| Anders Berg | 1d22924e | 2014-05-23 11:08:35 +0200 | [diff] [blame] | 1 | /* |
| 2 | * linux/arch/arm/mach-axxia/platsmp.c |
| 3 | * |
| 4 | * Copyright (C) 2012 LSI Corporation |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/io.h> |
| 13 | #include <linux/smp.h> |
| 14 | #include <linux/of.h> |
| 15 | #include <linux/of_address.h> |
| 16 | #include <asm/cacheflush.h> |
| 17 | |
| 18 | /* Syscon register offsets for releasing cores from reset */ |
| 19 | #define SC_CRIT_WRITE_KEY 0x1000 |
| 20 | #define SC_RST_CPU_HOLD 0x1010 |
| 21 | |
| 22 | /* |
| 23 | * Write the kernel entry point for secondary CPUs to the specified address |
| 24 | */ |
| 25 | static void write_release_addr(u32 release_phys) |
| 26 | { |
| 27 | u32 *virt = (u32 *) phys_to_virt(release_phys); |
| 28 | writel_relaxed(virt_to_phys(secondary_startup), virt); |
| 29 | /* Make sure this store is visible to other CPUs */ |
| 30 | smp_wmb(); |
| 31 | __cpuc_flush_dcache_area(virt, sizeof(u32)); |
| 32 | } |
| 33 | |
| 34 | static int axxia_boot_secondary(unsigned int cpu, struct task_struct *idle) |
| 35 | { |
| 36 | struct device_node *syscon_np; |
| 37 | void __iomem *syscon; |
| 38 | u32 tmp; |
| 39 | |
| 40 | syscon_np = of_find_compatible_node(NULL, NULL, "lsi,axxia-syscon"); |
| 41 | if (!syscon_np) |
| 42 | return -ENOENT; |
| 43 | |
| 44 | syscon = of_iomap(syscon_np, 0); |
| 45 | if (!syscon) |
| 46 | return -ENOMEM; |
| 47 | |
| 48 | tmp = readl(syscon + SC_RST_CPU_HOLD); |
| 49 | writel(0xab, syscon + SC_CRIT_WRITE_KEY); |
| 50 | tmp &= ~(1 << cpu); |
| 51 | writel(tmp, syscon + SC_RST_CPU_HOLD); |
| 52 | |
| 53 | return 0; |
| 54 | } |
| 55 | |
| 56 | static void __init axxia_smp_prepare_cpus(unsigned int max_cpus) |
| 57 | { |
| 58 | int cpu_count = 0; |
| 59 | int cpu; |
| 60 | |
| 61 | /* |
| 62 | * Initialise the present map, which describes the set of CPUs actually |
| 63 | * populated at the present time. |
| 64 | */ |
| 65 | for_each_possible_cpu(cpu) { |
| 66 | struct device_node *np; |
| 67 | u32 release_phys; |
| 68 | |
| 69 | np = of_get_cpu_node(cpu, NULL); |
| 70 | if (!np) |
| 71 | continue; |
| 72 | if (of_property_read_u32(np, "cpu-release-addr", &release_phys)) |
| 73 | continue; |
| 74 | |
| 75 | if (cpu_count < max_cpus) { |
| 76 | set_cpu_present(cpu, true); |
| 77 | cpu_count++; |
| 78 | } |
| 79 | |
| 80 | if (release_phys != 0) |
| 81 | write_release_addr(release_phys); |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | static struct smp_operations axxia_smp_ops __initdata = { |
| 86 | .smp_prepare_cpus = axxia_smp_prepare_cpus, |
| 87 | .smp_boot_secondary = axxia_boot_secondary, |
| 88 | }; |
| 89 | CPU_METHOD_OF_DECLARE(axxia_smp, "lsi,syscon-release", &axxia_smp_ops); |