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
   8 DECLARE_PER_CPU(u64, idle_spurr_cycles);
   9 DECLARE_PER_CPU(u64, idle_entry_purr_snap);
  10 DECLARE_PER_CPU(u64, idle_entry_spurr_snap);
  11
  12 static inline void snapshot_purr_idle_entry(void)
  13 {
  14         *this_cpu_ptr(&idle_entry_purr_snap) = mfspr(SPRN_PURR);
  15 }
  16
  17 static inline void snapshot_spurr_idle_entry(void)
  18 {
  19         *this_cpu_ptr(&idle_entry_spurr_snap) = mfspr(SPRN_SPURR);
  20 }
  21
  22 static 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
  32 static 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
  40 static 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
  52 static 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
  60 static 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
  76 static 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