1 /* $NetBSD: cpu_fdt.c,v 1.2 2023/06/12 19:04:13 skrll Exp $ */ 2 3 /*- 4 * Copyright (c) 2017 Jared McNeill <jmcneill@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: cpu_fdt.c,v 1.2 2023/06/12 19:04:13 skrll Exp $"); 33 34 #include <sys/param.h> 35 #include <sys/cpu.h> 36 37 #include <dev/fdt/fdtvar.h> 38 39 #include <riscv/cpufunc.h> 40 #include <riscv/cpuvar.h> 41 #include <riscv/machdep.h> 42 #include <riscv/sbi.h> 43 44 #include <riscv/fdt/riscv_fdtvar.h> 45 46 47 #ifdef MULTIPROCESSOR 48 static bool 49 riscv_fdt_cpu_okay(const int child) 50 { 51 const char *s; 52 53 s = fdtbus_get_string(child, "device_type"); 54 if (!s || strcmp(s, "cpu") != 0) 55 return false; 56 57 s = fdtbus_get_string(child, "status"); 58 if (s) { 59 if (strcmp(s, "okay") == 0) 60 return true; 61 if (strcmp(s, "disabled") == 0) 62 return false; 63 return false; 64 } else { 65 return true; 66 } 67 } 68 #endif /* MULTIPROCESSOR */ 69 70 void 71 riscv_fdt_cpu_bootstrap(void) 72 { 73 #ifdef MULTIPROCESSOR 74 75 const int cpus = OF_finddevice("/cpus"); 76 if (cpus == -1) { 77 aprint_error("%s: no /cpus node found\n", __func__); 78 riscv_cpu_max = 1; 79 return; 80 } 81 82 /* Count harts and add hart IDs to to cpu_hartid array */ 83 size_t cpuindex = 1; 84 for (int child = OF_child(cpus); child; child = OF_peer(child)) { 85 if (!riscv_fdt_cpu_okay(child)) 86 continue; 87 88 riscv_cpu_max++; 89 90 uint64_t reg; 91 if (fdtbus_get_reg64(child, 0, ®, NULL) != 0) 92 continue; 93 94 const cpuid_t hartid = reg; 95 96 struct sbiret sbiret = sbi_hart_get_status(hartid); 97 switch (sbiret.error) { 98 case SBI_ERR_INVALID_PARAM: 99 aprint_error("Unknown hart id %lx", hartid); 100 continue; 101 case SBI_SUCCESS: 102 break; 103 default: 104 aprint_error("Unexpected error (%ld) from get_status", 105 sbiret.error); 106 } 107 108 /* Assume the BP is the only one started. */ 109 if (sbiret.value == SBI_HART_STARTED) { 110 if (cpu_hartid[0] != -1) { 111 panic("more than 1 hart started"); 112 } 113 cpu_hartid[0] = hartid; 114 continue; 115 } 116 117 KASSERT(cpuindex < MAXCPUS); 118 cpu_hartid[cpuindex] = hartid; 119 cpu_dcache_wb_range((vaddr_t)&cpu_hartid[cpuindex], 120 sizeof(cpu_hartid[cpuindex])); 121 122 cpuindex++; 123 } 124 #endif 125 } 126 int 127 riscv_fdt_cpu_mpstart(void) 128 { 129 int ret = 0; 130 #ifdef MULTIPROCESSOR 131 const int cpus = OF_finddevice("/cpus"); 132 if (cpus == -1) { 133 aprint_error("%s: no /cpus node found\n", __func__); 134 return 0; 135 } 136 137 // riscv_fdt_cpu_bootstrap put the boot hart id in cpu_hartid[0] 138 const cpuid_t bp_hartid = cpu_hartid[0]; 139 140 /* BootAPs */ 141 size_t cpuindex = 1; 142 for (int child = OF_child(cpus); child; child = OF_peer(child)) { 143 if (!riscv_fdt_cpu_okay(child)) 144 continue; 145 146 uint64_t reg; 147 if (fdtbus_get_reg64(child, 0, ®, NULL) != 0) 148 continue; 149 150 cpuid_t hartid = reg; 151 152 if (hartid == bp_hartid) 153 continue; /* BP already started */ 154 155 const paddr_t entry = KERN_VTOPHYS(cpu_mpstart); 156 struct sbiret sbiret = sbi_hart_start(hartid, entry, 0); 157 switch (sbiret.error) { 158 case SBI_SUCCESS: 159 break; 160 case SBI_ERR_INVALID_ADDRESS: 161 break; 162 case SBI_ERR_INVALID_PARAM: 163 break; 164 case SBI_ERR_ALREADY_AVAILABLE: 165 break; 166 case SBI_ERR_FAILED: 167 break; 168 default: 169 aprint_error("%s: failed to enable CPU %#lx\n", 170 __func__, hartid); 171 } 172 173 size_t i; 174 /* Wait for AP to start */ 175 for (i = 0x10000000; i > 0; i--) { 176 if (cpu_hatched_p(cpuindex)) 177 break; 178 } 179 180 if (i == 0) { 181 ret++; 182 aprint_error("cpu%zu: WARNING: AP failed to start\n", 183 cpuindex); 184 } 185 186 cpuindex++; 187 } 188 #else 189 aprint_normal("%s: kernel compiled without MULTIPROCESSOR\n", __func__); 190 #endif /* MULTIPROCESSOR */ 191 return ret; 192 } 193 194 static int 195 cpu_fdt_match(device_t parent, cfdata_t cf, void *aux) 196 { 197 struct fdt_attach_args * const faa = aux; 198 const int phandle = faa->faa_phandle; 199 const char *device_type; 200 201 device_type = fdtbus_get_string(phandle, "device_type"); 202 return device_type != NULL && strcmp(device_type, "cpu") == 0; 203 } 204 205 static void 206 cpu_fdt_attach(device_t parent, device_t self, void *aux) 207 { 208 struct fdt_attach_args * const faa = aux; 209 const int phandle = faa->faa_phandle; 210 bus_addr_t cpuid; 211 212 if (fdtbus_get_reg(phandle, 0, &cpuid, NULL) != 0) 213 cpuid = 0; 214 215 /* Attach the CPU */ 216 cpu_attach(self, cpuid); 217 218 fdt_add_bus(self, phandle, faa); 219 } 220 221 CFATTACH_DECL_NEW(cpu_fdt, 0, cpu_fdt_match, cpu_fdt_attach, NULL, NULL); 222