arch/x86/xen/smp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/smp.h>
   3 #include <linux/cpu.h>
   4 #include <linux/slab.h>
   5 #include <linux/cpumask.h>
   6 #include <linux/percpu.h>
   7
   8 #include <xen/events.h>
   9
  10 #include <xen/hvc-console.h>
  11 #include "xen-ops.h"
  12 #include "smp.h"
  13
  14 static DEFINE_PER_CPU(struct xen_common_irq, xen_resched_irq) = { .irq = -1 };
  15 static DEFINE_PER_CPU(struct xen_common_irq, xen_callfunc_irq) = { .irq = -1 };
  16 static DEFINE_PER_CPU(struct xen_common_irq, xen_callfuncsingle_irq) = { .irq = -1 };
  17 static DEFINE_PER_CPU(struct xen_common_irq, xen_debug_irq) = { .irq = -1 };
  18
  19 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
  20 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
  21
  22 /*
  23  * Reschedule call back.
  24  */
  25 static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
  26 {
  27         inc_irq_stat(irq_resched_count);
  28         scheduler_ipi();
  29
  30         return IRQ_HANDLED;
  31 }
  32
  33 void xen_smp_intr_free(unsigned int cpu)
  34 {
  35         if (per_cpu(xen_resched_irq, cpu).irq >= 0) {
  36                 unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu).irq, NULL);
  37                 per_cpu(xen_resched_irq, cpu).irq = -1;
  38                 kfree(per_cpu(xen_resched_irq, cpu).name);
  39                 per_cpu(xen_resched_irq, cpu).name = NULL;
  40         }
  41         if (per_cpu(xen_callfunc_irq, cpu).irq >= 0) {
  42                 unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu).irq, NULL);
  43                 per_cpu(xen_callfunc_irq, cpu).irq = -1;
  44                 kfree(per_cpu(xen_callfunc_irq, cpu).name);
  45                 per_cpu(xen_callfunc_irq, cpu).name = NULL;
  46         }
  47         if (per_cpu(xen_debug_irq, cpu).irq >= 0) {
  48                 unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu).irq, NULL);
  49                 per_cpu(xen_debug_irq, cpu).irq = -1;
  50                 kfree(per_cpu(xen_debug_irq, cpu).name);
  51                 per_cpu(xen_debug_irq, cpu).name = NULL;
  52         }
  53         if (per_cpu(xen_callfuncsingle_irq, cpu).irq >= 0) {
  54                 unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu).irq,
  55                                        NULL);
  56                 per_cpu(xen_callfuncsingle_irq, cpu).irq = -1;
  57                 kfree(per_cpu(xen_callfuncsingle_irq, cpu).name);
  58                 per_cpu(xen_callfuncsingle_irq, cpu).name = NULL;
  59         }
  60 }
  61
  62 int xen_smp_intr_init(unsigned int cpu)
  63 {
  64         int rc;
  65         char *resched_name, *callfunc_name, *debug_name;
  66
  67         resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
  68         rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
  69                                     cpu,
  70                                     xen_reschedule_interrupt,
  71                                     IRQF_PERCPU|IRQF_NOBALANCING,
  72                                     resched_name,
  73                                     NULL);
  74         if (rc < 0)
  75                 goto fail;
  76         per_cpu(xen_resched_irq, cpu).irq = rc;
  77         per_cpu(xen_resched_irq, cpu).name = resched_name;
  78
  79         callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
  80         rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
  81                                     cpu,
  82                                     xen_call_function_interrupt,
  83                                     IRQF_PERCPU|IRQF_NOBALANCING,
  84                                     callfunc_name,
  85                                     NULL);
  86         if (rc < 0)
  87                 goto fail;
  88         per_cpu(xen_callfunc_irq, cpu).irq = rc;
  89         per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
  90
  91         if (!xen_fifo_events) {
  92                 debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
  93                 rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu,
  94                                              xen_debug_interrupt,
  95                                              IRQF_PERCPU | IRQF_NOBALANCING,
  96                                              debug_name, NULL);
  97                 if (rc < 0)
  98                         goto fail;
  99                 per_cpu(xen_debug_irq, cpu).irq = rc;
 100                 per_cpu(xen_debug_irq, cpu).name = debug_name;
 101         }
 102
 103         callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
 104         rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
 105                                     cpu,
 106                                     xen_call_function_single_interrupt,
 107                                     IRQF_PERCPU|IRQF_NOBALANCING,
 108                                     callfunc_name,
 109                                     NULL);
 110         if (rc < 0)
 111                 goto fail;
 112         per_cpu(xen_callfuncsingle_irq, cpu).irq = rc;
 113         per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
 114
 115         return 0;
 116
 117  fail:
 118         xen_smp_intr_free(cpu);
 119         return rc;
 120 }
 121
 122 void __init xen_smp_cpus_done(unsigned int max_cpus)
 123 {
 124         int cpu, rc, count = 0;
 125
 126         if (xen_hvm_domain())
 127                 native_smp_cpus_done(max_cpus);
 128         else
 129                 calculate_max_logical_packages();
 130
 131         if (xen_have_vcpu_info_placement)
 132                 return;
 133
 134         for_each_online_cpu(cpu) {
 135                 if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
 136                         continue;
 137
 138                 rc = remove_cpu(cpu);
 139
 140                 if (rc == 0) {
 141                         /*
 142                          * Reset vcpu_info so this cpu cannot be onlined again.
