[PATCH 00/18] remove extended cede offline mode and bogus topology update code

@@ -50,13 +50,6 @@ Command Line Switches
 
   This option is limited to the X86 and S390 architecture.
 
-``cede_offline={"off","on"}``
-  Use this option to disable/enable putting offlined processors to an extended
-  ``H_CEDE`` state on supported pseries platforms. If nothing is specified,
-  ``cede_offline`` is set to "on".
-
-  This option is limited to the PowerPC architecture.
-
 ``cpu0_hotplug``
   Allow to shutdown CPU0.
 

@@ -35,54 +35,10 @@
 #include <asm/topology.h>
 
 #include "pseries.h"
-#include "offline_states.h"
 
 /* This version can't take the spinlock, because it never returns */
 static int rtas_stop_self_token = RTAS_UNKNOWN_SERVICE;
 
-static DEFINE_PER_CPU(enum cpu_state_vals, preferred_offline_state) =
-							CPU_STATE_OFFLINE;
-static DEFINE_PER_CPU(enum cpu_state_vals, current_state) = CPU_STATE_OFFLINE;
-
-static enum cpu_state_vals default_offline_state = CPU_STATE_OFFLINE;
-
-static bool cede_offline_enabled __read_mostly = true;
-
-/*
- * Enable/disable cede_offline when available.
- */
-static int __init setup_cede_offline(char *str)
-{
-	return (kstrtobool(str, &cede_offline_enabled) == 0);
-}
-
-__setup("cede_offline=", setup_cede_offline);
-
-enum cpu_state_vals get_cpu_current_state(int cpu)
-{
-	return per_cpu(current_state, cpu);
-}
-
-void set_cpu_current_state(int cpu, enum cpu_state_vals state)
-{
-	per_cpu(current_state, cpu) = state;
-}
-
-enum cpu_state_vals get_preferred_offline_state(int cpu)
-{
-	return per_cpu(preferred_offline_state, cpu);
-}
-
-void set_preferred_offline_state(int cpu, enum cpu_state_vals state)
-{
-	per_cpu(preferred_offline_state, cpu) = state;
-}
-
-void set_default_offline_state(int cpu)
-{
-	per_cpu(preferred_offline_state, cpu) = default_offline_state;
-}
-
 static void rtas_stop_self(void)
 {
 	static struct rtas_args args;

@@ -101,9 +57,7 @@ static void rtas_stop_self(void)
 
 static void pseries_mach_cpu_die(void)
 {
-	unsigned int cpu = smp_processor_id();
 	unsigned int hwcpu = hard_smp_processor_id();
-	u8 cede_latency_hint = 0;
 
 	local_irq_disable();
 	idle_task_exit();

@@ -112,49 +66,6 @@ static void pseries_mach_cpu_die(void)
 	else
 		xics_teardown_cpu();
 
-	if (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
-		set_cpu_current_state(cpu, CPU_STATE_INACTIVE);
-		if (ppc_md.suspend_disable_cpu)
-			ppc_md.suspend_disable_cpu();
-
-		cede_latency_hint = 2;
-
-		get_lppaca()->idle = 1;
-		if (!lppaca_shared_proc(get_lppaca()))
-			get_lppaca()->donate_dedicated_cpu = 1;
-
-		while (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
-			while (!prep_irq_for_idle()) {
-				local_irq_enable();
-				local_irq_disable();
-			}
-
-			extended_cede_processor(cede_latency_hint);
-		}
-
-		local_irq_disable();
-
-		if (!lppaca_shared_proc(get_lppaca()))
-			get_lppaca()->donate_dedicated_cpu = 0;
-		get_lppaca()->idle = 0;
-
-		if (get_preferred_offline_state(cpu) == CPU_STATE_ONLINE) {
-			unregister_slb_shadow(hwcpu);
-
-			hard_irq_disable();
-			/*
-			 * 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();
-		}
-	}
-
-	/* 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(hwcpu);
 	rtas_stop_self();
 

@@ -200,24 +111,13 @@ static void pseries_cpu_die(unsigned int cpu)
 	int cpu_status = 1;
 	unsigned int pcpu = get_hard_smp_processor_id(cpu);
 
-	if (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
-		cpu_status = 1;
-		for (tries = 0; tries < 5000; tries++) {
-			if (get_cpu_current_state(cpu) == CPU_STATE_INACTIVE) {
-				cpu_status = 0;
-				break;
-			}
-			msleep(1);
-		}
-	} else if (get_preferred_offline_state(cpu) == CPU_STATE_OFFLINE) {
+	for (tries = 0; tries < 25; tries++) {
+		cpu_status = smp_query_cpu_stopped(pcpu);
+		if (cpu_status == QCSS_STOPPED ||
+		    cpu_status == QCSS_HARDWARE_ERROR)
+			break;
+		cpu_relax();
 
