diff options
Diffstat (limited to 'arch/x86/kernel/cpu/intel_rdt.c')
| -rw-r--r-- | arch/x86/kernel/cpu/intel_rdt.c | 403 |
1 files changed, 403 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c new file mode 100644 index 000000000000..5a533fefefa0 --- /dev/null +++ b/arch/x86/kernel/cpu/intel_rdt.c @@ -0,0 +1,403 @@ +/* + * Resource Director Technology(RDT) + * - Cache Allocation code. + * + * Copyright (C) 2016 Intel Corporation + * + * Authors: + * Fenghua Yu <fenghua.yu@intel.com> + * Tony Luck <tony.luck@intel.com> + * Vikas Shivappa <vikas.shivappa@intel.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * More information about RDT be found in the Intel (R) x86 Architecture + * Software Developer Manual June 2016, volume 3, section 17.17. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/cacheinfo.h> +#include <linux/cpuhotplug.h> + +#include <asm/intel-family.h> +#include <asm/intel_rdt.h> + +/* Mutex to protect rdtgroup access. */ +DEFINE_MUTEX(rdtgroup_mutex); + +DEFINE_PER_CPU_READ_MOSTLY(int, cpu_closid); + +#define domain_init(id) LIST_HEAD_INIT(rdt_resources_all[id].domains) + +struct rdt_resource rdt_resources_all[] = { + { + .name = "L3", + .domains = domain_init(RDT_RESOURCE_L3), + .msr_base = IA32_L3_CBM_BASE, + .min_cbm_bits = 1, + .cache_level = 3, + .cbm_idx_multi = 1, + .cbm_idx_offset = 0 + }, + { + .name = "L3DATA", + .domains = domain_init(RDT_RESOURCE_L3DATA), + .msr_base = IA32_L3_CBM_BASE, + .min_cbm_bits = 1, + .cache_level = 3, + .cbm_idx_multi = 2, + .cbm_idx_offset = 0 + }, + { + .name = "L3CODE", + .domains = domain_init(RDT_RESOURCE_L3CODE), + .msr_base = IA32_L3_CBM_BASE, + .min_cbm_bits = 1, + .cache_level = 3, + .cbm_idx_multi = 2, + .cbm_idx_offset = 1 + }, + { + .name = "L2", + .domains = domain_init(RDT_RESOURCE_L2), + .msr_base = IA32_L2_CBM_BASE, + .min_cbm_bits = 1, + .cache_level = 2, + .cbm_idx_multi = 1, + .cbm_idx_offset = 0 + }, +}; + +static int cbm_idx(struct rdt_resource *r, int closid) +{ + return closid * r->cbm_idx_multi + r->cbm_idx_offset; +} + +/* + * cache_alloc_hsw_probe() - Have to probe for Intel haswell server CPUs + * as they do not have CPUID enumeration support for Cache allocation. + * The check for Vendor/Family/Model is not enough to guarantee that + * the MSRs won't #GP fault because only the following SKUs support + * CAT: + * Intel(R) Xeon(R) CPU E5-2658 v3 @ 2.20GHz + * Intel(R) Xeon(R) CPU E5-2648L v3 @ 1.80GHz + * Intel(R) Xeon(R) CPU E5-2628L v3 @ 2.00GHz + * Intel(R) Xeon(R) CPU E5-2618L v3 @ 2.30GHz + * Intel(R) Xeon(R) CPU E5-2608L v3 @ 2.00GHz + * Intel(R) Xeon(R) CPU E5-2658A v3 @ 2.20GHz + * + * Probe by trying to write the first of the L3 cach mask registers + * and checking that the bits stick. Max CLOSids is always 4 and max cbm length + * is always 20 on hsw server parts. The minimum cache bitmask length + * allowed for HSW server is always 2 bits. Hardcode all of them. + */ +static inline bool cache_alloc_hsw_probe(void) +{ + if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && + boot_cpu_data.x86 == 6 && + boot_cpu_data.x86_model == INTEL_FAM6_HASWELL_X) { + struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3]; + u32 l, h, max_cbm = BIT_MASK(20) - 1; + + if (wrmsr_safe(IA32_L3_CBM_BASE, max_cbm, 0)) + return