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 __always_inline void snapshot_purr_idle_entry(void)
13{
14	*this_cpu_ptr(&idle_entry_purr_snap) = mfspr(SPRN_PURR);
15}
16
17static __always_inline void snapshot_spurr_idle_entry(void)
18{
19	*this_cpu_ptr(&idle_entry_spurr_snap) = mfspr(SPRN_SPURR);
20}
21
22static __always_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 __always_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 __always_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 __always_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