include/asm/idle.h

0001 /* SPDX-License-Identifier: GPL-2.0-or-later */
0002 #ifndef _ASM_POWERPC_IDLE_H
0003 #define _ASM_POWERPC_IDLE_H
0004 #include <asm/runlatch.h>
0005 #include <asm/paca.h>
0006
0007 #ifdef CONFIG_PPC_PSERIES
0008 DECLARE_PER_CPU(u64, idle_spurr_cycles);
0009 DECLARE_PER_CPU(u64, idle_entry_purr_snap);
0010 DECLARE_PER_CPU(u64, idle_entry_spurr_snap);
0011
0012 static inline void snapshot_purr_idle_entry(void)
0013 {
0014     *this_cpu_ptr(&idle_entry_purr_snap) = mfspr(SPRN_PURR);
0015 }
0016
0017 static inline void snapshot_spurr_idle_entry(void)
0018 {
0019     *this_cpu_ptr(&idle_entry_spurr_snap) = mfspr(SPRN_SPURR);
0020 }
0021
0022 static inline void update_idle_purr_accounting(void)
0023 {
0024     u64 wait_cycles;
0025     u64 in_purr = *this_cpu_ptr(&idle_entry_purr_snap);
0026
0027     wait_cycles = be64_to_cpu(get_lppaca()->wait_state_cycles);
0028     wait_cycles += mfspr(SPRN_PURR) - in_purr;
0029     get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles);
0030 }
0031
0032 static inline void update_idle_spurr_accounting(void)
0033 {
0034     u64 *idle_spurr_cycles_ptr = this_cpu_ptr(&idle_spurr_cycles);
0035     u64 in_spurr = *this_cpu_ptr(&idle_entry_spurr_snap);
0036
0037     *idle_spurr_cycles_ptr += mfspr(SPRN_SPURR) - in_spurr;
0038 }
0039
0040 static inline void pseries_idle_prolog(void)
0041 {
0042     ppc64_runlatch_off();
0043     snapshot_purr_idle_entry();
0044     snapshot_spurr_idle_entry();
0045     /*
0046      * Indicate to the HV that we are idle. Now would be
0047      * a good time to find other work to dispatch.
0048      */
0049     get_lppaca()->idle = 1;
0050 }
0051
0052 static inline void pseries_idle_epilog(void)
0053 {
0054     update_idle_purr_accounting();
0055     update_idle_spurr_accounting();
0056     get_lppaca()->idle = 0;
0057     ppc64_runlatch_on();
0058 }
0059
0060 static inline u64 read_this_idle_purr(void)
0061 {
0062     /*
0063      * If we are reading from an idle context, update the
0064      * idle-purr cycles corresponding to the last idle period.
0065      * Since the idle context is not yet over, take a fresh
0066      * snapshot of the idle-purr.
0067      */
0068     if (unlikely(get_lppaca()->idle == 1)) {
0069         update_idle_purr_accounting();
0070         snapshot_purr_idle_entry();
0071     }
0072
0073     return be64_to_cpu(get_lppaca()->wait_state_cycles);
0074 }
0075
0076 static inline u64 read_this_idle_spurr(void)
0077 {
0078     /*
0079      * If we are reading from an idle context, update the
0080      * idle-spurr cycles corresponding to the last idle period.
0081      * Since the idle context is not yet over, take a fresh
0082      * snapshot of the idle-spurr.
0083      */
0084     if (get_lppaca()->idle == 1) {
0085         update_idle_spurr_accounting();
0086         snapshot_spurr_idle_entry();
0087     }
0088
0089     return *this_cpu_ptr(&idle_spurr_cycles);
0090 }
0091
0092 #endif /* CONFIG_PPC_PSERIES */
0093 #endif