Commit 5d88aa85 authored by Jesse Larrew's avatar Jesse Larrew Committed by Benjamin Herrenschmidt
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powerpc/pseries: Update CPU maps when device tree is updated 



Platform events such as partition migration or the new PRRN firmware
feature can cause the NUMA characteristics of a CPU to change, and these
changes will be reflected in the device tree nodes for the affected
CPUs.

This patch registers a handler for Open Firmware device tree updates
and reconfigures the CPU and node maps whenever the associativity
changes. Currently, this is accomplished by marking the affected CPUs in
the cpu_associativity_changes_mask and allowing
arch_update_cpu_topology() to retrieve the new associativity information
using hcall_vphn().

Protecting the NUMA cpu maps from concurrent access during an update
operation will be addressed in a subsequent patch in this series.

Signed-off-by: default avatarNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 8002b0c5

arch/powerpc/include/asm/firmware.h

+2 −1
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ 
#define FW_FEATURE_SET_MODE	ASM_CONST(0x0000000040000000)

#define FW_FEATURE_BEST_ENERGY	ASM_CONST(0x0000000080000000)

#define FW_FEATURE_TYPE1_AFFINITY ASM_CONST(0x0000000100000000)

#define FW_FEATURE_PRRN		ASM_CONST(0x0000000200000000)



#ifndef __ASSEMBLY__
@@ -66,7 +67,7 @@ enum { 
		FW_FEATURE_MULTITCE | FW_FEATURE_SPLPAR | FW_FEATURE_LPAR |

		FW_FEATURE_CMO | FW_FEATURE_VPHN | FW_FEATURE_XCMO |

		FW_FEATURE_SET_MODE | FW_FEATURE_BEST_ENERGY |

		FW_FEATURE_TYPE1_AFFINITY,

		FW_FEATURE_TYPE1_AFFINITY | FW_FEATURE_PRRN,

	FW_FEATURE_PSERIES_ALWAYS = 0,

	FW_FEATURE_POWERNV_POSSIBLE = FW_FEATURE_OPAL | FW_FEATURE_OPALv2,

	FW_FEATURE_POWERNV_ALWAYS = 0,

arch/powerpc/include/asm/prom.h

+1 −0
Original line number Diff line number Diff line
@@ -128,6 +128,7 @@ struct of_drconf_cell { 
#define OV5_CMO			0x0480	/* Cooperative Memory Overcommitment */

#define OV5_XCMO		0x0440	/* Page Coalescing */

#define OV5_TYPE1_AFFINITY	0x0580	/* Type 1 NUMA affinity */

#define OV5_PRRN		0x0540	/* Platform Resource Reassignment */

#define OV5_PFO_HW_RNG		0x0E80	/* PFO Random Number Generator */

#define OV5_PFO_HW_842		0x0E40	/* PFO Compression Accelerator */

#define OV5_PFO_HW_ENCR		0x0E20	/* PFO Encryption Accelerator */

arch/powerpc/mm/numa.c

+75 −24
Original line number Diff line number Diff line
@@ -1257,7 +1257,8 @@ u64 memory_hotplug_max(void) 
static u8 vphn_cpu_change_counts[NR_CPUS][MAX_DISTANCE_REF_POINTS];

static cpumask_t cpu_associativity_changes_mask;

static int vphn_enabled;

static void set_topology_timer(void);

static int prrn_enabled;

static void reset_topology_timer(void);



/*

 * Store the current values of the associativity change counters in the
@@ -1293,11 +1294,9 @@ static void setup_cpu_associativity_change_counters(void) 
 */

static int update_cpu_associativity_changes_mask(void)

{

	int cpu, nr_cpus = 0;

	int cpu;

	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];
@@ -1311,11 +1310,10 @@ static int update_cpu_associativity_changes_mask(void) 
		}

		if (changed) {

			cpumask_set_cpu(cpu, changes);

			nr_cpus++;

		}

	}



	return nr_cpus;

	return cpumask_weight(changes);

