3 files changed, 79 insertions, 18 deletions

diff --git a/arch/powerpc/platforms/pseries/dtl.c b/arch/powerpc/platforms/pseries/dtl.c
index adfd5441b61..0357655db49 100644
--- a/arch/powerpc/platforms/pseries/dtl.c
+++ b/arch/powerpc/platforms/pseries/dtl.c
@@ -27,27 +27,10 @@
 #include <asm/system.h>
 #include <asm/uaccess.h>
 #include <asm/firmware.h>
+#include <asm/lppaca.h>
 
 #include "plpar_wrappers.h"
 
-/*
- * Layout of entries in the hypervisor's DTL buffer. Although we don't
- * actually access the internals of an entry (we only need to know the size),
- * we might as well define it here for reference.
- */
-struct dtl_entry {
-	u8	dispatch_reason;
-	u8	preempt_reason;
-	u16	processor_id;
-	u32	enqueue_to_dispatch_time;
-	u32	ready_to_enqueue_time;
-	u32	waiting_to_ready_time;
-	u64	timebase;
-	u64	fault_addr;
-	u64	srr0;
-	u64	srr1;
-};
-
 struct dtl {
 	struct dtl_entry	*buf;
 	struct dentry		*file;
@@ -237,6 +220,11 @@ static int dtl_init(void)
 	struct dentry *event_mask_file, *buf_entries_file;
 	int rc, i;
 
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+	/* disable this for now */
+	return -ENODEV;
+#endif
+
 	if (!firmware_has_feature(FW_FEATURE_SPLPAR))
 		return -ENODEV;
 
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index a17fe4a9059..f129040d974 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -248,6 +248,8 @@ void vpa_init(int cpu)
 	int hwcpu = get_hard_smp_processor_id(cpu);
 	unsigned long addr;
 	long ret;
+	struct paca_struct *pp;
+	struct dtl_entry *dtl;
 
 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
 		lppaca_of(cpu).vmxregs_in_use = 1;
@@ -274,6 +276,25 @@ void vpa_init(int cpu)
 			       "registration for cpu %d (hw %d) of area %lx "
 			       "returns %ld\n", cpu, hwcpu, addr, ret);
 	}
+
+	/*
+	 * Register dispatch trace log, if one has been allocated.
+	 */
+	pp = &paca[cpu];
+	dtl = pp->dispatch_log;
+	if (dtl) {
+		pp->dtl_ridx = 0;
+		pp->dtl_curr = dtl;
+		lppaca_of(cpu).dtl_idx = 0;
+
+		/* hypervisor reads buffer length from this field */
+		dtl->enqueue_to_dispatch_time = DISPATCH_LOG_BYTES;
+		ret = register_dtl(hwcpu, __pa(dtl));
+		if (ret)
+			pr_warn("DTL registration failed for cpu %d (%ld)\n",
+				cpu, ret);
+		lppaca_of(cpu).dtl_enable_mask = 2;
+	}
 }
 
 static long pSeries_lpar_hpte_insert(unsigned long hpte_group,
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index a6d19e3a505..d345bfd56bb 100644
--- 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 */