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authorVaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>2010-03-01 03:58:16 +0100
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2010-03-09 01:57:10 +0100
commit0212f2602a38e740d5a96aba4cebfc2ebc993ecf (patch)
treec65166065be1d195ca603b7d71f8ed4f5d32e223 /arch/powerpc/platforms/pseries/hotplug-cpu.c
parentpowerpc: Reset kernel stack on cpu online from cede state (diff)
downloadlinux-0212f2602a38e740d5a96aba4cebfc2ebc993ecf.tar.xz
linux-0212f2602a38e740d5a96aba4cebfc2ebc993ecf.zip
powerpc: Move checks in pseries_mach_cpu_die()
Rearrange condition checks for better code readability and prevention of possible race conditions when preferred_offline_state can potentially change during the execution of pseries_mach_cpu_die(). The patch will make pseries_mach_cpu_die() put cpu in one of the consistent states and not hit the run over BUG() Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/platforms/pseries/hotplug-cpu.c')
-rw-r--r--arch/powerpc/platforms/pseries/hotplug-cpu.c30
1 files changed, 15 insertions, 15 deletions
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 349e0af9389a..fefb7f84800b 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -140,25 +140,25 @@ static void pseries_mach_cpu_die(void)
if (!get_lppaca()->shared_proc)
get_lppaca()->donate_dedicated_cpu = 0;
get_lppaca()->idle = 0;
- }
- if (get_preferred_offline_state(cpu) == CPU_STATE_ONLINE) {
- unregister_slb_shadow(hwcpu, __pa(get_slb_shadow()));
+ if (get_preferred_offline_state(cpu) == CPU_STATE_ONLINE) {
+ unregister_slb_shadow(hwcpu, __pa(get_slb_shadow()));
- /*
- * Call to start_secondary_resume() will not return.
- * Kernel stack will be reset and start_secondary()
- * will be called to continue the online operation.
- */
- start_secondary_resume();
+ /*
+ * Call to start_secondary_resume() will not return.
+ * Kernel stack will be reset and start_secondary()
+ * will be called to continue the online operation.
+ */
+ start_secondary_resume();
+ }
+ }
- } else if (get_preferred_offline_state(cpu) == CPU_STATE_OFFLINE) {
+ /* Requested state is CPU_STATE_OFFLINE at this point */
+ WARN_ON(get_preferred_offline_state(cpu) != CPU_STATE_OFFLINE);
- set_cpu_current_state(cpu, CPU_STATE_OFFLINE);
- unregister_slb_shadow(hard_smp_processor_id(),
- __pa(get_slb_shadow()));
- rtas_stop_self();
- }
+ set_cpu_current_state(cpu, CPU_STATE_OFFLINE);
+ unregister_slb_shadow(hwcpu, __pa(get_slb_shadow()));
+ rtas_stop_self();
/* Should never get here... */
BUG();