kernel/arch/x86/kernel/apic/x2apic_cluster.c

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