arch/arm/mach-shmobile/smp-r8a7779.c

   1 /*
   2  * SMP support for R-Mobile / SH-Mobile - r8a7779 portion
   3  *
   4  * Copyright (C) 2011  Renesas Solutions Corp.
   5  * Copyright (C) 2011  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  * 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 <mach/r8a7779.h>
  28 #include <asm/cacheflush.h>
  29 #include <asm/smp_plat.h>
  30 #include <asm/smp_scu.h>
  31 #include <asm/smp_twd.h>
  32
  33 #define AVECR IOMEM(0xfe700040)
  34 #define R8A7779_SCU_BASE 0xf0000000
  35
  36 static struct r8a7779_pm_ch r8a7779_ch_cpu1 = {
  37         .chan_offs = 0x40, /* PWRSR0 .. PWRER0 */
  38         .chan_bit = 1, /* ARM1 */
  39         .isr_bit = 1, /* ARM1 */
  40 };
  41
  42 static struct r8a7779_pm_ch r8a7779_ch_cpu2 = {
  43         .chan_offs = 0x40, /* PWRSR0 .. PWRER0 */
  44         .chan_bit = 2, /* ARM2 */
  45         .isr_bit = 2, /* ARM2 */
  46 };
  47
  48 static struct r8a7779_pm_ch r8a7779_ch_cpu3 = {
  49         .chan_offs = 0x40, /* PWRSR0 .. PWRER0 */
  50         .chan_bit = 3, /* ARM3 */
  51         .isr_bit = 3, /* ARM3 */
  52 };
  53
  54 static struct r8a7779_pm_ch *r8a7779_ch_cpu[4] = {
  55         [1] = &r8a7779_ch_cpu1,
  56         [2] = &r8a7779_ch_cpu2,
  57         [3] = &r8a7779_ch_cpu3,
  58 };
  59
  60 #ifdef CONFIG_HAVE_ARM_TWD
  61 static DEFINE_TWD_LOCAL_TIMER(twd_local_timer, R8A7779_SCU_BASE + 0x600, 29);
  62 void __init r8a7779_register_twd(void)
  63 {
  64         twd_local_timer_register(&twd_local_timer);
  65 }
  66 #endif
  67
  68 static int r8a7779_platform_cpu_kill(unsigned int cpu)
  69 {
  70         struct r8a7779_pm_ch *ch = NULL;
  71         int ret = -EIO;
  72
  73         cpu = cpu_logical_map(cpu);
  74
  75         if (cpu < ARRAY_SIZE(r8a7779_ch_cpu))
  76                 ch = r8a7779_ch_cpu[cpu];
  77
  78         if (ch)
  79                 ret = r8a7779_sysc_power_down(ch);
  80
  81         return ret ? ret : 1;
  82 }
  83
  84 static int r8a7779_boot_secondary(unsigned int cpu, struct task_struct *idle)
  85 {
  86         struct r8a7779_pm_ch *ch = NULL;
  87         int ret = -EIO;
  88
  89         cpu = cpu_logical_map(cpu);
  90
  91         if (cpu < ARRAY_SIZE(r8a7779_ch_cpu))
  92                 ch = r8a7779_ch_cpu[cpu];
  93
  94         if (ch)
  95                 ret = r8a7779_sysc_power_up(ch);
  96
  97         return ret;
  98 }
  99
 100 static void __init r8a7779_smp_prepare_cpus(unsigned int max_cpus)
 101 {
 102         scu_enable(shmobile_scu_base);
 103
 104         /* Map the reset vector (in headsmp-scu.S, headsmp.S) */
 105         __raw_writel(__pa(shmobile_boot_vector), AVECR);
 106         shmobile_boot_fn = virt_to_phys(shmobile_boot_scu);
 107         shmobile_boot_arg = (unsigned long)shmobile_scu_base;
 108
 109         /* enable cache coherency on booting CPU */
 110         scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL);
 111
 112         r8a7779_pm_init();
 113
 114         /* power off secondary CPUs */
 115         r8a7779_platform_cpu_kill(1);
 116         r8a7779_platform_cpu_kill(2);
 117         r8a7779_platform_cpu_kill(3);
 118 }
 119
 120 static void __init r8a7779_smp_init_cpus(void)
 121 {
 122         /* setup r8a7779 specific SCU base */
 123         shmobile_scu_base = IOMEM(R8A7779_SCU_BASE);
 124
 125         shmobile_smp_init_cpus(scu_get_core_count(shmobile_scu_base));
 126 }
 127
 128 #ifdef CONFIG_HOTPLUG_CPU
 129 static int r8a7779_scu_psr_core_disabled(int cpu)
 130 {
 131         unsigned long mask = 3 << (cpu * 8);
 132
 133         if ((__raw_readl(shmobile_scu_base + 8) & mask) == mask)
 134                 return 1;
 135
 136         return 0;
 137 }
 138
 139 static int r8a7779_cpu_kill(unsigned int cpu)
 140 {
 141         int k;
 142
 143         /* this function is running on another CPU than the offline target,
 144          * here we need wait for shutdown code in platform_cpu_die() to
 145          * finish before asking SoC-specific code to power off the CPU core.
 146          */
 147         for (k = 0; k < 1000; k++) {
 148                 if (r8a7779_scu_psr_core_disabled(cpu))
 149                         return r8a7779_platform_cpu_kill(cpu);
 150
 151                 mdelay(1);
 152         }
 153
 154         return 0;
 155 }
 156
 157 static void r8a7779_cpu_die(unsigned int cpu)
 158 {
 159         dsb();
 160         flush_cache_all();
 161
 162         /* disable cache coherency */
 163         scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF);
 164
 165         /* Endless loop until power off from r8a7779_cpu_kill() */
 166         while (1)
 167                 cpu_do_idle();
 168 }
 169
 170 static int r8a7779_cpu_disable(unsigned int cpu)
 171 {
 172         /* only CPU1->3 have power domains, do not allow hotplug of CPU0 */
 173         return cpu == 0 ? -EPERM : 0;
 174 }
 175 #endif /* CONFIG_HOTPLUG_CPU */
 176
 177 struct smp_operations r8a7779_smp_ops  __initdata = {
 178         .smp_init_cpus          = r8a7779_smp_init_cpus,
 179         .smp_prepare_cpus       = r8a7779_smp_prepare_cpus,
 180         .smp_boot_secondary     = r8a7779_boot_secondary,
 181 #ifdef CONFIG_HOTPLUG_CPU
 182         .cpu_kill               = r8a7779_cpu_kill,
 183         .cpu_die                = r8a7779_cpu_die,
 184         .cpu_disable            = r8a7779_cpu_disable,
 185 #endif
 186 };