-		for (tries = 0; tries < 25; tries++) {
-			cpu_status = smp_query_cpu_stopped(pcpu);
-			if (cpu_status == QCSS_STOPPED ||
-			    cpu_status == QCSS_HARDWARE_ERROR)
-				break;
-			cpu_relax();
-		}
 	}
 
 	if (cpu_status != 0) {

@@ -359,28 +259,15 @@ static int dlpar_offline_cpu(struct device_node *dn)
 			if (get_hard_smp_processor_id(cpu) != thread)
 				continue;
 
-			if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)
+			if (!cpu_online(cpu))
 				break;
 
-			if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {
-				set_preferred_offline_state(cpu,
-							    CPU_STATE_OFFLINE);
-				cpu_maps_update_done();
-				timed_topology_update(1);
-				rc = device_offline(get_cpu_device(cpu));
-				if (rc)
-					goto out;
-				cpu_maps_update_begin();
-				break;
-			}
-
-			/*
-			 * The cpu is in CPU_STATE_INACTIVE.
-			 * Upgrade it's state to CPU_STATE_OFFLINE.
-			 */
-			set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
-			WARN_ON(plpar_hcall_norets(H_PROD, thread) != H_SUCCESS);
-			__cpu_die(cpu);
+			cpu_maps_update_done();
+			timed_topology_update(1);
+			rc = device_offline(get_cpu_device(cpu));
+			if (rc)
+				goto out;
+			cpu_maps_update_begin();
 			break;
 		}
 		if (cpu == num_possible_cpus()) {

@@ -414,8 +301,6 @@ static int dlpar_online_cpu(struct device_node *dn)
 		for_each_present_cpu(cpu) {
 			if (get_hard_smp_processor_id(cpu) != thread)
 				continue;
-			BUG_ON(get_cpu_current_state(cpu)
-					!= CPU_STATE_OFFLINE);
 			cpu_maps_update_done();
 			timed_topology_update(1);
 			find_and_online_cpu_nid(cpu);

@@ -1013,27 +898,8 @@ static struct notifier_block pseries_smp_nb = {
 	.notifier_call = pseries_smp_notifier,
 };
 
-#define MAX_CEDE_LATENCY_LEVELS		4
-#define	CEDE_LATENCY_PARAM_LENGTH	10
-#define CEDE_LATENCY_PARAM_MAX_LENGTH	\
-	(MAX_CEDE_LATENCY_LEVELS * CEDE_LATENCY_PARAM_LENGTH * sizeof(char))
-#define CEDE_LATENCY_TOKEN		45
-
-static char cede_parameters[CEDE_LATENCY_PARAM_MAX_LENGTH];
-
-static int parse_cede_parameters(void)
-{
-	memset(cede_parameters, 0, CEDE_LATENCY_PARAM_MAX_LENGTH);
-	return rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1,
-			 NULL,
-			 CEDE_LATENCY_TOKEN,
-			 __pa(cede_parameters),
-			 CEDE_LATENCY_PARAM_MAX_LENGTH);
-}
-
 static int __init pseries_cpu_hotplug_init(void)
 {
-	int cpu;
 	int qcss_tok;
 
 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE

@@ -1056,16 +922,8 @@ static int __init pseries_cpu_hotplug_init(void)
 	smp_ops->cpu_die = pseries_cpu_die;
 
 	/* Processors can be added/removed only on LPAR */
-	if (firmware_has_feature(FW_FEATURE_LPAR)) {
+	if (firmware_has_feature(FW_FEATURE_LPAR))
 		of_reconfig_notifier_register(&pseries_smp_nb);
-		cpu_maps_update_begin();
-		if (cede_offline_enabled && parse_cede_parameters() == 0) {
-			default_offline_state = CPU_STATE_INACTIVE;
-			for_each_online_cpu(cpu)
-				set_default_offline_state(cpu);
-		}
-		cpu_maps_update_done();
-	}
 
 	return 0;
 }

@@ -1,38 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _OFFLINE_STATES_H_
-#define _OFFLINE_STATES_H_
-
-/* Cpu offline states go here */
-enum cpu_state_vals {
-	CPU_STATE_OFFLINE,
-	CPU_STATE_INACTIVE,
-	CPU_STATE_ONLINE,
-	CPU_MAX_OFFLINE_STATES
-};
-
-#ifdef CONFIG_HOTPLUG_CPU
-extern enum cpu_state_vals get_cpu_current_state(int cpu);
-extern void set_cpu_current_state(int cpu, enum cpu_state_vals state);
-extern void set_preferred_offline_state(int cpu, enum cpu_state_vals state);
-extern void set_default_offline_state(int cpu);
-#else
-static inline enum cpu_state_vals get_cpu_current_state(int cpu)
-{
-	return CPU_STATE_ONLINE;
-}
-
-static inline void set_cpu_current_state(int cpu, enum cpu_state_vals state)
-{
-}
-
-static inline void set_preferred_offline_state(int cpu, enum cpu_state_vals state)
-{
-}
-
-static inline void set_default_offline_state(int cpu)
-{
-}
-#endif
-
-extern enum cpu_state_vals get_preferred_offline_state(int cpu);
-#endif

