arch/arm/mach-vexpress/platsmp.c

   1 /*
   2  *  linux/arch/arm/mach-vexpress/platsmp.c
   3  *
   4  *  Copyright (C) 2002 ARM Ltd.
   5  *  All Rights Reserved
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/init.h>
  12 #include <linux/errno.h>
  13 #include <linux/smp.h>
  14 #include <linux/io.h>
  15 #include <linux/of.h>
  16 #include <linux/of_fdt.h>
  17 #include <linux/vexpress.h>
  18
  19 #include <asm/mcpm.h>
  20 #include <asm/smp_scu.h>
  21 #include <asm/mach/map.h>
  22
  23 #include <mach/motherboard.h>
  24
  25 #include <plat/platsmp.h>
  26
  27 #include "core.h"
  28
  29 #if defined(CONFIG_OF)
  30
  31 static enum {
  32         GENERIC_SCU,
  33         CORTEX_A9_SCU,
  34 } vexpress_dt_scu __initdata = GENERIC_SCU;
  35
  36 static struct map_desc vexpress_dt_cortex_a9_scu_map __initdata = {
  37         .virtual        = V2T_PERIPH,
  38         /* .pfn set in vexpress_dt_init_cortex_a9_scu() */
  39         .length         = SZ_128,
  40         .type           = MT_DEVICE,
  41 };
  42
  43 static void *vexpress_dt_cortex_a9_scu_base __initdata;
  44
  45 const static char *vexpress_dt_cortex_a9_match[] __initconst = {
  46         "arm,cortex-a5-scu",
  47         "arm,cortex-a9-scu",
  48         NULL
  49 };
  50
  51 static int __init vexpress_dt_find_scu(unsigned long node,
  52                 const char *uname, int depth, void *data)
  53 {
  54         if (of_flat_dt_match(node, vexpress_dt_cortex_a9_match)) {
  55                 phys_addr_t phys_addr;
  56                 const __be32 *reg = of_get_flat_dt_prop(node, "reg", NULL);
  57
  58                 if (WARN_ON(!reg))
  59                         return -EINVAL;
  60
  61                 phys_addr = be32_to_cpup(reg);
  62                 vexpress_dt_scu = CORTEX_A9_SCU;
  63
  64                 vexpress_dt_cortex_a9_scu_map.pfn = __phys_to_pfn(phys_addr);
  65                 iotable_init(&vexpress_dt_cortex_a9_scu_map, 1);
  66                 vexpress_dt_cortex_a9_scu_base = ioremap(phys_addr, SZ_256);
  67                 if (WARN_ON(!vexpress_dt_cortex_a9_scu_base))
  68                         return -EFAULT;
  69         }
  70
  71         return 0;
  72 }
  73
  74 void __init vexpress_dt_smp_map_io(void)
  75 {
  76         if (initial_boot_params)
  77                 WARN_ON(of_scan_flat_dt(vexpress_dt_find_scu, NULL));
  78 }
  79
  80 static int __init vexpress_dt_cpus_num(unsigned long node, const char *uname,
  81                 int depth, void *data)
  82 {
  83         static int prev_depth = -1;
  84         static int nr_cpus = -1;
  85
  86         if (prev_depth > depth && nr_cpus > 0)
  87                 return nr_cpus;
  88
  89         if (nr_cpus < 0 && strcmp(uname, "cpus") == 0)
  90                 nr_cpus = 0;
  91
  92         if (nr_cpus >= 0) {
  93                 const char *device_type = of_get_flat_dt_prop(node,
  94                                 "device_type", NULL);
  95
  96                 if (device_type && strcmp(device_type, "cpu") == 0)
  97                         nr_cpus++;
  98         }
  99
 100         prev_depth = depth;
 101
 102         return 0;
 103 }
 104
 105 static void __init vexpress_dt_smp_init_cpus(void)
 106 {
 107         int ncores = 0, i;
 108
 109         switch (vexpress_dt_scu) {
 110         case GENERIC_SCU:
 111                 ncores = of_scan_flat_dt(vexpress_dt_cpus_num, NULL);
 112                 break;
 113         case CORTEX_A9_SCU:
 114                 ncores = scu_get_core_count(vexpress_dt_cortex_a9_scu_base);
