2 * Symmetric Multi Processing (SMP) support for Armada XP
4 * Copyright (C) 2012 Marvell
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>
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.
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
20 #include <linux/init.h>
21 #include <linux/smp.h>
22 #include <linux/clk.h>
24 #include <asm/cacheflush.h>
25 #include <asm/smp_plat.h>
27 #include "armada-370-xp.h"
29 #include "coherency.h"
31 void __init set_secondary_cpus_clock(void)
35 struct clk *cpu_clk = NULL;
36 struct device_node *np = NULL;
38 thiscpu = smp_processor_id();
39 for_each_node_by_type(np, "cpu") {
43 err = of_property_read_u32(np, "reg", &cpu);
48 cpu_clk = of_clk_get(np, 0);
52 if (WARN_ON(IS_ERR(cpu_clk)))
54 clk_prepare_enable(cpu_clk);
55 rate = clk_get_rate(cpu_clk);
57 /* set all the other CPU clk to the same rate than the boot CPU */
58 for_each_node_by_type(np, "cpu") {
62 err = of_property_read_u32(np, "reg", &cpu);
67 cpu_clk = of_clk_get(np, 0);
68 clk_set_rate(cpu_clk, rate);
73 static void __cpuinit armada_xp_secondary_init(unsigned int cpu)
75 armada_xp_mpic_smp_cpu_init();
78 static int __cpuinit armada_xp_boot_secondary(unsigned int cpu,
79 struct task_struct *idle)
81 pr_info("Booting CPU %d\n", cpu);
83 armada_xp_boot_cpu(cpu, armada_xp_secondary_startup);
88 static void __init armada_xp_smp_init_cpus(void)
90 unsigned int i, ncores;
91 ncores = coherency_get_cpu_count();
93 /* Limit possible CPUs to defconfig */
94 if (ncores > nr_cpu_ids) {
95 pr_warn("SMP: %d CPUs physically present. Only %d configured.",
97 pr_warn("Clipping CPU count to %d\n", nr_cpu_ids);
101 for (i = 0; i < ncores; i++)
102 set_cpu_possible(i, true);
104 set_smp_cross_call(armada_mpic_send_doorbell);
107 void __init armada_xp_smp_prepare_cpus(unsigned int max_cpus)
109 set_secondary_cpus_clock();
111 set_cpu_coherent(cpu_logical_map(smp_processor_id()), 0);
114 struct smp_operations armada_xp_smp_ops __initdata = {
115 .smp_init_cpus = armada_xp_smp_init_cpus,
116 .smp_prepare_cpus = armada_xp_smp_prepare_cpus,
117 .smp_secondary_init = armada_xp_secondary_init,
118 .smp_boot_secondary = armada_xp_boot_secondary,
119 #ifdef CONFIG_HOTPLUG_CPU
120 .cpu_die = armada_xp_cpu_die,