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

   1 /*
   2  * Copyright (C) 2015 Linus Walleij
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8 #include <linux/smp.h>
   9 #include <linux/io.h>
  10 #include <linux/of.h>
  11 #include <linux/of_address.h>
  12 #include <linux/regmap.h>
  13 #include <linux/mfd/syscon.h>
  14
  15 #include <asm/cacheflush.h>
  16 #include <asm/smp_plat.h>
  17 #include <asm/smp_scu.h>
  18
  19 #include <plat/platsmp.h>
  20 #include "hotplug.h"
  21
  22 #define REALVIEW_SYS_FLAGSSET_OFFSET    0x30
  23
  24 static const struct of_device_id realview_scu_match[] = {
  25         { .compatible = "arm,arm11mp-scu", },
  26         { .compatible = "arm,cortex-a9-scu", },
  27         { .compatible = "arm,cortex-a5-scu", },
  28         { }
  29 };
  30
  31 static const struct of_device_id realview_syscon_match[] = {
  32         { .compatible = "arm,core-module-integrator", },
  33         { .compatible = "arm,realview-eb-syscon", },
  34         { .compatible = "arm,realview-pb11mp-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         if (IS_ERR(map)) {
  74                 pr_err("PLATSMP: No syscon regmap\n");
  75                 return;
  76         }
  77         /* Put the boot address in this magic register */
  78         regmap_write(map, REALVIEW_SYS_FLAGSSET_OFFSET,
  79                      __pa_symbol(versatile_secondary_startup));
  80 }
  81
  82 static const struct smp_operations realview_dt_smp_ops __initconst = {
  83         .smp_prepare_cpus       = realview_smp_prepare_cpus,
  84         .smp_secondary_init     = versatile_secondary_init,
  85         .smp_boot_secondary     = versatile_boot_secondary,
  86 #ifdef CONFIG_HOTPLUG_CPU
  87         .cpu_die                = realview_cpu_die,
  88 #endif
  89 };
  90 CPU_METHOD_OF_DECLARE(realview_smp, "arm,realview-smp", &realview_dt_smp_ops);