1 files changed, 21 insertions, 28 deletions

diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index 46b4ebc33db7..2e08640bb3b4 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -32,29 +32,27 @@
 
 static DEFINE_PER_CPU(struct cpu, cpu_devices);
 
-/*
- * SMT snooze delay stuff, 64-bit only for now
- */
-
 #ifdef CONFIG_PPC64
 
-/* Time in microseconds we delay before sleeping in the idle loop */
-static DEFINE_PER_CPU(long, smt_snooze_delay) = { 100 };
+/*
+ * Snooze delay has not been hooked up since 3fa8cad82b94 ("powerpc/pseries/cpuidle:
+ * smt-snooze-delay cleanup.") and has been broken even longer. As was foretold in
+ * 2014:
+ *
+ *  "ppc64_util currently utilises it. Once we fix ppc64_util, propose to clean
+ *  up the kernel code."
+ *
+ * powerpc-utils stopped using it as of 1.3.8. At some point in the future this
+ * code should be removed.
+ */
 
 static ssize_t store_smt_snooze_delay(struct device *dev,
 				      struct device_attribute *attr,
 				      const char *buf,
 				      size_t count)
 {
-	struct cpu *cpu = container_of(dev, struct cpu, dev);
-	ssize_t ret;
-	long snooze;
-
-	ret = sscanf(buf, "%ld", &snooze);
-	if (ret != 1)
-		return -EINVAL;
-
-	per_cpu(smt_snooze_delay, cpu->dev.id) = snooze;
+	pr_warn_once("%s (%d) stored to unsupported smt_snooze_delay, which has no effect.\n",
+		     current->comm, current->pid);
 	return count;
 }
 
@@ -62,9 +60,9 @@ static ssize_t show_smt_snooze_delay(struct device *dev,
 				     struct device_attribute *attr,
 				     char *buf)
 {
-	struct cpu *cpu = container_of(dev, struct cpu, dev);
-
-	return sprintf(buf, "%ld\n", per_cpu(smt_snooze_delay, cpu->dev.id));
+	pr_warn_once("%s (%d) read from unsupported smt_snooze_delay\n",
+		     current->comm, current->pid);
+	return sprintf(buf, "100\n");
 }
 
 static DEVICE_ATTR(smt_snooze_delay, 0644, show_smt_snooze_delay,
@@ -72,16 +70,10 @@ static DEVICE_ATTR(smt_snooze_delay, 0644, show_smt_snooze_delay,
 
 static int __init setup_smt_snooze_delay(char *str)
 {
-	unsigned int cpu;
-	long snooze;
-
 	if (!cpu_has_feature(CPU_FTR_SMT))
 		return 1;
 
-	snooze = simple_strtol(str, NULL, 10);
-	for_each_possible_cpu(cpu)
-		per_cpu(smt_snooze_delay, cpu) = snooze;
-
+	pr_warn("smt-snooze-delay command line option has no effect\n");
 	return 1;
 }
 __setup("smt-snooze-delay=", setup_smt_snooze_delay);
@@ -225,14 +217,13 @@ static DEVICE_ATTR(dscr_default, 0600,
 static void sysfs_create_dscr_default(void)
 {
 	if (cpu_has_feature(CPU_FTR_DSCR)) {
-		int err = 0;
 		int cpu;
 
 		dscr_default = spr_default_dscr;
 		for_each_possible_cpu(cpu)
 			paca_ptrs[cpu]->dscr_default = dscr_default;
 
-		err = device_create_file(cpu_subsys.dev_root, &dev_attr_dscr_default);
+		device_create_file(cpu_subsys.dev_root, &dev_attr_dscr_default);
 	}
 }
 #endif /* CONFIG_PPC64 */
@@ -1168,6 +1159,7 @@ static int __init topology_init(void)
 	for_each_possible_cpu(cpu) {
 		struct cpu *c = &per_cpu(cpu_devices, cpu);
 
+#ifdef CONFIG_HOTPLUG_CPU
 		/*
 		 * For now, we just see if the system supports making
 		 * the RTAS calls for CPU hotplug.  But, there may be a
@@ -1175,8 +1167,9 @@ static int __init topology_init(void)
 		 * CPU.  For instance, the boot cpu might never be valid
 		 * for hotplugging.
 		 */
-		if (ppc_md.cpu_die)
+		if (smp_ops->cpu_offline_self)
 			c->hotpluggable = 1;
+#endif
 
 		if (cpu_online(cpu) || c->hotpluggable) {
 			register_cpu(c, cpu);