Commit 258c91e8 authored by James Morse's avatar James Morse Committed by Borislav Petkov (AMD)
Browse files

x86/resctrl: Add CPU offline callback for resctrl work 



The resctrl architecture specific code may need to free a domain when a CPU
goes offline, it also needs to reset the CPUs PQR_ASSOC register.  Amongst
other things, the resctrl filesystem code needs to clear this CPU from the
cpu_mask of any control and monitor groups.

Currently, this is all done in core.c and called from resctrl_offline_cpu(),
making the split between architecture and filesystem code unclear.

Move the filesystem work to remove the CPU from the control and monitor groups
into a filesystem helper called resctrl_offline_cpu(), and rename the one in
core.c resctrl_arch_offline_cpu().

Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarShaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Reviewed-by: default avatarBabu Moger <babu.moger@amd.com>
Tested-by: default avatarShaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: default avatarPeter Newman <peternewman@google.com>
Tested-by: default avatarBabu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-23-james.morse@arm.com


Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
parent 978fcca9

arch/x86/kernel/cpu/resctrl/core.c

+5 −20
Original line number Diff line number Diff line
@@ -625,31 +625,15 @@ static int resctrl_arch_online_cpu(unsigned int cpu) 
	return 0;

}



static void clear_childcpus(struct rdtgroup *r, unsigned int cpu)

static int resctrl_arch_offline_cpu(unsigned int cpu)

{

	struct rdtgroup *cr;



	list_for_each_entry(cr, &r->mon.crdtgrp_list, mon.crdtgrp_list) {

		if (cpumask_test_and_clear_cpu(cpu, &cr->cpu_mask)) {

			break;

		}

	}

}



static int resctrl_offline_cpu(unsigned int cpu)

{

	struct rdtgroup *rdtgrp;

	struct rdt_resource *r;



	mutex_lock(&rdtgroup_mutex);

	resctrl_offline_cpu(cpu);



	for_each_capable_rdt_resource(r)

		domain_remove_cpu(cpu, r);

	list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {

		if (cpumask_test_and_clear_cpu(cpu, &rdtgrp->cpu_mask)) {

			clear_childcpus(rdtgrp, cpu);

			break;

		}

	}

	clear_closid_rmid(cpu);

	mutex_unlock(&rdtgroup_mutex);
@@ -971,7 +955,8 @@ static int __init resctrl_late_init(void) 


	state = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,

				  "x86/resctrl/cat:online:",

				  resctrl_arch_online_cpu, resctrl_offline_cpu);

				  resctrl_arch_online_cpu,

				  resctrl_arch_offline_cpu);

	if (state < 0)

		return state;

arch/x86/kernel/cpu/resctrl/rdtgroup.c

+24 −0
Original line number Diff line number Diff line
@@ -4017,6 +4017,30 @@ void resctrl_online_cpu(unsigned int cpu) 
	cpumask_set_cpu(cpu, &rdtgroup_default.cpu_mask);

}



static void clear_childcpus(struct rdtgroup *r, unsigned int cpu)

{

	struct rdtgroup *cr;



	list_for_each_entry(cr, &r->mon.crdtgrp_list, mon.crdtgrp_list) {

		if (cpumask_test_and_clear_cpu(cpu, &cr->cpu_mask))

			break;

	}

}



void resctrl_offline_cpu(unsigned int cpu)

{

	struct rdtgroup *rdtgrp;



	lockdep_assert_held(&rdtgroup_mutex);



	list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {

		if (cpumask_test_and_clear_cpu(cpu, &rdtgrp->cpu_mask)) {

			clear_childcpus(rdtgrp, cpu);

			break;

		}

	}

}



/*

 * rdtgroup_init - rdtgroup initialization

 *

include/linux/resctrl.h

+1 −0
Original line number Diff line number Diff line
@@ -226,6 +226,7 @@ u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d, 
int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d);

void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d);

void resctrl_online_cpu(unsigned int cpu);

void resctrl_offline_cpu(unsigned int cpu);



/**

 * resctrl_arch_rmid_read() - Read the eventid counter corresponding to rmid