2 * Resource Director Technology(RDT)
3 * - Cache Allocation code.
5 * Copyright (C) 2016 Intel Corporation
8 * Fenghua Yu <fenghua.yu@intel.com>
9 * Tony Luck <tony.luck@intel.com>
10 * Vikas Shivappa <vikas.shivappa@intel.com>
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms and conditions of the GNU General Public License,
14 * version 2, as published by the Free Software Foundation.
16 * This program is distributed in the hope it will be useful, but WITHOUT
17 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
18 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
21 * More information about RDT be found in the Intel (R) x86 Architecture
22 * Software Developer Manual June 2016, volume 3, section 17.17.
25 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27 #include <linux/slab.h>
28 #include <linux/err.h>
29 #include <linux/cacheinfo.h>
30 #include <linux/cpuhotplug.h>
32 #include <asm/intel_rdt_common.h>
33 #include <asm/intel-family.h>
34 #include <asm/intel_rdt.h>
36 /* Mutex to protect rdtgroup access. */
37 DEFINE_MUTEX(rdtgroup_mutex);
39 #define domain_init(id) LIST_HEAD_INIT(rdt_resources_all[id].domains)
41 struct rdt_resource rdt_resources_all[] = {
44 .domains = domain_init(RDT_RESOURCE_L3),
45 .msr_base = IA32_L3_CBM_BASE,
53 .domains = domain_init(RDT_RESOURCE_L3DATA),
54 .msr_base = IA32_L3_CBM_BASE,
62 .domains = domain_init(RDT_RESOURCE_L3CODE),
63 .msr_base = IA32_L3_CBM_BASE,
71 .domains = domain_init(RDT_RESOURCE_L2),
72 .msr_base = IA32_L2_CBM_BASE,
80 static int cbm_idx(struct rdt_resource *r, int closid)
82 return closid * r->cbm_idx_multi + r->cbm_idx_offset;
86 * cache_alloc_hsw_probe() - Have to probe for Intel haswell server CPUs
87 * as they do not have CPUID enumeration support for Cache allocation.
88 * The check for Vendor/Family/Model is not enough to guarantee that
89 * the MSRs won't #GP fault because only the following SKUs support
91 * Intel(R) Xeon(R) CPU E5-2658 v3 @ 2.20GHz
92 * Intel(R) Xeon(R) CPU E5-2648L v3 @ 1.80GHz
93 * Intel(R) Xeon(R) CPU E5-2628L v3 @ 2.00GHz
94 * Intel(R) Xeon(R) CPU E5-2618L v3 @ 2.30GHz
95 * Intel(R) Xeon(R) CPU E5-2608L v3 @ 2.00GHz
96 * Intel(R) Xeon(R) CPU E5-2658A v3 @ 2.20GHz
98 * Probe by trying to write the first of the L3 cach mask registers
99 * and checking that the bits stick. Max CLOSids is always 4 and max cbm length
100 * is always 20 on hsw server parts. The minimum cache bitmask length
101 * allowed for HSW server is always 2 bits. Hardcode all of them.
103 static inline bool cache_alloc_hsw_probe(void)
105 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
106 boot_cpu_data.x86 == 6 &&
107 boot_cpu_data.x86_model == INTEL_FAM6_HASWELL_X) {
108 struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3];
109 u32 l, h, max_cbm = BIT_MASK(20) - 1;
111 if (wrmsr_safe(IA32_L3_CBM_BASE, max_cbm, 0))
113 rdmsr(IA32_L3_CBM_BASE, l, h);
115 /* If all the bits were set in MSR, return success */
121 r->max_cbm = max_cbm;
132 static void rdt_get_config(int idx, struct rdt_resource *r)
134 union cpuid_0x10_1_eax eax;
135 union cpuid_0x10_1_edx edx;
138 cpuid_count(0x00000010, idx, &eax.full, &ebx, &ecx, &edx.full);
139 r->num_closid = edx.split.cos_max + 1;
140 r->cbm_len = eax.split.cbm_len + 1;
141 r->max_cbm = BIT_MASK(eax.split.cbm_len + 1) - 1;
146 static void rdt_get_cdp_l3_config(int type)
148 struct rdt_resource *r_l3 = &rdt_resources_all[RDT_RESOURCE_L3];
149 struct rdt_resource *r = &rdt_resources_all[type];
151 r->num_closid = r_l3->num_closid / 2;
152 r->cbm_len = r_l3->cbm_len;
153 r->max_cbm = r_l3->max_cbm;
156 * By default, CDP is disabled. CDP can be enabled by mount parameter
157 * "cdp" during resctrl file system mount time.
