diff options
| author | Sundar Iyer <sundar.iyer@stericsson.com> | 2010-09-15 10:45:51 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-09-19 12:14:34 +0100 |
| commit | 9d704c04ff8ae61b60935d67ce334b18fc70f1b2 (patch) | |
| tree | d386810c2e9d3a91660871835657376850868389 /arch/arm/mach-ux500 | |
| parent | f0a7a98d1d400e2a5fd9a63ed56d30d30f2864cb (diff) | |
ARM: 6391/1: ux500: add CPU hotplug support
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Sundar Iyer <sundar.iyer@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-ux500')
| -rw-r--r-- | arch/arm/mach-ux500/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/mach-ux500/hotplug.c | 75 | ||||
| -rw-r--r-- | arch/arm/mach-ux500/platsmp.c | 2 |
3 files changed, 78 insertions, 0 deletions
diff --git a/arch/arm/mach-ux500/Makefile b/arch/arm/mach-ux500/Makefile index 00973186439..bb3e74e6ab3 100644 --- a/arch/arm/mach-ux500/Makefile +++ b/arch/arm/mach-ux500/Makefile @@ -8,4 +8,5 @@ obj-$(CONFIG_UX500_SOC_DB8500) += cpu-db8500.o devices-db8500.o prcmu.o obj-$(CONFIG_MACH_U8500_MOP) += board-mop500.o board-mop500-sdi.o obj-$(CONFIG_MACH_U5500) += board-u5500.o obj-$(CONFIG_SMP) += platsmp.o headsmp.o +obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o diff --git a/arch/arm/mach-ux500/hotplug.c b/arch/arm/mach-ux500/hotplug.c new file mode 100644 index 00000000000..b782a03024b --- /dev/null +++ b/arch/arm/mach-ux500/hotplug.c @@ -0,0 +1,75 @@ +/* + * Copyright (C) STMicroelectronics 2009 + * Copyright (C) ST-Ericsson SA 2010 + * + * License Terms: GNU General Public License v2 + * Based on ARM realview platform + * + * Author: Sundar Iyer <sundar.iyer@stericsson.com> + * + */ +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/smp.h> +#include <linux/completion.h> + +#include <asm/cacheflush.h> + +extern volatile int pen_release; + +static DECLARE_COMPLETION(cpu_killed); + +static inline void platform_do_lowpower(unsigned int cpu) +{ + flush_cache_all(); + + /* we put the platform to just WFI */ + for (;;) { + __asm__ __volatile__("dsb\n\t" "wfi\n\t" + : : : "memory"); + if (pen_release == cpu) { + /* + * OK, proper wakeup, we're done + */ + break; + } + } +} + +int platform_cpu_kill(unsigned int cpu) +{ + return wait_for_completion_timeout(&cpu_killed, 5000); +} + +/* + * platform-specific code to shutdown a CPU + * + * Called with IRQs disabled + */ +void platform_cpu_die(unsigned int cpu) +{ +#ifdef DEBUG + unsigned int this_cpu = hard_smp_processor_id(); + + if (cpu != this_cpu) { + printk(KERN_CRIT "Eek! platform_cpu_die running on %u, should be %u\n", + this_cpu, cpu); + BUG(); + } +#endif + + printk(KERN_NOTICE "CPU%u: shutdown\n", cpu); + complete(&cpu_killed); + + /* directly enter low power state, skipping secure registers */ + platform_do_lowpower(cpu); +} + +int platform_cpu_disable(unsigned int cpu) +{ + /* + * we don't allow CPU 0 to be shutdown (it is still too special + * e.g. clock tick interrupts) + */ + return cpu == 0 ? -EPERM : 0; +} diff --git a/arch/arm/mach-ux500/platsmp.c b/arch/arm/mach-ux500/platsmp.c index 438ef16aec9..9e4c678de78 100644 --- a/arch/arm/mach-ux500/platsmp.c +++ b/arch/arm/mach-ux500/platsmp.c @@ -78,6 +78,8 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle) __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release)); outer_clean_range(__pa(&pen_release), __pa(&pen_release) + 1); + smp_cross_call(cpumask_of(cpu)); + timeout = jiffies + (1 * HZ); while (time_before(jiffies, timeout)) { if (pen_release == -1) |