diff options
Diffstat (limited to 'arch/x86_64/kernel/process.c')
| -rw-r--r-- | arch/x86_64/kernel/process.c | 80 |
1 files changed, 76 insertions, 4 deletions
diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c index 761b6d35e33..7577f9d7a75 100644 --- a/arch/x86_64/kernel/process.c +++ b/arch/x86_64/kernel/process.c @@ -8,7 +8,8 @@ * * X86-64 port * Andi Kleen. - * + * + * CPU hotplug support - ashok.raj@intel.com * $Id: process.c,v 1.38 2002/01/15 10:08:03 ak Exp $ */ @@ -18,6 +19,7 @@ #include <stdarg.h> +#include <linux/cpu.h> #include <linux/errno.h> #include <linux/sched.h> #include <linux/kernel.h> @@ -34,6 +36,7 @@ #include <linux/ptrace.h> #include <linux/utsname.h> #include <linux/random.h> +#include <linux/kprobes.h> #include <asm/uaccess.h> #include <asm/pgtable.h> @@ -153,6 +156,29 @@ void cpu_idle_wait(void) } EXPORT_SYMBOL_GPL(cpu_idle_wait); +#ifdef CONFIG_HOTPLUG_CPU +DECLARE_PER_CPU(int, cpu_state); + +#include <asm/nmi.h> +/* We don't actually take CPU down, just spin without interrupts. */ +static inline void play_dead(void) +{ + idle_task_exit(); + wbinvd(); + mb(); + /* Ack it */ + __get_cpu_var(cpu_state) = CPU_DEAD; + + while (1) + safe_halt(); +} +#else +static inline void play_dead(void) +{ + BUG(); +} +#endif /* CONFIG_HOTPLUG_CPU */ + /* * The idle thread. There's no useful work to be * done, so just try to conserve power and have a @@ -173,6 +199,8 @@ void cpu_idle (void) idle = pm_idle; if (!idle) idle = default_idle; + if (cpu_is_offline(smp_processor_id())) + play_dead(); idle(); } @@ -203,7 +231,7 @@ static void mwait_idle(void) } } -void __init select_idle_routine(const struct cpuinfo_x86 *c) +void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) { static int printed; if (cpu_has(c, X86_FEATURE_MWAIT)) { @@ -293,6 +321,14 @@ void exit_thread(void) { struct task_struct *me = current; struct thread_struct *t = &me->thread; + + /* + * Remove function-return probe instances associated with this task + * and put them back on the free list. Do not insert an exit probe for + * this function, it will be disabled by kprobe_flush_task if you do. + */ + kprobe_flush_task(me); + if (me->thread.io_bitmap_ptr) { struct tss_struct *tss = &per_cpu(init_tss, get_cpu()); @@ -312,6 +348,13 @@ void flush_thread(void) struct task_struct *tsk = current; struct thread_info *t = current_thread_info(); + /* + * Remove function-return probe instances associated with this task + * and put them back on the free list. Do not insert an exit probe for + * this function, it will be disabled by kprobe_flush_task if you do. + */ + kprobe_flush_task(tsk); + if (t->flags & _TIF_ABI_PENDING) t->flags ^= (_TIF_ABI_PENDING | _TIF_IA32); @@ -439,6 +482,33 @@ out: } /* + * This function selects if the context switch from prev to next + * has to tweak the TSC disable bit in the cr4. + */ +static inline void disable_tsc(struct task_struct *prev_p, + struct task_struct *next_p) +{ + struct thread_info *prev, *next; + + /* + * gcc should eliminate the ->thread_info dereference if + * has_secure_computing returns 0 at compile time (SECCOMP=n). + */ + prev = prev_p->thread_info; + next = next_p->thread_info; + + if (has_secure_computing(prev) || has_secure_computing(next)) { + /* slow path here */ + if (has_secure_computing(prev) && + !has_secure_computing(next)) { + write_cr4(read_cr4() & ~X86_CR4_TSD); + } else if (!has_secure_computing(prev) && + has_secure_computing(next)) + write_cr4(read_cr4() | X86_CR4_TSD); + } +} + +/* * This special macro can be used to load a debugging register */ #define loaddebug(thread,r) set_debug(thread->debugreg ## r, r) @@ -556,6 +626,8 @@ struct task_struct *__switch_to(struct task_struct *prev_p, struct task_struct * } } + disable_tsc(prev_p, next_p); + return prev_p; } @@ -656,7 +728,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) switch (code) { case ARCH_SET_GS: - if (addr >= TASK_SIZE) + if (addr >= TASK_SIZE_OF(task)) return -EPERM; cpu = get_cpu(); /* handle small bases via the GDT because that's faster to @@ -682,7 +754,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) case ARCH_SET_FS: /* Not strictly needed for fs, but do it for symmetry with gs */ - if (addr >= TASK_SIZE) + if (addr >= TASK_SIZE_OF(task)) return -EPERM; cpu = get_cpu(); /* handle small bases via the GDT because that's faster to |