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/init.h> 7 #include <linux/dmar.h> 8 #include <linux/cpu.h> 9 10 #include <asm/smp.h> 11 #include <asm/x2apic.h> 12 13 static DEFINE_PER_CPU(u32, x86_cpu_to_logical_apicid); 14 static DEFINE_PER_CPU(cpumask_var_t, cpus_in_cluster); 15 static DEFINE_PER_CPU(cpumask_var_t, ipi_mask); 16 17 static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id) 18 { 19 return x2apic_enabled(); 20 } 21 22 static inline u32 x2apic_cluster(int cpu) 23 { 24 return per_cpu(x86_cpu_to_logical_apicid, cpu) >> 16; 25 } 26 27 static void 28 __x2apic_send_IPI_mask(const struct cpumask *mask, int vector, int apic_dest) 29 { 30 struct cpumask *cpus_in_cluster_ptr; 31 struct cpumask *ipi_mask_ptr; 32 unsigned int cpu, this_cpu; 33 unsigned long flags; 34 u32 dest; 35 36 x2apic_wrmsr_fence(); 37 38 local_irq_save(flags); 39 40 this_cpu = smp_processor_id(); 41 42 /* 43 * We are to modify mask, so we need an own copy 44 * and be sure it's manipulated with irq off. 45 */ 46 ipi_mask_ptr = __raw_get_cpu_var(ipi_mask); 47 cpumask_copy(ipi_mask_ptr, mask); 48 49 /* 50 * The idea is to send one IPI per cluster. 51 */ 52 for_each_cpu(cpu, ipi_mask_ptr) { 53 unsigned long i; 54 55 cpus_in_cluster_ptr = per_cpu(cpus_in_cluster, cpu); 56 dest = 0; 57 58 /* Collect cpus in cluster. */ 59 for_each_cpu_and(i, ipi_mask_ptr, cpus_in_cluster_ptr) { 60 if (apic_dest == APIC_DEST_ALLINC || i != this_cpu) 61 dest |= per_cpu(x86_cpu_to_logical_apicid, i); 62 } 63 64 if (!dest) 65 continue; 66 67 __x2apic_send_IPI_dest(dest, vector, apic->dest_logical); 68 /* 69 * Cluster sibling cpus should be discared now so 70 * we would not send IPI them second time. 71 */ 72 cpumask_andnot(ipi_mask_ptr, ipi_mask_ptr, cpus_in_cluster_ptr); 73 } 74 75 local_irq_restore(flags); 76 } 77 78 static void x2apic_send_IPI_mask(const struct cpumask *mask, int vector) 79 { 80 __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLINC); 81 } 82 83 static void 84 x2apic_send_IPI_mask_allbutself(const struct cpumask *mask, int vector) 85 { 86 __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLBUT); 87 } 88 89 static void x2apic_send_IPI_allbutself(int vector) 90 { 91 __x2apic_send_IPI_mask(cpu_online_mask, vector, APIC_DEST_ALLBUT); 92 } 93 94 static void x2apic_send_IPI_all(int vector) 95 { 96 __x2apic_send_IPI_mask(cpu_online_mask, vector, APIC_DEST_ALLINC); 97 } 98 99 static int 100 x2apic_cpu_mask_to_apicid_and(const struct cpumask *cpumask, 101 const struct cpumask *andmask, 102 unsigned int *apicid) 103 { 104 u32 dest = 0; 105 u16 cluster; 106 int i; 107 108 for_each_cpu_and(i, cpumask, andmask) { 109 if (!cpumask_test_cpu(i, cpu_online_mask)) 110 continue; 111 dest = per_cpu(x86_cpu_to_logical_apicid, i); 112 cluster = x2apic_cluster(i); 113 break; 114 } 115 116 if (!dest) 117 return -EINVAL; 118 119 for_each_cpu_and(i, cpumask, andmask) { 120 if (!cpumask_test_cpu(i, cpu_online_mask)) 121 continue; 122 if (cluster != x2apic_cluster(i)) 123 continue; 124 dest |= per_cpu(x86_cpu_to_logical_apicid, i); 125 } 126 127 *apicid = dest; 128 129 return 0; 130 } 131 132 static void init_x2apic_ldr(void) 133 { 134 unsigned int this_cpu = smp_processor_id(); 135 unsigned int cpu; 136 137 per_cpu(x86_cpu_to_logical_apicid, this_cpu) = apic_read(APIC_LDR); 138 139 __cpu_set(this_cpu, per_cpu(cpus_in_cluster, this_cpu)); 140 for_each_online_cpu(cpu) { 141 if (x2apic_cluster(this_cpu) != x2apic_cluster(cpu)) 142 continue; 143 __cpu_set(this_cpu, per_cpu(cpus_in_cluster, cpu)); 144 __cpu_set(cpu, per_cpu(cpus_in_cluster, this_cpu)); 145 } 146 } 147 148 /* 149 * At CPU state changes, update the x2apic cluster sibling info. 150 */ 151 static int __cpuinit 152 update_clusterinfo(struct notifier_block *nfb, unsigned long action, void *hcpu) 153 { 154 unsigned int this_cpu = (unsigned long)hcpu; 155 unsigned int cpu; 156 int err = 0; 157 158 switch (action) { 159 case CPU_UP_PREPARE: 160 if (!zalloc_cpumask_var(&per_cpu(cpus_in_cluster, this_cpu), 161 GFP_KERNEL)) { 162 err = -ENOMEM; 163 } else if (!zalloc_cpumask_var(&per_cpu(ipi_mask, this_cpu), 164 GFP_KERNEL)) { 165 