@@ -24,7 +24,6 @@
 #include <asm/topology.h>
 
 #include "pseries.h"
-#include "offline_states.h"
 
 static struct device_node *pmem_node;
 

@@ -44,8 +44,6 @@
 #include <asm/svm.h>
 
 #include "pseries.h"
-#include "offline_states.h"
-
 
 /*
  * The Primary thread of each non-boot processor was started from the OF client

@@ -108,10 +106,7 @@ static inline int smp_startup_cpu(unsigned int lcpu)
 
 	/* Fixup atomic count: it exited inside IRQ handler. */
 	task_thread_info(paca_ptrs[lcpu]->__current)->preempt_count	= 0;
-#ifdef CONFIG_HOTPLUG_CPU
-	if (get_cpu_current_state(lcpu) == CPU_STATE_INACTIVE)
-		goto out;
-#endif
+
 	/* 
 	 * If the RTAS start-cpu token does not exist then presume the
 	 * cpu is already spinning.

@@ -126,9 +121,6 @@ static inline int smp_startup_cpu(unsigned int lcpu)
 		return 0;
 	}
 
-#ifdef CONFIG_HOTPLUG_CPU
-out:
-#endif
 	return 1;
 }
 

@@ -143,10 +135,6 @@ static void smp_setup_cpu(int cpu)
 		vpa_init(cpu);
 
 	cpumask_clear_cpu(cpu, of_spin_mask);
-#ifdef CONFIG_HOTPLUG_CPU
-	set_cpu_current_state(cpu, CPU_STATE_ONLINE);
-	set_default_offline_state(cpu);
-#endif
 }
 
 static int smp_pSeries_kick_cpu(int nr)

@@ -163,20 +151,6 @@ static int smp_pSeries_kick_cpu(int nr)
 	 * the processor will continue on to secondary_start
 	 */
 	paca_ptrs[nr]->cpu_start = 1;
-#ifdef CONFIG_HOTPLUG_CPU
-	set_preferred_offline_state(nr, CPU_STATE_ONLINE);
-
-	if (get_cpu_current_state(nr) == CPU_STATE_INACTIVE) {
-		long rc;
-		unsigned long hcpuid;
-
-		hcpuid = get_hard_smp_processor_id(nr);
-		rc = plpar_hcall_norets(H_PROD, hcpuid);
-		if (rc != H_SUCCESS)
-			printk(KERN_ERR "Error: Prod to wake up processor %d "
-						"Ret= %ld\n", nr, rc);
-	}
-#endif
 
 	return 0;
 }

@@ -984,27 +984,7 @@ static int __init early_numa(char *p)
 }
 early_param("numa", early_numa);
 
-/*
- * The platform can inform us through one of several mechanisms
- * (post-migration device tree updates, PRRN or VPHN) that the NUMA
- * assignment of a resource has changed. This controls whether we act
- * on that. Disabled by default.
- */
-static bool topology_updates_enabled;
-
-static int __init early_topology_updates(char *p)
-{
-	if (!p)
-		return 0;
-
-	if (!strcmp(p, "on")) {
-		pr_warn("Caution: enabling topology updates\n");
-		topology_updates_enabled = true;
-	}
-
-	return 0;
-}
-early_param("topology_updates", early_topology_updates);
+static const bool topology_updates_enabled;
 
 #ifdef CONFIG_MEMORY_HOTPLUG
 /*

@@ -1632,52 +1612,6 @@ int prrn_is_enabled(void)
 	return prrn_enabled;
 }
 
-static int topology_read(struct seq_file *file, void *v)
-{
-	if (vphn_enabled || prrn_enabled)
-		seq_puts(file, "on\n");
-	else
-		seq_puts(file, "off\n");
-
-	return 0;
-}
-
-static int topology_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, topology_read, NULL);
-}
-
-static ssize_t topology_write(struct file *file, const char __user *buf,
-			      size_t count, loff_t *off)
-{
-	char kbuf[4]; /* "on" or "off" plus null. */
-	int read_len;
-
-	read_len = count < 3 ? count : 3;
-	if (copy_from_user(kbuf, buf, read_len))
-		return -EINVAL;
-
-	kbuf[read_len] = '\0';
-
-	if (!strncmp(kbuf, "on", 2)) {
-		topology_updates_enabled = true;
-		start_topology_update();
-	} else if (!strncmp(kbuf, "off", 3)) {
-		stop_topology_update();
-		topology_updates_enabled = false;
-	} else
-		return -EINVAL;
-
-	return count;
-}
-
-static const struct proc_ops topology_proc_ops = {
-	.proc_read	= seq_read,
-	.proc_write	= topology_write,
-	.proc_open	= topology_open,
-	.proc_release	= single_release,
-};
-
 static int topology_update_init(void)
 {
 	start_topology_update();

