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1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/cpuhotplug.h>
4#include <linux/cpumask.h>
5#include <linux/slab.h>
6#include <linux/mm.h>
7
8#include <asm/apic.h>
9
10#include "local.h"
11
12struct cluster_mask {
13 unsigned int clusterid;
14 int node;
15 struct cpumask mask;
16};
17
18static DEFINE_PER_CPU(u32, x86_cpu_to_logical_apicid);
19static DEFINE_PER_CPU(cpumask_var_t, ipi_mask);
20static DEFINE_PER_CPU(struct cluster_mask *, cluster_masks);
21static struct cluster_mask *cluster_hotplug_mask;
22
23static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
24{
25 return x2apic_enabled();
26}
27
28static void x2apic_send_IPI(int cpu, int vector)
29{
30 u32 dest = per_cpu(x86_cpu_to_logical_apicid, cpu);
31
32 x2apic_wrmsr_fence();
33 __x2apic_send_IPI_dest(dest, vector, APIC_DEST_LOGICAL);
34}
35
36static void
37__x2apic_send_IPI_mask(const struct cpumask *mask, int vector, int apic_dest)
38{
39 unsigned int cpu, clustercpu;
40 struct cpumask *tmpmsk;
41 unsigned long flags;
42 u32 dest;
43
44 x2apic_wrmsr_fence();
45 local_irq_save(flags);
46
47 tmpmsk = this_cpu_cpumask_var_ptr(ipi_mask);
48 cpumask_copy(tmpmsk, mask);
49 /* If IPI should not be sent to self, clear current CPU */
50 if (apic_dest != APIC_DEST_ALLINC)
51 __cpumask_clear_cpu(smp_processor_id(), tmpmsk);
52
53 /* Collapse cpus in a cluster so a single IPI per cluster is sent */
54 for_each_cpu(cpu, tmpmsk) {
55 struct cluster_mask *cmsk = per_cpu(cluster_masks, cpu);
56
57 dest = 0;
58 for_each_cpu_and(clustercpu, tmpmsk, &cmsk->mask)
59 dest |= per_cpu(x86_cpu_to_logical_apicid, clustercpu);
60
61 if (!dest)
62 continue;
63
64 __x2apic_send_IPI_dest(dest, vector, apic->dest_logical);
65 /* Remove cluster CPUs from tmpmask */
66 cpumask_andnot(tmpmsk, tmpmsk, &cmsk->mask);
67 }
68
69 local_irq_restore(flags);
70}
71
72static void x2apic_send_IPI_mask(const struct cpumask *mask, int vector)
73{
74 __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLINC);
75}
76
77static void
78x2apic_send_IPI_mask_allbutself(const struct cpumask *mask, int vector)
79{
80 __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLBUT);
81}
82
83static void x2apic_send_IPI_allbutself(int vector)
84{
85 __x2apic_send_IPI_shorthand(vector, APIC_DEST_ALLBUT);
86}
87
88static void x2apic_send_IPI_all(int vector)
89{
90 __x2apic_send_IPI_shorthand(vector, APIC_DEST_ALLINC);
91}
92
93static u32 x2apic_calc_apicid(unsigned int cpu)
94{
95 return per_cpu(x86_cpu_to_logical_apicid, cpu);
96}
97
98static void init_x2apic_ldr(void)
99{
100 struct cluster_mask *cmsk = this_cpu_read(cluster_masks);
101 u32 cluster, apicid = apic_read(APIC_LDR);
102 unsigned int cpu;
103
104 this_cpu_write(x86_cpu_to_logical_apicid, apicid);
105
106 if (cmsk)
107 goto update;
108
109 cluster = apicid >> 16;
110 for_each_online_cpu(cpu) {
111 cmsk = per_cpu(cluster_masks, cpu);
112 /* Matching cluster found. Link and update it. */
113 if (cmsk && cmsk->clusterid == cluster)
114 goto update;
115 }
116 cmsk = cluster_hotplug_mask;
117 cmsk->clusterid = cluster;
118 cluster_hotplug_mask = NULL;
119update:
120 this_cpu_write(cluster_masks, cmsk);
121 cpumask_set_cpu(smp_processor_id(), &cmsk->mask);
122}
123
124static int alloc_clustermask(unsigned int cpu, int node)
125{
126 if (per_cpu(cluster_masks, cpu))
127 return 0;
128 /*
129 * If a hotplug spare mask exists, check whether it's on the right
130 * node. If not, free it and allocate a new one.
