1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Uniprocessor-only support functions. The counterpart to kernel/smp.c 4 */ 5 6 #include <linux/interrupt.h> 7 #include <linux/kernel.h> 8 #include <linux/export.h> 9 #include <linux/smp.h> 10 #include <linux/hypervisor.h> 11 12 int smp_call_function_single(int cpu, void (*func) (void *info), void *info, 13 int wait) 14 { 15 unsigned long flags; 16 17 if (cpu != 0) 18 return -ENXIO; 19 20 local_irq_save(flags); 21 func(info); 22 local_irq_restore(flags); 23 24 return 0; 25 } 26 EXPORT_SYMBOL(smp_call_function_single); 27 28 int smp_call_function_single_async(int cpu, call_single_data_t *csd) 29 { 30 unsigned long flags; 31 32 local_irq_save(flags); 33 csd->func(csd->info); 34 local_irq_restore(flags); 35 return 0; 36 } 37 EXPORT_SYMBOL(smp_call_function_single_async); 38 39 void on_each_cpu(smp_call_func_t func, void *info, int wait) 40 { 41 unsigned long flags; 42 43 local_irq_save(flags); 44 func(info); 45 local_irq_restore(flags); 46 } 47 EXPORT_SYMBOL(on_each_cpu); 48 49 /* 50 * Note we still need to test the mask even for UP 51 * because we actually can get an empty mask from 52 * code that on SMP might call us without the local 53 * CPU in the mask. 54 */ 55 void on_each_cpu_mask(const struct cpumask *mask, 56 smp_call_func_t func, void *info, bool wait) 57 { 58 unsigned long flags; 59 60 if (cpumask_test_cpu(0, mask)) { 61 local_irq_save(flags); 62 func(info); 63 local_irq_restore(flags); 64 } 65 } 66 EXPORT_SYMBOL(on_each_cpu_mask); 67 68 /* 69 * Preemption is disabled here to make sure the cond_func is called under the 70 * same condtions in UP and SMP. 71 */ 72 void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func, 73 void *info, bool wait, const struct cpumask *mask) 74 { 75 unsigned long flags; 76 77 preempt_disable(); 78 if (cond_func(0, info)) { 79 local_irq_save(flags); 80 func(info); 81 local_irq_restore(flags); 82 } 83 preempt_enable(); 84 } 85 EXPORT_SYMBOL(on_each_cpu_cond_mask); 86 87 void on_each_cpu_cond(smp_cond_func_t cond_func, smp_call_func_t func, 88 void *info, bool wait) 89 { 90 on_each_cpu_cond_mask(cond_func, func, info, wait, NULL); 91 } 92 EXPORT_SYMBOL(on_each_cpu_cond); 93 94 int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys) 95 { 96 int ret; 97 98 if (cpu != 0) 99 return -ENXIO; 100 101 if (phys) 102 hypervisor_pin_vcpu(0); 103 ret = func(par); 104 if (phys) 105 hypervisor_pin_vcpu(-1); 106 107 return ret; 108 } 109 EXPORT_SYMBOL_GPL(smp_call_on_cpu); 110