linux/arch/powerpc/include/asm/cpuidle.h
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   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
  74struct 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
  84extern struct pnv_idle_states_t *pnv_idle_states;
  85extern int nr_pnv_idle_states;
  86
  87unsigned long pnv_cpu_offline(unsigned int cpu);
  88int validate_psscr_val_mask(u64 *psscr_val, u64 *psscr_mask, u32 flags);
  89static 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