 143                          */
 144                         xen_vcpu_info_reset(cpu);
 145                         count++;
 146                 } else {
 147                         pr_warn("%s: failed to bring CPU %d down, error %d\n",
 148                                 __func__, cpu, rc);
 149                 }
 150         }
 151         WARN(count, "%s: brought %d CPUs offline\n", __func__, count);
 152 }
 153
 154 void xen_smp_send_reschedule(int cpu)
 155 {
 156         xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
 157 }
 158
 159 static void __xen_send_IPI_mask(const struct cpumask *mask,
 160                               int vector)
 161 {
 162         unsigned cpu;
 163
 164         for_each_cpu_and(cpu, mask, cpu_online_mask)
 165                 xen_send_IPI_one(cpu, vector);
 166 }
 167
 168 void xen_smp_send_call_function_ipi(const struct cpumask *mask)
 169 {
 170         int cpu;
 171
 172         __xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
 173
 174         /* Make sure other vcpus get a chance to run if they need to. */
 175         for_each_cpu(cpu, mask) {
 176                 if (xen_vcpu_stolen(cpu)) {
 177                         HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
 178                         break;
 179                 }
 180         }
 181 }
 182
 183 void xen_smp_send_call_function_single_ipi(int cpu)
 184 {
 185         __xen_send_IPI_mask(cpumask_of(cpu),
 186                           XEN_CALL_FUNCTION_SINGLE_VECTOR);
 187 }
 188
 189 static inline int xen_map_vector(int vector)
 190 {
 191         int xen_vector;
 192
 193         switch (vector) {
 194         case RESCHEDULE_VECTOR:
 195                 xen_vector = XEN_RESCHEDULE_VECTOR;
 196                 break;
 197         case CALL_FUNCTION_VECTOR:
 198                 xen_vector = XEN_CALL_FUNCTION_VECTOR;
 199                 break;
 200         case CALL_FUNCTION_SINGLE_VECTOR:
 201                 xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
 202                 break;
 203         case IRQ_WORK_VECTOR:
 204                 xen_vector = XEN_IRQ_WORK_VECTOR;
 205                 break;
 206 #ifdef CONFIG_X86_64
 207         case NMI_VECTOR:
 208         case APIC_DM_NMI: /* Some use that instead of NMI_VECTOR */
 209                 xen_vector = XEN_NMI_VECTOR;
 210                 break;
 211 #endif
 212         default:
 213                 xen_vector = -1;
 214                 printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
 215                         vector);
 216         }
 217
 218         return xen_vector;
 219 }
 220
 221 void xen_send_IPI_mask(const struct cpumask *mask,
 222                               int vector)
 223 {
 224         int xen_vector = xen_map_vector(vector);
 225
 226         if (xen_vector >= 0)
 227                 __xen_send_IPI_mask(mask, xen_vector);
 228 }
 229
 230 void xen_send_IPI_all(int vector)
 231 {
 232         int xen_vector = xen_map_vector(vector);
 233
 234         if (xen_vector >= 0)
 235                 __xen_send_IPI_mask(cpu_online_mask, xen_vector);
 236 }
 237
 238 void xen_send_IPI_self(int vector)
 239 {
 240         int xen_vector = xen_map_vector(vector);
 241
 242         if (xen_vector >= 0)
 243                 xen_send_IPI_one(smp_processor_id(), xen_vector);
 244 }
 245
 246 void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
 247                                 int vector)
 248 {
 249         unsigned cpu;
 250         unsigned int this_cpu = smp_processor_id();
 251         int xen_vector = xen_map_vector(vector);
 252
 253         if (!(num_online_cpus() > 1) || (xen_vector < 0))
 254                 return;
 255
 256         for_each_cpu_and(cpu, mask, cpu_online_mask) {
 257                 if (this_cpu == cpu)
 258                         continue;
 259
 260                 xen_send_IPI_one(cpu, xen_vector);
 261         }
 262 }
 263
 264 void xen_send_IPI_allbutself(int vector)
 265 {
 266         xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
 267 }
 268
 269 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
 270 {
 271         irq_enter();
 272         generic_smp_call_function_interrupt();
 273         inc_irq_stat(irq_call_count);
 274         irq_exit();
 275
 276         return IRQ_HANDLED;
 277 }
 278
 279 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
 280 {
 281         irq_enter();
 282         generic_smp_call_function_single_interrupt();
 283         inc_irq_stat(irq_call_count);
 284         irq_exit();
 285
 286         return IRQ_HANDLED;
 287 }