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 x2apic_send_IPI(int cpu, int vector)
  27 {
  28         u32 dest = per_cpu(x86_cpu_to_logical_apicid, cpu);
  29
  30         x2apic_wrmsr_fence();
  31         __x2apic_send_IPI_dest(dest, vector, APIC_DEST_LOGICAL);
  32 }
  33
  34 static void
  35 __x2apic_send_IPI_mask(const struct cpumask *mask, int vector, int apic_dest)
  36 {
  37         struct cpumask *cpus_in_cluster_ptr;
  38         struct cpumask *ipi_mask_ptr;
  39         unsigned int cpu, this_cpu;
  40         unsigned long flags;
  41         u32 dest;
  42
  43         x2apic_wrmsr_fence();
  44
  45         local_irq_save(flags);
  46
  47         this_cpu = smp_processor_id();
  48
  49         /*
  50          * We are to modify mask, so we need an own copy
  51          * and be sure it's manipulated with irq off.
  52          */
  53         ipi_mask_ptr = this_cpu_cpumask_var_ptr(ipi_mask);
  54         cpumask_copy(ipi_mask_ptr, mask);
  55
  56         /*
  57          * The idea is to send one IPI per cluster.
  58          */
  59         for_each_cpu(cpu, ipi_mask_ptr) {
  60                 unsigned long i;
  61
  62                 cpus_in_cluster_ptr = per_cpu(cpus_in_cluster, cpu);
  63                 dest = 0;
  64
  65                 /* Collect cpus in cluster. */
  66                 for_each_cpu_and(i, ipi_mask_ptr, cpus_in_cluster_ptr) {
  67                         if (apic_dest == APIC_DEST_ALLINC || i != this_cpu)
  68                                 dest |= per_cpu(x86_cpu_to_logical_apicid, i);
  69                 }
  70
  71                 if (!dest)
  72                         continue;
  73
  74                 __x2apic_send_IPI_dest(dest, vector, apic->dest_logical);
  75                 /*
  76                  * Cluster sibling cpus should be discared now so
  77                  * we would not send IPI them second time.
  78                  */
  79                 cpumask_andnot(ipi_mask_ptr, ipi_mask_ptr, cpus_in_cluster_ptr);
  80         }
  81
  82         local_irq_restore(flags);
  83 }
  84
  85 static void x2apic_send_IPI_mask(const struct cpumask *mask, int vector)
  86 {
  87         __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLINC);
  88 }
  89
  90 static void
  91 x2apic_send_IPI_mask_allbutself(const struct cpumask *mask, int vector)
  92 {
  93         __x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLBUT);
  94 }
  95
  96 static void x2apic_send_IPI_allbutself(int vector)
  97 {
  98         __x2apic_send_IPI_mask(cpu_online_mask, vector, APIC_DEST_ALLBUT);
  99 }
 100
 101 static void x2apic_send_IPI_all(int vector)
 102 {
 103         __x2apic_send_IPI_mask(cpu_online_mask, vector, APIC_DEST_ALLINC);
 104 }
 105
 106 static int
 107 x2apic_cpu_mask_to_apicid_and(const struct cpumask *cpumask,
 108                               const struct cpumask *andmask,
 109                               unsigned int *apicid)
 110 {
 111         u32 dest = 0;
 112         u16 cluster;
 113         int i;
 114
 115         for_each_cpu_and(i, cpumask, andmask) {
 116                 if (!cpumask_test_cpu(i, cpu_online_mask))
 117                         continue;
 118                 dest = per_cpu(x86_cpu_to_logical_apicid, i);
 119                 cluster = x2apic_cluster(i);
 120                 break;
 121         }
 122
 123         if (!dest)
 124                 return -EINVAL;
 125
 126         for_each_cpu_and(i, cpumask, andmask) {
 127                 if (!cpumask_test_cpu(i, cpu_online_mask))
 128                         continue;
 129                 if (cluster != x2apic_cluster(i))
 130                         continue;
 131                 dest |= per_cpu(x86_cpu_to_logical_apicid, i);
 132         }
 133
 134         *apicid = dest;
 135
 136         return 0;
 137 }
 138
 139 static void init_x2apic_ldr(void)
 140 {
 141         unsigned int this_cpu = smp_processor_id();
 142         unsigned int cpu;
 143
 144         per_cpu(x86_cpu_to_logical_apicid, this_cpu) = apic_read(APIC_LDR);
 145
 146         cpumask_set_cpu(this_cpu, per_cpu(cpus_in_cluster, this_cpu));
 147         for_each_online_cpu(cpu) {
 148                 if (x2apic_cluster(this_cpu) != x2apic_cluster(cpu))
 149                         continue;
 150                 cpumask_set_cpu(this_cpu, per_cpu(cpus_in_cluster, cpu));
 151                 cpumask_set_cpu(cpu, per_cpu(cpus_in_cluster, this_cpu));
 152         }
 153 }
 154
 155  /*
 156   * At CPU state changes, update the x2apic cluster sibling info.