131 */
132 if (cluster_hotplug_mask) {
133 if (cluster_hotplug_mask->node == node)
134 return 0;
135 kfree(cluster_hotplug_mask);
136 }
137
138 cluster_hotplug_mask = kzalloc_node(sizeof(*cluster_hotplug_mask),
139 GFP_KERNEL, node);
140 if (!cluster_hotplug_mask)
141 return -ENOMEM;
142 cluster_hotplug_mask->node = node;
143 return 0;
144}
145
146static int x2apic_prepare_cpu(unsigned int cpu)
147{
148 if (alloc_clustermask(cpu, cpu_to_node(cpu)) < 0)
149 return -ENOMEM;
150 if (!zalloc_cpumask_var(&per_cpu(ipi_mask, cpu), GFP_KERNEL))
151 return -ENOMEM;
152 return 0;
153}
154
155static int x2apic_dead_cpu(unsigned int dead_cpu)
156{
157 struct cluster_mask *cmsk = per_cpu(cluster_masks, dead_cpu);
158
159 if (cmsk)
160 cpumask_clear_cpu(dead_cpu, &cmsk->mask);
161 free_cpumask_var(per_cpu(ipi_mask, dead_cpu));
162 return 0;
163}
164
165static int x2apic_cluster_probe(void)
166{
167 if (!x2apic_mode)
168 return 0;
169
170 if (cpuhp_setup_state(CPUHP_X2APIC_PREPARE, "x86/x2apic:prepare",
171 x2apic_prepare_cpu, x2apic_dead_cpu) < 0) {
172 pr_err("Failed to register X2APIC_PREPARE\n");
173 return 0;
174 }
175 init_x2apic_ldr();
176 return 1;
177}
178
179static struct apic apic_x2apic_cluster __ro_after_init = {
180
181 .name = "cluster x2apic",
182 .probe = x2apic_cluster_probe,
183 .acpi_madt_oem_check = x2apic_acpi_madt_oem_check,
184 .apic_id_valid = x2apic_apic_id_valid,
185 .apic_id_registered = x2apic_apic_id_registered,
186
187 .irq_delivery_mode = dest_Fixed,
188 .irq_dest_mode = 1, /* logical */
189
190 .disable_esr = 0,
191 .dest_logical = APIC_DEST_LOGICAL,
192 .check_apicid_used = NULL,
193
194 .init_apic_ldr = init_x2apic_ldr,
195
196 .ioapic_phys_id_map = NULL,
197 .setup_apic_routing = NULL,
198 .cpu_present_to_apicid = default_cpu_present_to_apicid,
199 .apicid_to_cpu_present = NULL,
200 .check_phys_apicid_present = default_check_phys_apicid_present,
201 .phys_pkg_id = x2apic_phys_pkg_id,
202
203 .get_apic_id = x2apic_get_apic_id,
204 .set_apic_id = x2apic_set_apic_id,
205
206 .calc_dest_apicid = x2apic_calc_apicid,
207
208 .send_IPI = x2apic_send_IPI,
209 .send_IPI_mask = x2apic_send_IPI_mask,
210 .send_IPI_mask_allbutself = x2apic_send_IPI_mask_allbutself,
211 .send_IPI_allbutself = x2apic_send_IPI_allbutself,
