arch/arm/mach-shmobile/smp-r8a7791.c

   1 /*
   2  * SMP support for r8a7791
   3  *
   4  * Copyright (C) 2013 Renesas Solutions Corp.
   5  * Copyright (C) 2013 Magnus Damm
   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 as published by
   9  * the Free Software Foundation; version 2 of the License.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16 #include <linux/kernel.h>
  17 #include <linux/init.h>
  18 #include <linux/smp.h>
  19 #include <linux/io.h>
  20 #include <asm/smp_plat.h>
  21 #include <mach/common.h>
  22 #include <mach/r8a7791.h>
  23 #include <mach/rcar-gen2.h>
  24
  25 #define RST             0xe6160000
  26 #define CA15BAR         0x0020
  27 #define CA15RESCNT      0x0040
  28 #define RAM             0xe6300000
  29
  30 static void __init r8a7791_smp_prepare_cpus(unsigned int max_cpus)
  31 {
  32         void __iomem *p;
  33         u32 bar;
  34
  35         /* let APMU code install data related to shmobile_boot_vector */
  36         shmobile_smp_apmu_prepare_cpus(max_cpus);
  37
  38         /* RAM for jump stub, because BAR requires 256KB aligned address */
  39         p = ioremap_nocache(RAM, shmobile_boot_size);
  40         memcpy_toio(p, shmobile_boot_vector, shmobile_boot_size);
  41         iounmap(p);
  42
  43         /* setup reset vectors */
  44         p = ioremap_nocache(RST, 0x63);
  45         bar = (RAM >> 8) & 0xfffffc00;
  46         writel_relaxed(bar, p + CA15BAR);
  47         writel_relaxed(bar | 0x10, p + CA15BAR);
  48
  49         /* enable clocks to all CPUs */
  50         writel_relaxed((readl_relaxed(p + CA15RESCNT) & ~0x0f) | 0xa5a50000,
  51                        p + CA15RESCNT);
  52         iounmap(p);
  53 }
  54
  55 static int r8a7791_smp_boot_secondary(unsigned int cpu,
  56                                       struct task_struct *idle)
  57 {
  58         /* Error out when hardware debug mode is enabled */
  59         if (rcar_gen2_read_mode_pins() & BIT(21)) {
  60                 pr_warn("Unable to boot CPU%u when MD21 is set\n", cpu);
  61                 return -ENOTSUPP;
  62         }
  63
  64         return shmobile_smp_apmu_boot_secondary(cpu, idle);
  65 }
  66
  67 struct smp_operations r8a7791_smp_ops __initdata = {
  68         .smp_prepare_cpus       = r8a7791_smp_prepare_cpus,
  69         .smp_boot_secondary     = r8a7791_smp_boot_secondary,
  70 #ifdef CONFIG_HOTPLUG_CPU
  71         .cpu_disable            = shmobile_smp_cpu_disable,
  72         .cpu_die                = shmobile_smp_apmu_cpu_die,
  73         .cpu_kill               = shmobile_smp_apmu_cpu_kill,
  74 #endif
  75 };