diff options
| author | Paul Mackerras <paulus@samba.org> | 2005-09-10 21:13:13 +1000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-10 10:15:11 -0700 |
| commit | 31139971b3dc9fbb2e8a8572fb81e6e8470f363a (patch) | |
| tree | 644fc6833fe6e18d00dbc8b6b281f77e7b923d35 /arch/ppc/kernel/idle.c | |
| parent | bb0bb3b6596cdb08adb0b72453cc67d48e139c2c (diff) | |
[PATCH] ppc32: support hotplug cpu on powermacs
This allows cpus to be off-lined on 32-bit SMP powermacs. When a cpu
is off-lined, it is put into sleep mode with interrupts disabled. It
can be on-lined again by asserting its soft-reset pin, which is
connected to a GPIO pin.
With this I can off-line the second cpu in my dual G4 powermac, which
means that I can then suspend the machine (the suspend/resume code
refuses to suspend if more than one cpu is online, and making it cope
with multiple cpus is surprisingly messy).
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/ppc/kernel/idle.c')
| -rw-r--r-- | arch/ppc/kernel/idle.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/ppc/kernel/idle.c b/arch/ppc/kernel/idle.c index 53547b6de45b..fba29c876b62 100644 --- a/arch/ppc/kernel/idle.c +++ b/arch/ppc/kernel/idle.c @@ -22,6 +22,7 @@ #include <linux/ptrace.h> #include <linux/slab.h> #include <linux/sysctl.h> +#include <linux/cpu.h> #include <asm/pgtable.h> #include <asm/uaccess.h> @@ -35,6 +36,7 @@ void default_idle(void) { void (*powersave)(void); + int cpu = smp_processor_id(); powersave = ppc_md.power_save; @@ -44,7 +46,7 @@ void default_idle(void) #ifdef CONFIG_SMP else { set_thread_flag(TIF_POLLING_NRFLAG); - while (!need_resched()) + while (!need_resched() && !cpu_is_offline(cpu)) barrier(); clear_thread_flag(TIF_POLLING_NRFLAG); } @@ -52,6 +54,8 @@ void default_idle(void) } if (need_resched()) schedule(); + if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING) + cpu_die(); } /* |