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 } 288