xref: /openbmc/linux/arch/powerpc/include/asm/cpuidle.h (revision be58f710)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_POWERPC_CPUIDLE_H
3 #define _ASM_POWERPC_CPUIDLE_H
4 
5 #ifdef CONFIG_PPC_POWERNV
6 /* Thread state used in powernv idle state management */
7 #define PNV_THREAD_RUNNING              0
8 #define PNV_THREAD_NAP                  1
9 #define PNV_THREAD_SLEEP                2
10 #define PNV_THREAD_WINKLE               3
11 
12 /*
13  * Core state used in powernv idle for POWER8.
14  *
15  * The lock bit synchronizes updates to the state, as well as parts of the
16  * sleep/wake code (see kernel/idle_book3s.S).
17  *
18  * Bottom 8 bits track the idle state of each thread. Bit is cleared before
19  * the thread executes an idle instruction (nap/sleep/winkle).
20  *
21  * Then there is winkle tracking. A core does not lose complete state
22  * until every thread is in winkle. So the winkle count field counts the
23  * number of threads in winkle (small window of false positives is okay
24  * around the sleep/wake, so long as there are no false negatives).
25  *
26  * When the winkle count reaches 8 (the COUNT_ALL_BIT becomes set), then
27  * the THREAD_WINKLE_BITS are set, which indicate which threads have not
28  * yet woken from the winkle state.
29  */
30 #define NR_PNV_CORE_IDLE_LOCK_BIT		28
31 #define PNV_CORE_IDLE_LOCK_BIT			(1ULL << NR_PNV_CORE_IDLE_LOCK_BIT)
32 
33 #define PNV_CORE_IDLE_WINKLE_COUNT_SHIFT	16
34 #define PNV_CORE_IDLE_WINKLE_COUNT		0x00010000
35 #define PNV_CORE_IDLE_WINKLE_COUNT_BITS		0x000F0000
36 #define PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT	8
37 #define PNV_CORE_IDLE_THREAD_WINKLE_BITS	0x0000FF00
38 
39 #define PNV_CORE_IDLE_THREAD_BITS       	0x000000FF
40 
41 /*
42  * ============================ NOTE =================================
43  * The older firmware populates only the RL field in the psscr_val and
44  * sets the psscr_mask to 0xf. On such a firmware, the kernel sets the
45  * remaining PSSCR fields to default values as follows:
46  *
47  * - ESL and EC bits are to 1. So wakeup from any stop state will be
48  *   at vector 0x100.
49  *
50  * - MTL and PSLL are set to the maximum allowed value as per the ISA,
51  *    i.e. 15.
52  *
53  * - The Transition Rate, TR is set to the Maximum value 3.
54  */
55 #define PSSCR_HV_DEFAULT_VAL    (PSSCR_ESL | PSSCR_EC |		    \
56 				PSSCR_PSLL_MASK | PSSCR_TR_MASK |   \
57 				PSSCR_MTL_MASK)
58 
59 #define PSSCR_HV_DEFAULT_MASK   (PSSCR_ESL | PSSCR_EC |		    \
60 				PSSCR_PSLL_MASK | PSSCR_TR_MASK |   \
61 				PSSCR_MTL_MASK | PSSCR_RL_MASK)
62 #define PSSCR_EC_SHIFT    20
63 #define PSSCR_ESL_SHIFT   21
64 #define GET_PSSCR_EC(x)   (((x) & PSSCR_EC) >> PSSCR_EC_SHIFT)
65 #define GET_PSSCR_ESL(x)  (((x) & PSSCR_ESL) >> PSSCR_ESL_SHIFT)
66 #define GET_PSSCR_RL(x)   ((x) & PSSCR_RL_MASK)
67 
68 #define ERR_EC_ESL_MISMATCH		-1
69 #define ERR_DEEP_STATE_ESL_MISMATCH	-2
70 
71 #ifndef __ASSEMBLY__
72 
73 #define PNV_IDLE_NAME_LEN    16
74 struct pnv_idle_states_t {
75 	char name[PNV_IDLE_NAME_LEN];
76 	u32 latency_ns;
77 	u32 residency_ns;
78 	u64 psscr_val;
79 	u64 psscr_mask;
80 	u32 flags;
81 	bool valid;
82 };
83 
84 extern struct pnv_idle_states_t *pnv_idle_states;
85 extern int nr_pnv_idle_states;
86 
87 unsigned long pnv_cpu_offline(unsigned int cpu);
88 int validate_psscr_val_mask(u64 *psscr_val, u64 *psscr_mask, u32 flags);
89 static inline void report_invalid_psscr_val(u64 psscr_val, int err)
90 {
91 	switch (err) {
92 	case ERR_EC_ESL_MISMATCH:
93 		pr_warn("Invalid psscr 0x%016llx : ESL,EC bits unequal",
94 			psscr_val);
95 		break;
96 	case ERR_DEEP_STATE_ESL_MISMATCH:
97 		pr_warn("Invalid psscr 0x%016llx : ESL cleared for deep stop-state",
98 			psscr_val);
99 	}
100 }
101 #endif
102 
103 #endif
104 
105 #endif
106