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 debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu); 92 rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt, 93 IRQF_PERCPU | IRQF_NOBALANCING, 94 debug_name, NULL); 95 if (rc < 0) 96 goto fail; 97 per_cpu(xen_debug_irq, cpu).irq = rc; 98 per_cpu(xen_debug_irq, cpu).name = debug_name; 99 100 callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu); 101 rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR, 102 cpu, 103 xen_call_function_single_interrupt, 104 IRQF_PERCPU|IRQF_NOBALANCING, 105 callfunc_name, 106 NULL); 107 if (rc < 0) 108 goto fail; 109 per_cpu(xen_callfuncsingle_irq, cpu).irq = rc; 110 per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name; 111 112 return 0; 113 114 fail: 115 xen_smp_intr_free(cpu); 116 return rc; 117 } 118 119 void __init xen_smp_cpus_done(unsigned int max_cpus) 120 { 121 int cpu, rc, count = 0; 122 123 if (xen_hvm_domain()) 124 native_smp_cpus_done(max_cpus); 125 else 126 calculate_max_logical_packages(); 127 128 if (xen_have_vcpu_info_placement) 129 return; 130 131 for_each_online_cpu(cpu) { 132 if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS) 133 continue; 134 135 rc = remove_cpu(cpu); 136 137 if (rc == 0) { 138 /* 139 * Reset vcpu_info so this cpu cannot be onlined again. 140 */ 141 xen_vcpu_info_reset(cpu); 142 count++; 143 } else { 144 pr_warn("%s: failed to bring CPU %d down, error %d\n", 145 __func__, cpu, rc); 146 } 147 } 148 WARN(count, "%s: brought %d CPUs offline\n", __func__, count); 149 } 150 151 void xen_smp_send_reschedule(int cpu) 152 { 153 xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR); 154 } 155 156 static void __xen_send_IPI_mask(const struct cpumask *mask, 157 int vector) 158 { 159 unsigned cpu; 160 161 for_each_cpu_and(cpu, mask, cpu_online_mask) 162 xen_send_IPI_one(cpu, vector); 163 } 164 165 void xen_smp_send_call_function_ipi(const struct cpumask *mask) 166 { 167 int cpu; 168 169 __xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR); 170 171 /* Make sure other vcpus get a chance to run if they need to. */ 172 for_each_cpu(cpu, mask) { 173 if (xen_vcpu_stolen(cpu)) { 174 HYPERVISOR_sched_op(SCHEDOP_yield, NULL); 175 break; 176 } 177 } 178 } 179 180 void xen_smp_send_call_function_single_ipi(int cpu) 181 { 182 __xen_send_IPI_mask(cpumask_of(cpu), 183 XEN_CALL_FUNCTION_SINGLE_VECTOR); 184 } 185 186 static inline int xen_map_vector(int vector) 187 { 188 int xen_vector; 189 190 switch (vector) { 191 case RESCHEDULE_VECTOR: 192 xen_vector = XEN_RESCHEDULE_VECTOR; 193 break; 194 case CALL_FUNCTION_VECTOR: 195 xen_vector = XEN_CALL_FUNCTION_VECTOR; 196 break; 197 case CALL_FUNCTION_SINGLE_VECTOR: 198 xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR; 199 break; 200 case IRQ_WORK_VECTOR: 201 xen_vector = XEN_IRQ_WORK_VECTOR; 202 break; 203 #ifdef CONFIG_X86_64 204 case NMI_VECTOR: 205 case APIC_DM_NMI: /* Some use that instead of NMI_VECTOR */ 206 xen_vector = XEN_NMI_VECTOR; 207 break; 208 #endif 209 default: 210 xen_vector = -1; 211 printk(KERN_ERR "xen: vector 0x%x is not implemented\n", 212 vector); 213 } 214 215 return xen_vector; 216 } 217 218 void xen_send_IPI_mask(const struct cpumask *mask, 219 int vector) 220 { 221 int xen_vector = xen_map_vector(vector); 222 223 if (xen_vector >= 0) 224 __xen_send_IPI_mask(mask, xen_vector); 225 } 226 227 void xen_send_IPI_all(int vector) 228 { 229 int xen_vector = xen_map_vector(vector); 230 231 if (xen_vector >= 0) 232 __xen_send_IPI_mask(cpu_online_mask, xen_vector); 233 } 234 235 void xen_send_IPI_self(int vector) 236 { 237 int xen_vector = xen_map_vector(vector); 238 239 if (xen_vector >= 0) 240 xen_send_IPI_one(smp_processor_id(), xen_vector); 241 } 242 243 void xen_send_IPI_mask_allbutself(const struct cpumask *mask, 244 int vector) 245 { 246 unsigned cpu; 247 unsigned int this_cpu = smp_processor_id(); 248 int xen_vector = xen_map_vector(vector); 249 250 if (!(num_online_cpus() > 1) || (xen_vector < 0)) 251 return; 252 253 for_each_cpu_and(cpu, mask, cpu_online_mask) { 254 if (this_cpu == cpu) 255 continue; 256 257 xen_send_IPI_one(cpu, xen_vector); 258 } 259 } 260 261 void xen_send_IPI_allbutself(int vector) 262 { 263 xen_send_IPI_mask_allbutself(cpu_online_mask, vector); 264 } 265 266 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id) 267 { 268 irq_enter(); 269 generic_smp_call_function_interrupt(); 270 inc_irq_stat(irq_call_count); 271 irq_exit(); 272 273 return IRQ_HANDLED; 274 } 275 276 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id) 277 { 278 irq_enter(); 279 generic_smp_call_function_single_interrupt(); 280 inc_irq_stat(irq_call_count); 281 irq_exit(); 282 283 return IRQ_HANDLED; 284 } 285