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 WARN_ON(cpu != 0); 18 19 local_irq_save(flags); 20 func(info); 21 local_irq_restore(flags); 22 23 return 0; 24 } 25 EXPORT_SYMBOL(smp_call_function_single); 26 27 int smp_call_function_single_async(int cpu, call_single_data_t *csd) 28 { 29 unsigned long flags; 30 31 local_irq_save(flags); 32 csd->func(csd->info); 33 local_irq_restore(flags); 34 return 0; 35 } 36 EXPORT_SYMBOL(smp_call_function_single_async); 37 38 int on_each_cpu(smp_call_func_t func, void *info, int wait) 39 { 40 unsigned long flags; 41 42 local_irq_save(flags); 43 func(info); 44 local_irq_restore(flags); 45 return 0; 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(bool (*cond_func)(int cpu, void *info), 73 smp_call_func_t func, void *info, bool wait, 74 gfp_t gfp_flags, const struct cpumask *mask) 75 { 76 unsigned long flags; 77 78 preempt_disable(); 79 if (cond_func(0, info)) { 80 local_irq_save(flags); 81 func(info); 82 local_irq_restore(flags); 83 } 84 preempt_enable(); 85 } 86 EXPORT_SYMBOL(on_each_cpu_cond_mask); 87 88 void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info), 89 smp_call_func_t func, void *info, bool wait, 90 gfp_t gfp_flags) 91 { 92 on_each_cpu_cond_mask(cond_func, func, info, wait, gfp_flags, NULL); 93 } 94 EXPORT_SYMBOL(on_each_cpu_cond); 95 96 int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys) 97 { 98 int ret; 99 100 if (cpu != 0) 101 return -ENXIO; 102 103 if (phys) 104 hypervisor_pin_vcpu(0); 105 ret = func(par); 106 if (phys) 107 hypervisor_pin_vcpu(-1); 108 109 return ret; 110 } 111 EXPORT_SYMBOL_GPL(smp_call_on_cpu); 112