mirror of
https://github.com/torvalds/linux
synced 2024-10-24 12:17:07 +00:00
e4b8b3f33f
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>
102 lines
2.5 KiB
C
102 lines
2.5 KiB
C
/*
|
|
* CPU-measurement facilities
|
|
*
|
|
* Copyright IBM Corp. 2012
|
|
* Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
|
|
* Jan Glauber <jang@linux.vnet.ibm.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License (version 2 only)
|
|
* as published by the Free Software Foundation.
|
|
*/
|
|
#ifndef _ASM_S390_CPU_MF_H
|
|
#define _ASM_S390_CPU_MF_H
|
|
|
|
#include <asm/facility.h>
|
|
|
|
#define CPU_MF_INT_SF_IAE (1 << 31) /* invalid entry address */
|
|
#define CPU_MF_INT_SF_ISE (1 << 30) /* incorrect SDBT entry */
|
|
#define CPU_MF_INT_SF_PRA (1 << 29) /* program request alert */
|
|
#define CPU_MF_INT_SF_SACA (1 << 23) /* sampler auth. change alert */
|
|
#define CPU_MF_INT_SF_LSDA (1 << 22) /* loss of sample data alert */
|
|
#define CPU_MF_INT_CF_CACA (1 << 7) /* counter auth. change alert */
|
|
#define CPU_MF_INT_CF_LCDA (1 << 6) /* loss of counter data alert */
|
|
#define CPU_MF_INT_RI_HALTED (1 << 5) /* run-time instr. halted */
|
|
#define CPU_MF_INT_RI_BUF_FULL (1 << 4) /* run-time instr. program
|
|
buffer full */
|
|
|
|
#define CPU_MF_INT_CF_MASK (CPU_MF_INT_CF_CACA|CPU_MF_INT_CF_LCDA)
|
|
#define CPU_MF_INT_SF_MASK (CPU_MF_INT_SF_IAE|CPU_MF_INT_SF_ISE| \
|
|
CPU_MF_INT_SF_PRA|CPU_MF_INT_SF_SACA| \
|
|
CPU_MF_INT_SF_LSDA)
|
|
#define CPU_MF_INT_RI_MASK (CPU_MF_INT_RI_HALTED|CPU_MF_INT_RI_BUF_FULL)
|
|
|
|
/* CPU measurement facility support */
|
|
static inline int cpum_cf_avail(void)
|
|
{
|
|
return MACHINE_HAS_SPP && test_facility(67);
|
|
}
|
|
|
|
static inline int cpum_sf_avail(void)
|
|
{
|
|
return MACHINE_HAS_SPP && test_facility(68);
|
|
}
|
|
|
|
|
|
struct cpumf_ctr_info {
|
|
u16 cfvn;
|
|
u16 auth_ctl;
|
|
u16 enable_ctl;
|
|
u16 act_ctl;
|
|
u16 max_cpu;
|
|
u16 csvn;
|
|
u16 max_cg;
|
|
u16 reserved1;
|
|
u32 reserved2[12];
|
|
} __packed;
|
|
|
|
/* Query counter information */
|
|
static inline int qctri(struct cpumf_ctr_info *info)
|
|
{
|
|
int rc = -EINVAL;
|
|
|
|
asm volatile (
|
|
"0: .insn s,0xb28e0000,%1\n"
|
|
"1: lhi %0,0\n"
|
|
"2:\n"
|
|
EX_TABLE(1b, 2b)
|
|
: "+d" (rc), "=Q" (*info));
|
|
return rc;
|
|
}
|
|
|
|
/* Load CPU-counter-set controls */
|
|
static inline int lcctl(u64 ctl)
|
|
{
|
|
int cc;
|
|
|
|
asm volatile (
|
|
" .insn s,0xb2840000,%1\n"
|
|
" ipm %0\n"
|
|
" srl %0,28\n"
|
|
: "=d" (cc) : "m" (ctl) : "cc");
|
|
return cc;
|
|
}
|
|
|
|
/* Extract CPU counter */
|
|
static inline int ecctr(u64 ctr, u64 *val)
|
|
{
|
|
register u64 content asm("4") = 0;
|
|
int cc;
|
|
|
|
asm volatile (
|
|
" .insn rre,0xb2e40000,%0,%2\n"
|
|
" ipm %1\n"
|
|
" srl %1,28\n"
|
|
: "=d" (content), "=d" (cc) : "d" (ctr) : "cc");
|
|
if (!cc)
|
|
*val = content;
|
|
return cc;
|
|
}
|
|
|
|
#endif /* _ASM_S390_CPU_MF_H */
|