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>
12 #include <asm/x2apic.h>
14 static DEFINE_PER_CPU(u32, x86_cpu_to_logical_apicid);
15 static DEFINE_PER_CPU(cpumask_var_t, cpus_in_cluster);
16 static DEFINE_PER_CPU(cpumask_var_t, ipi_mask);
18 static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
20 return x2apic_enabled();
23 static inline u32 x2apic_cluster(int cpu)
25 return per_cpu(x86_cpu_to_logical_apicid, cpu) >> 16;
28 static void x2apic_send_IPI(int cpu, int vector)
30 u32 dest = per_cpu(x86_cpu_to_logical_apicid, cpu);
33 __x2apic_send_IPI_dest(dest, vector, APIC_DEST_LOGICAL);
37 __x2apic_send_IPI_mask(const struct cpumask *mask, int vector, int apic_dest)
39 struct cpumask *cpus_in_cluster_ptr;
40 struct cpumask *ipi_mask_ptr;
41 unsigned int cpu, this_cpu;
47 local_irq_save(flags);
49 this_cpu = smp_processor_id();
52 * We are to modify mask, so we need an own copy
53 * and be sure it's manipulated with irq off.
55 ipi_mask_ptr = this_cpu_cpumask_var_ptr(ipi_mask);
56 cpumask_copy(ipi_mask_ptr, mask);
59 * The idea is to send one IPI per cluster.
61 for_each_cpu(cpu, ipi_mask_ptr) {
64 cpus_in_cluster_ptr = per_cpu(cpus_in_cluster, cpu);
67 /* Collect cpus in cluster. */
68 for_each_cpu_and(i, ipi_mask_ptr, cpus_in_cluster_ptr) {
69 if (apic_dest == APIC_DEST_ALLINC || i != this_cpu)
70 dest |= per_cpu(x86_cpu_to_logical_apicid, i);
76 __x2apic_send_IPI_dest(dest, vector, apic->dest_logical);
78 * Cluster sibling cpus should be discared now so
79 * we would not send IPI them second time.
81 cpumask_andnot(ipi_mask_ptr, ipi_mask_ptr, cpus_in_cluster_ptr);
84 local_irq_restore(flags);
87 static void x2apic_send_IPI_mask(const struct cpumask *mask, int vector)
89 __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLINC);
93 x2apic_send_IPI_mask_allbutself(const struct cpumask *mask, int vector)
95 __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLBUT);
98 static void x2apic_send_IPI_allbutself(int vector)
100 __x2apic_send_IPI_mask(cpu_online_mask, vector, APIC_DEST_ALLBUT);
103 static void x2apic_send_IPI_all(int vector)
105 __x2apic_send_IPI_mask(cpu_online_mask, vector, APIC_DEST_ALLINC);
109 x2apic_cpu_mask_to_apicid(const struct cpumask *mask, struct irq_data *irqdata,
110 unsigned int *apicid)
112 struct cpumask *effmsk = irq_data_get_effective_affinity_mask(irqdata);
117 cpu = cpumask_first(mask);
118 if (cpu >= nr_cpu_ids)
121 dest = per_cpu(x86_cpu_to_logical_apicid, cpu);
122 cluster = x2apic_cluster(cpu);
124 cpumask_clear(effmsk);
125 for_each_cpu(cpu, mask) {
126 if (cluster != x2apic_cluster(cpu))
128 dest |= per_cpu(x86_cpu_to_logical_apicid, cpu);
129 cpumask_set_cpu(cpu, effmsk);
136 static void init_x2apic_ldr(void)
138 unsigned int this_cpu = smp_processor_id();
141 per_cpu(x86_cpu_to_logical_apicid, this_cpu) = apic_read(APIC_LDR);
143 cpumask_set_cpu(this_cpu, per_cpu(cpus_in_cluster, this_cpu));
144 for_each_online_cpu(cpu) {
145 if (x2apic_cluster(this_cpu) != x2apic_cluster(cpu))
147 cpumask_set_cpu(this_cpu, per_cpu(cpus_in_cluster, cpu));
148 cpumask_set_cpu(cpu, per_cpu(cpus_in_cluster, this_cpu));
153 * At CPU state changes, update the x2apic cluster sibling info.
