diff options
Diffstat (limited to 'arch/arm/mach-axxia/platsmp.c')
-rw-r--r-- | arch/arm/mach-axxia/platsmp.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/arch/arm/mach-axxia/platsmp.c b/arch/arm/mach-axxia/platsmp.c new file mode 100644 index 000000000000..959d4df3d2b6 --- /dev/null +++ b/arch/arm/mach-axxia/platsmp.c @@ -0,0 +1,89 @@ +/* + * linux/arch/arm/mach-axxia/platsmp.c + * + * Copyright (C) 2012 LSI Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/init.h> +#include <linux/io.h> +#include <linux/smp.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <asm/cacheflush.h> + +/* Syscon register offsets for releasing cores from reset */ +#define SC_CRIT_WRITE_KEY 0x1000 +#define SC_RST_CPU_HOLD 0x1010 + +/* + * Write the kernel entry point for secondary CPUs to the specified address + */ +static void write_release_addr(u32 release_phys) +{ + u32 *virt = (u32 *) phys_to_virt(release_phys); + writel_relaxed(virt_to_phys(secondary_startup), virt); + /* Make sure this store is visible to other CPUs */ + smp_wmb(); + __cpuc_flush_dcache_area(virt, sizeof(u32)); +} + +static int axxia_boot_secondary(unsigned int cpu, struct task_struct *idle) +{ + struct device_node *syscon_np; + void __iomem *syscon; + u32 tmp; + + syscon_np = of_find_compatible_node(NULL, NULL, "lsi,axxia-syscon"); + if (!syscon_np) + return -ENOENT; + + syscon = of_iomap(syscon_np, 0); + if (!syscon) + return -ENOMEM; + + tmp = readl(syscon + SC_RST_CPU_HOLD); + writel(0xab, syscon + SC_CRIT_WRITE_KEY); + tmp &= ~(1 << cpu); + writel(tmp, syscon + SC_RST_CPU_HOLD); + + return 0; +} + +static void __init axxia_smp_prepare_cpus(unsigned int max_cpus) +{ + int cpu_count = 0; + int cpu; + + /* + * Initialise the present map, which describes the set of CPUs actually + * populated at the present time. + */ + for_each_possible_cpu(cpu) { + struct device_node *np; + u32 release_phys; + + np = of_get_cpu_node(cpu, NULL); + if (!np) + continue; + if (of_property_read_u32(np, "cpu-release-addr", &release_phys)) + continue; + + if (cpu_count < max_cpus) { + set_cpu_present(cpu, true); + cpu_count++; + } + + if (release_phys != 0) + write_release_addr(release_phys); + } +} + +static struct smp_operations axxia_smp_ops __initdata = { + .smp_prepare_cpus = axxia_smp_prepare_cpus, + .smp_boot_secondary = axxia_boot_secondary, +}; +CPU_METHOD_OF_DECLARE(axxia_smp, "lsi,syscon-release", &axxia_smp_ops); |