1 files changed, 210 insertions, 77 deletions

diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 1f032483c02..20d62975856 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -19,111 +19,215 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/interrupt.h>
 #include <linux/delay.h>
+#include <linux/sched.h>	/* for idle_task_exit */
 #include <linux/cpu.h>
-#include <asm/system.h>
+#include <linux/of.h>
 #include <asm/prom.h>
 #include <asm/rtas.h>
 #include <asm/firmware.h>
 #include <asm/machdep.h>
 #include <asm/vdso_datapage.h>
-#include <asm/pSeries_reconfig.h>
-#include "xics.h"
-#include "plpar_wrappers.h"
+#include <asm/xics.h>
+#include <asm/plpar_wrappers.h>
+
+#include "offline_states.h"
 
 /* This version can't take the spinlock, because it never returns */
-static struct rtas_args rtas_stop_self_args = {
-	.token = RTAS_UNKNOWN_SERVICE,
-	.nargs = 0,
-	.nret = 1,
-	.rets = &rtas_stop_self_args.args[0],
-};
+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 int cede_offline_enabled __read_mostly = 1;
+
+/*
+ * Enable/disable cede_offline when available.
+ */
+static int __init setup_cede_offline(char *str)
+{
+	if (!strcmp(str, "off"))
+		cede_offline_enabled = 0;
+	else if (!strcmp(str, "on"))
+		cede_offline_enabled = 1;
+	else
+		return 0;
+	return 1;
+}
+
+__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)
 {
-	struct rtas_args *args = &rtas_stop_self_args;
+	static struct rtas_args args = {
+		.nargs = 0,
+		.nret = 1,
+		.rets = &args.args[0],
+	};
+
+	args.token = cpu_to_be32(rtas_stop_self_token);
 
 	local_irq_disable();
 
-	BUG_ON(args->token == RTAS_UNKNOWN_SERVICE);
+	BUG_ON(rtas_stop_self_token == RTAS_UNKNOWN_SERVICE);
 
 	printk("cpu %u (hwid %u) Ready to die...\n",
 	       smp_processor_id(), hard_smp_processor_id());
-	enter_rtas(__pa(args));
+	enter_rtas(__pa(&args));
 
 	panic("Alas, I survived.\n");
 }
 
 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();
 	xics_teardown_cpu();
-	unregister_slb_shadow(hard_smp_processor_id(), __pa(get_slb_shadow()));
-	rtas_stop_self();
-	/* Should never get here... */
-	BUG();
-	for(;;);
-}
 
-static int qcss_tok;	/* query-cpu-stopped-state token */
+	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();
 
-/* Get state of physical CPU.
- * Return codes:
- *	0	- The processor is in the RTAS stopped state
- *	1	- stop-self is in progress
- *	2	- The processor is not in the RTAS stopped state
- *	-1	- Hardware Error
- *	-2	- Hardware Busy, Try again later.
- */
-static int query_cpu_stopped(unsigned int pcpu)
-{
-	int cpu_status, status;
+		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);
 
-	status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu);
-	if (status != 0) {
-		printk(KERN_ERR
-		       "RTAS query-cpu-stopped-state failed: %i\n", status);
-		return status;
+			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();
+		}
 	}
 
-	return cpu_status;
+	/* 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();
+
+	/* Should never get here... */
+	BUG();
+	for(;;);
 }
 
 static int pseries_cpu_disable(void)
 {
 	int cpu = smp_processor_id();
 
-	cpu_clear(cpu, cpu_online_map);
+	set_cpu_online(cpu, false);
 	vdso_data->processorCount--;
 
 	/*fix boot_cpuid here*/
 	if (cpu == boot_cpuid)
-		boot_cpuid = any_online_cpu(cpu_online_map);
+		boot_cpuid = cpumask_any(cpu_online_mask);
 
 	/* FIXME: abstract this to not be platform specific later on */
 	xics_migrate_irqs_away();
 	return 0;
 }
 
