arch/arm/mach-highbank/platsmp.c

   1 /*
   2  * Copyright 2010-2011 Calxeda, Inc.
   3  * Based on platsmp.c, Copyright (C) 2002 ARM Ltd.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17 #include <linux/init.h>
  18 #include <linux/smp.h>
  19 #include <linux/io.h>
  20
  21 #include <asm/smp_scu.h>
  22 #include <asm/hardware/gic.h>
  23
  24 #include "core.h"
  25
  26 extern void secondary_startup(void);
  27
  28 void __cpuinit platform_secondary_init(unsigned int cpu)
  29 {
  30         gic_secondary_init(0);
  31 }
  32
  33 int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
  34 {
  35         gic_raise_softirq(cpumask_of(cpu), 0);
  36         return 0;
  37 }
  38
  39 /*
  40  * Initialise the CPU possible map early - this describes the CPUs
  41  * which may be present or become present in the system.
  42  */
  43 void __init smp_init_cpus(void)
  44 {
  45         unsigned int i, ncores;
  46
  47         ncores = scu_get_core_count(scu_base_addr);
  48
  49         /* sanity check */
  50         if (ncores > NR_CPUS) {
  51                 printk(KERN_WARNING
  52                        "highbank: no. of cores (%d) greater than configured "
  53                        "maximum of %d - clipping\n",
  54                        ncores, NR_CPUS);
  55                 ncores = NR_CPUS;
  56         }
  57
  58         for (i = 0; i < ncores; i++)
  59                 set_cpu_possible(i, true);
  60
  61         set_smp_cross_call(gic_raise_softirq);
  62 }
  63
  64 void __init platform_smp_prepare_cpus(unsigned int max_cpus)
  65 {
  66         int i;
  67
  68         scu_enable(scu_base_addr);
  69
  70         /*
  71          * Write the address of secondary startup into the jump table
  72          * The cores are in wfi and wait until they receive a soft interrupt
  73          * and a non-zero value to jump to. Then the secondary CPU branches
  74          * to this address.
  75          */
  76         for (i = 1; i < max_cpus; i++)
  77                 highbank_set_cpu_jump(i, secondary_startup);
  78 }