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 <linux/irqchip/arm-gic.h>
  27 #include <mach/common.h>
  28 #include <asm/cacheflush.h>
  29 #include <asm/smp_plat.h>
  30 #include <mach/sh73a0.h>
  31 #include <asm/smp_scu.h>
  32 #include <asm/smp_twd.h>
  33
  34 #define WUPCR           IOMEM(0xe6151010)
  35 #define SRESCR          IOMEM(0xe6151018)
  36 #define PSTR            IOMEM(0xe6151040)
  37 #define SBAR            IOMEM(0xe6180020)
  38 #define APARMBAREA      IOMEM(0xe6f10020)
  39
  40 #define PSTR_SHUTDOWN_MODE      3
  41
  42 static void __iomem *scu_base_addr(void)
  43 {
  44         return (void __iomem *)0xf0000000;
  45 }
  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 unsigned int __init sh73a0_get_core_count(void)
  56 {
  57         void __iomem *scu_base = scu_base_addr();
  58
  59         return scu_get_core_count(scu_base);
  60 }
  61
  62 static void __cpuinit sh73a0_secondary_init(unsigned int cpu)
  63 {
  64         gic_secondary_init(0);
  65 }
  66
  67 static int __cpuinit sh73a0_boot_secondary(unsigned int cpu, struct task_struct *idle)
  68 {
  69         cpu = cpu_logical_map(cpu);
  70
  71         if (((__raw_readl(PSTR) >> (4 * cpu)) & 3) == 3)
  72                 __raw_writel(1 << cpu, WUPCR);  /* wake up */
  73         else
  74                 __raw_writel(1 << cpu, SRESCR); /* reset */
  75
  76         return 0;
  77 }
  78
  79 static void __init sh73a0_smp_prepare_cpus(unsigned int max_cpus)
  80 {
  81         scu_enable(scu_base_addr());
  82
  83         /* Map the reset vector (in headsmp-sh73a0.S) */
  84         __raw_writel(0, APARMBAREA);      /* 4k */
  85         __raw_writel(__pa(sh73a0_secondary_vector), SBAR);
  86
  87         /* enable cache coherency on booting CPU */
  88         scu_power_mode(scu_base_addr(), SCU_PM_NORMAL);
  89 }
  90
  91 static void __init sh73a0_smp_init_cpus(void)
  92 {
  93         unsigned int ncores = sh73a0_get_core_count();
  94
  95         shmobile_smp_init_cpus(ncores);
  96 }
  97
  98 #ifdef CONFIG_HOTPLUG_CPU
  99 static int sh73a0_cpu_kill(unsigned int cpu)
 100 {
 101
 102         int k;
 103         u32 pstr;
 104
 105         /*
 106          * wait until the power status register confirms the shutdown of the
 107          * offline target
 108          */
 109         for (k = 0; k < 1000; k++) {
 110                 pstr = (__raw_readl(PSTR) >> (4 * cpu)) & 3;
 111                 if (pstr == PSTR_SHUTDOWN_MODE)
 112                         return 1;
 113
 114                 mdelay(1);
 115         }
 116
 117         return 0;
 118 }
 119
 120 static void sh73a0_cpu_die(unsigned int cpu)
 121 {
 122         /* Set power off mode. This takes the CPU out of the MP cluster */
 123         scu_power_mode(scu_base_addr(), SCU_PM_POWEROFF);
 124
 125         /* Enter shutdown mode */
 126         cpu_do_idle();
 127 }
 128 #endif /* CONFIG_HOTPLUG_CPU */
 129
 130 struct smp_operations sh73a0_smp_ops __initdata = {
 131         .smp_init_cpus          = sh73a0_smp_init_cpus,
 132         .smp_prepare_cpus       = sh73a0_smp_prepare_cpus,
 133         .smp_secondary_init     = sh73a0_secondary_init,
 134         .smp_boot_secondary     = sh73a0_boot_secondary,
 135 #ifdef CONFIG_HOTPLUG_CPU
 136         .cpu_kill               = sh73a0_cpu_kill,
 137         .cpu_die                = sh73a0_cpu_die,
 138         .cpu_disable            = shmobile_cpu_disable_any,
 139 #endif
 140 };