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_wrmsr_fence(); 33 __x2apic_send_IPI_dest(dest, vector, APIC_DEST_LOGICAL); 34 } 35 36 static 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 72 static void x2apic_send_IPI_mask(const struct cpumask *mask, int vector) 73 { 74 __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLINC); 75 } 76 77 static void 78 x2apic_send_IPI_mask_allbutself(const struct cpumask *mask, int vector) 79 { 80 __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLBUT); 81 } 82 83 static void x2apic_send_IPI_allbutself(int vector) 84 { 85 __x2apic_send_IPI_shorthand(vector, APIC_DEST_ALLBUT); 86 } 87 88 static void x2apic_send_IPI_all(int vector) 89 { 90 __x2apic_send_IPI_shorthand(vector, APIC_DEST_ALLINC); 91 } 92 93 static u32 x2apic_calc_apicid(unsigned int cpu) 94 { 95 return per_cpu(x86_cpu_to_logical_apicid, cpu); 96 } 97 98 static 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; 119 update: 120 this_cpu_write(cluster_masks, cmsk); 121 cpumask_set_cpu(smp_processor_id(), &cmsk->mask); 122 } 123 124 static 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 } 145 146 static 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 } 154 155 static 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 } 164 165 static 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 } 178 179 static 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 .delivery_mode = APIC_DELIVERY_MODE_FIXED, 188 .dest_mode_logical = true, 189 190 .disable_esr = 0, 191 192 .check_apicid_used = NULL, 193 .init_apic_ldr = init_x2apic_ldr, 194 .ioapic_phys_id_map = NULL, 195 .setup_apic_routing = NULL, 196 .cpu_present_to_apicid = default_cpu_present_to_apicid, 197 .apicid_to_cpu_present = NULL, 198 .check_phys_apicid_present = default_check_phys_apicid_present, 199 .phys_pkg_id = x2apic_phys_pkg_id, 200 201 .get_apic_id = x2apic_get_apic_id, 202 .set_apic_id = x2apic_set_apic_id, 203 204 .calc_dest_apicid = x2apic_calc_apicid, 205 206 .send_IPI = x2apic_send_IPI, 207 .send_IPI_mask = x2apic_send_IPI_mask, 208 .send_IPI_mask_allbutself = x2apic_send_IPI_mask_allbutself, 209 .send_IPI_allbutself = x2apic_send_IPI_allbutself, 210 .send_IPI_all = x2apic_send_IPI_all, 211 .send_IPI_self = x2apic_send_IPI_self, 212 213 .inquire_remote_apic = NULL, 214 215 .read = native_apic_msr_read, 216 .write = native_apic_msr_write, 217 .eoi_write = native_apic_msr_eoi_write, 218 .icr_read = native_x2apic_icr_read, 219 .icr_write = native_x2apic_icr_write, 220 .wait_icr_idle = native_x2apic_wait_icr_idle, 221 .safe_wait_icr_idle = native_safe_x2apic_wait_icr_idle, 222 }; 223 224 apic_driver(apic_x2apic_cluster); 225