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 12 struct cluster_mask { 13 unsigned int clusterid; 14 int node; 15 struct cpumask mask; 16 }; 17 18 static DEFINE_PER_CPU(u32, x86_cpu_to_logical_apicid); 19 static DEFINE_PER_CPU(cpumask_var_t, ipi_mask); 20 static DEFINE_PER_CPU(struct cluster_mask *, cluster_masks); 21 static struct cluster_mask *cluster_hotplug_mask; 22 23 static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id) 24 { 25 return x2apic_enabled(); 26 } 27 28 static void x2apic_send_IPI(int cpu, int vector) 29 { 30 u32 dest = per_cpu(x86_cpu_to_logical_apicid, cpu); 31 32 /* x2apic MSRs are special and need a special fence: */ 33 weak_wrmsr_fence(); 34 __x2apic_send_IPI_dest(dest, vector, APIC_DEST_LOGICAL); 35 } 36 37 static void 38 __x2apic_send_IPI_mask(const struct cpumask *mask, int vector, int apic_dest) 39 { 40 unsigned int cpu, clustercpu; 41 struct cpumask *tmpmsk; 42 unsigned long flags; 43 u32 dest; 44 45 /* x2apic MSRs are special and need a special fence: */ 46 weak_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 74 static void x2apic_send_IPI_mask(const struct cpumask *mask, int vector) 75 { 76 __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLINC); 77 } 78 79 static void 80 x2apic_send_IPI_mask_allbutself(const struct cpumask *mask, int vector) 81 { 82 __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLBUT); 83 } 84 85 static void x2apic_send_IPI_allbutself(int vector) 86 { 87 __x2apic_send_IPI_shorthand(vector, APIC_DEST_ALLBUT); 88 } 89 90 static void x2apic_send_IPI_all(int vector) 91 { 92 __x2apic_send_IPI_shorthand(vector, APIC_DEST_ALLINC); 93 } 94 95 static u32 x2apic_calc_apicid(unsigned int cpu) 96 { 97 return per_cpu(x86_cpu_to_logical_apicid, cpu); 98 } 99 100 static 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; 121 update: 122 this_cpu_write(cluster_masks, cmsk); 123 cpumask_set_cpu(smp_processor_id(), &cmsk->mask); 124 } 125 126 static 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 } 147 148 static 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 } 156 157 static int x2apic_dead_cpu(unsigned int dead_cpu) 158 { 159 struct cluster_mask *cmsk = per_cpu(cluster_masks, dead_cpu); 160 161 if (cmsk) 162 cpumask_clear_cpu(dead_cpu, &cmsk->mask); 163 free_cpumask_var(per_cpu(ipi_mask, dead_cpu)); 164 return 0; 165 } 166 167 static int x2apic_cluster_probe(void) 168 { 169 if (!x2apic_mode) 170 return 0; 171 172 if (cpuhp_setup_state(CPUHP_X2APIC_PREPARE, "x86/x2apic:prepare", 173 x2apic_prepare_cpu, x2apic_dead_cpu) < 0) { 174 pr_err("Failed to register X2APIC_PREPARE\n"); 175 return 0; 176 } 177 init_x2apic_ldr(); 178 return 1; 179 } 180 181 static struct apic apic_x2apic_cluster __ro_after_init = { 182 183 .name = "cluster x2apic", 184 .probe = x2apic_cluster_probe, 185 .acpi_madt_oem_check = x2apic_acpi_madt_oem_check, 186 .apic_id_valid = x2apic_apic_id_valid, 187 .apic_id_registered = x2apic_apic_id_registered, 188 189 .irq_delivery_mode = dest_Fixed, 190 .irq_dest_mode = 1, /* logical */ 191 192 .disable_esr = 0, 193 .dest_logical = APIC_DEST_LOGICAL, 194 .check_apicid_used = NULL, 195 196 .init_apic_ldr = init_x2apic_ldr, 197 198 .ioapic_phys_id_map = NULL, 199 .setup_apic_routing = NULL, 200 .cpu_present_to_apicid = default_cpu_present_to_apicid, 201 .apicid_to_cpu_present = NULL, 202 .check_phys_apicid_present = default_check_phys_apicid_present, 203 .phys_pkg_id = x2apic_phys_pkg_id, 204 205 .get_apic_id = x2apic_get_apic_id, 206 .set_apic_id = x2apic_set_apic_id, 207 208 .calc_dest_apicid = x2apic_calc_apicid, 209 210 .send_IPI = x2apic_send_IPI, 211 .send_IPI_mask = x2apic_send_IPI_mask, 212 .send_IPI_mask_allbutself = x2apic_send_IPI_mask_allbutself, 213 .send_IPI_allbutself = x2apic_send_IPI_allbutself, 214 .send_IPI_all = x2apic_send_IPI_all, 215 .send_IPI_self = x2apic_send_IPI_self, 216 217 .inquire_remote_apic = NULL, 218 219 .read = native_apic_msr_read, 220 .write = native_apic_msr_write, 221 .eoi_write = native_apic_msr_eoi_write, 222 .icr_read = native_x2apic_icr_read, 223 .icr_write = native_x2apic_icr_write, 224 .wait_icr_idle = native_x2apic_wait_icr_idle, 225 .safe_wait_icr_idle = native_safe_x2apic_wait_icr_idle, 226 }; 227 228 apic_driver(apic_x2apic_cluster); 229