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[tip:x86/cache] x86/intel_rdt: Hot cpu support for Cache Allocation

From tip-bot for Fenghua Yu <tipbot@zytor.com>
Newsgroups linux.kernel
Subject [tip:x86/cache] x86/intel_rdt: Hot cpu support for Cache Allocation
Date 2015-12-18 22:40 +0100
Message-ID <qHaUP-2Dm-49@gated-at.bofh.it> (permalink)
References <qGN2b-48Z-39@gated-at.bofh.it>
Organization linux.* mail to news gateway

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Commit-ID:  cf0978cd31053d58c99ab74e613147f86ecd1724
Gitweb:     http://git.kernel.org/tip/cf0978cd31053d58c99ab74e613147f86ecd1724
Author:     Fenghua Yu <fenghua.yu@intel.com>
AuthorDate: Thu, 17 Dec 2015 14:46:13 -0800
Committer:  H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Fri, 18 Dec 2015 13:17:56 -0800

x86/intel_rdt: Hot cpu support for Cache Allocation

From: Vikas Shivappa <vikas.shivappa@linux.intel.com>

This patch adds hot plug cpu support for Intel Cache allocation. Support
includes updating the cache bitmask MSRs IA32_L3_QOS_n when a new CPU
package comes online or goes offline. The IA32_L3_QOS_n MSRs are one per
Class of service on each CPU package. The new package's MSRs are
synchronized with the values of existing MSRs. Also the software cache
for IA32_PQR_ASSOC MSRs are reset during hot cpu notifications.

Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Link: http://lkml.kernel.org/r/1450392376-6397-9-git-send-email-fenghua.yu@intel.com
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 arch/x86/kernel/cpu/intel_rdt.c | 76 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)

diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index 8379df8..31f8588 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -24,6 +24,7 @@
 
 #include <linux/slab.h>
 #include <linux/err.h>
+#include <linux/cpu.h>
 #include <linux/sched.h>
 #include <asm/pqr_common.h>
 #include <asm/intel_rdt.h>
@@ -234,6 +235,75 @@ static inline bool rdt_cpumask_update(int cpu)
 	return false;
 }
 
+/*
+ * cbm_update_msrs() - Updates all the existing IA32_L3_MASK_n MSRs
+ * which are one per CLOSid on the current package.
+ */
+static void cbm_update_msrs(void *dummy)
+{
+	int maxid = boot_cpu_data.x86_cache_max_closid;
+	struct rdt_remote_data info;
+	unsigned int i;
+
+	for (i = 0; i < maxid; i++) {
+		if (cctable[i].clos_refcnt) {
+			info.msr = CBM_FROM_INDEX(i);
+			info.val = cctable[i].l3_cbm;
+			msr_cpu_update(&info);
+		}
+	}
+}
+
+static inline void intel_rdt_cpu_start(int cpu)
+{
+	struct intel_pqr_state *state = &per_cpu(pqr_state, cpu);
+
+	state->closid = 0;
+	mutex_lock(&rdt_group_mutex);
+	if (rdt_cpumask_update(cpu))
+		smp_call_function_single(cpu, cbm_update_msrs, NULL, 1);
+	mutex_unlock(&rdt_group_mutex);
+}
+
+static void intel_rdt_cpu_exit(unsigned int cpu)
+{
+	int i;
+
+	mutex_lock(&rdt_group_mutex);
+	if (!cpumask_test_and_clear_cpu(cpu, &rdt_cpumask)) {
+		mutex_unlock(&rdt_group_mutex);
+		return;
+	}
+
+	cpumask_and(&tmp_cpumask, topology_core_cpumask(cpu), cpu_online_mask);
+	cpumask_clear_cpu(cpu, &tmp_cpumask);
+	i = cpumask_any(&tmp_cpumask);
+
+	if (i < nr_cpu_ids)
+		cpumask_set_cpu(i, &rdt_cpumask);
+	mutex_unlock(&rdt_group_mutex);
+}
+
+static int intel_rdt_cpu_notifier(struct notifier_block *nb,
+				  unsigned long action, void *hcpu)
+{
+	unsigned int cpu  = (unsigned long)hcpu;
+
+	switch (action) {
+	case CPU_DOWN_FAILED:
+	case CPU_ONLINE:
+		intel_rdt_cpu_start(cpu);
+		break;
+	case CPU_DOWN_PREPARE:
+		intel_rdt_cpu_exit(cpu);
+		break;
+	default:
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
 static int __init intel_rdt_late_init(void)
 {
 	struct cpuinfo_x86 *c = &boot_cpu_data;
@@ -261,9 +331,15 @@ static int __init intel_rdt_late_init(void)
 		goto out_err;
 	}
 
+	cpu_notifier_register_begin();
+
 	for_each_online_cpu(i)
 		rdt_cpumask_update(i);
 
+	__hotcpu_notifier(intel_rdt_cpu_notifier, 0);
+
+	cpu_notifier_register_done();
+
 	static_key_slow_inc(&rdt_enable_key);
 	pr_info("Intel cache allocation enabled\n");
 out_err:
--
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Thread