false; + rdmsr(IA32_L3_CBM_BASE, l, h); + + /* If all the bits were set in MSR, return success */ + if (l != max_cbm) + return false; + + r->num_closid = 4; + r->cbm_len = 20; + r->max_cbm = max_cbm; + r->min_cbm_bits = 2; + r->capable = true; + r->enabled = true; + + return true; + } + + return false; +} + +static void rdt_get_config(int idx, struct rdt_resource *r) +{ + union cpuid_0x10_1_eax eax; + union cpuid_0x10_1_edx edx; + u32 ebx, ecx; + + cpuid_count(0x00000010, idx, &eax.full, &ebx, &ecx, &edx.full); + r->num_closid = edx.split.cos_max + 1; + r->cbm_len = eax.split.cbm_len + 1; + r->max_cbm = BIT_MASK(eax.split.cbm_len + 1) - 1; + r->capable = true; + r->enabled = true; +} + +static void rdt_get_cdp_l3_config(int type) +{ + struct rdt_resource *r_l3 = &rdt_resources_all[RDT_RESOURCE_L3]; + struct rdt_resource *r = &rdt_resources_all[type]; + + r->num_closid = r_l3->num_closid / 2; + r->cbm_len = r_l3->cbm_len; + r->max_cbm = r_l3->max_cbm; + r->capable = true; + /* + * By default, CDP is disabled. CDP can be enabled by mount parameter + * "cdp" during resctrl file system mount time. + */ + r->enabled = false; +} + +static inline bool get_rdt_resources(void) +{ + bool ret = false; + + if (cache_alloc_hsw_probe()) + return true; + + if (!boot_cpu_has(X86_FEATURE_RDT_A)) + return false; + + if (boot_cpu_has(X86_FEATURE_CAT_L3)) { + rdt_get_config(1, &rdt_resources_all[RDT_RESOURCE_L3]); + if (boot_cpu_has(X86_FEATURE_CDP_L3)) { + rdt_get_cdp_l3_config(RDT_RESOURCE_L3DATA); + rdt_get_cdp_l3_config(RDT_RESOURCE_L3CODE); + } + ret = true; + } + if (boot_cpu_has(X86_FEATURE_CAT_L2)) { + /* CPUID 0x10.2 fields are same format at 0x10.1 */ + rdt_get_config(2, &rdt_resources_all[RDT_RESOURCE_L2]); + ret = true; + } + + return ret; +} + +static int get_cache_id(int cpu, int level) +{ + struct cpu_cacheinfo *ci = get_cpu_cacheinfo(cpu); + int i; + + for (i = 0; i < ci->num_leaves; i++) { + if (ci->info_list[i].level == level) + return ci->info_list[i].id; + } + + return -1; +} + +void rdt_cbm_update(void *arg) +{ + struct msr_param *m = (struct msr_param *)arg; + struct rdt_resource *r = m->res; + int i, cpu = smp_processor_id(); + struct rdt_domain *d; + + list_for_each_entry(d, &r->domains, list) { + /* Find the domain that contains this CPU */ + if (cpumask_test_cpu(cpu, &d->cpu_mask)) + goto found; + } + pr_info_once("cpu %d not found in any domain for resource %s\n", + cpu, r->name); + + return; + +found: + for (i = m->low; i < m->high; i++) { + int idx = cbm_idx(r, i); + + wrmsrl(r->msr_base + idx, d->cbm[i]); + } +} + +/* + * rdt_find_domain - Find a domain in a resource that matches input resource id + * + * Search resource r's domain list to find the resource id. If the resource + * id is found in a domain, return the domain. Otherwise, if requested by + * caller, return the first domain whose id is bigger than the input id. + * The domain list is sorted by id in ascending order. + */ +static struct rdt_domain *rdt_find_domain(struct rdt_resource *r, int id, + struct list_head **pos) +{ + struct rdt_domain *d; + struct list_head *l; + + if (id < 0) + return ERR_PTR(id); + + list_for_each(l, &r->domains) { + d = list_entry(l, struct rdt_domain, list); + /* When id is found, return its domain. */ + if (id == d->id) + return d; + /* Stop