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/cacheflush.h>
  28 #include <asm/smp_plat.h>
  29 #include <mach/sh73a0.h>
  30 #include <asm/smp_scu.h>
  31 #include <asm/smp_twd.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 #define PSTR_SHUTDOWN_MODE      3
  40
  41 #define SH73A0_SCU_BASE 0xf0000000
  42
  43 #ifdef CONFIG_HAVE_ARM_TWD
  44 static DEFINE_TWD_LOCAL_TIMER(twd_local_timer, SH73A0_SCU_BASE + 0x600, 29);
  45 void __init sh73a0_register_twd(void)
  46 {
  47         twd_local_timer_register(&twd_local_timer);
  48 }
  49 #endif
  50
  51 static int __cpuinit sh73a0_boot_secondary(unsigned int cpu, struct task_struct *idle)
  52 {
  53         cpu = cpu_logical_map(cpu);
  54
  55         if (((__raw_readl(PSTR) >> (4 * cpu)) & 3) == 3)
  56                 __raw_writel(1 << cpu, WUPCR);  /* wake up */
  57         else
  58                 __raw_writel(1 << cpu, SRESCR); /* reset */
  59
  60         return 0;
  61 }
  62
  63 static void __init sh73a0_smp_prepare_cpus(unsigned int max_cpus)
  64 {
  65         scu_enable(shmobile_scu_base);
  66
  67         /* Map the reset vector (in headsmp-scu.S) */
  68         __raw_writel(0, APARMBAREA);      /* 4k */
  69         __raw_writel(__pa(shmobile_secondary_vector_scu), SBAR);
  70
  71         /* enable cache coherency on booting CPU */
  72         scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL);
  73 }
  74
  75 static void __init sh73a0_smp_init_cpus(void)
  76 {
  77         /* setup sh73a0 specific SCU base */
  78         shmobile_scu_base = IOMEM(SH73A0_SCU_BASE);
  79
  80         shmobile_smp_init_cpus(scu_get_core_count(shmobile_scu_base));
  81 }
  82
  83 #ifdef CONFIG_HOTPLUG_CPU
  84 static int sh73a0_cpu_kill(unsigned int cpu)
  85 {
  86
  87         int k;
  88         u32 pstr;
  89
  90         /*
  91          * wait until the power status register confirms the shutdown of the
  92          * offline target
  93          */
  94         for (k = 0; k < 1000; k++) {
  95                 pstr = (__raw_readl(PSTR) >> (4 * cpu)) & 3;
  96                 if (pstr == PSTR_SHUTDOWN_MODE)
  97                         return 1;
  98
  99                 mdelay(1);
 100         }
 101
 102         return 0;
 103 }
 104
 105 static void sh73a0_cpu_die(unsigned int cpu)
 106 {
 107         /* Set power off mode. This takes the CPU out of the MP cluster */
 108         scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF);
 109
 110         /* Enter shutdown mode */
 111         cpu_do_idle();
 112 }
 113
 114 static int sh73a0_cpu_disable(unsigned int cpu)
 115 {
 116         return 0; /* CPU0 and CPU1 supported */
 117 }
 118 #endif /* CONFIG_HOTPLUG_CPU */
 119
 120 struct smp_operations sh73a0_smp_ops __initdata = {
 121         .smp_init_cpus          = sh73a0_smp_init_cpus,
 122         .smp_prepare_cpus       = sh73a0_smp_prepare_cpus,
 123         .smp_boot_secondary     = sh73a0_boot_secondary,
 124 #ifdef CONFIG_HOTPLUG_CPU
 125         .cpu_kill               = sh73a0_cpu_kill,
 126         .cpu_die                = sh73a0_cpu_die,
 127         .cpu_disable            = sh73a0_cpu_disable,
 128 #endif
 129 };