_C70,
IOINT_TAP,
IOINT_VMR,
IOINT_LCS,
IOINT_CLW,
IOINT_CTC,
IOINT_APB,
IOINT_ADM,
IOINT_CSC,
NMI_NMI,
NR_IRQS,
};
struct ext_code {
unsigned short subcode;
unsigned short code;
};
typedef void (*ext_int_handler_t)(struct ext_code, unsigned int, unsigned long);
int register_external_interrupt(u16 code, ext_int_handler_t handler);
int unregister_external_interrupt(u16 code, ext_int_handler_t handler);
void service_subclass_irq_register(void);
void service_subclass_irq_unregister(void);
void measurement_alert_subclass_register(void);
void measurement_alert_subclass_unregister(void);
#endif /* _ASM_IRQ_H */