@@ -1685,9 +1619,6 @@ static int topology_update_init(void)
 	if (vphn_enabled)
 		topology_schedule_update();
 
-	if (!proc_create("powerpc/topology_updates", 0644, NULL, &topology_proc_ops))
-		return -ENOMEM;
-
 	topology_inited = 1;
 	return 0;
 }

@@ -253,8 +253,6 @@ extern int rtas_set_indicator_fast(int indicator, int index, int new_value);
 extern void rtas_progress(char *s, unsigned short hex);
 extern int rtas_suspend_cpu(struct rtas_suspend_me_data *data);
 extern int rtas_suspend_last_cpu(struct rtas_suspend_me_data *data);
-extern int rtas_online_cpus_mask(cpumask_var_t cpus);
-extern int rtas_offline_cpus_mask(cpumask_var_t cpus);
 extern int rtas_ibm_suspend_me(u64 handle);
 
 struct rtc_time;

@@ -843,96 +843,6 @@ static void rtas_percpu_suspend_me(void *info)
 	__rtas_suspend_cpu((struct rtas_suspend_me_data *)info, 1);
 }
 
-enum rtas_cpu_state {
-	DOWN,
-	UP,
-};
-
-#ifndef CONFIG_SMP
-static int rtas_cpu_state_change_mask(enum rtas_cpu_state state,
-				cpumask_var_t cpus)
-{
-	if (!cpumask_empty(cpus)) {
-		cpumask_clear(cpus);
-		return -EINVAL;
-	} else
-		return 0;
-}
-#else
-/* On return cpumask will be altered to indicate CPUs changed.
- * CPUs with states changed will be set in the mask,
- * CPUs with status unchanged will be unset in the mask. */
-static int rtas_cpu_state_change_mask(enum rtas_cpu_state state,
-				cpumask_var_t cpus)
-{
-	int cpu;
-	int cpuret = 0;
-	int ret = 0;
-
-	if (cpumask_empty(cpus))
-		return 0;
-
-	for_each_cpu(cpu, cpus) {
-		struct device *dev = get_cpu_device(cpu);
-
-		switch (state) {
-		case DOWN:
-			cpuret = device_offline(dev);
-			break;
-		case UP:
-			cpuret = device_online(dev);
-			break;
-		}
-		if (cpuret < 0) {
-			pr_debug("%s: cpu_%s for cpu#%d returned %d.\n",
-					__func__,
-					((state == UP) ? "up" : "down"),
-					cpu, cpuret);
-			if (!ret)
-				ret = cpuret;
-			if (state == UP) {
-				/* clear bits for unchanged cpus, return */
-				cpumask_shift_right(cpus, cpus, cpu);
-				cpumask_shift_left(cpus, cpus, cpu);
-				break;
-			} else {
-				/* clear bit for unchanged cpu, continue */
-				cpumask_clear_cpu(cpu, cpus);
-			}
-		}
-		cond_resched();
-	}
-
-	return ret;
-}
-#endif
-
-int rtas_online_cpus_mask(cpumask_var_t cpus)
-{
-	int ret;
-
-	ret = rtas_cpu_state_change_mask(UP, cpus);
-
-	if (ret) {
-		cpumask_var_t tmp_mask;
-
-		if (!alloc_cpumask_var(&tmp_mask, GFP_KERNEL))
-			return ret;
-
-		/* Use tmp_mask to preserve cpus mask from first failure */
-		cpumask_copy(tmp_mask, cpus);
-		rtas_offline_cpus_mask(tmp_mask);
-		free_cpumask_var(tmp_mask);
-	}
-
-	return ret;
-}
-
-int rtas_offline_cpus_mask(cpumask_var_t cpus)
-{
-	return rtas_cpu_state_change_mask(DOWN, cpus);
-}
-
 int rtas_ibm_suspend_me(u64 handle)
 {
 	long state;

@@ -940,8 +850,6 @@ int rtas_ibm_suspend_me(u64 handle)
 	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
 	struct rtas_suspend_me_data data;
 	DECLARE_COMPLETION_ONSTACK(done);
-	cpumask_var_t offline_mask;
-	int cpuret;
 
 	if (!rtas_service_present("ibm,suspend-me"))
 		return -ENOSYS;

@@ -962,9 +870,6 @@ int rtas_ibm_suspend_me(u64 handle)
 		return -EIO;
 	}
 
-	if (!alloc_cpumask_var(&offline_mask, GFP_KERNEL))
-		return -ENOMEM;
-
 	atomic_set(&data.working, 0);
 	atomic_set(&data.done, 0);
 	atomic_set(&data.error, 0);

@@ -973,24 +878,8 @@ int rtas_ibm_suspend_me(u64 handle)
 
 	lock_device_hotplug();
 
