linux-kernel - [PATCH v5 19/40] x86/resctrl: Add resctrl_arch_is_evt

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Message-Id: <20241004180347.19985-20-james.morse@arm.com>
Date: Fri,  4 Oct 2024 18:03:26 +0000
From: James Morse <james.morse@....com>
To: x86@...nel.org,
	linux-kernel@...r.kernel.org
Cc: Fenghua Yu <fenghua.yu@...el.com>,
	Reinette Chatre <reinette.chatre@...el.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	H Peter Anvin <hpa@...or.com>,
	Babu Moger <Babu.Moger@....com>,
	James Morse <james.morse@....com>,
	shameerali.kolothum.thodi@...wei.com,
	D Scott Phillips OS <scott@...amperecomputing.com>,
	carl@...amperecomputing.com,
	lcherian@...vell.com,
	bobo.shaobowang@...wei.com,
	tan.shaopeng@...itsu.com,
	baolin.wang@...ux.alibaba.com,
	Jamie Iles <quic_jiles@...cinc.com>,
	Xin Hao <xhao@...ux.alibaba.com>,
	peternewman@...gle.com,
	dfustini@...libre.com,
	amitsinght@...vell.com,
	David Hildenbrand <david@...hat.com>,
	Rex Nie <rex.nie@...uarmicro.com>,
	Dave Martin <dave.martin@....com>,
	Shaopeng Tan <tan.shaopeng@...fujitsu.com>
Subject: [PATCH v5 19/40] x86/resctrl: Add resctrl_arch_is_evt_configurable() to abstract BMEC

When BMEC is supported the resctrl event can be configured in a number
of ways. This depends on architecture support. rdt_get_mon_l3_config()
modifies the struct mon_evt and calls mbm_config_rftype_init() to create
the files that allow the configuration.

Splitting this into separate architecture and filesystem parts would
require the struct mon_evt and mbm_config_rftype_init() to be exposed.

Instead, add resctrl_arch_is_evt_configurable(), and use this from
resctrl_mon_resource_init() to initialise struct mon_evt and call
mbm_config_rftype_init().
resctrl_arch_is_evt_configurable() calls rdt_cpu_has() so it doesn't
obviously benefit from being inlined. Putting it in core.c will allow
rdt_cpu_has() to eventually become static.

Signed-off-by: James Morse <james.morse@....com>
Tested-by: Carl Worth <carl@...amperecomputing.com> # arm64
Tested-by: Shaopeng Tan <tan.shaopeng@...fujitsu.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@...fujitsu.com>
---
Changes since v4:
 * Moved all the __init changes to a later patch now that the exit gubbins
   comes first.
---
 arch/x86/kernel/cpu/resctrl/core.c    | 15 +++++++++++++++
 arch/x86/kernel/cpu/resctrl/monitor.c | 18 +++++++++---------
 include/linux/resctrl.h               |  2 ++
 3 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 8db946ebc4ff..b5ad1ed2a4de 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -866,6 +866,21 @@ bool __init rdt_cpu_has(int flag)
 	return ret;
 }
 
+bool __init resctrl_arch_is_evt_configurable(enum resctrl_event_id evt)
+{
+	if (!rdt_cpu_has(X86_FEATURE_BMEC))
+		return false;
+
+	switch (evt) {
+	case QOS_L3_MBM_TOTAL_EVENT_ID:
+		return rdt_cpu_has(X86_FEATURE_CQM_MBM_TOTAL);
+	case QOS_L3_MBM_LOCAL_EVENT_ID:
+		return rdt_cpu_has(X86_FEATURE_CQM_MBM_LOCAL);
+	default:
+		return false;
+	}
+}
+
 static __init bool get_mem_config(void)
 {
 	struct rdt_hw_resource *hw_res = &rdt_resources_all[RDT_RESOURCE_MBA];
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 68e05bd0eb94..ae8552ef98e6 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -1205,6 +1205,15 @@ int __init resctrl_mon_resource_init(void)
 
 	l3_mon_evt_init(r);
 
+	if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_TOTAL_EVENT_ID)) {
+		mbm_total_event.configurable = true;
+		mbm_config_rftype_init("mbm_total_bytes_config");
+	}
+	if (resctrl_arch_is_evt_configurable(QOS_L3_MBM_LOCAL_EVENT_ID)) {
+		mbm_local_event.configurable = true;
+		mbm_config_rftype_init("mbm_local_bytes_config");
+	}
+
 	return 0;
 }
 
@@ -1248,15 +1257,6 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
 		/* Detect list of bandwidth sources that can be tracked */
 		cpuid_count(0x80000020, 3, &eax, &ebx, &ecx, &edx);
 		hw_res->mbm_cfg_mask = ecx & MAX_EVT_CONFIG_BITS;
-
-		if (rdt_cpu_has(X86_FEATURE_CQM_MBM_TOTAL)) {
-			mbm_total_event.configurable = true;
-			mbm_config_rftype_init("mbm_total_bytes_config");
-		}
-		if (rdt_cpu_has(X86_FEATURE_CQM_MBM_LOCAL)) {
-			mbm_local_event.configurable = true;
-			mbm_config_rftype_init("mbm_local_bytes_config");
-		}
 	}
 
 	r->mon_capable = true;
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index f75f0409ae09..224a14d9aa7a 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -313,6 +313,8 @@ struct rdt_domain_hdr *resctrl_arch_find_domain(struct list_head *domain_list,
 						int id);
 int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid);
 
+bool __init resctrl_arch_is_evt_configurable(enum resctrl_event_id evt);
+
 /*
  * Update the ctrl_val and apply this config right now.
  * Must be called on one of the domain's CPUs.
-- 
2.39.2