 157   */
 158 static int
 159 update_clusterinfo(struct notifier_block *nfb, unsigned long action, void *hcpu)
 160 {
 161         unsigned int this_cpu = (unsigned long)hcpu;
 162         unsigned int cpu;
 163         int err = 0;
 164
 165         switch (action) {
 166         case CPU_UP_PREPARE:
 167                 if (!zalloc_cpumask_var(&per_cpu(cpus_in_cluster, this_cpu),
 168                                         GFP_KERNEL)) {
 169                         err = -ENOMEM;
 170                 } else if (!zalloc_cpumask_var(&per_cpu(ipi_mask, this_cpu),
 171                                                GFP_KERNEL)) {
 172                         free_cpumask_var(per_cpu(cpus_in_cluster, this_cpu));
 173                         err = -ENOMEM;
 174                 }
 175                 break;
 176         case CPU_UP_CANCELED:
 177         case CPU_UP_CANCELED_FROZEN:
 178         case CPU_DEAD:
 179                 for_each_online_cpu(cpu) {
 180                         if (x2apic_cluster(this_cpu) != x2apic_cluster(cpu))
 181                                 continue;
 182                         cpumask_clear_cpu(this_cpu, per_cpu(cpus_in_cluster, cpu));
 183                         cpumask_clear_cpu(cpu, per_cpu(cpus_in_cluster, this_cpu));
 184                 }
 185                 free_cpumask_var(per_cpu(cpus_in_cluster, this_cpu));
 186                 free_cpumask_var(per_cpu(ipi_mask, this_cpu));
 187                 break;
 188         }
 189
 190         return notifier_from_errno(err);
 191 }
 192
 193 static struct notifier_block x2apic_cpu_notifier = {
 194         .notifier_call = update_clusterinfo,
 195 };
 196
 197 static int x2apic_init_cpu_notifier(void)
 198 {
 199         int cpu = smp_processor_id();
 200
 201         zalloc_cpumask_var(&per_cpu(cpus_in_cluster, cpu), GFP_KERNEL);
 202         zalloc_cpumask_var(&per_cpu(ipi_mask, cpu), GFP_KERNEL);
 203
 204         BUG_ON(!per_cpu(cpus_in_cluster, cpu) || !per_cpu(ipi_mask, cpu));
 205
 206         cpumask_set_cpu(cpu, per_cpu(cpus_in_cluster, cpu));
 207         register_hotcpu_notifier(&x2apic_cpu_notifier);
 208         return 1;
 209 }
 210
 211 static int x2apic_cluster_probe(void)
 212 {
 213         if (x2apic_mode)
 214                 return x2apic_init_cpu_notifier();
 215         else
 216                 return 0;
 217 }
 218
 219 static const struct cpumask *x2apic_cluster_target_cpus(void)
 220 {
 221         return cpu_all_mask;
 222 }
 223
 224 /*
 225  * Each x2apic cluster is an allocation domain.
 226  */
 227 static void cluster_vector_allocation_domain(int cpu, struct cpumask *retmask,
 228                                              const struct cpumask *mask)
 229 {
 230         /*
 231          * To minimize vector pressure, default case of boot, device bringup
 232          * etc will use a single cpu for the interrupt destination.
 233          *
 234          * On explicit migration requests coming from irqbalance etc,
 235          * interrupts will be routed to the x2apic cluster (cluster-id
 236          * derived from the first cpu in the mask) members specified
 237          * in the mask.
 238          */
 239         if (mask == x2apic_cluster_target_cpus())
 240                 cpumask_copy(retmask, cpumask_of(cpu));
 241         else
 242                 cpumask_and(retmask, mask, per_cpu(cpus_in_cluster, cpu));
 243 }
 244
 245 static struct apic apic_x2apic_cluster = {
 246
 247         .name                           = "cluster x2apic",
 248         .probe                          = x2apic_cluster_probe,
 249         .acpi_madt_oem_check            = x2apic_acpi_madt_oem_check,
 250         .apic_id_valid                  = x2apic_apic_id_valid,
 251         .apic_id_registered             = x2apic_apic_id_registered,
 252
 253         .irq_delivery_mode              = dest_LowestPrio,
 254         .irq_dest_mode                  = 1, /* logical */
 255
 256         .target_cpus                    = x2apic_cluster_target_cpus,
 257         .disable_esr                    = 0,
 258         .dest_logical                   = APIC_DEST_LOGICAL,
 259         .check_apicid_used              = NULL,
 260
 261         .vector_allocation_domain       = cluster_vector_allocation_domain,
 262         .init_apic_ldr                  = init_x2apic_ldr,
 263
 264         .ioapic_phys_id_map             = NULL,
 265         .setup_apic_routing             = NULL,
 266         .cpu_present_to_apicid          = default_cpu_present_to_apicid,
 267         .apicid_to_cpu_present          = NULL,
 268         .check_phys_apicid_present      = default_check_phys_apicid_present,
 269         .phys_pkg_id                    = x2apic_phys_pkg_id,
 270
 271         .get_apic_id                    = x2apic_get_apic_id,
 272         .set_apic_id                    = x2apic_set_apic_id,
 273         .apic_id_mask                   = 0xFFFFFFFFu,
 274
 275         .cpu_mask_to_apicid_and         = x2apic_cpu_mask_to_apicid_and,
 276
 277         .send_IPI                       = x2apic_send_IPI,
 278         .send_IPI_mask                  = x2apic_send_IPI_mask,
 279         .send_IPI_mask_allbutself       = x2apic_send_IPI_mask_allbutself,
 280         .send_IPI_allbutself            = x2apic_send_IPI_allbutself,
 281         .send_IPI_all                   = x2apic_send_IPI_all,
 282         .send_IPI_self                  = x2apic_send_IPI_self,
 283
 284         .inquire_remote_apic            = NULL,
 285
 286         .read                           = native_apic_msr_read,
 287         .write                          = native_apic_msr_write,
 288         .eoi_write                      = native_apic_msr_eoi_write,
 289         .icr_read                       = native_x2apic_icr_read,
 290         .icr_write                      = native_x2apic_icr_write,
 291         .wait_icr_idle                  = native_x2apic_wait_icr_idle,
 292         .safe_wait_icr_idle             = native_safe_x2apic_wait_icr_idle,
 293 };
 294
 295 apic_driver(apic_x2apic_cluster);