arch/arm/mach-socfpga/platsmp.c

   1 /*
   2  * Copyright 2010-2011 Calxeda, Inc.
   3  * Copyright 2012 Pavel Machek <pavel@denx.de>
   4  * Based on platsmp.c, Copyright (C) 2002 ARM Ltd.
   5  * Copyright (C) 2012 Altera Corporation
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms and conditions of the GNU General Public License,
   9  * version 2, as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along with
  17  * this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #include <linux/delay.h>
  20 #include <linux/init.h>
  21 #include <linux/smp.h>
  22 #include <linux/io.h>
  23 #include <linux/of.h>
  24 #include <linux/of_address.h>
  25
  26 #include <asm/cacheflush.h>
  27 #include <asm/smp_scu.h>
  28 #include <asm/smp_plat.h>
  29
  30 #include "core.h"
  31
  32 static int socfpga_boot_secondary(unsigned int cpu, struct task_struct *idle)
  33 {
  34         int trampoline_size = &secondary_trampoline_end - &secondary_trampoline;
  35
  36         if (socfpga_cpu1start_addr) {
  37                 /* This will put CPU #1 into reset. */
  38                 writel(RSTMGR_MPUMODRST_CPU1,
  39                        rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST);
  40
  41                 memcpy(phys_to_virt(0), &secondary_trampoline, trampoline_size);
  42
  43                 writel(__pa_symbol(secondary_startup),
  44                        sys_manager_base_addr + (socfpga_cpu1start_addr & 0x000000ff));
  45
  46                 flush_cache_all();
  47                 smp_wmb();
  48                 outer_clean_range(0, trampoline_size);
  49
  50                 /* This will release CPU #1 out of reset. */
  51                 writel(0, rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST);
  52         }
  53
  54         return 0;
  55 }
  56
  57 static int socfpga_a10_boot_secondary(unsigned int cpu, struct task_struct *idle)
  58 {
  59         int trampoline_size = &secondary_trampoline_end - &secondary_trampoline;
  60
  61         if (socfpga_cpu1start_addr) {
  62                 writel(RSTMGR_MPUMODRST_CPU1, rst_manager_base_addr +
  63                        SOCFPGA_A10_RSTMGR_MODMPURST);
  64                 memcpy(phys_to_virt(0), &secondary_trampoline, trampoline_size);
  65
  66                 writel(__pa_symbol(secondary_startup),
  67                        sys_manager_base_addr + (socfpga_cpu1start_addr & 0x00000fff));
  68
  69                 flush_cache_all();
  70                 smp_wmb();
  71                 outer_clean_range(0, trampoline_size);
  72
  73                 /* This will release CPU #1 out of reset. */
  74                 writel(0, rst_manager_base_addr + SOCFPGA_A10_RSTMGR_MODMPURST);
  75         }
  76
  77         return 0;
  78 }
  79
  80 static void __init socfpga_smp_prepare_cpus(unsigned int max_cpus)
  81 {
  82         struct device_node *np;
  83         void __iomem *socfpga_scu_base_addr;
  84
  85         np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
  86         if (!np) {
  87                 pr_err("%s: missing scu\n", __func__);
  88                 return;
  89         }
  90
  91         socfpga_scu_base_addr = of_iomap(np, 0);
  92         if (!socfpga_scu_base_addr)
  93                 return;
  94         scu_enable(socfpga_scu_base_addr);
  95 }
  96
  97 #ifdef CONFIG_HOTPLUG_CPU
  98 /*
  99  * platform-specific code to shutdown a CPU
 100  *
 101  * Called with IRQs disabled
 102  */
 103 static void socfpga_cpu_die(unsigned int cpu)
 104 {
 105         /* Do WFI. If we wake up early, go back into WFI */
 106         while (1)
 107                 cpu_do_idle();
 108 }
 109
 110 /*
 111  * We need a dummy function so that platform_can_cpu_hotplug() knows
 112  * we support CPU hotplug. However, the function does not need to do
 113  * anything, because CPUs going offline just do WFI. We could reset
 114  * the CPUs but it would increase power consumption.
 115  */
 116 static int socfpga_cpu_kill(unsigned int cpu)
 117 {
 118         return 1;
 119 }
 120 #endif
 121
 122 static const struct smp_operations socfpga_smp_ops __initconst = {
 123         .smp_prepare_cpus       = socfpga_smp_prepare_cpus,
 124         .smp_boot_secondary     = socfpga_boot_secondary,
 125 #ifdef CONFIG_HOTPLUG_CPU
 126         .cpu_die                = socfpga_cpu_die,
 127         .cpu_kill               = socfpga_cpu_kill,
 128 #endif
 129 };
 130
 131 static const struct smp_operations socfpga_a10_smp_ops __initconst = {
 132         .smp_prepare_cpus       = socfpga_smp_prepare_cpus,
 133         .smp_boot_secondary     = socfpga_a10_boot_secondary,
 134 #ifdef CONFIG_HOTPLUG_CPU
 135         .cpu_die                = socfpga_cpu_die,
 136         .cpu_kill               = socfpga_cpu_kill,
 137 #endif
 138 };
 139
 140 CPU_METHOD_OF_DECLARE(socfpga_smp, "altr,socfpga-smp", &socfpga_smp_ops);
 141 CPU_METHOD_OF_DECLARE(socfpga_a10_smp, "altr,socfpga-a10-smp", &socfpga_a10_smp_ops);