Magnus Damm | bd5a875 | 2012-05-16 15:45:25 +0900 | [diff] [blame] | 1 | /* |
| 2 | * SMP support for Emma Mobile EV2 |
| 3 | * |
| 4 | * Copyright (C) 2012 Renesas Solutions Corp. |
| 5 | * Copyright (C) 2012 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/emev2.h> |
| 28 | #include <asm/smp_plat.h> |
| 29 | #include <asm/smp_scu.h> |
| 30 | #include <asm/hardware/gic.h> |
| 31 | #include <asm/cacheflush.h> |
| 32 | |
| 33 | #define EMEV2_SCU_BASE 0x1e000000 |
| 34 | |
| 35 | static DEFINE_SPINLOCK(scu_lock); |
| 36 | static void __iomem *scu_base; |
| 37 | |
| 38 | static void modify_scu_cpu_psr(unsigned long set, unsigned long clr) |
| 39 | { |
| 40 | unsigned long tmp; |
| 41 | |
| 42 | /* we assume this code is running on a different cpu |
| 43 | * than the one that is changing coherency setting */ |
| 44 | spin_lock(&scu_lock); |
| 45 | tmp = readl(scu_base + 8); |
| 46 | tmp &= ~clr; |
| 47 | tmp |= set; |
| 48 | writel(tmp, scu_base + 8); |
| 49 | spin_unlock(&scu_lock); |
| 50 | |
| 51 | } |
| 52 | |
Marc Zyngier | a62580e | 2011-09-08 13:15:22 +0100 | [diff] [blame] | 53 | static unsigned int __init emev2_get_core_count(void) |
Magnus Damm | bd5a875 | 2012-05-16 15:45:25 +0900 | [diff] [blame] | 54 | { |
| 55 | if (!scu_base) { |
| 56 | scu_base = ioremap(EMEV2_SCU_BASE, PAGE_SIZE); |
| 57 | emev2_clock_init(); /* need ioremapped SMU */ |
| 58 | } |
| 59 | |
| 60 | WARN_ON_ONCE(!scu_base); |
| 61 | |
| 62 | return scu_base ? scu_get_core_count(scu_base) : 1; |
| 63 | } |
| 64 | |
Marc Zyngier | a62580e | 2011-09-08 13:15:22 +0100 | [diff] [blame] | 65 | static int emev2_platform_cpu_kill(unsigned int cpu) |
Magnus Damm | bd5a875 | 2012-05-16 15:45:25 +0900 | [diff] [blame] | 66 | { |
| 67 | return 0; /* not supported yet */ |
| 68 | } |
| 69 | |
Marc Zyngier | a62580e | 2011-09-08 13:15:22 +0100 | [diff] [blame] | 70 | static int __maybe_unused emev2_cpu_kill(unsigned int cpu) |
| 71 | { |
| 72 | int k; |
| 73 | |
| 74 | /* this function is running on another CPU than the offline target, |
| 75 | * here we need wait for shutdown code in platform_cpu_die() to |
| 76 | * finish before asking SoC-specific code to power off the CPU core. |
| 77 | */ |
| 78 | for (k = 0; k < 1000; k++) { |
| 79 | if (shmobile_cpu_is_dead(cpu)) |
| 80 | return emev2_platform_cpu_kill(cpu); |
| 81 | mdelay(1); |
| 82 | } |
| 83 | |
| 84 | return 0; |
| 85 | } |
| 86 | |
| 87 | |
| 88 | static void __cpuinit emev2_secondary_init(unsigned int cpu) |
Magnus Damm | bd5a875 | 2012-05-16 15:45:25 +0900 | [diff] [blame] | 89 | { |
| 90 | gic_secondary_init(0); |
| 91 | } |
| 92 | |
Marc Zyngier | a62580e | 2011-09-08 13:15:22 +0100 | [diff] [blame] | 93 | static int __cpuinit emev2_boot_secondary(unsigned int cpu, struct task_struct *idle) |
Magnus Damm | bd5a875 | 2012-05-16 15:45:25 +0900 | [diff] [blame] | 94 | { |
| 95 | cpu = cpu_logical_map(cpu); |
| 96 | |
| 97 | /* enable cache coherency */ |
| 98 | modify_scu_cpu_psr(0, 3 << (cpu * 8)); |
| 99 | |
| 100 | /* Tell ROM loader about our vector (in headsmp.S) */ |
| 101 | emev2_set_boot_vector(__pa(shmobile_secondary_vector)); |
| 102 | |
Stephen Boyd | e91d5d9 | 2012-08-22 20:05:34 +0100 | [diff] [blame] | 103 | gic_raise_softirq(cpumask_of(cpu), 0); |
Magnus Damm | bd5a875 | 2012-05-16 15:45:25 +0900 | [diff] [blame] | 104 | return 0; |
| 105 | } |
| 106 | |
Marc Zyngier | a62580e | 2011-09-08 13:15:22 +0100 | [diff] [blame] | 107 | static void __init emev2_smp_prepare_cpus(unsigned int max_cpus) |
Magnus Damm | bd5a875 | 2012-05-16 15:45:25 +0900 | [diff] [blame] | 108 | { |
| 109 | int cpu = cpu_logical_map(0); |
| 110 | |
| 111 | scu_enable(scu_base); |
| 112 | |
| 113 | /* enable cache coherency on CPU0 */ |
| 114 | modify_scu_cpu_psr(0, 3 << (cpu * 8)); |
| 115 | } |
Marc Zyngier | a62580e | 2011-09-08 13:15:22 +0100 | [diff] [blame] | 116 | |
| 117 | static void __init emev2_smp_init_cpus(void) |
| 118 | { |
| 119 | unsigned int ncores = emev2_get_core_count(); |
| 120 | |
| 121 | shmobile_smp_init_cpus(ncores); |
| 122 | } |
| 123 | |
| 124 | struct smp_operations emev2_smp_ops __initdata = { |
| 125 | .smp_init_cpus = emev2_smp_init_cpus, |
| 126 | .smp_prepare_cpus = emev2_smp_prepare_cpus, |
| 127 | .smp_secondary_init = emev2_secondary_init, |
| 128 | .smp_boot_secondary = emev2_boot_secondary, |
| 129 | #ifdef CONFIG_HOTPLUG_CPU |
| 130 | .cpu_kill = emev2_cpu_kill, |
| 131 | .cpu_die = shmobile_cpu_die, |
| 132 | .cpu_disable = shmobile_cpu_disable, |
| 133 | #endif |
| 134 | }; |