212 .send_IPI_all = x2apic_send_IPI_all,
213 .send_IPI_self = x2apic_send_IPI_self,
214
215 .inquire_remote_apic = NULL,
216
217 .read = native_apic_msr_read,
218 .write = native_apic_msr_write,
219 .eoi_write = native_apic_msr_eoi_write,
220 .icr_read = native_x2apic_icr_read,
221 .icr_write = native_x2apic_icr_write,
222 .wait_icr_idle = native_x2apic_wait_icr_idle,
223 .safe_wait_icr_idle = native_safe_x2apic_wait_icr_idle,
224};
225
226apic_driver(apic_x2apic_cluster);
1#include <linux/threads.h>
2#include <linux/cpumask.h>
3#include <linux/string.h>
4#include <linux/kernel.h>
5#include <linux/ctype.h>
6#include <linux/dmar.h>
7#include <linux/cpu.h>
8
9#include <asm/smp.h>
10#include <asm/x2apic.h>
11
12static DEFINE_PER_CPU(u32, x86_cpu_to_logical_apicid);
13static DEFINE_PER_CPU(cpumask_var_t, cpus_in_cluster);
14static DEFINE_PER_CPU(cpumask_var_t, ipi_mask);
15
16static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
17{
18 return x2apic_enabled();
19}
20
21static inline u32 x2apic_cluster(int cpu)
22{
23 return per_cpu(x86_cpu_to_logical_apicid, cpu) >> 16;
24}
25
26static void
27__x2apic_send_IPI_mask(const struct cpumask *mask, int vector, int apic_dest)
28{
29 struct cpumask *cpus_in_cluster_ptr;
30 struct cpumask *ipi_mask_ptr;
31 unsigned int cpu, this_cpu;
32 unsigned long flags;
33 u32 dest;
34
35 x2apic_wrmsr_fence();
36
37 local_irq_save(flags);
38
39 this_cpu = smp_processor_id();
40
41 /*
42 * We are to modify mask, so we need an own copy
43 * and be sure it's manipulated with irq off.
44 */
45 ipi_mask_ptr = __raw_get_cpu_var(ipi_mask);
46 cpumask_copy(ipi_mask_ptr, mask);
47
48 /*
49 * The idea is to send one IPI per cluster.
50 */
51 for_each_cpu(cpu, ipi_mask_ptr) {
52 unsigned long i;
53
54 cpus_in_cluster_ptr = per_cpu(cpus_in_cluster, cpu);
55 dest = 0;
56
57 /* Collect cpus in cluster. */
58 for_each_cpu_and(i, ipi_mask_ptr, cpus_in_cluster_ptr) {
59 if (apic_dest == APIC_DEST_ALLINC || i != this_cpu)
60 dest |= per_cpu(x86_cpu_to_logical_apicid, i);
61 }
62
63 if (!dest)
64 continue;
65
66 __x2apic_send_IPI_dest(dest, vector, apic->dest_logical);
67 /*
68 * Cluster sibling cpus should be discared now so
69 * we would not send IPI them second time.