free_cpumask_var(per_cpu(cpus_in_cluster, this_cpu)); 166 err = -ENOMEM; 167 } 168 break; 169 case CPU_UP_CANCELED: 170 case CPU_UP_CANCELED_FROZEN: 171 case CPU_DEAD: 172 for_each_online_cpu(cpu) { 173 if (x2apic_cluster(this_cpu) != x2apic_cluster(cpu)) 174 continue; 175 __cpu_clear(this_cpu, per_cpu(cpus_in_cluster, cpu)); 176 __cpu_clear(cpu, per_cpu(cpus_in_cluster, this_cpu)); 177 } 178 free_cpumask_var(per_cpu(cpus_in_cluster, this_cpu)); 179 free_cpumask_var(per_cpu(ipi_mask, this_cpu)); 180 break; 181 } 182 183 return notifier_from_errno(err); 184 } 185 186 static struct notifier_block __refdata x2apic_cpu_notifier = { 187 .notifier_call = update_clusterinfo, 188 }; 189 190 static int x2apic_init_cpu_notifier(void) 191 { 192 int cpu = smp_processor_id(); 193 194 zalloc_cpumask_var(&per_cpu(cpus_in_cluster, cpu), GFP_KERNEL); 195 zalloc_cpumask_var(&per_cpu(ipi_mask, cpu), GFP_KERNEL); 196 197 BUG_ON(!per_cpu(cpus_in_cluster, cpu) || !per_cpu(ipi_mask, cpu)); 198 199 __cpu_set(cpu, per_cpu(cpus_in_cluster, cpu)); 200 register_hotcpu_notifier(&x2apic_cpu_notifier); 201 return 1; 202 } 203 204 static int x2apic_cluster_probe(void) 205 { 206 if (x2apic_mode) 207 return x2apic_init_cpu_notifier(); 208 else 209 return 0; 210 } 211 212 static const struct cpumask *x2apic_cluster_target_cpus(void) 213 { 214 return cpu_all_mask; 215 } 216 217 /* 218 * Each x2apic cluster is an allocation domain. 219 */ 220 static void cluster_vector_allocation_domain(int cpu, struct cpumask *retmask, 221 const struct cpumask *mask) 222 { 223 /* 224 * To minimize vector pressure, default case of boot, device bringup 225 * etc will use a single cpu for the interrupt destination. 226 * 227 * On explicit migration requests coming from irqbalance etc, 228 * interrupts will be routed to the x2apic cluster (cluster-id 229 * derived from the first cpu in the mask) members specified 230 * in the mask. 231 */ 232 if (mask == x2apic_cluster_target_cpus()) 233 cpumask_copy(retmask, cpumask_of(cpu)); 234 else 235 cpumask_and(retmask, mask, per_cpu(cpus_in_cluster, cpu)); 236 } 237 238 static struct apic apic_x2apic_cluster = { 239 240 .name = "cluster x2apic", 241 .probe = x2apic_cluster_probe, 242 .acpi_madt_oem_check = x2apic_acpi_madt_oem_check, 243 .apic_id_valid = x2apic_apic_id_valid, 244 .apic_id_registered = x2apic_apic_id_registered, 245 246 .irq_delivery_mode = dest_LowestPrio, 247 .irq_dest_mode = 1, /* logical */ 248 249 .target_cpus = x2apic_cluster_target_cpus, 250 .disable_esr = 0, 251 .dest_logical = APIC_DEST_LOGICAL, 252 .check_apicid_used = NULL, 253 .check_apicid_present = NULL, 254 255 .vector_allocation_domain = cluster_vector_allocation_domain, 256 .init_apic_ldr = init_x2apic_ldr, 257 258 .ioapic_phys_id_map = NULL, 259 .setup_apic_routing = NULL, 260 .multi_timer_check = NULL, 261 .cpu_present_to_apicid = default_cpu_present_to_apicid, 262 .apicid_to_cpu_present = NULL, 263 .setup_portio_remap = NULL, 264 .check_phys_apicid_present = default_check_phys_apicid_present, 265 .enable_apic_mode = NULL, 266 .phys_pkg_id = x2apic_phys_pkg_id, 267 .mps_oem_check = NULL, 268 269 .get_apic_id = x2apic_get_apic_id, 270 .set_apic_id = x2apic_set_apic_id, 271 .apic_id_mask = 0xFFFFFFFFu, 272 273 .cpu_mask_to_apicid_and = x2apic_cpu_mask_to_apicid_and, 274 275 .send_IPI_mask = x2apic_send_IPI_mask, 276 .send_IPI_mask_allbutself = x2apic_send_IPI_mask_allbutself, 277 .send_IPI_allbutself = x2apic_send_IPI_allbutself, 278 .send_IPI_all = x2apic_send_IPI_all, 279 .send_IPI_self = x2apic_send_IPI_self, 280 281 .trampoline_phys_low = DEFAULT_TRAMPOLINE_PHYS_LOW, 282 .trampoline_phys_high = DEFAULT_TRAMPOLINE_PHYS_HIGH, 283 .wait_for_init_deassert = NULL, 284 .smp_callin_clear_local_apic = NULL, 285 .inquire_remote_apic = NULL, 286 287 .read = native_apic_msr_read, 288 .write = native_apic_msr_write, 289 .eoi_write = native_apic_msr_eoi_write, 290 .icr_read = native_x2apic_icr_read, 291 .icr_write = native_x2apic_icr_write, 292 .wait_icr_idle = native_x2apic_wait_icr_idle, 293 .safe_wait_icr_idle = native_safe_x2apic_wait_icr_idle, 294 }; 295 296 apic_driver(apic_x2apic_cluster); 297