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      1 /* $NetBSD: psci.c,v 1.9 2026/05/15 22:44:58 jmcneill Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2017-2026 Jared McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: psci.c,v 1.9 2026/05/15 22:44:58 jmcneill Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/bus.h>
     34 #include <sys/cpu.h>
     35 #include <sys/device.h>
     36 #include <sys/xcall.h>
     37 
     38 #include <arm/arm/psci.h>
     39 
     40 /* PSCI methods */
     41 #define	PSCI_VERSION		0x84000000
     42 #define	PSCI_CPU_OFF		0x84000002
     43 #define	PSCI_SYSTEM_OFF		0x84000008
     44 #define	PSCI_SYSTEM_RESET	0x84000009
     45 #define	PSCI_FEATURES		0x8400000a
     46 
     47 #if defined(__aarch64__)
     48 #define	PSCI_CPU_SUSPEND	0xc4000001
     49 #define	PSCI_CPU_ON		0xc4000003
     50 #define	PSCI_AFFINITY_INFO	0xc4000004
     51 #else
     52 #define	PSCI_CPU_SUSPEND	0x84000001
     53 #define	PSCI_CPU_ON		0x84000003
     54 #define	PSCI_AFFINITY_INFO	0x84000004
     55 #endif
     56 
     57 static psci_fn psci_call_fn;
     58 
     59 static uint32_t psci_functions[PSCI_FUNC_MAX] = {
     60         [PSCI_FUNC_VERSION] = PSCI_VERSION,
     61         [PSCI_FUNC_SYSTEM_OFF] = PSCI_SYSTEM_OFF,
     62 	[PSCI_FUNC_SYSTEM_RESET] = PSCI_SYSTEM_RESET,
     63 	[PSCI_FUNC_CPU_SUSPEND] = PSCI_CPU_SUSPEND,
     64 	[PSCI_FUNC_CPU_ON] = PSCI_CPU_ON,
     65 	[PSCI_FUNC_CPU_OFF] = PSCI_CPU_OFF,
     66 	[PSCI_FUNC_AFFINITY_INFO] = PSCI_AFFINITY_INFO,
     67 	[PSCI_FUNC_FEATURES] = PSCI_FEATURES,
     68 };
     69 
     70 int
     71 psci_call(register_t fid, register_t arg1, register_t arg2, register_t arg3)
     72 {
     73 	KASSERT(psci_call_fn != NULL);
     74 
     75 	if (fid == 0)
     76 		return PSCI_NOT_SUPPORTED;
     77 
     78 	return psci_call_fn(fid, arg1, arg2, arg3);
     79 }
     80 
     81 enum psci_conduit
     82 psci_conduit(void)
     83 {
     84 	if (psci_call_fn == psci_call_smc) {
     85 		return PSCI_CONDUIT_SMC;
     86 	} else if (psci_call_fn == psci_call_hvc) {
     87 		return PSCI_CONDUIT_HVC;
     88 	} else {
     89 		return PSCI_CONDUIT_NONE;
     90 	}
     91 }
     92 
     93 uint32_t
     94 psci_version(void)
     95 {
     96 	if (psci_functions[PSCI_FUNC_VERSION] == 0) {
     97 		/* Pre-0.2 implementation */
     98 		return __SHIFTIN(0, PSCI_VERSION_MAJOR) |
     99 		       __SHIFTIN(1, PSCI_VERSION_MINOR);
    100 	}
    101 
    102 	return psci_call(psci_functions[PSCI_FUNC_VERSION], 0, 0, 0);
    103 }
    104 
    105 int
    106 psci_cpu_on(register_t target_cpu, register_t entry_point_address,
    107     register_t context_id)
    108 {
    109 	return psci_call(psci_functions[PSCI_FUNC_CPU_ON], target_cpu,
    110 	    entry_point_address, context_id);
    111 }
    112 
    113 int
    114 psci_cpu_off(void)
    115 {
    116 	return psci_call(psci_functions[PSCI_FUNC_CPU_OFF], 0, 0, 0);
    117 }
    118 
    119 int
    120 psci_cpu_suspend(uint32_t power_state)
    121 {
    122 	return psci_call(psci_functions[PSCI_FUNC_CPU_SUSPEND], power_state,
    123 	    0, 0);
    124 }
    125 
    126 int
    127 psci_affinity_info(uint64_t target_affinity, uint32_t lowest_affinity_level)
    128 {
    129 	return psci_call(psci_functions[PSCI_FUNC_AFFINITY_INFO],
    130 	    target_affinity, lowest_affinity_level, 0);
    131 }
    132 
    133 
    134 void
    135 psci_system_off(void)
    136 {
    137 	psci_call(psci_functions[PSCI_FUNC_SYSTEM_OFF], 0, 0, 0);
    138 }
    139 
    140 void
    141 psci_system_reset(void)
    142 {
    143 	psci_call(psci_functions[PSCI_FUNC_SYSTEM_RESET], 0, 0, 0);
    144 }
    145 
    146 int
    147 psci_features(uint32_t fid)
    148 {
    149 	if (psci_functions[PSCI_FUNC_FEATURES] == 0) {
    150 		return PSCI_NOT_SUPPORTED;
    151 	}
    152 	return psci_call(psci_functions[PSCI_FUNC_FEATURES], fid, 0, 0);
    153 }
    154 
    155 void
    156 psci_init(psci_fn fn)
    157 {
    158 	psci_call_fn = fn;
    159 }
    160 
    161 bool
    162 psci_available(void)
    163 {
    164 	return psci_call_fn != NULL;
    165 }
    166 
    167 void
    168 psci_clearfunc(void)
    169 {
    170 	for (int i = 0; i < PSCI_FUNC_MAX; i++)
    171 		psci_setfunc(i, 0);
    172 }
    173 
    174 void
    175 psci_setfunc(enum psci_function func, uint32_t fid)
    176 {
    177 	psci_functions[func] = fid;
    178 }
    179 
    180 static void
    181 psci_cpu_off_xcall(void *arg1, void *arg2)
    182 {
    183 	if (curcpu() != arg1) {
    184 		aprint_debug("%s: power down\n", cpu_name(curcpu()));
    185 		psci_cpu_off();
    186 		printf("WARNING: %s power down failed\n", cpu_name(curcpu()));
    187 	}
    188 }
    189 
    190 void
    191 psci_poweroff(void)
    192 {
    193 	if (ncpuonline > 1) {
    194 		CPU_INFO_ITERATOR cii;
    195 		struct cpu_info *ci;
    196 		int ret;
    197 
    198 		/* Call PSCI_CPU_OFF on all CPUs except for ourselves. */
    199 		xc_broadcast(0, psci_cpu_off_xcall, curcpu(), NULL);
    200 
    201 		/* Wait for all CPUs to enter OFF state. */
    202 		for (CPU_INFO_FOREACH(cii, ci)) {
    203 			if (ci == curcpu()) {
    204 				continue;
    205 			}
    206 			for (;;) {
    207 				ret = psci_affinity_info(ci->ci_cpuid, 0);
    208 				if (ret < 0) {
    209 					printf("WARNING: %s state %d\n",
    210 					    cpu_name(ci), ret);
    211 				}
    212 				if (ret != PSCI_AFFINITY_INFO_ON) {
    213 					break;
    214 				}
    215 			}
    216 		}
    217 	}
    218 
    219 	/* Power off the system. */
    220 	psci_system_off();
    221 }
    222