powerpc: Account time using timebase rather than PURR

[cascardo/linux.git] / arch / powerpc / platforms / pseries / setup.c

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 6710761..d345bfd 100644 (file)
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -273,6 +273,58 @@ static struct notifier_block pci_dn_reconfig_nb = {
        .notifier_call = pci_dn_reconfig_notifier,
 };
 
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+/*
+ * Allocate space for the dispatch trace log for all possible cpus
+ * and register the buffers with the hypervisor.  This is used for
+ * computing time stolen by the hypervisor.
+ */
+static int alloc_dispatch_logs(void)
+{
+       int cpu, ret;
+       struct paca_struct *pp;
+       struct dtl_entry *dtl;
+
+       if (!firmware_has_feature(FW_FEATURE_SPLPAR))
+               return 0;
+
+       for_each_possible_cpu(cpu) {
+               pp = &paca[cpu];
+               dtl = kmalloc_node(DISPATCH_LOG_BYTES, GFP_KERNEL,
+                                  cpu_to_node(cpu));
+               if (!dtl) {
+                       pr_warn("Failed to allocate dispatch trace log for cpu %d\n",
+                               cpu);
+                       pr_warn("Stolen time statistics will be unreliable\n");
+                       break;
+               }
+
+               pp->dtl_ridx = 0;
+               pp->dispatch_log = dtl;
+               pp->dispatch_log_end = dtl + N_DISPATCH_LOG;
+               pp->dtl_curr = dtl;
+       }
+
+       /* Register the DTL for the current (boot) cpu */
+       dtl = get_paca()->dispatch_log;
+       get_paca()->dtl_ridx = 0;
+       get_paca()->dtl_curr = dtl;
+       get_paca()->lppaca_ptr->dtl_idx = 0;
+
+       /* hypervisor reads buffer length from this field */
+       dtl->enqueue_to_dispatch_time = DISPATCH_LOG_BYTES;
+       ret = register_dtl(hard_smp_processor_id(), __pa(dtl));
+       if (ret)
+               pr_warn("DTL registration failed for boot cpu %d (%d)\n",
+                       smp_processor_id(), ret);
+       get_paca()->lppaca_ptr->dtl_enable_mask = 2;
+
+       return 0;
+}
+
+early_initcall(alloc_dispatch_logs);
+#endif /* CONFIG_VIRT_CPU_ACCOUNTING */
+
 static void __init pSeries_setup_arch(void)
 {
        /* Discover PIC type and setup ppc_md accordingly */
@@ -496,13 +548,14 @@ static int __init pSeries_probe(void)
 }
 
 
-DECLARE_PER_CPU(unsigned long, smt_snooze_delay);
+DECLARE_PER_CPU(long, smt_snooze_delay);
 
 static void pseries_dedicated_idle_sleep(void)
 { 
        unsigned int cpu = smp_processor_id();
        unsigned long start_snooze;
        unsigned long in_purr, out_purr;
+       long snooze = __get_cpu_var(smt_snooze_delay);
 
        /*
         * Indicate to the HV that we are idle. Now would be
@@ -517,13 +570,12 @@ static void pseries_dedicated_idle_sleep(void)
         * has been checked recently.  If we should poll for a little
         * while, do so.
         */
-       if (__get_cpu_var(smt_snooze_delay)) {
-               start_snooze = get_tb() +
-                       __get_cpu_var(smt_snooze_delay) * tb_ticks_per_usec;
+       if (snooze) {
+               start_snooze = get_tb() + snooze * tb_ticks_per_usec;
                local_irq_enable();
                set_thread_flag(TIF_POLLING_NRFLAG);
 
-               while (get_tb() < start_snooze) {
+               while ((snooze < 0) || (get_tb() < start_snooze)) {
                        if (need_resched() || cpu_is_offline(cpu))
                                goto out;
                        ppc64_runlatch_off();