arch/arm/mach-shmobile/smp-sh73a0.c

   1 /*
   2  * SMP support for R-Mobile / SH-Mobile - sh73a0 portion
   3  *
   4  * Copyright (C) 2010  Magnus Damm
   5  * Copyright (C) 2010  Takashi Yoshii
   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  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  */
  20 #include <linux/kernel.h>
  21 #include <linux/init.h>
  22 #include <linux/smp.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/io.h>
  25 #include <linux/delay.h>
  26 #include <mach/common.h>
  27 #include <asm/smp_plat.h>
  28 #include <mach/sh73a0.h>
  29 #include <asm/smp_scu.h>
  30 #include <asm/smp_twd.h>
  31 #include <asm/hardware/gic.h>
  32
  33 #define WUPCR           IOMEM(0xe6151010)
  34 #define SRESCR          IOMEM(0xe6151018)
  35 #define PSTR            IOMEM(0xe6151040)
  36 #define SBAR            IOMEM(0xe6180020)
  37 #define APARMBAREA      IOMEM(0xe6f10020)
  38
  39 static void __iomem *scu_base_addr(void)
  40 {
  41         return (void __iomem *)0xf0000000;
  42 }
  43
  44 static DEFINE_SPINLOCK(scu_lock);
  45 static unsigned long tmp;
  46
  47 #ifdef CONFIG_HAVE_ARM_TWD
  48 static DEFINE_TWD_LOCAL_TIMER(twd_local_timer, 0xf0000600, 29);
  49 void __init sh73a0_register_twd(void)
  50 {
  51         twd_local_timer_register(&twd_local_timer);
  52 }
  53 #endif
  54
  55 static void modify_scu_cpu_psr(unsigned long set, unsigned long clr)
  56 {
  57         void __iomem *scu_base = scu_base_addr();
  58
  59         spin_lock(&scu_lock);
  60         tmp = __raw_readl(scu_base + 8);
  61         tmp &= ~clr;
  62         tmp |= set;
  63         spin_unlock(&scu_lock);
  64
  65         /* disable cache coherency after releasing the lock */
  66         __raw_writel(tmp, scu_base + 8);
  67 }
  68
  69 static unsigned int __init sh73a0_get_core_count(void)
  70 {
  71         void __iomem *scu_base = scu_base_addr();
  72
  73         return scu_get_core_count(scu_base);
  74 }
  75
  76 static void __cpuinit sh73a0_secondary_init(unsigned int cpu)
  77 {
  78         gic_secondary_init(0);
  79 }
  80
  81 static int __cpuinit sh73a0_boot_secondary(unsigned int cpu, struct task_struct *idle)
  82 {
  83         cpu = cpu_logical_map(cpu);
  84
  85         /* enable cache coherency */
  86         modify_scu_cpu_psr(0, 3 << (cpu * 8));
  87
  88         if (((__raw_readl(PSTR) >> (4 * cpu)) & 3) == 3)
  89                 __raw_writel(1 << cpu, WUPCR);  /* wake up */
  90         else
  91                 __raw_writel(1 << cpu, SRESCR); /* reset */
  92
  93         return 0;
  94 }
  95
  96 static void __init sh73a0_smp_prepare_cpus(unsigned int max_cpus)
  97 {
  98         int cpu = cpu_logical_map(0);
  99
 100         scu_enable(scu_base_addr());
 101
 102         /* Map the reset vector (in headsmp.S) */
 103         __raw_writel(0, APARMBAREA);      /* 4k */
 104         __raw_writel(__pa(shmobile_secondary_vector), SBAR);
 105
 106         /* enable cache coherency on CPU0 */
 107         modify_scu_cpu_psr(0, 3 << (cpu * 8));
 108 }
 109
 110 static void __init sh73a0_smp_init_cpus(void)
 111 {
 112         unsigned int ncores = sh73a0_get_core_count();
 113
 114         shmobile_smp_init_cpus(ncores);
 115 }
 116
 117 static int __maybe_unused sh73a0_cpu_kill(unsigned int cpu)
 118 {
 119         int k;
 120
 121         /* this function is running on another CPU than the offline target,
 122          * here we need wait for shutdown code in platform_cpu_die() to
 123          * finish before asking SoC-specific code to power off the CPU core.
 124          */
 125         for (k = 0; k < 1000; k++) {
 126                 if (shmobile_cpu_is_dead(cpu))
 127                         return 1;
 128
 129                 mdelay(1);
 130         }
 131
 132         return 0;
 133 }
 134
 135
 136 struct smp_operations sh73a0_smp_ops __initdata = {
 137         .smp_init_cpus          = sh73a0_smp_init_cpus,
 138         .smp_prepare_cpus       = sh73a0_smp_prepare_cpus,
 139         .smp_secondary_init     = sh73a0_secondary_init,
 140         .smp_boot_secondary     = sh73a0_boot_secondary,
 141 #ifdef CONFIG_HOTPLUG_CPU
 142         .cpu_kill               = sh73a0_cpu_kill,
 143         .cpu_die                = shmobile_cpu_die,
 144         .cpu_disable            = shmobile_cpu_disable,
 145 #endif
 146 };