powerpc/pseries: Poll VPA for topology changes and update NUMA maps (9eff1a38) · Commits · 戴 / test

arch/powerpc/include/asm/lppaca.h

+4 −1

Original line number	Original line	Diff line number	Diff line
	@@ -62,7 +62,10 @@ struct lppaca {
	volatile u32 dyn_pir; // Dynamic ProcIdReg value x20-x23		volatile u32 dyn_pir; // Dynamic ProcIdReg value x20-x23
	u32 dsei_data; // DSEI data x24-x27		u32 dsei_data; // DSEI data x24-x27
	u64 sprg3; // SPRG3 value x28-x2F		u64 sprg3; // SPRG3 value x28-x2F
	u8 reserved3[80]; // Reserved x30-x7F		u8 reserved3[40]; // Reserved x30-x57
			volatile u8 vphn_assoc_counts[8]; // Virtual processor home node
			// associativity change counters x58-x5F
			u8 reserved4[32]; // Reserved x60-x7F

	//=============================================================================		//=============================================================================
	// CACHE_LINE_2 0x0080 - 0x00FF Contains local read-write data		// CACHE_LINE_2 0x0080 - 0x00FF Contains local read-write data

arch/powerpc/mm/numa.c

+267 −10

Original line number	Original line	Diff line number	Diff line
	@@ -20,10 +20,14 @@
	#include <linux/memblock.h>		#include <linux/memblock.h>
	#include <linux/of.h>		#include <linux/of.h>
	#include <linux/pfn.h>		#include <linux/pfn.h>
			#include <linux/cpuset.h>
			#include <linux/node.h>
	#include <asm/sparsemem.h>		#include <asm/sparsemem.h>
	#include <asm/prom.h>		#include <asm/prom.h>
	#include <asm/system.h>		#include <asm/system.h>
	#include <asm/smp.h>		#include <asm/smp.h>
			#include <asm/firmware.h>
			#include <asm/paca.h>

	static int numa_enabled = 1;		static int numa_enabled = 1;

	@@ -246,32 +250,41 @@ static void initialize_distance_lookup_table(int nid,
	/* Returns nid in the range [0..MAX_NUMNODES-1], or -1 if no useful numa		/* Returns nid in the range [0..MAX_NUMNODES-1], or -1 if no useful numa
	* info is found.		* info is found.
	*/		*/
	static int of_node_to_nid_single(struct device_node *device)		static int associativity_to_nid(const unsigned int *associativity)
	{		{
	int nid = -1;		int nid = -1;
	const unsigned int *tmp;

	if (min_common_depth == -1)		if (min_common_depth == -1)
	goto out;		goto out;

	tmp = of_get_associativity(device);		if (associativity[0] >= min_common_depth)
	if (!tmp)		nid = associativity[min_common_depth];
	goto out;

	if (tmp[0] >= min_common_depth)
	nid = tmp[min_common_depth];

	/* POWER4 LPAR uses 0xffff as invalid node */		/* POWER4 LPAR uses 0xffff as invalid node */
	if (nid == 0xffff \|\| nid >= MAX_NUMNODES)		if (nid == 0xffff \|\| nid >= MAX_NUMNODES)
	nid = -1;		nid = -1;

	if (nid > 0 && tmp[0] >= distance_ref_points_depth)		if (nid > 0 && associativity[0] >= distance_ref_points_depth)
	initialize_distance_lookup_table(nid, tmp);		initialize_distance_lookup_table(nid, associativity);

	out:		out:
	return nid;		return nid;
	}		}

			/* Returns the nid associated with the given device tree node,
			* or -1 if not found.
			*/
			static int of_node_to_nid_single(struct device_node *device)
			{
			int nid = -1;
			const unsigned int *tmp;

			tmp = of_get_associativity(device);
			if (tmp)
			nid = associativity_to_nid(tmp);
			return nid;
			}

	/* Walk the device tree upwards, looking for an associativity id */		/* Walk the device tree upwards, looking for an associativity id */
	int of_node_to_nid(struct device_node *device)		int of_node_to_nid(struct device_node *device)
	{		{
	@@ -1274,3 +1287,247 @@ u64 memory_hotplug_max(void)
	return max(hot_add_drconf_memory_max(), memblock_end_of_DRAM());		return max(hot_add_drconf_memory_max(), memblock_end_of_DRAM());
	}		}
	#endif /* CONFIG_MEMORY_HOTPLUG */		#endif /* CONFIG_MEMORY_HOTPLUG */

			/* Vrtual Processor Home Node (VPHN) support */
			#define VPHN_NR_CHANGE_CTRS (8)
			static u8 vphn_cpu_change_counts[NR_CPUS][VPHN_NR_CHANGE_CTRS];
			static cpumask_t cpu_associativity_changes_mask;
			static int vphn_enabled;
			static void set_topology_timer(void);
			int stop_topology_update(void);

			/*
			* Store the current values of the associativity change counters in the
			* hypervisor.
			*/
			static void setup_cpu_associativity_change_counters(void)
			{
			int cpu = 0;

			for_each_possible_cpu(cpu) {
			int i = 0;
			u8 *counts = vphn_cpu_change_counts[cpu];
			volatile u8 *hypervisor_counts = lppaca[cpu].vphn_assoc_counts;

			for (i = 0; i < VPHN_NR_CHANGE_CTRS; 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 = 0, nr_cpus = 0;
			cpumask_t *changes = &cpu_associativity_changes_mask;

			cpumask_clear(changes);

			for_each_possible_cpu(cpu) {
			int i, changed = 0;
			u8 *counts = vphn_cpu_change_counts[cpu];
			volatile u8 *hypervisor_counts = lppaca[cpu].vphn_assoc_counts;

			for (i = 0; i < VPHN_NR_CHANGE_CTRS; i++) {
			if (hypervisor_counts[i] > counts[i]) {
			counts[i] = hypervisor_counts[i];
			changed = 1;
			}
			}
			if (changed) {
			cpumask_set_cpu(cpu, changes);
			nr_cpus++;
			}
			}

			return nr_cpus;
			}

			/* 6 64-bit registers unpacked into 12 32-bit associativity values */
			#define VPHN_ASSOC_BUFSIZE (6*sizeof(u64)/sizeof(u32))

