1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 #ifndef _ASM_POWERPC_PARAVIRT_H 3 #define _ASM_POWERPC_PARAVIRT_H 4 5 #include <linux/jump_label.h> 6 #include <asm/smp.h> 7 #ifdef CONFIG_PPC64 8 #include <asm/paca.h> 9 #include <asm/hvcall.h> 10 #endif 11 12 #ifdef CONFIG_PPC_SPLPAR 13 #include <asm/kvm_guest.h> 14 #include <asm/cputhreads.h> 15 16 DECLARE_STATIC_KEY_FALSE(shared_processor); 17 18 static inline bool is_shared_processor(void) 19 { 20 return static_branch_unlikely(&shared_processor); 21 } 22 23 /* If bit 0 is set, the cpu has been preempted */ 24 static inline u32 yield_count_of(int cpu) 25 { 26 __be32 yield_count = READ_ONCE(lppaca_of(cpu).yield_count); 27 return be32_to_cpu(yield_count); 28 } 29 30 static inline void yield_to_preempted(int cpu, u32 yield_count) 31 { 32 plpar_hcall_norets(H_CONFER, get_hard_smp_processor_id(cpu), yield_count); 33 } 34 35 static inline void prod_cpu(int cpu) 36 { 37 plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu)); 38 } 39 40 static inline void yield_to_any(void) 41 { 42 plpar_hcall_norets(H_CONFER, -1, 0); 43 } 44 #else 45 static inline bool is_shared_processor(void) 46 { 47 return false; 48 } 49 50 static inline u32 yield_count_of(int cpu) 51 { 52 return 0; 53 } 54 55 extern void ___bad_yield_to_preempted(void); 56 static inline void yield_to_preempted(int cpu, u32 yield_count) 57 { 58 ___bad_yield_to_preempted(); /* This would be a bug */ 59 } 60 61 extern void ___bad_yield_to_any(void); 62 static inline void yield_to_any(void) 63 { 64 ___bad_yield_to_any(); /* This would be a bug */ 65 } 66 67 extern void ___bad_prod_cpu(void); 68 static inline void prod_cpu(int cpu) 69 { 70 ___bad_prod_cpu(); /* This would be a bug */ 71 } 72 73 #endif 74 75 #define vcpu_is_preempted vcpu_is_preempted 76 static inline bool vcpu_is_preempted(int cpu) 77 { 78 if (!is_shared_processor()) 79 return false; 80 81 #ifdef CONFIG_PPC_SPLPAR 82 if (!is_kvm_guest()) { 83 int first_cpu = cpu_first_thread_sibling(smp_processor_id()); 84 85 /* 86 * Preemption can only happen at core granularity. This CPU 87 * is not preempted if one of the CPU of this core is not 88 * preempted. 89 */ 90 if (cpu_first_thread_sibling(cpu) == first_cpu) 91 return false; 92 } 93 #endif 94 95 if (yield_count_of(cpu) & 1) 96 return true; 97 return false; 98 } 99 100 static inline bool pv_is_native_spin_unlock(void) 101 { 102 return !is_shared_processor(); 103 } 104 105 #endif /* _ASM_POWERPC_PARAVIRT_H */ 106