+/*
+ * pseries_cpu_die: Wait for the cpu to die.
+ * @cpu: logical processor id of the CPU whose death we're awaiting.
+ *
+ * This function is called from the context of the thread which is performing
+ * the cpu-offline. Here we wait for long enough to allow the cpu in question
+ * to self-destroy so that the cpu-offline thread can send the CPU_DEAD
+ * notifications.
+ *
+ * OTOH, pseries_mach_cpu_die() is called by the @cpu when it wants to
+ * self-destruct.
+ */
 static void pseries_cpu_die(unsigned int cpu)
 {
 	int tries;
-	int cpu_status;
+	int cpu_status = 1;
 	unsigned int pcpu = get_hard_smp_processor_id(cpu);
 
-	for (tries = 0; tries < 25; tries++) {
-		cpu_status = query_cpu_stopped(pcpu);
-		if (cpu_status == 0 || cpu_status == -1)
-			break;
-		msleep(200);
+	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();
+		}
 	}
+
 	if (cpu_status != 0) {
 		printk("Querying DEAD? cpu %i (%i) shows %i\n",
 		       cpu, pcpu, cpu_status);
 	}
 
-	/* Isolation and deallocation are definatly done by
+	/* Isolation and deallocation are definitely done by
 	 * drslot_chrp_cpu.  If they were not they would be
 	 * done here.  Change isolate state to Isolate and
 	 * change allocation-state to Unusable.
@@ -132,7 +236,7 @@ static void pseries_cpu_die(unsigned int cpu)
 }
 
 /*
- * Update cpu_present_map and paca(s) for a new cpu node.  The wrinkle
+ * Update cpu_present_mask and paca(s) for a new cpu node.  The wrinkle
  * here is that a cpu device node may represent up to two logical cpus
  * in the SMT case.  We must honor the assumption in other code that
  * the logical ids for sibling SMT threads x and y are adjacent, such
@@ -141,7 +245,7 @@ static void pseries_cpu_die(unsigned int cpu)
 static int pseries_add_processor(struct device_node *np)
 {
 	unsigned int cpu;
-	cpumask_t candidate_map, tmp = CPU_MASK_NONE;
+	cpumask_var_t candidate_mask, tmp;
 	int err = -ENOSPC, len, nthreads, i;
 	const u32 *intserv;
 
@@ -149,48 +253,53 @@ static int pseries_add_processor(struct device_node *np)
 	if (!intserv)
 		return 0;
 
+	zalloc_cpumask_var(&candidate_mask, GFP_KERNEL);
+	zalloc_cpumask_var(&tmp, GFP_KERNEL);
+
 	nthreads = len / sizeof(u32);
 	for (i = 0; i < nthreads; i++)
-		cpu_set(i, tmp);
+		cpumask_set_cpu(i, tmp);
 
 	cpu_maps_update_begin();
 
-	BUG_ON(!cpus_subset(cpu_present_map, cpu_possible_map));
+	BUG_ON(!cpumask_subset(cpu_present_mask, cpu_possible_mask));
 
 	/* Get a bitmap of unoccupied slots. */
-	cpus_xor(candidate_map, cpu_possible_map, cpu_present_map);
-	if (cpus_empty(candidate_map)) {
+	cpumask_xor(candidate_mask, cpu_possible_mask, cpu_present_mask);
+	if (cpumask_empty(candidate_mask)) {
 		/* If we get here, it most likely means that NR_CPUS is
 		 * less than the partition's max processors setting.
 		 */
 		printk(KERN_ERR "Cannot add cpu %s; this system configuration"
 		       " supports %d logical cpus.\n", np->full_name,
-		       cpus_weight(cpu_possible_map));
+		       cpumask_weight(cpu_possible_mask));
 		goto out_unlock;
 	}
 