 115                 break;
 116         default:
 117                 WARN_ON(1);
 118                 break;
 119         }
 120
 121         if (ncores < 2)
 122                 return;
 123
 124         if (ncores > nr_cpu_ids) {
 125                 pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
 126                                 ncores, nr_cpu_ids);
 127                 ncores = nr_cpu_ids;
 128         }
 129
 130         for (i = 0; i < ncores; ++i)
 131                 set_cpu_possible(i, true);
 132 }
 133
 134 static void __init vexpress_dt_smp_prepare_cpus(unsigned int max_cpus)
 135 {
 136         int i;
 137
 138         switch (vexpress_dt_scu) {
 139         case GENERIC_SCU:
 140                 for (i = 0; i < max_cpus; i++)
 141                         set_cpu_present(i, true);
 142                 break;
 143         case CORTEX_A9_SCU:
 144                 scu_enable(vexpress_dt_cortex_a9_scu_base);
 145                 break;
 146         default:
 147                 WARN_ON(1);
 148                 break;
 149         }
 150 }
 151
 152 #else
 153
 154 static void __init vexpress_dt_smp_init_cpus(void)
 155 {
 156         WARN_ON(1);
 157 }
 158
 159 void __init vexpress_dt_smp_prepare_cpus(unsigned int max_cpus)
 160 {
 161         WARN_ON(1);
 162 }
 163
 164 #endif
 165
 166 /*
 167  * Initialise the CPU possible map early - this describes the CPUs
 168  * which may be present or become present in the system.
 169  */
 170 static void __init vexpress_smp_init_cpus(void)
 171 {
 172         if (ct_desc)
 173                 ct_desc->init_cpu_map();
 174         else
 175                 vexpress_dt_smp_init_cpus();
 176
 177 }
 178
 179 static void __init vexpress_smp_prepare_cpus(unsigned int max_cpus)
 180 {
 181         /*
 182          * Initialise the present map, which describes the set of CPUs
 183          * actually populated at the present time.
 184          */
 185         if (ct_desc)
 186                 ct_desc->smp_enable(max_cpus);
 187         else
 188                 vexpress_dt_smp_prepare_cpus(max_cpus);
 189
 190         /*
 191          * Write the address of secondary startup into the
 192          * system-wide flags register. The boot monitor waits
 193          * until it receives a soft interrupt, and then the
 194          * secondary CPU branches to this address.
 195          */
 196         vexpress_flags_set(virt_to_phys(versatile_secondary_startup));
 197 }
 198
 199 struct smp_operations __initdata vexpress_smp_ops = {
 200         .smp_init_cpus          = vexpress_smp_init_cpus,
 201         .smp_prepare_cpus       = vexpress_smp_prepare_cpus,
 202         .smp_secondary_init     = versatile_secondary_init,
 203         .smp_boot_secondary     = versatile_boot_secondary,
 204 #ifdef CONFIG_HOTPLUG_CPU
 205         .cpu_die                = vexpress_cpu_die,
 206 #endif
 207 };
 208
 209 bool __init vexpress_smp_init_ops(void)
 210 {
 211 #ifdef CONFIG_MCPM
 212         /*
 213          * The best way to detect a multi-cluster configuration at the moment
 214          * is to look for the presence of a CCI in the system.
 215          * Override the default vexpress_smp_ops if so.
 216          */
 217         struct device_node *node;
 218         node = of_find_compatible_node(NULL, NULL, "arm,cci-400");
 219         if (node && of_device_is_available(node)) {
 220                 mcpm_smp_set_ops();
 221                 return true;
 222         }
 223 #endif
 224         return false;
 225 }