LXR linux/arch/powerpc/include/asm/idle.h

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2#ifndef _ASM_POWERPC_IDLE_H
   3#define _ASM_POWERPC_IDLE_H
   4#include <asm/runlatch.h>
   5#include <asm/paca.h>
   6
   7#ifdef CONFIG_PPC_PSERIES
   8DECLARE_PER_CPU(u64, idle_spurr_cycles);
   9DECLARE_PER_CPU(u64, idle_entry_purr_snap);
  10DECLARE_PER_CPU(u64, idle_entry_spurr_snap);
  11
  12static inline void snapshot_purr_idle_entry(void)
  13{
  14        *this_cpu_ptr(&idle_entry_purr_snap) = mfspr(SPRN_PURR);
  15}
  16
  17static inline void snapshot_spurr_idle_entry(void)
  18{
  19        *this_cpu_ptr(&idle_entry_spurr_snap) = mfspr(SPRN_SPURR);
  20}
  21
  22static inline void update_idle_purr_accounting(void)
  23{
  24        u64 wait_cycles;
  25        u64 in_purr = *this_cpu_ptr(&idle_entry_purr_snap);
  26
  27        wait_cycles = be64_to_cpu(get_lppaca()->wait_state_cycles);
  28        wait_cycles += mfspr(SPRN_PURR) - in_purr;
  29        get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles);
  30}
  31
  32static inline void update_idle_spurr_accounting(void)
  33{
  34        u64 *idle_spurr_cycles_ptr = this_cpu_ptr(&idle_spurr_cycles);
  35        u64 in_spurr = *this_cpu_ptr(&idle_entry_spurr_snap);
  36
  37        *idle_spurr_cycles_ptr += mfspr(SPRN_SPURR) - in_spurr;
  38}
  39
  40static inline void pseries_idle_prolog(void)
  41{
  42        ppc64_runlatch_off();
  43        snapshot_purr_idle_entry();
  44        snapshot_spurr_idle_entry();
  45        /*
  46         * Indicate to the HV that we are idle. Now would be
  47         * a good time to find other work to dispatch.
  48         */
  49        get_lppaca()->idle = 1;
  50}
  51
  52static inline void pseries_idle_epilog(void)
  53{
  54        update_idle_purr_accounting();
  55        update_idle_spurr_accounting();
  56        get_lppaca()->idle = 0;
  57        ppc64_runlatch_on();
  58}
  59
  60static inline u64 read_this_idle_purr(void)
  61{
  62        /*
  63         * If we are reading from an idle context, update the
  64         * idle-purr cycles corresponding to the last idle period.
  65         * Since the idle context is not yet over, take a fresh
  66         * snapshot of the idle-purr.
  67         */
  68        if (unlikely(get_lppaca()->idle == 1)) {
  69                update_idle_purr_accounting();
  70                snapshot_purr_idle_entry();
  71        }
  72
  73        return be64_to_cpu(get_lppaca()->wait_state_cycles);
  74}
  75
  76static inline u64 read_this_idle_spurr(void)
  77{
  78        /*
  79         * If we are reading from an idle context, update the
  80         * idle-spurr cycles corresponding to the last idle period.
  81         * Since the idle context is not yet over, take a fresh
  82         * snapshot of the idle-spurr.
  83         */
  84        if (get_lppaca()->idle == 1) {
  85                update_idle_spurr_accounting();
  86                snapshot_spurr_idle_entry();
  87        }
  88
  89        return *this_cpu_ptr(&idle_spurr_cycles);
  90}
  91
  92#endif /* CONFIG_PPC_PSERIES */
  93#endif
  94