Commit-ID: cf0978cd31053d58c99ab74e613147f86ecd1724 Gitweb: http://git.kernel.org/tip/cf0978cd31053d58c99ab74e613147f86ecd1724 Author: Fenghua Yu <fenghua...@intel.com> AuthorDate: Thu, 17 Dec 2015 14:46:13 -0800 Committer: H. Peter Anvin <h...@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.shiva...@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.shiva...@linux.intel.com> Link: http://lkml.kernel.org/r/1450392376-6397-9-git-send-email-fenghua...@intel.com Signed-off-by: Fenghua Yu <fenghua...@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: -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
