arch/arm/mach-realview/platsmp.c

   1 /*
   2  *  linux/arch/arm/mach-realview/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
  16 #include "hardware.h"
  17 #include <asm/mach-types.h>
  18 #include <asm/smp_scu.h>
  19
  20 #include "board-eb.h"
  21 #include "board-pb11mp.h"
  22 #include "board-pbx.h"
  23
  24 #include <plat/platsmp.h>
  25
  26 #include "core.h"
  27
  28 static void __iomem *scu_base_addr(void)
  29 {
  30         if (machine_is_realview_eb_mp())
  31                 return __io_address(REALVIEW_EB11MP_SCU_BASE);
  32         else if (machine_is_realview_pb11mp())
  33                 return __io_address(REALVIEW_TC11MP_SCU_BASE);
  34         else if (machine_is_realview_pbx() &&
  35                  (core_tile_pbx11mp() || core_tile_pbxa9mp()))
  36                 return __io_address(REALVIEW_PBX_TILE_SCU_BASE);
  37         else
  38                 return (void __iomem *)0;
  39 }
  40
  41 /*
  42  * Initialise the CPU possible map early - this describes the CPUs
  43  * which may be present or become present in the system.
  44  */
  45 static void __init realview_smp_init_cpus(void)
  46 {
  47         void __iomem *scu_base = scu_base_addr();
  48         unsigned int i, ncores;
  49
  50         ncores = scu_base ? scu_get_core_count(scu_base) : 1;
  51
  52         /* sanity check */
  53         if (ncores > nr_cpu_ids) {
  54                 pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
  55                         ncores, nr_cpu_ids);
  56                 ncores = nr_cpu_ids;
  57         }
  58
  59         for (i = 0; i < ncores; i++)
  60                 set_cpu_possible(i, true);
  61 }
  62
  63 static void __init realview_smp_prepare_cpus(unsigned int max_cpus)
  64 {
  65
  66         scu_enable(scu_base_addr());
  67
  68         /*
  69          * Write the address of secondary startup into the
  70          * system-wide flags register. The BootMonitor waits
  71          * until it receives a soft interrupt, and then the
  72          * secondary CPU branches to this address.
  73          */
  74         __raw_writel(virt_to_phys(versatile_secondary_startup),
  75                      __io_address(REALVIEW_SYS_FLAGSSET));
  76 }
  77
  78 const struct smp_operations realview_smp_ops __initconst = {
  79         .smp_init_cpus          = realview_smp_init_cpus,
  80         .smp_prepare_cpus       = realview_smp_prepare_cpus,
  81         .smp_secondary_init     = versatile_secondary_init,
  82         .smp_boot_secondary     = versatile_boot_secondary,
  83 #ifdef CONFIG_HOTPLUG_CPU
  84         .cpu_die                = realview_cpu_die,
  85 #endif
  86 };