-	/* All present CPUs must be online */
-	cpumask_andnot(offline_mask, cpu_present_mask, cpu_online_mask);
-	cpuret = rtas_online_cpus_mask(offline_mask);
-	if (cpuret) {
-		pr_err("%s: Could not bring present CPUs online.\n", __func__);
-		atomic_set(&data.error, cpuret);
-		goto out;
-	}
-
 	cpu_hotplug_disable();
 
-	/* Check if we raced with a CPU-Offline Operation */
-	if (!cpumask_equal(cpu_present_mask, cpu_online_mask)) {
-		pr_info("%s: Raced against a concurrent CPU-Offline\n", __func__);
-		atomic_set(&data.error, -EAGAIN);
-		goto out_hotplug_enable;
-	}
-
 	/* Call function on all CPUs.  One of us will make the
 	 * rtas call
 	 */

@@ -1001,18 +890,11 @@ int rtas_ibm_suspend_me(u64 handle)
 	if (atomic_read(&data.error) != 0)
 		printk(KERN_ERR "Error doing global join\n");
 
-out_hotplug_enable:
-	cpu_hotplug_enable();
 
-	/* Take down CPUs not online prior to suspend */
-	cpuret = rtas_offline_cpus_mask(offline_mask);
-	if (cpuret)
-		pr_warn("%s: Could not restore CPUs to offline state.\n",
-				__func__);
+	cpu_hotplug_enable();
 
-out:
 	unlock_device_hotplug();
-	free_cpumask_var(offline_mask);
+
 	return atomic_read(&data.error);
 }
 

@@ -132,15 +132,11 @@ static ssize_t store_hibernate(struct device *dev,
 			       struct device_attribute *attr,
 			       const char *buf, size_t count)
 {
-	cpumask_var_t offline_mask;
 	int rc;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	if (!alloc_cpumask_var(&offline_mask, GFP_KERNEL))
-		return -ENOMEM;
-
 	stream_id = simple_strtoul(buf, NULL, 16);
 
 	do {

@@ -150,32 +146,16 @@ static ssize_t store_hibernate(struct device *dev,
 	} while (rc == -EAGAIN);
 
 	if (!rc) {
-		/* All present CPUs must be online */
-		cpumask_andnot(offline_mask, cpu_present_mask,
-				cpu_online_mask);
-		rc = rtas_online_cpus_mask(offline_mask);
-		if (rc) {
-			pr_err("%s: Could not bring present CPUs online.\n",
-					__func__);
-			goto out;
-		}
-
 		stop_topology_update();
 		rc = pm_suspend(PM_SUSPEND_MEM);
 		start_topology_update();
-
-		/* Take down CPUs not online prior to suspend */
-		if (!rtas_offline_cpus_mask(offline_mask))
-			pr_warn("%s: Could not restore CPUs to offline "
-					"state.\n", __func__);
 	}
 
 	stream_id = 0;
 
 	if (!rc)
 		rc = count;
-out:
-	free_cpumask_var(offline_mask);
+
 	return rc;
 }
 

@@ -984,8 +984,6 @@ static int __init early_numa(char *p)
 }
 early_param("numa", early_numa);
 
-static const bool topology_updates_enabled;
-
 #ifdef CONFIG_MEMORY_HOTPLUG
 /*
  * Find the node associated with a hot added memory section for

@@ -1133,7 +1131,6 @@ struct topology_update_data {
 
 #define TOPOLOGY_DEF_TIMER_SECS	60
 
-static u8 vphn_cpu_change_counts[NR_CPUS][MAX_DISTANCE_REF_POINTS];
 static cpumask_t cpu_associativity_changes_mask;
 static int vphn_enabled;
 static int prrn_enabled;

@@ -1158,63 +1155,6 @@ int timed_topology_update(int nsecs)
 	return 0;
 }
 
-/*
- * Store the current values of the associativity change counters in the
- * hypervisor.
- */
-static void setup_cpu_associativity_change_counters(void)
-{
-	int cpu;
-
-	/* The VPHN feature supports a maximum of 8 reference points */
-	BUILD_BUG_ON(MAX_DISTANCE_REF_POINTS > 8);
-
-	for_each_possible_cpu(cpu) {
-		int i;
-		u8 *counts = vphn_cpu_change_counts[cpu];
-		volatile u8 *hypervisor_counts = lppaca_of(cpu).vphn_assoc_counts;
-
-		for (i = 0; i < distance_ref_points_depth; i++)
-			counts[i] = hypervisor_counts[i];
-	}
-}
-
-/*
- * The hypervisor maintains a set of 8 associativity change counters in
- * the VPA of each cpu that correspond to the associativity levels in the
- * ibm,associativity-reference-points property. When an associativity
- * level changes, the corresponding counter is incremented.
- *
- * Set a bit in cpu_associativity_changes_mask for each cpu whose home
- * node associativity levels have changed.
- *
- * Returns the number of cpus with unhandled associativity changes.
- */
-static int update_cpu_associativity_changes_mask(void)
-{
-	int cpu;
-	cpumask_t *changes = &cpu_associativity_changes_mask;
-
-	for_each_possible_cpu(cpu) {
-		int i, changed = 0;
-		u8 *counts = vphn_cpu_change_counts[cpu];
-		volatile u8 *hypervisor_counts = lppaca_of(cpu).vphn_assoc_counts;
-
-		for (i = 0; i < distance_ref_points_depth; i++) {
-			if (hypervisor_counts[i] != counts[i]) {
-				counts[i] = hypervisor_counts[i];
-				changed = 1;
-			}
-		}
-		if (changed) {
-			cpumask_or(changes, changes, cpu_sibling_mask(cpu));
-			cpu = cpu_last_thread_sibling(cpu);
-		}
-	}
-
-	return cpumask_weight(changes);
-}
-
 /*
  * Retrieve the new associativity information for a virtual processor's
  * home node.