			/*
			* Convert the associativity domain numbers returned from the hypervisor
			* to the sequence they would appear in the ibm,associativity property.
			*/
			static int vphn_unpack_associativity(const long packed, unsigned int unpacked)
			{
			int i = 0;
			int nr_assoc_doms = 0;
			const u16 field = (const u16) packed;

			#define VPHN_FIELD_UNUSED (0xffff)
			#define VPHN_FIELD_MSB (0x8000)
			#define VPHN_FIELD_MASK (~VPHN_FIELD_MSB)

			for (i = 0; i < VPHN_ASSOC_BUFSIZE; i++) {
			if (*field == VPHN_FIELD_UNUSED) {
			/* All significant fields processed, and remaining
			* fields contain the reserved value of all 1's.
			* Just store them.
			*/
			unpacked[i] = ((u32)field);
			field += 2;
			}
			else if (*field & VPHN_FIELD_MSB) {
			/* Data is in the lower 15 bits of this field */
			unpacked[i] = *field & VPHN_FIELD_MASK;
			field++;
			nr_assoc_doms++;
			}
			else {
			/* Data is in the lower 15 bits of this field
			* concatenated with the next 16 bit field
			*/
			unpacked[i] = ((u32)field);
			field += 2;
			nr_assoc_doms++;
			}
			}

			return nr_assoc_doms;
			}

			/*
			* Retrieve the new associativity information for a virtual processor's
			* home node.
			*/
			static long hcall_vphn(unsigned long cpu, unsigned int *associativity)
			{
			long rc = 0;
			long retbuf[PLPAR_HCALL9_BUFSIZE] = {0};
			u64 flags = 1;
			int hwcpu = get_hard_smp_processor_id(cpu);

			rc = plpar_hcall9(H_HOME_NODE_ASSOCIATIVITY, retbuf, flags, hwcpu);
			vphn_unpack_associativity(retbuf, associativity);

			return rc;
			}

			static long vphn_get_associativity(unsigned long cpu,
			unsigned int *associativity)
			{
			long rc = 0;

			rc = hcall_vphn(cpu, associativity);

			switch (rc) {
			case H_FUNCTION:
			printk(KERN_INFO
			"VPHN is not supported. Disabling polling...\n");
			stop_topology_update();
			break;
			case H_HARDWARE:
			printk(KERN_ERR
			"hcall_vphn() experienced a hardware fault "
			"preventing VPHN. Disabling polling...\n");
			stop_topology_update();
			}

			return rc;
			}

			/*
			* Update the node maps and sysfs entries for each cpu whose home node
			* has changed.
			*/
			int arch_update_cpu_topology(void)
			{
			int cpu = 0, nid = 0, old_nid = 0;
			unsigned int associativity[VPHN_ASSOC_BUFSIZE] = {0};
			struct sys_device *sysdev = NULL;

			for_each_cpu_mask(cpu, cpu_associativity_changes_mask) {
			vphn_get_associativity(cpu, associativity);
			nid = associativity_to_nid(associativity);

			if (nid < 0 \|\| !node_online(nid))
			nid = first_online_node;

			old_nid = numa_cpu_lookup_table[cpu];

			/* Disable hotplug while we update the cpu
			* masks and sysfs.
			*/
			get_online_cpus();
			unregister_cpu_under_node(cpu, old_nid);
			unmap_cpu_from_node(cpu);
			map_cpu_to_node(cpu, nid);
			register_cpu_under_node(cpu, nid);
			put_online_cpus();

			sysdev = get_cpu_sysdev(cpu);
			if (sysdev)
			kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
			}

			return 1;
			}

			static void topology_work_fn(struct work_struct *work)
			{
			rebuild_sched_domains();
			}
			static DECLARE_WORK(topology_work, topology_work_fn);

			void topology_schedule_update(void)
			{
			schedule_work(&topology_work);
			}

			static void topology_timer_fn(unsigned long ignored)
			{
			if (!vphn_enabled)
			return;
			if (update_cpu_associativity_changes_mask() > 0)
			topology_schedule_update();
			set_topology_timer();
			}
			static struct timer_list topology_timer =
			TIMER_INITIALIZER(topology_timer_fn, 0, 0);

			static void set_topology_timer(void)
			{
			topology_timer.data = 0;
			topology_timer.expires = jiffies + 60 * HZ;
			add_timer(&topology_timer);
			}

			/*
			* Start polling for VPHN associativity changes.
			*/
			int start_topology_update(void)
			{
			int rc = 0;

			if (firmware_has_feature(FW_FEATURE_VPHN)) {
			vphn_enabled = 1;
			setup_cpu_associativity_change_counters();
			init_timer_deferrable(&topology_timer);
			set_topology_timer();
			rc = 1;
			}

			return rc;
			}
			__initcall(start_topology_update);

			/*
			* Disable polling for VPHN associativity changes.
			*/
			int stop_topology_update(void)
			{
			vphn_enabled = 0;
			return del_timer_sync(&topology_timer);
			}

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