linux/arch/s390/include/asm/smp.h
Heiko Carstens 4797e9b506 s390/smp: Implement raw_smp_processor_id() with inline assembly
Implement raw_smp_processor_id() with an inline assembly, which makes
use of the ALTERNATIVE macro, to read cpu_nr from lowcore. Provide an
alternative instruction with a different offset in case lowcore is
relocated.

This replaces sequences of two instructions with one instruction.

Before:
  1000b6:       a5 1e 00 00             llilh   %r1,0
  1000ba:       58 20 13 a0             l       %r2,928(%r1)

After:
  1000b6:       e3 20 03 a0 00 58       ly      %r2,928

Kernel image size change:
add/remove: 753/755 grow/shrink: 230/1510 up/down: 30538/-35832 (-5294)

Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2025-03-18 17:13:04 +01:00

90 lines
2.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright IBM Corp. 1999, 2012
* Author(s): Denis Joseph Barrow,
* Martin Schwidefsky <schwidefsky@de.ibm.com>,
*/
#ifndef __ASM_SMP_H
#define __ASM_SMP_H
#include <asm/processor.h>
#include <asm/lowcore.h>
#include <asm/machine.h>
#include <asm/sigp.h>
static __always_inline unsigned int raw_smp_processor_id(void)
{
unsigned long lc_cpu_nr;
unsigned int cpu;
BUILD_BUG_ON(sizeof_field(struct lowcore, cpu_nr) != sizeof(cpu));
lc_cpu_nr = offsetof(struct lowcore, cpu_nr);
asm_inline(
ALTERNATIVE(" ly %[cpu],%[offzero](%%r0)\n",
" ly %[cpu],%[offalt](%%r0)\n",
ALT_FEATURE(MFEATURE_LOWCORE))
: [cpu] "=d" (cpu)
: [offzero] "i" (lc_cpu_nr),
[offalt] "i" (lc_cpu_nr + LOWCORE_ALT_ADDRESS),
"m" (((struct lowcore *)0)->cpu_nr));
return cpu;
}
#define arch_scale_cpu_capacity smp_cpu_get_capacity
extern struct mutex smp_cpu_state_mutex;
extern unsigned int smp_cpu_mt_shift;
extern unsigned int smp_cpu_mtid;
extern __vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
extern cpumask_t cpu_setup_mask;
extern int __cpu_up(unsigned int cpu, struct task_struct *tidle);
extern void arch_send_call_function_single_ipi(int cpu);
extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
extern void smp_call_ipl_cpu(void (*func)(void *), void *);
extern void smp_emergency_stop(void);
extern int smp_find_processor_id(u16 address);
extern int smp_store_status(int cpu);
extern void smp_save_dump_ipl_cpu(void);
extern void smp_save_dump_secondary_cpus(void);
extern void smp_yield_cpu(int cpu);
extern void smp_cpu_set_polarization(int cpu, int val);
extern int smp_cpu_get_polarization(int cpu);
extern void smp_cpu_set_capacity(int cpu, unsigned long val);
extern void smp_set_core_capacity(int cpu, unsigned long val);
extern unsigned long smp_cpu_get_capacity(int cpu);
extern int smp_cpu_get_cpu_address(int cpu);
extern void smp_fill_possible_mask(void);
extern void smp_detect_cpus(void);
static inline void smp_stop_cpu(void)
{
u16 pcpu = stap();
for (;;) {
__pcpu_sigp(pcpu, SIGP_STOP, 0, NULL);
cpu_relax();
}
}
/* Return thread 0 CPU number as base CPU */
static inline int smp_get_base_cpu(int cpu)
{
return cpu - (cpu % (smp_cpu_mtid + 1));
}
static inline void smp_cpus_done(unsigned int max_cpus)
{
}
extern int smp_rescan_cpus(bool early);
extern void __noreturn cpu_die(void);
extern void __cpu_die(unsigned int cpu);
extern int __cpu_disable(void);
extern void schedule_mcck_handler(void);
void notrace smp_yield_cpu(int cpu);
#endif /* __ASM_SMP_H */