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
  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_cpu_ids) {
  55                 pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
  56                         ncores, nr_cpu_ids);
  57                 ncores = nr_cpu_ids;
  58         }
  59
  60         for (i = 0; i < ncores; i++)
  61                 set_cpu_possible(i, true);
  62
  63         set_smp_cross_call(gic_raise_softirq);
  64 }
  65
  66 void __init platform_smp_prepare_cpus(unsigned int max_cpus)
  67 {
  68
  69         scu_enable(scu_base_addr());
  70
  71         /*
  72          * Write the address of secondary startup into the
  73          * system-wide flags register. The BootMonitor waits
  74          * until it receives a soft interrupt, and then the
  75          * secondary CPU branches to this address.
  76          */
  77         __raw_writel(virt_to_phys(versatile_secondary_startup),
  78                      __io_address(REALVIEW_SYS_FLAGSSET));
  79 }