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