[PATCH v7 21/24] x86/resctrl: Configure mbm_cntr_assign mode if supported

From: Babu Moger
Date: Wed Sep 04 2024 - 18:27:48 EST


Configure mbm_cntr_assign on AMD.

'mbm_cntr_assign' mode in AMD is ABMC (Assignable Bandwidth Monitoring
Counters). When the ABMC is updated, it must be updated on all logical
processors in the resctrl domain.

Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
v7: Introduced resctrl_arch_mbm_cntr_assign_configure() to configure.
Moved the default settings to rdt_get_mon_l3_config(). It should be
done before the hotplug handler is called. It cannot be done at
rdtgroup_init().

v6: Keeping the default enablement in arch init code for now.
This may need some discussion.
Renamed resctrl_arch_configure_abmc to resctrl_arch_mbm_cntr_assign_configure.

v5: New patch to enable ABMC by default.
---
arch/x86/kernel/cpu/resctrl/internal.h | 1 +
arch/x86/kernel/cpu/resctrl/monitor.c | 1 +
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 11 +++++++++++
3 files changed, 13 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 9a65a13ccbe9..3250561f0187 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -709,6 +709,7 @@ int rdtgroup_assign_cntr(struct rdt_resource *r, struct rdtgroup *rdtgrp,
struct rdt_mon_domain *d, enum resctrl_event_id evtid);
int rdtgroup_unassign_cntr(struct rdt_resource *r, struct rdtgroup *rdtgrp,
struct rdt_mon_domain *d, enum resctrl_event_id evtid);
+void resctrl_arch_mbm_cntr_assign_configure(struct rdt_resource *r);
void rdt_staged_configs_clear(void);
bool closid_allocated(unsigned int closid);
int resctrl_find_cleanest_closid(void);
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 09b1d8bb0aa0..314c0b297470 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -1261,6 +1261,7 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
cpuid_count(0x80000020, 5, &eax, &ebx, &ecx, &edx);
r->mon.num_mbm_cntrs = (ebx & 0xFFFF) + 1;
resctrl_file_fflags_init("num_mbm_cntrs", RFTYPE_MON_INFO);
+ hw_res->mbm_cntr_assign_enabled = true;
}
}

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 7a8ece12d7da..1054583bef9d 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2726,6 +2726,13 @@ int resctrl_arch_mbm_cntr_assign_set(struct rdt_resource *r, bool enable)
return 0;
}

+void resctrl_arch_mbm_cntr_assign_configure(struct rdt_resource *r)
+{
+ struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
+
+ resctrl_abmc_set_one_amd(&hw_res->mbm_cntr_assign_enabled);
+}
+
/*
* We don't allow rdtgroup directories to be created anywhere
* except the root directory. Thus when looking for the rdtgroup
@@ -4510,9 +4517,13 @@ int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d)

void resctrl_online_cpu(unsigned int cpu)
{
+ struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
+
mutex_lock(&rdtgroup_mutex);
/* The CPU is set in default rdtgroup after online. */
cpumask_set_cpu(cpu, &rdtgroup_default.cpu_mask);
+ if (r->mon.mbm_cntr_assignable)
+ resctrl_arch_mbm_cntr_assign_configure(r);
mutex_unlock(&rdtgroup_mutex);
}

--
2.34.1