root/arch/arm/mach-rockchip/platsmp.c

DEFINITIONS

1. pmu_power_domain_is_on
2. rockchip_get_core_reset
3. pmu_set_power_domain
4. rockchip_boot_secondary
5. rockchip_smp_prepare_sram
6. rockchip_smp_prepare_pmu
7. rockchip_smp_prepare_cpus
8. rk3036_smp_prepare_cpus
9. rockchip_cpu_kill
10. rockchip_cpu_die

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (c) 2013 MundoReader S.L.
   4  * Author: Heiko Stuebner <heiko@sntech.de>
   5  */
   6 
   7 #include <linux/delay.h>
   8 #include <linux/init.h>
   9 #include <linux/smp.h>
  10 #include <linux/io.h>
  11 #include <linux/of.h>
  12 #include <linux/of_address.h>
  13 #include <linux/regmap.h>
  14 #include <linux/mfd/syscon.h>
  15 
  16 #include <linux/reset.h>
  17 #include <linux/cpu.h>
  18 #include <asm/cacheflush.h>
  19 #include <asm/cp15.h>
  20 #include <asm/smp_scu.h>
  21 #include <asm/smp_plat.h>
  22 #include <asm/mach/map.h>
  23 
  24 #include "core.h"
  25 
  26 static void __iomem *scu_base_addr;
  27 static void __iomem *sram_base_addr;
  28 static int ncores;
  29 
  30 #define PMU_PWRDN_CON           0x08
  31 #define PMU_PWRDN_ST            0x0c
  32 
  33 #define PMU_PWRDN_SCU           4
  34 
  35 static struct regmap *pmu;
  36 static int has_pmu = true;
  37 
  38 static int pmu_power_domain_is_on(int pd)
  39 {
  40         u32 val;
  41         int ret;
  42 
  43         ret = regmap_read(pmu, PMU_PWRDN_ST, &val);
  44         if (ret < 0)
  45                 return ret;
  46 
  47         return !(val & BIT(pd));
  48 }
  49 
  50 static struct reset_control *rockchip_get_core_reset(int cpu)
  51 {
  52         struct device *dev = get_cpu_device(cpu);
  53         struct device_node *np;
  54 
  55         /* The cpu device is only available after the initial core bringup */
  56         if (dev)
  57                 np = dev->of_node;
  58         else
  59                 np = of_get_cpu_node(cpu, NULL);
  60 
  61         return of_reset_control_get_exclusive(np, NULL);
  62 }
  63 
  64 static int pmu_set_power_domain(int pd, bool on)
  65 {
  66         u32 val = (on) ? 0 : BIT(pd);
  67         struct reset_control *rstc = rockchip_get_core_reset(pd);
  68         int ret;
  69 
  70         if (IS_ERR(rstc) && read_cpuid_part() != ARM_CPU_PART_CORTEX_A9) {
  71                 pr_err("%s: could not get reset control for core %d\n",
  72                        __func__, pd);
  73                 return PTR_ERR(rstc);
  74         }
  75 
  76         /*
  77          * We need to soft reset the cpu when we turn off the cpu power domain,
  78          * or else the active processors might be stalled when the individual
  79          * processor is powered down.
  80          */
  81         if (!IS_ERR(rstc) && !on)
  82                 reset_control_assert(rstc);
  83 
  84         if (has_pmu) {
  85                 ret = regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), val);
  86                 if (ret < 0) {
  87                         pr_err("%s: could not update power domain\n",
  88                                __func__);
  89                         return ret;
  90                 }
  91 
  92                 ret = -1;
  93                 while (ret != on) {
  94                         ret = pmu_power_domain_is_on(pd);
  95                         if (ret < 0) {
  96                                 pr_err("%s: could not read power domain state\n",
  97                                        __func__);
  98                                 return ret;
  99                         }
 100                 }
 101         }
 102 
 103         if (!IS_ERR(rstc)) {
 104                 if (on)
 105                         reset_control_deassert(rstc);
 106                 reset_control_put(rstc);
 107         }
 108 
 109         return 0;
 110 }
 111 
 112 /*
 113  * Handling of CPU cores
 114  */
 115 
 116 static int rockchip_boot_secondary(unsigned int cpu, struct task_struct *idle)
 117 {
 118         int ret;
 119 
 120         if (!sram_base_addr || (has_pmu && !pmu)) {
 121                 pr_err("%s: sram or pmu missing for cpu boot\n", __func__);
 122                 return -ENXIO;
 123         }
 124 
 125         if (cpu >= ncores) {
 126                 pr_err("%s: cpu %d outside maximum number of cpus %d\n",
 127                        __func__, cpu, ncores);
 128                 return -ENXIO;
 129         }
 130 
 131         /* start the core */
 132         ret = pmu_set_power_domain(0 + cpu, true);
 133         if (ret < 0)
 134                 return ret;
 135 
 136         if (read_cpuid_part() != ARM_CPU_PART_CORTEX_A9) {
 137                 /*
 138                  * We communicate with the bootrom to active the cpus other
 139                  * than cpu0, after a blob of initialize code, they will
 140                  * stay at wfe state, once they are actived, they will check
 141                  * the mailbox:
 142                  * sram_base_addr + 4: 0xdeadbeaf
 143                  * sram_base_addr + 8: start address for pc
 144                  * The cpu0 need to wait the other cpus other than cpu0 entering
 145                  * the wfe state.The wait time is affected by many aspects.
