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>
15 unsigned int clusterid;
20 static DEFINE_PER_CPU(u32, x86_cpu_to_logical_apicid);
21 static DEFINE_PER_CPU(cpumask_var_t, ipi_mask);
22 static DEFINE_PER_CPU(struct cluster_mask *, cluster_masks);
23 static struct cluster_mask *cluster_hotplug_mask;
25 static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
27 return x2apic_enabled();
30 static void x2apic_send_IPI(int cpu, int vector)
32 u32 dest = per_cpu(x86_cpu_to_logical_apicid, cpu);
34 /* x2apic MSRs are special and need a special fence: */
36 __x2apic_send_IPI_dest(dest, vector, APIC_DEST_LOGICAL);
40 __x2apic_send_IPI_mask(const struct cpumask *mask, int vector, int apic_dest)
42 unsigned int cpu, clustercpu;
43 struct cpumask *tmpmsk;
47 /* x2apic MSRs are special and need a special fence: */
49 local_irq_save(flags);
51 tmpmsk = this_cpu_cpumask_var_ptr(ipi_mask);
52 cpumask_copy(tmpmsk, mask);
53 /* If IPI should not be sent to self, clear current CPU */
54 if (apic_dest != APIC_DEST_ALLINC)
55 cpumask_clear_cpu(smp_processor_id(), tmpmsk);
57 /* Collapse cpus in a cluster so a single IPI per cluster is sent */
58 for_each_cpu(cpu, tmpmsk) {
59 struct cluster_mask *cmsk = per_cpu(cluster_masks, cpu);
62 for_each_cpu_and(clustercpu, tmpmsk, &cmsk->mask)
63 dest |= per_cpu(x86_cpu_to_logical_apicid, clustercpu);
68 __x2apic_send_IPI_dest(dest, vector, apic->dest_logical);
69 /* Remove cluster CPUs from tmpmask */
70 cpumask_andnot(tmpmsk, tmpmsk, &cmsk->mask);
73 local_irq_restore(flags);
76 static void x2apic_send_IPI_mask(const struct cpumask *mask, int vector)
78 __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLINC);
82 x2apic_send_IPI_mask_allbutself(const struct cpumask *mask, int vector)
84 __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLBUT);
87 static void x2apic_send_IPI_allbutself(int vector)
89 __x2apic_send_IPI_mask(cpu_online_mask, vector, APIC_DEST_ALLBUT);
92 static void x2apic_send_IPI_all(int vector)
94 __x2apic_send_IPI_mask(cpu_online_mask, vector, APIC_DEST_ALLINC);
97 static u32 x2apic_calc_apicid(unsigned int cpu)
99 return per_cpu(x86_cpu_to_logical_apicid, cpu);
102 static void init_x2apic_ldr(void)
104 struct cluster_mask *cmsk = this_cpu_read(cluster_masks);
105 u32 cluster, apicid = apic_read(APIC_LDR);
108 this_cpu_write(x86_cpu_to_logical_apicid, apicid);
113 cluster = apicid >> 16;
114 for_each_online_cpu(cpu) {
115 cmsk = per_cpu(cluster_masks, cpu);
116 /* Matching cluster found. Link and update it. */
117 if (cmsk && cmsk->clusterid == cluster)
120 cmsk = cluster_hotplug_mask;
121 cmsk->clusterid = cluster;
122 cluster_hotplug_mask = NULL;
124 this_cpu_write(cluster_masks, cmsk);
125 cpumask_set_cpu(smp_processor_id(), &cmsk->mask);
128 static int alloc_clustermask(unsigned int cpu, int node)
130 if (per_cpu(cluster_masks, cpu))
133 * If a hotplug spare mask exists, check whether it's on the right
134 * node. If not, free it and allocate a new one.
136 if (cluster_hotplug_mask) {
137 if (cluster_hotplug_mask->node == node)
139 kfree(cluster_hotplug_mask);
142 cluster_hotplug_mask = kzalloc_node(sizeof(*cluster_hotplug_mask),
144 if (!cluster_hotplug_mask)
146 cluster_hotplug_mask->node = node;
150 static int x2apic_prepare_cpu(unsigned int cpu)
152 if (alloc_clustermask(cpu, cpu_to_node(cpu)) < 0)
154 if (!zalloc_cpumask_var(&per_cpu(ipi_mask, cpu), GFP_KERNEL))
159 static int x2apic_dead_cpu(unsigned int dead_cpu)
161 struct cluster_mask *cmsk = per_cpu(cluster_masks, dead_cpu);
164 cpumask_clear_cpu(dead_cpu, &cmsk->mask);
165 free_cpumask_var(per_cpu(ipi_mask, dead_cpu));
169 static int x2apic_cluster_probe(void)
174 if (cpuhp_setup_state(CPUHP_X2APIC_PREPARE, "x86/x2apic:prepare",
175 x2apic_prepare_cpu, x2apic_dead_cpu) < 0) {
176 pr_err("Failed to register X2APIC_PREPARE\n");
183 static struct apic apic_x2apic_cluster __ro_after_init = {
185 .name = "cluster x2apic",
186 .probe = x2apic_cluster_probe,
187 .acpi_madt_oem_check = x2apic_acpi_madt_oem_check,
188 .apic_id_valid = x2apic_apic_id_valid,
189 .apic_id_registered = x2apic_apic_id_registered,
191 .irq_delivery_mode = dest_Fixed,
192 .irq_dest_mode = 1, /* logical */
195 .dest_logical = APIC_DEST_LOGICAL,
196 .check_apicid_used = NULL,
198 .init_apic_ldr = init_x2apic_ldr,
200 .ioapic_phys_id_map = NULL,
201 .setup_apic_routing = NULL,
202 .cpu_present_to_apicid = default_cpu_present_to_apicid,
203 .apicid_to_cpu_present = NULL,
204 .check_phys_apicid_present = default_check_phys_apicid_present,
205 .phys_pkg_id = x2apic_phys_pkg_id,
207 .get_apic_id = x2apic_get_apic_id,
208 .set_apic_id = x2apic_set_apic_id,
210 .calc_dest_apicid = x2apic_calc_apicid,
212 .send_IPI = x2apic_send_IPI,
213 .send_IPI_mask = x2apic_send_IPI_mask,
214 .send_IPI_mask_allbutself = x2apic_send_IPI_mask_allbutself,
215 .send_IPI_allbutself = x2apic_send_IPI_allbutself,
216 .send_IPI_all = x2apic_send_IPI_all,
217 .send_IPI_self = x2apic_send_IPI_self,
219 .inquire_remote_apic = NULL,
221 .read = native_apic_msr_read,
222 .write = native_apic_msr_write,
223 .eoi_write = native_apic_msr_eoi_write,
224 .icr_read = native_x2apic_icr_read,
225 .icr_write = native_x2apic_icr_write,
226 .wait_icr_idle = native_x2apic_wait_icr_idle,
227 .safe_wait_icr_idle = native_safe_x2apic_wait_icr_idle,
230 apic_driver(apic_x2apic_cluster);