@@ -1498,16 +1438,6 @@ static void topology_schedule_update(void)
 	schedule_work(&topology_work);
 }
 
-static void topology_timer_fn(struct timer_list *unused)
-{
-	if (prrn_enabled && cpumask_weight(&cpu_associativity_changes_mask))
-		topology_schedule_update();
-	else if (vphn_enabled) {
-		if (update_cpu_associativity_changes_mask() > 0)
-			topology_schedule_update();
-		reset_topology_timer();
-	}
-}
 static struct timer_list topology_timer;
 
 static void reset_topology_timer(void)

@@ -1516,69 +1446,12 @@ static void reset_topology_timer(void)
 		mod_timer(&topology_timer, jiffies + topology_timer_secs * HZ);
 }
 
-#ifdef CONFIG_SMP
-
-static int dt_update_callback(struct notifier_block *nb,
-				unsigned long action, void *data)
-{
-	struct of_reconfig_data *update = data;
-	int rc = NOTIFY_DONE;
-
-	switch (action) {
-	case OF_RECONFIG_UPDATE_PROPERTY:
-		if (of_node_is_type(update->dn, "cpu") &&
-		    !of_prop_cmp(update->prop->name, "ibm,associativity")) {
-			u32 core_id;
-			of_property_read_u32(update->dn, "reg", &core_id);
-			rc = dlpar_cpu_readd(core_id);
-			rc = NOTIFY_OK;
-		}
-		break;
-	}
-
-	return rc;
-}
-
-static struct notifier_block dt_update_nb = {
-	.notifier_call = dt_update_callback,
-};
-
-#endif
-
 /*
  * Start polling for associativity changes.
  */
 int start_topology_update(void)
 {
-	int rc = 0;
-
-	if (!topology_updates_enabled)
-		return 0;
-
-	if (firmware_has_feature(FW_FEATURE_PRRN)) {
-		if (!prrn_enabled) {
-			prrn_enabled = 1;
-#ifdef CONFIG_SMP
-			rc = of_reconfig_notifier_register(&dt_update_nb);
-#endif
-		}
-	}
-	if (firmware_has_feature(FW_FEATURE_VPHN) &&
-		   lppaca_shared_proc(get_lppaca())) {
-		if (!vphn_enabled) {
-			vphn_enabled = 1;
-			setup_cpu_associativity_change_counters();
-			timer_setup(&topology_timer, topology_timer_fn,
-				    TIMER_DEFERRABLE);
-			reset_topology_timer();
-		}
-	}
-
-	pr_info("Starting topology update%s%s\n",
-		(prrn_enabled ? " prrn_enabled" : ""),
-		(vphn_enabled ? " vphn_enabled" : ""));
-
-	return rc;
+	return 0;
 }
 
 /*

@@ -1586,25 +1459,7 @@ int start_topology_update(void)
  */
 int stop_topology_update(void)
 {
-	int rc = 0;
-
-	if (!topology_updates_enabled)
-		return 0;
-
-	if (prrn_enabled) {
-		prrn_enabled = 0;
-#ifdef CONFIG_SMP
-		rc = of_reconfig_notifier_unregister(&dt_update_nb);
-#endif
-	}
-	if (vphn_enabled) {
-		vphn_enabled = 0;
-		rc = del_timer_sync(&topology_timer);
-	}
-
-	pr_info("Stopping topology update\n");
-
-	return rc;
+	return 0;
 }
 
 int prrn_is_enabled(void)

@@ -1132,8 +1132,8 @@ struct topology_update_data {
 #define TOPOLOGY_DEF_TIMER_SECS	60
 
 static cpumask_t cpu_associativity_changes_mask;
-static int vphn_enabled;
-static int prrn_enabled;
+static const int vphn_enabled;
+static const int prrn_enabled;
 static void reset_topology_timer(void);
 static int topology_timer_secs = 1;
 static int topology_inited;

@@ -1129,13 +1129,9 @@ struct topology_update_data {
 	int new_nid;
 };
 
