LXR linux/arch/arm/mach-socfpga/platsmp.c

   1/*
   2 * Copyright 2010-2011 Calxeda, Inc.
   3 * Copyright 2012 Pavel Machek <pavel@denx.de>
   4 * Based on platsmp.c, Copyright (C) 2002 ARM Ltd.
   5 * Copyright (C) 2012 Altera Corporation
   6 *
   7 * This program is free software; you can redistribute it and/or modify it
   8 * under the terms and conditions of the GNU General Public License,
   9 * version 2, as published by the Free Software Foundation.
  10 *
  11 * This program is distributed in the hope it will be useful, but WITHOUT
  12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14 * more details.
  15 *
  16 * You should have received a copy of the GNU General Public License along with
  17 * this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19#include <linux/delay.h>
  20#include <linux/init.h>
  21#include <linux/smp.h>
  22#include <linux/io.h>
  23#include <linux/of.h>
  24#include <linux/of_address.h>
  25
  26#include <asm/cacheflush.h>
  27#include <asm/smp_scu.h>
  28#include <asm/smp_plat.h>
  29
  30#include "core.h"
  31
  32static int socfpga_boot_secondary(unsigned int cpu, struct task_struct *idle)
  33{
  34        int trampoline_size = &secondary_trampoline_end - &secondary_trampoline;
  35
  36        if (cpu1start_addr) {
  37                memcpy(phys_to_virt(0), &secondary_trampoline, trampoline_size);
  38
  39                __raw_writel(virt_to_phys(socfpga_secondary_startup),
  40                        (sys_manager_base_addr + (cpu1start_addr & 0x000000ff)));
  41
  42                flush_cache_all();
  43                smp_wmb();
  44                outer_clean_range(0, trampoline_size);
  45
  46                /* This will release CPU #1 out of reset.*/
  47                __raw_writel(0, rst_manager_base_addr + 0x10);
  48        }
  49
  50        return 0;
  51}
  52
  53/*
  54 * Initialise the CPU possible map early - this describes the CPUs
  55 * which may be present or become present in the system.
  56 */
  57static void __init socfpga_smp_init_cpus(void)
  58{
  59        unsigned int i, ncores;
  60
  61        ncores = scu_get_core_count(socfpga_scu_base_addr);
  62
  63        for (i = 0; i < ncores; i++)
  64                set_cpu_possible(i, true);
  65
  66        /* sanity check */
  67        if (ncores > num_possible_cpus()) {
  68                pr_warn("socfpga: no. of cores (%d) greater than configured"
  69                        "maximum of %d - clipping\n", ncores, num_possible_cpus());
  70                ncores = num_possible_cpus();
  71        }
  72
  73        for (i = 0; i < ncores; i++)
  74                set_cpu_possible(i, true);
  75}
  76
  77static void __init socfpga_smp_prepare_cpus(unsigned int max_cpus)
  78{
  79        scu_enable(socfpga_scu_base_addr);
  80}
  81
  82/*
  83 * platform-specific code to shutdown a CPU
  84 *
  85 * Called with IRQs disabled
  86 */
  87static void socfpga_cpu_die(unsigned int cpu)
  88{
  89        cpu_do_idle();
  90
  91        /* We should have never returned from idle */
  92        panic("cpu %d unexpectedly exit from shutdown\n", cpu);
  93}
  94
  95struct smp_operations socfpga_smp_ops __initdata = {
  96        .smp_init_cpus          = socfpga_smp_init_cpus,
  97        .smp_prepare_cpus       = socfpga_smp_prepare_cpus,
  98        .smp_boot_secondary     = socfpga_boot_secondary,
  99#ifdef CONFIG_HOTPLUG_CPU
 100        .cpu_die                = socfpga_cpu_die,
 101#endif
 102};
 103