70 */
71 cpumask_andnot(ipi_mask_ptr, ipi_mask_ptr, cpus_in_cluster_ptr);
72 }
73
74 local_irq_restore(flags);
75}
76
77static void x2apic_send_IPI_mask(const struct cpumask *mask, int vector)
78{
79 __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLINC);
80}
81
82static void
83x2apic_send_IPI_mask_allbutself(const struct cpumask *mask, int vector)
84{
85 __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLBUT);
86}
87
88static void x2apic_send_IPI_allbutself(int vector)
89{
90 __x2apic_send_IPI_mask(cpu_online_mask, vector, APIC_DEST_ALLBUT);
91}
92
93static void x2apic_send_IPI_all(int vector)
94{
95 __x2apic_send_IPI_mask(cpu_online_mask, vector, APIC_DEST_ALLINC);
96}
97
98static int
99x2apic_cpu_mask_to_apicid_and(const struct cpumask *cpumask,
100 const struct cpumask *andmask,
101 unsigned int *apicid)
102{
103 u32 dest = 0;
104 u16 cluster;
105 int i;
106
107 for_each_cpu_and(i, cpumask, andmask) {
108 if (!cpumask_test_cpu(i, cpu_online_mask))
109 continue;
110 dest = per_cpu(x86_cpu_to_logical_apicid, i);
111 cluster = x2apic_cluster(i);
112 break;
113 }
114
115 if (!dest)
116 return -EINVAL;
117
118 for_each_cpu_and(i, cpumask, andmask) {
119 if (!cpumask_test_cpu(i, cpu_online_mask))
120 continue;
121 if (cluster != x2apic_cluster(i))
122 continue;
123 dest |= per_cpu(x86_cpu_to_logical_apicid, i);
124 }
125
126 *apicid = dest;
127
128 return 0;
129}
130
131static void init_x2apic_ldr(void)
132{
133 unsigned int this_cpu = smp_processor_id();
134 unsigned int cpu;
135
136 per_cpu(x86_cpu_to_logical_apicid, this_cpu) = apic_read(APIC_LDR);
137
138 __cpu_set(this_cpu, per_cpu(cpus_in_cluster, this_cpu));
139 for_each_online_cpu(cpu) {
140 if (x2apic_cluster(this_cpu) != x2apic_cluster(cpu))
141 continue;
142 __cpu_set(this_cpu, per_cpu(cpus_in_cluster, cpu));
143 __cpu_set(cpu, per_cpu(cpus_in_cluster, this_cpu));
144 }
145}
146
147 /*
148 * At CPU state changes, update the x2apic cluster sibling info.
149 */
150static int
151update_clusterinfo(struct notifier_block *nfb, unsigned long action, void *hcpu)
152{
153 unsigned int this_cpu = (unsigned long)hcpu;
154 unsigned int cpu;
155 int err = 0;
156
157 switch (action) {
158 case CPU_UP_PREPARE:
159 if (!zalloc_cpumask_var(&per_cpu(cpus_in_cluster, this_cpu),
160 GFP_KERNEL)) {
161 err = -ENOMEM;
162 } else if (!zalloc_cpumask_var(&per_cpu(ipi_mask, this_cpu),
163 GFP_KERNEL)) {
164 free_cpumask_var(per_cpu(cpus_in_cluster, this_cpu));
165 err = -ENOMEM;
166 }
167 break;
168 case CPU_UP_CANCELED:
169 case CPU_UP_CANCELED_FROZEN:
170 case CPU_DEAD:
171 for_each_online_cpu(cpu) {
172 if (x2apic_cluster(this_cpu) != x2apic_cluster(cpu))
173 continue;
174 __cpu_clear(this_cpu, per_cpu(cpus_in_cluster, cpu));
175 __cpu_clear(cpu, per_cpu(cpus_in_cluster, this_cpu));
176 }
177 free_cpumask_var(per_cpu(cpus_in_cluster, this_cpu));
178 free_cpumask_var(per_cpu(ipi_mask, this_cpu));
179 break;
180 }
181
182 return notifier_from_errno(err);
183}
184
185static struct notifier_block __refdata x2apic_cpu_notifier = {
186 .notifier_call = update_clusterinfo,
187};
188
189static int x2apic_init_cpu_notifier(void)
190{
191 int cpu = smp_processor_id();
192
193 zalloc_cpumask_var(&per_cpu(cpus_in_cluster, cpu), GFP_KERNEL);
194 zalloc_cpumask_var(&per_cpu(ipi_mask, cpu), GFP_KERNEL);
195
196 BUG_ON(!per_cpu(cpus_in_cluster, cpu) || !per_cpu(ipi_mask, cpu));
197
198 __cpu_set(cpu, per_cpu(cpus_in_cluster, cpu));
199 register_hotcpu_notifier(&x2apic_cpu_notifier);
200 return 1;
201}
202
203static int x2apic_cluster_probe(void)
204{
205 if (x2apic_mode)
206 return x2apic_init_cpu_notifier();
207 else
208 return 0;
209}
210
211static const struct cpumask *x2apic_cluster_target_cpus(void)
212{
213 return cpu_all_mask;
214}
215
216/*
217 * Each x2apic cluster is an allocation domain.