 146                  * (e.g: cpu frequency, bootrom frequency, sram frequency, ...)
 147                  */
 148                 mdelay(1); /* ensure the cpus other than cpu0 to startup */
 149 
 150                 writel(__pa_symbol(secondary_startup), sram_base_addr + 8);
 151                 writel(0xDEADBEAF, sram_base_addr + 4);
 152                 dsb_sev();
 153         }
 154 
 155         return 0;
 156 }
 157 
 158 /**
 159  * rockchip_smp_prepare_sram - populate necessary sram block
 160  * Starting cores execute the code residing at the start of the on-chip sram
 161  * after power-on. Therefore make sure, this sram region is reserved and
 162  * big enough. After this check, copy the trampoline code that directs the
 163  * core to the real startup code in ram into the sram-region.
 164  * @node: mmio-sram device node
 165  */
 166 static int __init rockchip_smp_prepare_sram(struct device_node *node)
 167 {
 168         unsigned int trampoline_sz = &rockchip_secondary_trampoline_end -
 169                                             &rockchip_secondary_trampoline;
 170         struct resource res;
 171         unsigned int rsize;
 172         int ret;
 173 
 174         ret = of_address_to_resource(node, 0, &res);
 175         if (ret < 0) {
 176                 pr_err("%s: could not get address for node %pOF\n",
 177                        __func__, node);
 178                 return ret;
 179         }
 180 
 181         rsize = resource_size(&res);
 182         if (rsize < trampoline_sz) {
 183                 pr_err("%s: reserved block with size 0x%x is to small for trampoline size 0x%x\n",
 184                        __func__, rsize, trampoline_sz);
 185                 return -EINVAL;
 186         }
 187 
 188         /* set the boot function for the sram code */
 189         rockchip_boot_fn = __pa_symbol(secondary_startup);
 190 
 191         /* copy the trampoline to sram, that runs during startup of the core */
 192         memcpy(sram_base_addr, &rockchip_secondary_trampoline, trampoline_sz);
 193         flush_cache_all();
 194         outer_clean_range(0, trampoline_sz);
 195 
 196         dsb_sev();
 197 
 198         return 0;
 199 }
 200 
 201 static const struct regmap_config rockchip_pmu_regmap_config = {
 202         .name = "rockchip-pmu",
 203         .reg_bits = 32,
 204         .val_bits = 32,
 205         .reg_stride = 4,
 206 };
 207 
 208 static int __init rockchip_smp_prepare_pmu(void)
 209 {
 210         struct device_node *node;
 211         void __iomem *pmu_base;
 212 
 213         /*
 214          * This function is only called via smp_ops->smp_prepare_cpu().
 215          * That only happens if a "/cpus" device tree node exists
 216          * and has an "enable-method" property that selects the SMP
 217          * operations defined herein.
