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psci_fdt.c revision 1.17 
      1 /* $NetBSD: psci_fdt.c,v 1.17 2018/09/09 21:16:05 jmcneill Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2017 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 "opt_multiprocessor.h"
     30 
     31 #include <sys/cdefs.h>
     32 __KERNEL_RCSID(0, "$NetBSD: psci_fdt.c,v 1.17 2018/09/09 21:16:05 jmcneill Exp $");
     33 
     34 #include <sys/param.h>
     35 #include <sys/bus.h>
     36 #include <sys/device.h>
     37 #include <sys/systm.h>
     38 #include <sys/kernel.h>
     39 #include <sys/atomic.h>
     40 
     41 #include <dev/fdt/fdtvar.h>
     42 
     43 #include <arm/locore.h>
     44 #include <arm/armreg.h>
     45 #include <arm/cpufunc.h>
     46 
     47 #include <arm/arm/psci.h>
     48 #include <arm/fdt/psci_fdt.h>
     49 
     50 static int	psci_fdt_match(device_t, cfdata_t, void *);
     51 static void	psci_fdt_attach(device_t, device_t, void *);
     52 
     53 static int	psci_fdt_init(const int);
     54 
     55 static const char * const compatible[] = {
     56 	"arm,psci",
     57 	"arm,psci-0.2",
     58 	"arm,psci-1.0",
     59 	NULL
     60 };
     61 
     62 CFATTACH_DECL_NEW(psci_fdt, 0, psci_fdt_match, psci_fdt_attach, NULL, NULL);
     63 
     64 static void
     65 psci_fdt_power_reset(device_t dev)
     66 {
     67 	delay(500000);
     68 	psci_system_reset();
     69 }
     70 
     71 static void
     72 psci_fdt_power_poweroff(device_t dev)
     73 {
     74 	delay(500000);
     75 	psci_system_off();
     76 }
     77 
     78 static const struct fdtbus_power_controller_func psci_power_funcs = {
     79 	.reset = psci_fdt_power_reset,
     80 	.poweroff = psci_fdt_power_poweroff,
     81 };
     82 
     83 static int
     84 psci_fdt_match(device_t parent, cfdata_t cf, void *aux)
     85 {
     86 	struct fdt_attach_args * const faa = aux;
     87 
     88 	return of_match_compatible(faa->faa_phandle, compatible);
     89 }
     90 
     91 static void
     92 psci_fdt_attach(device_t parent, device_t self, void *aux)
     93 {
     94 	struct fdt_attach_args * const faa = aux;
     95 	const int phandle = faa->faa_phandle;
     96 
     97 	psci_fdt_init(phandle);
     98 
     99 	const uint32_t ver = psci_version();
    100 	const u_int ver_maj = __SHIFTOUT(ver, PSCI_VERSION_MAJOR);
    101 	const u_int ver_min = __SHIFTOUT(ver, PSCI_VERSION_MINOR);
    102 
    103 	aprint_naive("\n");
    104 	aprint_normal(": PSCI %u.%u\n", ver_maj, ver_min);
    105 
    106 	fdtbus_register_power_controller(self, phandle,
    107 	    &psci_power_funcs);
    108 }
    109 
    110 static int
    111 psci_fdt_init(const int phandle)
    112 {
    113 	const char *method, *psciver;
    114 	uint32_t val;
    115 
    116 	method = fdtbus_get_string(phandle, "method");
    117 	psciver = fdtbus_get_string(phandle, "compatible");
    118 	if (method == NULL || psciver == NULL) {
    119 		aprint_error("PSCI: missing required property on /psci\n");
    120 		return EINVAL;
    121 	}
    122 
    123 	if (strcmp(method, "smc") == 0)
    124 		psci_init(psci_call_smc);
    125 	else if (strcmp(method, "hvc") == 0)
    126 		psci_init(psci_call_hvc);
    127 	else {
    128 		aprint_error("PSCI: unsupported method '%s'\n", method);
    129 		return EINVAL;
    130 	}
    131 
    132 	/*
    133 	 * If the first compatible string is "arm,psci" then we
    134 	 * are dealing with PSCI 0.1
    135 	 */
    136 	if (strcmp(psciver, "arm,psci") == 0) {
    137 		psci_clearfunc();
