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