218 */
219static void cluster_vector_allocation_domain(int cpu, struct cpumask *retmask,
220 const struct cpumask *mask)
221{
222 /*
223 * To minimize vector pressure, default case of boot, device bringup
224 * etc will use a single cpu for the interrupt destination.
225 *
226 * On explicit migration requests coming from irqbalance etc,
227 * interrupts will be routed to the x2apic cluster (cluster-id
228 * derived from the first cpu in the mask) members specified
229 * in the mask.
230 */
231 if (mask == x2apic_cluster_target_cpus())
232 cpumask_copy(retmask, cpumask_of(cpu));
233 else
234 cpumask_and(retmask, mask, per_cpu(cpus_in_cluster, cpu));
235}
236
237static struct apic apic_x2apic_cluster = {
238
239 .name = "cluster x2apic",
240 .probe = x2apic_cluster_probe,
241 .acpi_madt_oem_check = x2apic_acpi_madt_oem_check,
242 .apic_id_valid = x2apic_apic_id_valid,
243 .apic_id_registered = x2apic_apic_id_registered,
244
245 .irq_delivery_mode = dest_LowestPrio,
246 .irq_dest_mode = 1, /* logical */
247
248 .target_cpus = x2apic_cluster_target_cpus,
249 .disable_esr = 0,
250 .dest_logical = APIC_DEST_LOGICAL,
251 .check_apicid_used = NULL,
252 .check_apicid_present = NULL,
253
254 .vector_allocation_domain = cluster_vector_allocation_domain,
255 .init_apic_ldr = init_x2apic_ldr,
256
257 .ioapic_phys_id_map = NULL,
258 .setup_apic_routing = NULL,
259 .multi_timer_check = NULL,
260 .cpu_present_to_apicid = default_cpu_present_to_apicid,
261 .apicid_to_cpu_present = NULL,
262 .setup_portio_remap = NULL,
263 .check_phys_apicid_present = default_check_phys_apicid_present,
264 .enable_apic_mode = NULL,
265 .phys_pkg_id = x2apic_phys_pkg_id,
266 .mps_oem_check = NULL,
267
268 .get_apic_id = x2apic_get_apic_id,
269 .set_apic_id = x2apic_set_apic_id,
270 .apic_id_mask = 0xFFFFFFFFu,
271
272 .cpu_mask_to_apicid_and = x2apic_cpu_mask_to_apicid_and,
273
274 .send_IPI_mask = x2apic_send_IPI_mask,
275 .send_IPI_mask_allbutself = x2apic_send_IPI_mask_allbutself,
276 .send_IPI_allbutself = x2apic_send_IPI_allbutself,
277 .send_IPI_all = x2apic_send_IPI_all,
278 .send_IPI_self = x2apic_send_IPI_self,
279
280 .trampoline_phys_low = DEFAULT_TRAMPOLINE_PHYS_LOW,
281 .trampoline_phys_high = DEFAULT_TRAMPOLINE_PHYS_HIGH,
282 .wait_for_init_deassert = false,
283 .smp_callin_clear_local_apic = NULL,
284 .inquire_remote_apic = NULL,
285
286 .read = native_apic_msr_read,
287 .write = native_apic_msr_write,
288 .eoi_write = native_apic_msr_eoi_write,
289 .icr_read = native_x2apic_icr_read,
290 .icr_write = native_x2apic_icr_write,
291 .wait_icr_idle = native_x2apic_wait_icr_idle,
292 .safe_wait_icr_idle = native_safe_x2apic_wait_icr_idle,
293};
294
295apic_driver(apic_x2apic_cluster);