diff options
Diffstat (limited to 'arch/i386/kernel/smpcommon.c')
-rw-r--r-- | arch/i386/kernel/smpcommon.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/arch/i386/kernel/smpcommon.c b/arch/i386/kernel/smpcommon.c new file mode 100644 index 0000000..1868ae1 --- /dev/null +++ b/arch/i386/kernel/smpcommon.c @@ -0,0 +1,79 @@ +/* + * SMP stuff which is common to all sub-architectures. + */ +#include <linux/module.h> +#include <asm/smp.h> + +DEFINE_PER_CPU(unsigned long, this_cpu_off); +EXPORT_PER_CPU_SYMBOL(this_cpu_off); + +/* Initialize the CPU's GDT. This is either the boot CPU doing itself + (still using the master per-cpu area), or a CPU doing it for a + secondary which will soon come up. */ +__cpuinit void init_gdt(int cpu) +{ + struct desc_struct *gdt = get_cpu_gdt_table(cpu); + + pack_descriptor((u32 *)&gdt[GDT_ENTRY_PERCPU].a, + (u32 *)&gdt[GDT_ENTRY_PERCPU].b, + __per_cpu_offset[cpu], 0xFFFFF, + 0x80 | DESCTYPE_S | 0x2, 0x8); + + per_cpu(this_cpu_off, cpu) = __per_cpu_offset[cpu]; + per_cpu(cpu_number, cpu) = cpu; +} + + +/** + * smp_call_function(): Run a function on all other CPUs. + * @func: The function to run. This must be fast and non-blocking. + * @info: An arbitrary pointer to pass to the function. + * @nonatomic: Unused. + * @wait: If true, wait (atomically) until function has completed on other CPUs. + * + * Returns 0 on success, else a negative status code. + * + * If @wait is true, then returns once @func has returned; otherwise + * it returns just before the target cpu calls @func. + * + * You must not call this function with disabled interrupts or from a + * hardware interrupt handler or from a bottom half handler. + */ +int smp_call_function(void (*func) (void *info), void *info, int nonatomic, + int wait) +{ + return smp_call_function_mask(cpu_online_map, func, info, wait); +} +EXPORT_SYMBOL(smp_call_function); + +/** + * smp_call_function_single - Run a function on another CPU + * @cpu: The target CPU. Cannot be the calling CPU. + * @func: The function to run. This must be fast and non-blocking. + * @info: An arbitrary pointer to pass to the function. + * @nonatomic: Unused. + * @wait: If true, wait until function has completed on other CPUs. + * + * Returns 0 on success, else a negative status code. + * + * If @wait is true, then returns once @func has returned; otherwise + * it returns just before the target cpu calls @func. + */ +int smp_call_function_single(int cpu, void (*func) (void *info), void *info, + int nonatomic, int wait) +{ + /* prevent preemption and reschedule on another processor */ + int ret; + int me = get_cpu(); + if (cpu == me) { + WARN_ON(1); + put_cpu(); + return -EBUSY; + } + + ret = smp_call_function_mask(cpumask_of_cpu(cpu), func, info, wait); + + put_cpu(); + return ret; +} +EXPORT_SYMBOL(smp_call_function_single); |