powerpc: Default arch idle could cede processor on pseries

[~andy/linux] / arch / powerpc / platforms / pseries / setup.c

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index d64feb3ea0be48600d71ca97f3bbd3c561181ed8..1f97e2b87a62b85d30bf848a8dbab31938304f21 100644 (file)
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -354,7 +354,7 @@ static int alloc_dispatch_log_kmem_cache(void)
 }
 early_initcall(alloc_dispatch_log_kmem_cache);
 
-static void pSeries_idle(void)
+static void pseries_lpar_idle(void)
 {
        /* This would call on the cpuidle framework, and the back-end pseries
         * driver to  go to idle states
@@ -362,10 +362,22 @@ static void pSeries_idle(void)
        if (cpuidle_idle_call()) {
                /* On error, execute default handler
                 * to go into low thread priority and possibly
-                * low power mode.
+                * low power mode by cedeing processor to hypervisor
                 */
-               HMT_low();
-               HMT_very_low();
+
+               /* Indicate to hypervisor that we are idle. */
+               get_lppaca()->idle = 1;
+
+               /*
+                * Yield the processor to the hypervisor.  We return if
+                * an external interrupt occurs (which are driven prior
+                * to returning here) or if a prod occurs from another
+                * processor. When returning here, external interrupts
+                * are enabled.
+                */
+               cede_processor();
+
+               get_lppaca()->idle = 0;
        }
 }
 
@@ -456,15 +468,14 @@ static void __init pSeries_setup_arch(void)
 
        pSeries_nvram_init();
 
-       if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
+       if (firmware_has_feature(FW_FEATURE_LPAR)) {
                vpa_init(boot_cpuid);
-               ppc_md.power_save = pSeries_idle;
-       }
-
-       if (firmware_has_feature(FW_FEATURE_LPAR))
+               ppc_md.power_save = pseries_lpar_idle;
                ppc_md.enable_pmcs = pseries_lpar_enable_pmcs;
-       else
+       } else {
+               /* No special idle routine */
                ppc_md.enable_pmcs = power4_enable_pmcs;
+       }
 
        ppc_md.pcibios_root_bridge_prepare = pseries_root_bridge_prepare;