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 <mach/hardware.h>
  17 #include <asm/hardware/gic.h>
  18 #include <asm/mach-types.h>
  19 #include <asm/smp_scu.h>
  20 #include <asm/unified.h>
  21
  22 #include <mach/board-eb.h>
  23 #include <mach/board-pb11mp.h>
  24 #include <mach/board-pbx.h>
  25
  26 #include "core.h"
  27
  28 extern void versatile_secondary_startup(void);
  29
  30 static void __iomem *scu_base_addr(void)
  31 {
  32         if (machine_is_realview_eb_mp())
  33                 return __io_address(REALVIEW_EB11MP_SCU_BASE);
  34         else if (machine_is_realview_pb11mp())
  35                 return __io_address(REALVIEW_TC11MP_SCU_BASE);
  36         else if (machine_is_realview_pbx() &&
  37                  (core_tile_pbx11mp() || core_tile_pbxa9mp()))
  38                 return __io_address(REALVIEW_PBX_TILE_SCU_BASE);
  39         else
  40                 return (void __iomem *)0;
  41 }
  42
  43 /*
  44  * Initialise the CPU possible map early - this describes the CPUs
  45  * which may be present or become present in the system.
  46  */
  47 void __init smp_init_cpus(void)
  48 {
  49         void __iomem *scu_base = scu_base_addr();
  50         unsigned int i, ncores;
  51
  52         ncores = scu_base ? scu_get_core_count(scu_base) : 1;
  53
  54         /* sanity check */
  55         if (ncores > NR_CPUS) {
  56                 printk(KERN_WARNING
  57                        "Realview: no. of cores (%d) greater than configured "
  58                        "maximum of %d - clipping\n",
  59                        ncores, NR_CPUS);
  60                 ncores = NR_CPUS;
  61         }
  62
  63         for (i = 0; i < ncores; i++)
  64                 set_cpu_possible(i, true);
  65
  66         set_smp_cross_call(gic_raise_softirq);
  67 }
  68
  69 void __init platform_smp_prepare_cpus(unsigned int max_cpus)
  70 {
  71
  72         scu_enable(scu_base_addr());
  73
  74         /*
  75          * Write the address of secondary startup into the
  76          * system-wide flags register. The BootMonitor waits
  77          * until it receives a soft interrupt, and then the
  78          * secondary CPU branches to this address.
  79          */
  80         __raw_writel(BSYM(virt_to_phys(versatile_secondary_startup)),
  81                      __io_address(REALVIEW_SYS_FLAGSSET));
  82 }