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/mach-types.h>
  18 #include <asm/smp_scu.h>
  19 #include <asm/unified.h>
  20
  21 #include <mach/board-eb.h>
  22 #include <mach/board-pb11mp.h>
  23 #include <mach/board-pbx.h>
  24
  25 #include "core.h"
  26
  27 extern void versatile_secondary_startup(void);
  28
  29 static void __iomem *scu_base_addr(void)
  30 {
  31         if (machine_is_realview_eb_mp())
  32                 return __io_address(REALVIEW_EB11MP_SCU_BASE);
  33         else if (machine_is_realview_pb11mp())
  34                 return __io_address(REALVIEW_TC11MP_SCU_BASE);
  35         else if (machine_is_realview_pbx() &&
  36                  (core_tile_pbx11mp() || core_tile_pbxa9mp()))
  37                 return __io_address(REALVIEW_PBX_TILE_SCU_BASE);
  38         else
  39                 return (void __iomem *)0;
  40 }
  41
  42 /*
  43  * Initialise the CPU possible map early - this describes the CPUs
  44  * which may be present or become present in the system.
  45  */
  46 void __init smp_init_cpus(void)
  47 {
  48         void __iomem *scu_base = scu_base_addr();
  49         unsigned int i, ncores;
  50
  51         ncores = scu_base ? scu_get_core_count(scu_base) : 1;
  52
  53         /* sanity check */
  54         if (ncores > NR_CPUS) {
  55                 printk(KERN_WARNING
  56                        "Realview: no. of cores (%d) greater than configured "
  57                        "maximum of %d - clipping\n",
  58                        ncores, NR_CPUS);
  59                 ncores = NR_CPUS;
  60         }
  61
  62         for (i = 0; i < ncores; i++)
  63                 set_cpu_possible(i, true);
  64 }
  65
  66 void __init platform_smp_prepare_cpus(unsigned int max_cpus)
  67 {
  68         int i;
  69
  70         /*
  71          * Initialise the present map, which describes the set of CPUs
  72          * actually populated at the present time.
  73          */
  74         for (i = 0; i < max_cpus; i++)
  75                 set_cpu_present(i, true);
  76
  77         scu_enable(scu_base_addr());
  78
  79         /*
  80          * Write the address of secondary startup into the
  81          * system-wide flags register. The BootMonitor waits
  82          * until it receives a soft interrupt, and then the
  83          * secondary CPU branches to this address.
  84          */
  85         __raw_writel(BSYM(virt_to_phys(versatile_secondary_startup)),
  86                      __io_address(REALVIEW_SYS_FLAGSSET));
  87 }