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
  21 #include "core.h"
  22
  23 #define REALVIEW_SYS_FLAGSSET_OFFSET    0x30
  24
  25 static const struct of_device_id realview_scu_match[] = {
  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-pb11mp-syscon", },
  36         { .compatible = "arm,realview-pbx-syscon", },
  37         { },
  38 };
  39
  40 static void __init realview_smp_prepare_cpus(unsigned int max_cpus)
  41 {
  42         struct device_node *np;
  43         void __iomem *scu_base;
  44         struct regmap *map;
  45         unsigned int ncores;
  46         int i;
  47
  48         np = of_find_matching_node(NULL, realview_scu_match);
  49         if (!np) {
  50                 pr_err("PLATSMP: No SCU base address\n");
  51                 return;
  52         }
  53         scu_base = of_iomap(np, 0);
  54         of_node_put(np);
  55         if (!scu_base) {
  56                 pr_err("PLATSMP: No SCU remap\n");
  57                 return;
  58         }
  59
  60         scu_enable(scu_base);
  61         ncores = scu_get_core_count(scu_base);
  62         pr_info("SCU: %d cores detected\n", ncores);
  63         for (i = 0; i < ncores; i++)
  64                 set_cpu_possible(i, true);
  65         iounmap(scu_base);
  66
  67         /* The syscon contains the magic SMP start address registers */
  68         np = of_find_matching_node(NULL, realview_syscon_match);
  69         if (!np) {
  70                 pr_err("PLATSMP: No syscon match\n");
  71                 return;
  72         }
  73         map = syscon_node_to_regmap(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                      virt_to_phys(versatile_secondary_startup));
  81 }
  82
  83 static const struct smp_operations realview_dt_smp_ops __initconst = {
  84         .smp_prepare_cpus       = realview_smp_prepare_cpus,
  85         .smp_secondary_init     = versatile_secondary_init,
  86         .smp_boot_secondary     = versatile_boot_secondary,
  87 #ifdef CONFIG_HOTPLUG_CPU
  88         .cpu_die                = realview_cpu_die,
  89 #endif
  90 };
  91 CPU_METHOD_OF_DECLARE(realview_smp, "arm,realview-smp", &realview_dt_smp_ops);