-	while (!cpus_empty(tmp))
-		if (cpus_subset(tmp, candidate_map))
+	while (!cpumask_empty(tmp))
+		if (cpumask_subset(tmp, candidate_mask))
 			/* Found a range where we can insert the new cpu(s) */
 			break;
 		else
-			cpus_shift_left(tmp, tmp, nthreads);
+			cpumask_shift_left(tmp, tmp, nthreads);
 
-	if (cpus_empty(tmp)) {
-		printk(KERN_ERR "Unable to find space in cpu_present_map for"
+	if (cpumask_empty(tmp)) {
+		printk(KERN_ERR "Unable to find space in cpu_present_mask for"
 		       " processor %s with %d thread(s)\n", np->name,
 		       nthreads);
 		goto out_unlock;
 	}
 
-	for_each_cpu_mask(cpu, tmp) {
-		BUG_ON(cpu_isset(cpu, cpu_present_map));
-		cpu_set(cpu, cpu_present_map);
+	for_each_cpu(cpu, tmp) {
+		BUG_ON(cpu_present(cpu));
+		set_cpu_present(cpu, true);
 		set_hard_smp_processor_id(cpu, *intserv++);
 	}
 	err = 0;
 out_unlock:
 	cpu_maps_update_done();
+	free_cpumask_var(candidate_mask);
+	free_cpumask_var(tmp);
 	return err;
 }
 
@@ -217,11 +326,11 @@ static void pseries_remove_processor(struct device_node *np)
 			if (get_hard_smp_processor_id(cpu) != intserv[i])
 				continue;
 			BUG_ON(cpu_online(cpu));
-			cpu_clear(cpu, cpu_present_map);
+			set_cpu_present(cpu, false);
 			set_hard_smp_processor_id(cpu, -1);
 			break;
 		}
-		if (cpu == NR_CPUS)
+		if (cpu >= nr_cpu_ids)
 			printk(KERN_WARNING "Could not find cpu to remove "
 			       "with physical id 0x%x\n", intserv[i]);
 	}
@@ -231,31 +340,47 @@ static void pseries_remove_processor(struct device_node *np)
 static int pseries_smp_notifier(struct notifier_block *nb,
 				unsigned long action, void *node)
 {
-	int err = NOTIFY_OK;
+	int err = 0;
 
 	switch (action) {
-	case PSERIES_RECONFIG_ADD:
-		if (pseries_add_processor(node))
-			err = NOTIFY_BAD;
+	case OF_RECONFIG_ATTACH_NODE:
+		err = pseries_add_processor(node);
 		break;
-	case PSERIES_RECONFIG_REMOVE:
+	case OF_RECONFIG_DETACH_NODE:
 		pseries_remove_processor(node);
 		break;
-	default:
-		err = NOTIFY_DONE;
-		break;
 	}
-	return err;
+	return notifier_from_errno(err);
 }
 
 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)
 {
 	struct device_node *np;
 	const char *typep;
+	int cpu;
+	int qcss_tok;
 
 	for_each_node_by_name(np, "interrupt-controller") {
 		typep = of_get_property(np, "compatible", NULL);
@@ -268,10 +393,10 @@ static int __init pseries_cpu_hotplug_init(void)
 		}
 	}
 
-	rtas_stop_self_args.token = rtas_token("stop-self");
+	rtas_stop_self_token = rtas_token("stop-self");
 	qcss_tok = rtas_token("query-cpu-stopped-state");
 
-	if (rtas_stop_self_args.token == RTAS_UNKNOWN_SERVICE ||
+	if (rtas_stop_self_token == RTAS_UNKNOWN_SERVICE ||
 			qcss_tok == RTAS_UNKNOWN_SERVICE) {
 		printk(KERN_INFO "CPU Hotplug not supported by firmware "
 				"- disabling.\n");
@@ -283,9 +408,17 @@ 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))
-		pSeries_reconfig_notifier_register(&pseries_smp_nb);
+	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;
 }
-arch_initcall(pseries_cpu_hotplug_init);
+machine_arch_initcall(pseries, pseries_cpu_hotplug_init);