searching when finding id's position in sorted list. */ + if (id < d->id) + break; + } + + if (pos) + *pos = l; + + return NULL; +} + +/* + * domain_add_cpu - Add a cpu to a resource's domain list. + * + * If an existing domain in the resource r's domain list matches the cpu's + * resource id, add the cpu in the domain. + * + * Otherwise, a new domain is allocated and inserted into the right position + * in the domain list sorted by id in ascending order. + * + * The order in the domain list is visible to users when we print entries + * in the schemata file and schemata input is validated to have the same order + * as this list. + */ +static void domain_add_cpu(int cpu, struct rdt_resource *r) +{ + int i, id = get_cache_id(cpu, r->cache_level); + struct list_head *add_pos = NULL; + struct rdt_domain *d; + + d = rdt_find_domain(r, id, &add_pos); + if (IS_ERR(d)) { + pr_warn("Could't find cache id for cpu %d\n", cpu); + return; + } + + if (d) { + cpumask_set_cpu(cpu, &d->cpu_mask); + return; + } + + d = kzalloc_node(sizeof(*d), GFP_KERNEL, cpu_to_node(cpu)); + if (!d) + return; + + d->id = id; + + d->cbm = kmalloc_array(r->num_closid, sizeof(*d->cbm), GFP_KERNEL); + if (!d->cbm) { + kfree(d); + return; + } + + for (i = 0; i < r->num_closid; i++) { + int idx = cbm_idx(r, i); + + d->cbm[i] = r->max_cbm; + wrmsrl(r->msr_base + idx, d->cbm[i]); + } + + cpumask_set_cpu(cpu, &d->cpu_mask); + list_add_tail(&d->list, add_pos); + r->num_domains++; +} + +static void domain_remove_cpu(int cpu, struct rdt_resource *r) +{ + int id = get_cache_id(cpu, r->cache_level); + struct rdt_domain *d; + + d = rdt_find_domain(r, id, NULL); + if (IS_ERR_OR_NULL(d)) { + pr_warn("Could't find cache id for cpu %d\n", cpu); + return; + } + + cpumask_clear_cpu(cpu, &d->cpu_mask); + if (cpumask_empty(&d->cpu_mask)) { + r->num_domains--; + kfree(d->cbm); + list_del(&d->list); + kfree(d); + } +} + +static void clear_closid(int cpu) +{ + struct intel_pqr_state *state = this_cpu_ptr(&pqr_state); + + per_cpu(cpu_closid, cpu) = 0; + state->closid = 0; + wrmsr(MSR_IA32_PQR_ASSOC, state->rmid, 0); +} + +static int intel_rdt_online_cpu(unsigned int cpu) +{ + struct rdt_resource *r; + + mutex_lock(&rdtgroup_mutex); + for_each_capable_rdt_resource(r) + domain_add_cpu(cpu, r); + /* The cpu is set in default rdtgroup after online. */ + cpumask_set_cpu(cpu, &rdtgroup_default.cpu_mask); + clear_closid(cpu); + mutex_unlock(&rdtgroup_mutex); + + return 0; +} + +static int intel_rdt_offline_cpu(unsigned int cpu) +{ + struct rdtgroup *rdtgrp; + struct rdt_resource *r; + + mutex_lock(&rdtgroup_mutex); + 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)) + break; + } + clear_closid(cpu); + mutex_unlock(&rdtgroup_mutex); + + return 0; +} + +static int __init intel_rdt_late_init(void) +{ + struct rdt_resource *r; + int state, ret; + + if (!get_rdt_resources()) + return -ENODEV; + + state = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, + "x86/rdt/cat:online:", + intel_rdt_online_cpu, intel_rdt_offline_cpu); + if (state < 0) + return state; + + ret = rdtgroup_init(); + if (ret) { + cpuhp_remove_state(state); + return ret; + } + + for_each_capable_rdt_resource(r) + pr_info("Intel RDT %s allocation detected\n", r->name); + + return 0; +} + +late_initcall(intel_rdt_late_init); |