162 static inline bool get_rdt_resources(void)
166 if (cache_alloc_hsw_probe())
169 if (!boot_cpu_has(X86_FEATURE_RDT_A))
172 if (boot_cpu_has(X86_FEATURE_CAT_L3)) {
173 rdt_get_config(1, &rdt_resources_all[RDT_RESOURCE_L3]);
174 if (boot_cpu_has(X86_FEATURE_CDP_L3)) {
175 rdt_get_cdp_l3_config(RDT_RESOURCE_L3DATA);
176 rdt_get_cdp_l3_config(RDT_RESOURCE_L3CODE);
180 if (boot_cpu_has(X86_FEATURE_CAT_L2)) {
181 /* CPUID 0x10.2 fields are same format at 0x10.1 */
182 rdt_get_config(2, &rdt_resources_all[RDT_RESOURCE_L2]);
189 static int get_cache_id(int cpu, int level)
191 struct cpu_cacheinfo *ci = get_cpu_cacheinfo(cpu);
194 for (i = 0; i < ci->num_leaves; i++) {
195 if (ci->info_list[i].level == level)
196 return ci->info_list[i].id;
202 void rdt_cbm_update(void *arg)
204 struct msr_param *m = (struct msr_param *)arg;
205 struct rdt_resource *r = m->res;
206 int i, cpu = smp_processor_id();
207 struct rdt_domain *d;
209 list_for_each_entry(d, &r->domains, list) {
210 /* Find the domain that contains this CPU */
211 if (cpumask_test_cpu(cpu, &d->cpu_mask))
214 pr_info_once("cpu %d not found in any domain for resource %s\n",
220 for (i = m->low; i < m->high; i++) {
221 int idx = cbm_idx(r, i);
223 wrmsrl(r->msr_base + idx, d->cbm[i]);
228 * rdt_find_domain - Find a domain in a resource that matches input resource id
230 * Search resource r's domain list to find the resource id. If the resource
231 * id is found in a domain, return the domain. Otherwise, if requested by
232 * caller, return the first domain whose id is bigger than the input id.
233 * The domain list is sorted by id in ascending order.
235 static struct rdt_domain *rdt_find_domain(struct rdt_resource *r, int id,
236 struct list_head **pos)
238 struct rdt_domain *d;
244 list_for_each(l, &r->domains) {
245 d = list_entry(l, struct rdt_domain, list);
246 /* When id is found, return its domain. */
249 /* Stop searching when finding id's position in sorted list. */
261 * domain_add_cpu - Add a cpu to a resource's domain list.
263 * If an existing domain in the resource r's domain list matches the cpu's
264 * resource id, add the cpu in the domain.
266 * Otherwise, a new domain is allocated and inserted into the right position
267 * in the domain list sorted by id in ascending order.
269 * The order in the domain list is visible to users when we print entries
270 * in the schemata file and schemata input is validated to have the same order
273 static void domain_add_cpu(int cpu, struct rdt_resource *r)
275 int i, id = get_cache_id(cpu, r->cache_level);
276 struct list_head *add_pos = NULL;
277 struct rdt_domain *d;
279 d = rdt_find_domain(r, id, &add_pos);
281 pr_warn("Could't find cache id for cpu %d\n", cpu);
286 cpumask_set_cpu(cpu, &d->cpu_mask);
290 d = kzalloc_node(sizeof(*d), GFP_KERNEL, cpu_to_node(cpu));
296 d->cbm = kmalloc_array(r->num_closid, sizeof(*d->cbm), GFP_KERNEL);
302 for (i = 0; i < r->num_closid; i++) {
303 int idx = cbm_idx(r, i);
305 d->cbm[i] = r->max_cbm;
306 wrmsrl(r->msr_base + idx, d->cbm[i]);
309 cpumask_set_cpu(cpu, &d->cpu_mask);
310 list_add_tail(&d->list, add_pos);
314 static void domain_remove_cpu(int cpu, struct rdt_resource *r)
316 int id = get_cache_id(cpu, r->cache_level);
317 struct rdt_domain *d;
319 d = rdt_find_domain(r, id, NULL);
320 if (IS_ERR_OR_NULL(d)) {
321 pr_warn("Could't find cache id for cpu %d\n", cpu);
325 cpumask_clear_cpu(cpu, &d->cpu_mask);
326 if (cpumask_empty(&d->cpu_mask)) {
334 static int intel_rdt_online_cpu(unsigned int cpu)
336 struct intel_pqr_state *state = this_cpu_ptr(&pqr_state);
337 struct rdt_resource *r;
339 mutex_lock(&rdtgroup_mutex);
340 for_each_capable_rdt_resource(r)
341 domain_add_cpu(cpu, r);
343 wrmsr(MSR_IA32_PQR_ASSOC, state->rmid, 0);
344 mutex_unlock(&rdtgroup_mutex);
349 static int intel_rdt_offline_cpu(unsigned int cpu)
351 struct rdt_resource *r;
353 mutex_lock(&rdtgroup_mutex);
354 for_each_capable_rdt_resource(r)
355 domain_remove_cpu(cpu, r);
356 mutex_unlock(&rdtgroup_mutex);
361 static int __init intel_rdt_late_init(void)
363 struct rdt_resource *r;
366 if (!get_rdt_resources())
369 state = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
370 "x86/rdt/cat:online:",
371 intel_rdt_online_cpu, intel_rdt_offline_cpu);
375 for_each_capable_rdt_resource(r)
376 pr_info("Intel RDT %s allocation detected\n", r->name);
381 late_initcall(intel_rdt_late_init);