arch/arm/mach-versatile/platsmp-realview.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2015 Linus Walleij
   4  */
   5 #include <linux/smp.h>
   6 #include <linux/io.h>
   7 #include <linux/of.h>
   8 #include <linux/of_address.h>
   9 #include <linux/regmap.h>
  10 #include <linux/mfd/syscon.h>
  11
  12 #include <asm/cacheflush.h>
  13 #include <asm/smp_plat.h>
  14 #include <asm/smp_scu.h>
  15
  16 #include "platsmp.h"
  17
  18 #define REALVIEW_SYS_FLAGSSET_OFFSET    0x30
  19
  20 static const struct of_device_id realview_scu_match[] = {
  21         /*
  22          * The ARM11MP SCU compatible is only provided as fallback for
  23          * old RealView EB Cortex-A9 device trees that were using this
  24          * compatible by mistake.
  25          */
  26         { .compatible = "arm,arm11mp-scu", },
  27         { .compatible = "arm,cortex-a9-scu", },
  28         { .compatible = "arm,cortex-a5-scu", },
  29         { }
  30 };
  31
  32 static const struct of_device_id realview_syscon_match[] = {
  33         { .compatible = "arm,core-module-integrator", },
  34         { .compatible = "arm,realview-eb-syscon", },
  35         { .compatible = "arm,realview-pbx-syscon", },
  36         { },
  37 };
  38
  39 static void __init realview_smp_prepare_cpus(unsigned int max_cpus)
  40 {
  41         struct device_node *np;
  42         void __iomem *scu_base;
  43         struct regmap *map;
  44         unsigned int ncores;
  45         int i;
  46
  47         np = of_find_matching_node(NULL, realview_scu_match);
  48         if (!np) {
  49                 pr_err("PLATSMP: No SCU base address\n");
  50                 return;
  51         }
  52         scu_base = of_iomap(np, 0);
  53         of_node_put(np);
  54         if (!scu_base) {
  55                 pr_err("PLATSMP: No SCU remap\n");
  56                 return;
  57         }
  58
  59         scu_enable(scu_base);
  60         ncores = scu_get_core_count(scu_base);
  61         pr_info("SCU: %d cores detected\n", ncores);
  62         for (i = 0; i < ncores; i++)
  63                 set_cpu_possible(i, true);
  64         iounmap(scu_base);
  65
  66         /* The syscon contains the magic SMP start address registers */
  67         np = of_find_matching_node(NULL, realview_syscon_match);
  68         if (!np) {
  69                 pr_err("PLATSMP: No syscon match\n");
  70                 return;
  71         }
  72         map = syscon_node_to_regmap(np);
  73         of_node_put(np);
  74         if (IS_ERR(map)) {
  75                 pr_err("PLATSMP: No syscon regmap\n");
  76                 return;
  77         }
  78         /* Put the boot address in this magic register */
  79         regmap_write(map, REALVIEW_SYS_FLAGSSET_OFFSET,
  80                      __pa_symbol(versatile_secondary_startup));
  81 }
  82
  83 #ifdef CONFIG_HOTPLUG_CPU
  84 static void realview_cpu_die(unsigned int cpu)
  85 {
  86         return versatile_immitation_cpu_die(cpu, 0x20);
  87 }
  88 #endif
  89
  90 static const struct smp_operations realview_dt_smp_ops __initconst = {
  91         .smp_prepare_cpus       = realview_smp_prepare_cpus,
  92         .smp_secondary_init     = versatile_secondary_init,
  93         .smp_boot_secondary     = versatile_boot_secondary,
  94 #ifdef CONFIG_HOTPLUG_CPU
  95         .cpu_die                = realview_cpu_die,
  96 #endif
  97 };
  98 CPU_METHOD_OF_DECLARE(realview_smp, "arm,realview-smp", &realview_dt_smp_ops);