-#define TOPOLOGY_DEF_TIMER_SECS	60
-
 static cpumask_t cpu_associativity_changes_mask;
 static const int vphn_enabled;
 static const int prrn_enabled;
-static void reset_topology_timer(void);
-static int topology_timer_secs = 1;
 static int topology_inited;
 
 /*

@@ -1143,15 +1139,6 @@ static int topology_inited;
  */
 int timed_topology_update(int nsecs)
 {
-	if (vphn_enabled) {
-		if (nsecs > 0)
-			topology_timer_secs = nsecs;
-		else
-			topology_timer_secs = TOPOLOGY_DEF_TIMER_SECS;
-
-		reset_topology_timer();
-	}
-
 	return 0;
 }
 

@@ -1438,14 +1425,6 @@ static void topology_schedule_update(void)
 	schedule_work(&topology_work);
 }
 
-static struct timer_list topology_timer;
-
-static void reset_topology_timer(void)
-{
-	if (vphn_enabled)
-		mod_timer(&topology_timer, jiffies + topology_timer_secs * HZ);
-}
-
 /*
  * Start polling for associativity changes.
  */

@@ -1414,17 +1414,6 @@ int arch_update_cpu_topology(void)
 	return numa_update_cpu_topology(true);
 }
 
-static void topology_work_fn(struct work_struct *work)
-{
-	rebuild_sched_domains();
-}
-static DECLARE_WORK(topology_work, topology_work_fn);
-
-static void topology_schedule_update(void)
-{
-	schedule_work(&topology_work);
-}
-
 /*
  * Start polling for associativity changes.
  */

@@ -1450,9 +1439,6 @@ static int topology_update_init(void)
 {
 	start_topology_update();
 
-	if (vphn_enabled)
-		topology_schedule_update();
-
 	topology_inited = 1;
 	return 0;
 }

@@ -1130,8 +1130,6 @@ struct topology_update_data {
 };
 
 static cpumask_t cpu_associativity_changes_mask;
-static const int vphn_enabled;
-static const int prrn_enabled;
 static int topology_inited;
 
 /*

@@ -1292,7 +1290,7 @@ int numa_update_cpu_topology(bool cpus_locked)
 	struct device *dev;
 	int weight, new_nid, i = 0;
 
-	if (!prrn_enabled && !vphn_enabled && topology_inited)
+	if (topology_inited)
 		return 0;
 
 	weight = cpumask_weight(&cpu_associativity_changes_mask);

@@ -1432,7 +1430,7 @@ int stop_topology_update(void)
 
 int prrn_is_enabled(void)
 {
-	return prrn_enabled;
+	return 0;
 }
 
 static int topology_update_init(void)

@@ -1122,14 +1122,6 @@ u64 memory_hotplug_max(void)
 
 /* Virtual Processor Home Node (VPHN) support */
 #ifdef CONFIG_PPC_SPLPAR
-struct topology_update_data {
-	struct topology_update_data *next;
-	unsigned int cpu;
-	int old_nid;
-	int new_nid;
-};
-
-static cpumask_t cpu_associativity_changes_mask;
 static int topology_inited;
 
 /*

@@ -1219,192 +1211,9 @@ int find_and_online_cpu_nid(int cpu)
 	return new_nid;
 }
 
