arch/arm/mach-mvebu/platsmp.c

   1 /*
   2  * Symmetric Multi Processing (SMP) support for Armada XP
   3  *
   4  * Copyright (C) 2012 Marvell
   5  *
   6  * Lior Amsalem <alior@marvell.com>
   7  * Yehuda Yitschak <yehuday@marvell.com>
   8  * Gregory CLEMENT <gregory.clement@free-electrons.com>
   9  * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  10  *
  11  * This file is licensed under the terms of the GNU General Public
  12  * License version 2.  This program is licensed "as is" without any
  13  * warranty of any kind, whether express or implied.
  14  *
  15  * The Armada XP SoC has 4 ARMv7 PJ4B CPUs running in full HW coherency
  16  * This file implements the routines for preparing the SMP infrastructure
  17  * and waking up the secondary CPUs
  18  */
  19
  20 #include <linux/init.h>
  21 #include <linux/smp.h>
  22 #include <linux/clk.h>
  23 #include <linux/of.h>
  24 #include <linux/of_address.h>
  25 #include <linux/mbus.h>
  26 #include <asm/cacheflush.h>
  27 #include <asm/smp_plat.h>
  28 #include "common.h"
  29 #include "armada-370-xp.h"
  30 #include "pmsu.h"
  31 #include "coherency.h"
  32
  33 #define AXP_BOOTROM_BASE 0xfff00000
  34 #define AXP_BOOTROM_SIZE 0x100000
  35
  36 static struct clk *__init get_cpu_clk(int cpu)
  37 {
  38         struct clk *cpu_clk;
  39         struct device_node *np = of_get_cpu_node(cpu, NULL);
  40
  41         if (WARN(!np, "missing cpu node\n"))
  42                 return NULL;
  43         cpu_clk = of_clk_get(np, 0);
  44         if (WARN_ON(IS_ERR(cpu_clk)))
  45                 return NULL;
  46         return cpu_clk;
  47 }
  48
  49 static void __init set_secondary_cpus_clock(void)
  50 {
  51         int thiscpu, cpu;
  52         unsigned long rate;
  53         struct clk *cpu_clk;
  54
  55         thiscpu = smp_processor_id();
  56         cpu_clk = get_cpu_clk(thiscpu);
  57         if (!cpu_clk)
  58                 return;
  59         clk_prepare_enable(cpu_clk);
  60         rate = clk_get_rate(cpu_clk);
  61
  62         /* set all the other CPU clk to the same rate than the boot CPU */
  63         for_each_possible_cpu(cpu) {
  64                 if (cpu == thiscpu)
  65                         continue;
  66                 cpu_clk = get_cpu_clk(cpu);
  67                 if (!cpu_clk)
  68                         return;
  69                 clk_set_rate(cpu_clk, rate);
  70         }
  71 }
  72
  73 static void armada_xp_secondary_init(unsigned int cpu)
  74 {
  75         armada_xp_mpic_smp_cpu_init();
  76 }
  77
  78 static int armada_xp_boot_secondary(unsigned int cpu, struct task_struct *idle)
  79 {
  80         pr_info("Booting CPU %d\n", cpu);
  81
  82         armada_xp_boot_cpu(cpu, armada_xp_secondary_startup);
  83
  84         return 0;
  85 }
  86
  87 static void __init armada_xp_smp_init_cpus(void)
  88 {
  89         unsigned int ncores = num_possible_cpus();
  90
  91         if (ncores == 0 || ncores > ARMADA_XP_MAX_CPUS)
  92                 panic("Invalid number of CPUs in DT\n");
  93
  94         set_smp_cross_call(armada_mpic_send_doorbell);
  95 }
  96
  97 static void __init armada_xp_smp_prepare_cpus(unsigned int max_cpus)
  98 {
  99         struct device_node *node;
 100         struct resource res;
 101         int err;
 102
 103         set_secondary_cpus_clock();
 104         flush_cache_all();
 105         set_cpu_coherent(cpu_logical_map(smp_processor_id()), 0);
 106
 107         /*
 108          * In order to boot the secondary CPUs we need to ensure
 109          * the bootROM is mapped at the correct address.
 110          */
 111         node = of_find_compatible_node(NULL, NULL, "marvell,bootrom");
 112         if (!node)
 113                 panic("Cannot find 'marvell,bootrom' compatible node");
 114
 115         err = of_address_to_resource(node, 0, &res);
 116         if (err < 0)
 117                 panic("Cannot get 'bootrom' node address");
 118
 119         if (res.start != AXP_BOOTROM_BASE ||
 120             resource_size(&res) != AXP_BOOTROM_SIZE)
 121                 panic("The address for the BootROM is incorrect");
 122 }
 123
 124 struct smp_operations armada_xp_smp_ops __initdata = {
 125         .smp_init_cpus          = armada_xp_smp_init_cpus,
 126         .smp_prepare_cpus       = armada_xp_smp_prepare_cpus,
 127         .smp_secondary_init     = armada_xp_secondary_init,
 128         .smp_boot_secondary     = armada_xp_boot_secondary,
 129 #ifdef CONFIG_HOTPLUG_CPU
 130         .cpu_die                = armada_xp_cpu_die,
 131 #endif
 132 };