}



/*
@@ -1438,6 +1436,7 @@ int arch_update_cpu_topology(void) 
		dev = get_cpu_device(cpu);

		if (dev)

			kobject_uevent(&dev->kobj, KOBJ_CHANGE);

		cpumask_clear_cpu(cpu, &cpu_associativity_changes_mask);

		changed = 1;

	}
@@ -1457,37 +1456,80 @@ void topology_schedule_update(void) 


static void topology_timer_fn(unsigned long ignored)

{

	if (!vphn_enabled)

		return;

	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();

	set_topology_timer();

		reset_topology_timer();

	}

}

static struct timer_list topology_timer =

	TIMER_INITIALIZER(topology_timer_fn, 0, 0);



static void set_topology_timer(void)

static void reset_topology_timer(void)

{

	topology_timer.data = 0;

	topology_timer.expires = jiffies + 60 * HZ;

	add_timer(&topology_timer);

	mod_timer(&topology_timer, topology_timer.expires);

}



static void stage_topology_update(int core_id)

{

	cpumask_or(&cpu_associativity_changes_mask,

		&cpu_associativity_changes_mask, cpu_sibling_mask(core_id));

	reset_topology_timer();

}



static int dt_update_callback(struct notifier_block *nb,

				unsigned long action, void *data)

{

	struct of_prop_reconfig *update;

	int rc = NOTIFY_DONE;



	switch (action) {

	case OF_RECONFIG_ADD_PROPERTY:

	case OF_RECONFIG_UPDATE_PROPERTY:

		update = (struct of_prop_reconfig *)data;

		if (!of_prop_cmp(update->dn->type, "cpu")) {

			u32 core_id;

			of_property_read_u32(update->dn, "reg", &core_id);

			stage_topology_update(core_id);

			rc = NOTIFY_OK;

		}

		break;

	}



	return rc;

}



static struct notifier_block dt_update_nb = {

	.notifier_call = dt_update_callback,

};



/*

 * Start polling for VPHN associativity changes.

 * Start polling for associativity changes.

 */

int start_topology_update(void)

{

	int rc = 0;



	/* Disabled until races with load balancing are fixed */

	if (0 && firmware_has_feature(FW_FEATURE_VPHN) &&

	if (firmware_has_feature(FW_FEATURE_PRRN)) {

		if (!prrn_enabled) {

			prrn_enabled = 1;

			vphn_enabled = 0;

			rc = of_reconfig_notifier_register(&dt_update_nb);

		}

	} else if (0 && firmware_has_feature(FW_FEATURE_VPHN) &&

		   get_lppaca()->shared_proc) {

		/* Disabled until races with load balancing are fixed */

		if (!vphn_enabled) {

			prrn_enabled = 0;

			vphn_enabled = 1;

			setup_cpu_associativity_change_counters();

			init_timer_deferrable(&topology_timer);

		set_topology_timer();

		rc = 1;

			reset_topology_timer();

		}

	}



	return rc;
@@ -1499,7 +1541,16 @@ __initcall(start_topology_update); 
 */

int stop_topology_update(void)

{

	int rc = 0;



	if (prrn_enabled) {

		prrn_enabled = 0;

		rc = of_reconfig_notifier_unregister(&dt_update_nb);

	} else if (vphn_enabled) {

		vphn_enabled = 0;

	return del_timer_sync(&topology_timer);

		rc = del_timer_sync(&topology_timer);

	}



	return rc;

}

#endif /* CONFIG_PPC_SPLPAR */

arch/powerpc/platforms/pseries/firmware.c

+1 −0
Original line number Diff line number Diff line
@@ -110,6 +110,7 @@ struct vec5_fw_feature { 
static __initdata struct vec5_fw_feature

vec5_fw_features_table[] = {

	{FW_FEATURE_TYPE1_AFFINITY,	OV5_TYPE1_AFFINITY},

	{FW_FEATURE_PRRN,		OV5_PRRN},

};



void __init fw_vec5_feature_init(const char *vec5, unsigned long len)

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