155 static int x2apic_prepare_cpu(unsigned int cpu)
157 if (!zalloc_cpumask_var(&per_cpu(cpus_in_cluster, cpu), GFP_KERNEL))
160 if (!zalloc_cpumask_var(&per_cpu(ipi_mask, cpu), GFP_KERNEL)) {
161 free_cpumask_var(per_cpu(cpus_in_cluster, cpu));
168 static int x2apic_dead_cpu(unsigned int this_cpu)
172 for_each_online_cpu(cpu) {
173 if (x2apic_cluster(this_cpu) != x2apic_cluster(cpu))
175 cpumask_clear_cpu(this_cpu, per_cpu(cpus_in_cluster, cpu));
176 cpumask_clear_cpu(cpu, per_cpu(cpus_in_cluster, this_cpu));
178 free_cpumask_var(per_cpu(cpus_in_cluster, this_cpu));
179 free_cpumask_var(per_cpu(ipi_mask, this_cpu));
183 static int x2apic_cluster_probe(void)
185 int cpu = smp_processor_id();
191 ret = cpuhp_setup_state(CPUHP_X2APIC_PREPARE, "x86/x2apic:prepare",
192 x2apic_prepare_cpu, x2apic_dead_cpu);
194 pr_err("Failed to register X2APIC_PREPARE\n");
197 cpumask_set_cpu(cpu, per_cpu(cpus_in_cluster, cpu));
201 static const struct cpumask *x2apic_cluster_target_cpus(void)
207 * Each x2apic cluster is an allocation domain.
209 static void cluster_vector_allocation_domain(int cpu, struct cpumask *retmask,
210 const struct cpumask *mask)
213 * To minimize vector pressure, default case of boot, device bringup
214 * etc will use a single cpu for the interrupt destination.
216 * On explicit migration requests coming from irqbalance etc,
217 * interrupts will be routed to the x2apic cluster (cluster-id
218 * derived from the first cpu in the mask) members specified
221 if (mask == x2apic_cluster_target_cpus())
222 cpumask_copy(retmask, cpumask_of(cpu));
224 cpumask_and(retmask, mask, per_cpu(cpus_in_cluster, cpu));
227 static struct apic apic_x2apic_cluster __ro_after_init = {
229 .name = "cluster x2apic",
230 .probe = x2apic_cluster_probe,
231 .acpi_madt_oem_check = x2apic_acpi_madt_oem_check,
232 .apic_id_valid = x2apic_apic_id_valid,
233 .apic_id_registered = x2apic_apic_id_registered,
235 .irq_delivery_mode = dest_LowestPrio,
236 .irq_dest_mode = 1, /* logical */
238 .target_cpus = x2apic_cluster_target_cpus,
240 .dest_logical = APIC_DEST_LOGICAL,
241 .check_apicid_used = NULL,
243 .vector_allocation_domain = cluster_vector_allocation_domain,
244 .init_apic_ldr = init_x2apic_ldr,
246 .ioapic_phys_id_map = NULL,
247 .setup_apic_routing = NULL,
248 .cpu_present_to_apicid = default_cpu_present_to_apicid,
249 .apicid_to_cpu_present = NULL,
250 .check_phys_apicid_present = default_check_phys_apicid_present,
251 .phys_pkg_id = x2apic_phys_pkg_id,
253 .get_apic_id = x2apic_get_apic_id,
254 .set_apic_id = x2apic_set_apic_id,
256 .cpu_mask_to_apicid = x2apic_cpu_mask_to_apicid,
258 .send_IPI = x2apic_send_IPI,
259 .send_IPI_mask = x2apic_send_IPI_mask,
260 .send_IPI_mask_allbutself = x2apic_send_IPI_mask_allbutself,
261 .send_IPI_allbutself = x2apic_send_IPI_allbutself,
262 .send_IPI_all = x2apic_send_IPI_all,
263 .send_IPI_self = x2apic_send_IPI_self,
265 .inquire_remote_apic = NULL,
267 .read = native_apic_msr_read,
268 .write = native_apic_msr_write,
269 .eoi_write = native_apic_msr_eoi_write,
270 .icr_read = native_x2apic_icr_read,
271 .icr_write = native_x2apic_icr_write,
272 .wait_icr_idle = native_x2apic_wait_icr_idle,
273 .safe_wait_icr_idle = native_safe_x2apic_wait_icr_idle,
276 apic_driver(apic_x2apic_cluster);