    138 		if (of_getprop_uint32(phandle, "cpu_on", &val) == 0)
    139 			psci_setfunc(PSCI_FUNC_CPU_ON, val);
    140 	}
    141 
    142 	return 0;
    143 }
    144 
    145 static int
    146 psci_fdt_preinit(void)
    147 {
    148 	const int phandle = OF_finddevice("/psci");
    149 	if (phandle == -1) {
    150 		aprint_error("PSCI: no /psci node found\n");
    151 		return ENODEV;
    152 	}
    153 
    154 	return psci_fdt_init(phandle);
    155 }
    156 
    157 #ifdef MULTIPROCESSOR
    158 
    159 static register_t
    160 psci_fdt_mpstart_pa(void)
    161 {
    162 #ifdef __aarch64__
    163 	extern void aarch64_mpstart(void);
    164 	return (register_t)aarch64_kern_vtophys((vaddr_t)aarch64_mpstart);
    165 #else
    166 	extern void cortex_mpstart(void);
    167 	return (register_t)cortex_mpstart;
    168 #endif
    169 }
    170 #endif
    171 
    172 static bool
    173 psci_fdt_cpu_okay(const int child)
    174 {
    175 	const char *s;
    176 
    177 	s = fdtbus_get_string(child, "device_type");
    178 	if (!s || strcmp(s, "cpu") != 0)
    179 		return false;
    180 
    181 	s = fdtbus_get_string(child, "status");
    182 	if (s) {
    183 		if (strcmp(s, "okay") == 0)
    184 			return false;
    185 		if (strcmp(s, "disabled") == 0)
    186 			return of_hasprop(child, "enable-method");
    187 		return false;
    188 	} else {
    189 		return true;
    190 	}
    191 }
    192 
    193 void
    194 psci_fdt_bootstrap(void)
    195 {
    196 #ifdef MULTIPROCESSOR
    197 	uint64_t mpidr, bp_mpidr;
    198 	u_int cpuindex;
    199 	int child;
    200 	const char *devtype;
    201 
    202 	const int cpus = OF_finddevice("/cpus");
    203 	if (cpus == -1) {
    204 		aprint_error("PSCI: no /cpus node found\n");
    205 		arm_cpu_max = 1;
    206 		return;
    207 	}
    208 
    209 	/* Count CPUs */
    210 	arm_cpu_max = 0;
    211 	for (child = OF_child(cpus); child; child = OF_peer(child))
    212 		if (fdtbus_status_okay(child) && ((devtype =
    213 		    fdtbus_get_string(child, "device_type")) != NULL) &&
    214 		    (strcmp(devtype, "cpu") == 0))
    215 			arm_cpu_max++;
    216 
    217 	if (psci_fdt_preinit() != 0)
    218 		return;
    219 
    220 	/* MPIDR affinity levels of boot processor. */
    221 	bp_mpidr = cpu_mpidr_aff_read();
    222 
    223 	/* Boot APs */
    224 	cpuindex = 1;
    225 	for (child = OF_child(cpus); child; child = OF_peer(child)) {
    226 		if (!psci_fdt_cpu_okay(child))
    227 			continue;
    228 		if (fdtbus_get_reg64(child, 0, &mpidr, NULL) != 0)
    229 			continue;
    230 		if (mpidr == bp_mpidr)
    231 			continue; 	/* BP already started */
    232 
    233 #ifdef __aarch64__
    234 		/* argument for mpstart() */
    235 		arm_cpu_hatch_arg = cpuindex;
    236 		cpu_dcache_wb_range((vaddr_t)&arm_cpu_hatch_arg,
    237 		    sizeof(arm_cpu_hatch_arg));
    238 #endif
    239 
    240 		int ret = psci_cpu_on(mpidr, psci_fdt_mpstart_pa(), 0);
    241 		if (ret != PSCI_SUCCESS)
    242 			continue;
    243 
    244 		/* Wait for APs to start */
    245 		for (u_int i = 0x4000000; i > 0; i--) {
    246 			membar_consumer();
    247 			if (arm_cpu_hatched & __BIT(cpuindex))
    248 				break;
    249 		}
    250 
    251 		cpuindex++;
    252 	}
    253 #endif
    254 }
    255 
    256 void
    257 psci_fdt_reset(void)
    258 {
    259 	if (psci_fdt_preinit() != 0) {
    260 		aprint_error("PSCI: reset failed\n");
    261 		return;
    262 	}
    263 
    264 	psci_system_reset();
    265 }
    266