[PATCH V16 00/11] x86: Intel Cache Allocation Technology Support "Fenghua Yu" <fenghua.yu@intel.com> - 2015-12-17 21:10 +0100
  [PATCH V16 01/11] x86/intel_cqm: Modify hot cpu notification handling "Fenghua Yu" <fenghua.yu@intel.com> - 2015-12-17 21:10 +0100
    [tip:x86/cache] x86/intel_cqm:   Modify hot cpu notification handling tip-bot for Fenghua Yu <tipbot@zytor.com> - 2015-12-18 22:40 +0100
  [PATCH V16 03/11] x86/intel_rdt: Cache Allocation documentation "Fenghua Yu" <fenghua.yu@intel.com> - 2015-12-17 21:10 +0100
    [tip:x86/cache] x86/intel_rdt: Cache Allocation documentation tip-bot for Fenghua Yu <tipbot@zytor.com> - 2015-12-18 22:40 +0100
  [PATCH V16 07/11] x86/intel_rdt: Implement scheduling support for Intel RDT "Fenghua Yu" <fenghua.yu@intel.com> - 2015-12-17 21:10 +0100
    [tip:x86/cache] x86/intel_rdt:   Implement scheduling support for Intel RDT tip-bot for Fenghua Yu <tipbot@zytor.com> - 2015-12-18 22:40 +0100
  [PATCH V16 04/11] x86/intel_rdt: Add support for Cache Allocation detection "Fenghua Yu" <fenghua.yu@intel.com> - 2015-12-17 21:10 +0100
    [tip:x86/cache] x86/intel_rdt:   Add support for Cache Allocation detection tip-bot for Fenghua Yu <tipbot@zytor.com> - 2015-12-18 22:40 +0100
  [PATCH V16 09/11] x86/intel_rdt: Intel haswell Cache Allocation enumeration "Fenghua Yu" <fenghua.yu@intel.com> - 2015-12-17 21:10 +0100
    [tip:x86/cache] x86/intel_rdt:   Intel haswell Cache Allocation enumeration tip-bot for Fenghua Yu <tipbot@zytor.com> - 2015-12-18 22:40 +0100
  [PATCH V16 08/11] x86/intel_rdt: Hot cpu support for Cache Allocation "Fenghua Yu" <fenghua.yu@intel.com> - 2015-12-17 21:10 +0100
    [tip:x86/cache] x86/intel_rdt:   Hot cpu support for Cache Allocation tip-bot for Fenghua Yu <tipbot@zytor.com> - 2015-12-18 22:40 +0100
  [PATCH V16 06/11] x86/intel_rdt: Add L3 cache capacity bitmask management "Fenghua Yu" <fenghua.yu@intel.com> - 2015-12-17 21:10 +0100
    [tip:x86/cache] x86/intel_rdt:   Add L3 cache capacity bitmask management tip-bot for Fenghua Yu <tipbot@zytor.com> - 2015-12-18 22:40 +0100
  [PATCH V16 11/11] x86,cgroup/intel_rdt : Add a cgroup interface to manage Intel cache allocation "Fenghua Yu" <fenghua.yu@intel.com> - 2015-12-17 21:10 +0100
    [tip:x86/cache] x86,cgroup/intel_rdt :   Add a cgroup interface to manage Intel cache allocation tip-bot for Fenghua Yu <tipbot@zytor.com> - 2015-12-18 22:40 +0100
    Re: [PATCH V16 11/11] x86,cgroup/intel_rdt : Add a cgroup interface  to manage Intel cache allocation Thomas Gleixner <tglx@linutronix.de> - 2015-12-19 11:50 +0100
      Re: [PATCH V16 11/11] x86,cgroup/intel_rdt : Add a cgroup interface  to manage Intel cache allocation Marcelo Tosatti <mtosatti@redhat.com> - 2015-12-21 13:00 +0100
        Re: [PATCH V16 11/11] x86,cgroup/intel_rdt : Add a cgroup interface  to manage Intel cache allocation Thomas Gleixner <tglx@linutronix.de> - 2015-12-21 14:50 +0100
        Re: [PATCH V16 11/11] x86,cgroup/intel_rdt : Add a cgroup interface  to manage Intel cache allocation Luiz Capitulino <lcapitulino@redhat.com> - 2015-12-21 16:50 +0100
          Re: [PATCH V16 11/11] x86,cgroup/intel_rdt : Add a cgroup interface  to manage Intel cache allocation Marcelo Tosatti <mtosatti@redhat.com> - 2015-12-22 00:10 +0100
  Re: [PATCH V16 00/11] x86: Intel Cache Allocation Technology  Support Christoph Lameter <cl@linux.com> - 2015-12-18 18:50 +0100
    Re: [PATCH V16 00/11] x86: Intel Cache Allocation Technology Support Marcelo Tosatti <mtosatti@redhat.com> - 2015-12-21 13:00 +0100
      Re: [PATCH V16 00/11] x86: Intel Cache Allocation Technology  Support Christoph Lameter <cl@linux.com> - 2015-12-21 14:00 +0100
  Re: [PATCH V16 00/11] x86: Intel Cache Allocation Technology  Support Luiz Capitulino <lcapitulino@redhat.com> - 2015-12-21 17:00 +0100
  Re: [PATCH V16 00/11] x86: Intel Cache Allocation Technology Support Tejun Heo <tj@kernel.org> - 2015-12-23 17:00 +0100

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