 218          */
 219         node = of_find_node_by_path("/cpus");
 220 
 221         pmu = syscon_regmap_lookup_by_phandle(node, "rockchip,pmu");
 222         of_node_put(node);
 223         if (!IS_ERR(pmu))
 224                 return 0;
 225 
 226         pmu = syscon_regmap_lookup_by_compatible("rockchip,rk3066-pmu");
 227         if (!IS_ERR(pmu))
 228                 return 0;
 229 
 230         /* fallback, create our own regmap for the pmu area */
 231         pmu = NULL;
 232         node = of_find_compatible_node(NULL, NULL, "rockchip,rk3066-pmu");
 233         if (!node) {
 234                 pr_err("%s: could not find pmu dt node\n", __func__);
 235                 return -ENODEV;
 236         }
 237 
 238         pmu_base = of_iomap(node, 0);
 239         of_node_put(node);
 240         if (!pmu_base) {
 241                 pr_err("%s: could not map pmu registers\n", __func__);
 242                 return -ENOMEM;
 243         }
 244 
 245         pmu = regmap_init_mmio(NULL, pmu_base, &rockchip_pmu_regmap_config);
 246         if (IS_ERR(pmu)) {
 247                 int ret = PTR_ERR(pmu);
 248 
 249                 iounmap(pmu_base);
 250                 pmu = NULL;
 251                 pr_err("%s: regmap init failed\n", __func__);
 252                 return ret;
 253         }
 254 
 255         return 0;
 256 }
 257 
 258 static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus)
 259 {
 260         struct device_node *node;
 261         unsigned int i;
 262 
 263         node = of_find_compatible_node(NULL, NULL, "rockchip,rk3066-smp-sram");
 264         if (!node) {
 265                 pr_err("%s: could not find sram dt node\n", __func__);
 266                 return;
 267         }
 268 
 269         sram_base_addr = of_iomap(node, 0);
 270         if (!sram_base_addr) {
 271                 pr_err("%s: could not map sram registers\n", __func__);
 272                 of_node_put(node);
 273                 return;
 274         }
 275 
 276         if (has_pmu && rockchip_smp_prepare_pmu()) {
 277                 of_node_put(node);
 278                 return;
 279         }
 280 
 281         if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
 282                 if (rockchip_smp_prepare_sram(node)) {
 283                         of_node_put(node);
 284                         return;
 285                 }
 286 
 287                 /* enable the SCU power domain */
 288                 pmu_set_power_domain(PMU_PWRDN_SCU, true);
 289 
 290                 of_node_put(node);
 291                 node = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
 292                 if (!node) {
 293                         pr_err("%s: missing scu\n", __func__);
 294                         return;
 295                 }
 296 
 297                 scu_base_addr = of_iomap(node, 0);
 298                 if (!scu_base_addr) {
 299                         pr_err("%s: could not map scu registers\n", __func__);
 300                         of_node_put(node);
 301                         return;
 302                 }
 303 
 304                 /*
 305                  * While the number of cpus is gathered from dt, also get the
 306                  * number of cores from the scu to verify this value when
 307                  * booting the cores.
 308                  */
 309                 ncores = scu_get_core_count(scu_base_addr);
 310                 pr_err("%s: ncores %d\n", __func__, ncores);
 311 
 312                 scu_enable(scu_base_addr);
 313         } else {
 314                 unsigned int l2ctlr;
 315 
 316                 asm ("mrc p15, 1, %0, c9, c0, 2\n" : "=r" (l2ctlr));
 317                 ncores = ((l2ctlr >> 24) & 0x3) + 1;
 318         }
 319         of_node_put(node);
 320 
 321         /* Make sure that all cores except the first are really off */
 322         for (i = 1; i < ncores; i++)
 323                 pmu_set_power_domain(0 + i, false);
 324 }
 325 
 326 static void __init rk3036_smp_prepare_cpus(unsigned int max_cpus)
 327 {
 328         has_pmu = false;
 329 
 330         rockchip_smp_prepare_cpus(max_cpus);
 331 }
 332 
 333 #ifdef CONFIG_HOTPLUG_CPU
 334 static int rockchip_cpu_kill(unsigned int cpu)
 335 {
 336         /*
 337          * We need a delay here to ensure that the dying CPU can finish
 338          * executing v7_coherency_exit() and reach the WFI/WFE state
 339          * prior to having the power domain disabled.
 340          */
 341         mdelay(1);
 342 
 343         pmu_set_power_domain(0 + cpu, false);
 344         return 1;
 345 }
 346 
 347 static void rockchip_cpu_die(unsigned int cpu)
 348 {
 349         v7_exit_coherency_flush(louis);
 350         while (1)
 351                 cpu_do_idle();
 352 }
 353 #endif
 354 
 355 static const struct smp_operations rk3036_smp_ops __initconst = {
 356         .smp_prepare_cpus       = rk3036_smp_prepare_cpus,
 357         .smp_boot_secondary     = rockchip_boot_secondary,
 358 #ifdef CONFIG_HOTPLUG_CPU
 359         .cpu_kill               = rockchip_cpu_kill,
 360         .cpu_die                = rockchip_cpu_die,
 361 #endif
 362 };
 363 
 364 static const struct smp_operations rockchip_smp_ops __initconst = {
 365         .smp_prepare_cpus       = rockchip_smp_prepare_cpus,
 366         .smp_boot_secondary     = rockchip_boot_secondary,
 367 #ifdef CONFIG_HOTPLUG_CPU
 368         .cpu_kill               = rockchip_cpu_kill,
 369         .cpu_die                = rockchip_cpu_die,
 370 #endif
 371 };
 372 
 373 CPU_METHOD_OF_DECLARE(rk3036_smp, "rockchip,rk3036-smp", &rk3036_smp_ops);
 374 CPU_METHOD_OF_DECLARE(rk3066_smp, "rockchip,rk3066-smp", &rockchip_smp_ops);