-/*
- * Update the CPU maps and sysfs entries for a single CPU when its NUMA
- * characteristics change. This function doesn't perform any locking and is
- * only safe to call from stop_machine().
- */
-static int update_cpu_topology(void *data)
-{
-	struct topology_update_data *update;
-	unsigned long cpu;
-
-	if (!data)
-		return -EINVAL;
-
-	cpu = smp_processor_id();
-
-	for (update = data; update; update = update->next) {
-		int new_nid = update->new_nid;
-		if (cpu != update->cpu)
-			continue;
-
-		unmap_cpu_from_node(cpu);
-		map_cpu_to_node(cpu, new_nid);
-		set_cpu_numa_node(cpu, new_nid);
-		set_cpu_numa_mem(cpu, local_memory_node(new_nid));
-		vdso_getcpu_init();
-	}
-
-	return 0;
-}
-
-static int update_lookup_table(void *data)
-{
-	struct topology_update_data *update;
-
-	if (!data)
-		return -EINVAL;
-
-	/*
-	 * Upon topology update, the numa-cpu lookup table needs to be updated
-	 * for all threads in the core, including offline CPUs, to ensure that
-	 * future hotplug operations respect the cpu-to-node associativity
-	 * properly.
-	 */
-	for (update = data; update; update = update->next) {
-		int nid, base, j;
-
-		nid = update->new_nid;
-		base = cpu_first_thread_sibling(update->cpu);
-
-		for (j = 0; j < threads_per_core; j++) {
-			update_numa_cpu_lookup_table(base + j, nid);
-		}
-	}
-
-	return 0;
-}
-
-/*
- * Update the node maps and sysfs entries for each cpu whose home node
- * has changed. Returns 1 when the topology has changed, and 0 otherwise.
- *
- * cpus_locked says whether we already hold cpu_hotplug_lock.
- */
 int numa_update_cpu_topology(bool cpus_locked)
 {
-	unsigned int cpu, sibling, changed = 0;
-	struct topology_update_data *updates, *ud;
-	cpumask_t updated_cpus;
-	struct device *dev;
-	int weight, new_nid, i = 0;
-
-	if (topology_inited)
-		return 0;
-
-	weight = cpumask_weight(&cpu_associativity_changes_mask);
-	if (!weight)
-		return 0;
-
-	updates = kcalloc(weight, sizeof(*updates), GFP_KERNEL);
-	if (!updates)
-		return 0;
-
-	cpumask_clear(&updated_cpus);
-
-	for_each_cpu(cpu, &cpu_associativity_changes_mask) {
-		/*
-		 * If siblings aren't flagged for changes, updates list
-		 * will be too short. Skip on this update and set for next
-		 * update.
-		 */
-		if (!cpumask_subset(cpu_sibling_mask(cpu),
-					&cpu_associativity_changes_mask)) {
-			pr_info("Sibling bits not set for associativity "
-					"change, cpu%d\n", cpu);
-			cpumask_or(&cpu_associativity_changes_mask,
-					&cpu_associativity_changes_mask,
-					cpu_sibling_mask(cpu));
-			cpu = cpu_last_thread_sibling(cpu);
-			continue;
-		}
-
-		new_nid = find_and_online_cpu_nid(cpu);
-
-		if (new_nid == numa_cpu_lookup_table[cpu]) {
-			cpumask_andnot(&cpu_associativity_changes_mask,
-					&cpu_associativity_changes_mask,
-					cpu_sibling_mask(cpu));
-			dbg("Assoc chg gives same node %d for cpu%d\n",
-					new_nid, cpu);
-			cpu = cpu_last_thread_sibling(cpu);
-			continue;
-		}
-
-		for_each_cpu(sibling, cpu_sibling_mask(cpu)) {
-			ud = &updates[i++];
-			ud->next = &updates[i];
-			ud->cpu = sibling;
-			ud->new_nid = new_nid;
-			ud->old_nid = numa_cpu_lookup_table[sibling];
-			cpumask_set_cpu(sibling, &updated_cpus);
-		}
-		cpu = cpu_last_thread_sibling(cpu);
-	}
-
-	/*
-	 * Prevent processing of 'updates' from overflowing array
-	 * where last entry filled in a 'next' pointer.
-	 */
-	if (i)
-		updates[i-1].next = NULL;
-
-	pr_debug("Topology update for the following CPUs:\n");
-	if (cpumask_weight(&updated_cpus)) {
-		for (ud = &updates[0]; ud; ud = ud->next) {
-			pr_debug("cpu %d moving from node %d "
-					  "to %d\n", ud->cpu,
-					  ud->old_nid, ud->new_nid);
-		}
-	}
-
-	/*
-	 * In cases where we have nothing to update (because the updates list
-	 * is too short or because the new topology is same as the old one),
-	 * skip invoking update_cpu_topology() via stop-machine(). This is
-	 * necessary (and not just a fast-path optimization) since stop-machine
-	 * can end up electing a random CPU to run update_cpu_topology(), and
-	 * thus trick us into setting up incorrect cpu-node mappings (since
-	 * 'updates' is kzalloc()'ed).
-	 *
-	 * And for the similar reason, we will skip all the following updating.
-	 */
-	if (!cpumask_weight(&updated_cpus))
-		goto out;
-
-	if (cpus_locked)
-		stop_machine_cpuslocked(update_cpu_topology, &updates[0],
-					&updated_cpus);
-	else
-		stop_machine(update_cpu_topology, &updates[0], &updated_cpus);
-
-	/*
-	 * Update the numa-cpu lookup table with the new mappings, even for
-	 * offline CPUs. It is best to perform this update from the stop-
-	 * machine context.
-	 */
-	if (cpus_locked)
-		stop_machine_cpuslocked(update_lookup_table, &updates[0],
-					cpumask_of(raw_smp_processor_id()));
-	else
-		stop_machine(update_lookup_table, &updates[0],
-			     cpumask_of(raw_smp_processor_id()));
-
-	for (ud = &updates[0]; ud; ud = ud->next) {
-		unregister_cpu_under_node(ud->cpu, ud->old_nid);
-		register_cpu_under_node(ud->cpu, ud->new_nid);
-
-		dev = get_cpu_device(ud->cpu);
-		if (dev)
-			kobject_uevent(&dev->kobj, KOBJ_CHANGE);
-		cpumask_clear_cpu(ud->cpu, &cpu_associativity_changes_mask);
-		changed = 1;
-	}
-
-out:
-	kfree(updates);
-	return changed;
+	return 0;
 }
 
 int arch_update_cpu_topology(void)