xref: /openbmc/linux/arch/x86/include/asm/irqflags.h (revision 2b5a0e42) 
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _X86_IRQFLAGS_H_
3 #define _X86_IRQFLAGS_H_
4 
5 #include <asm/processor-flags.h>
6 
7 #ifndef __ASSEMBLY__
8 
9 #include <asm/nospec-branch.h>
10 
11 /*
12  * Interrupt control:
13  */
14 
15 /* Declaration required for gcc < 4.9 to prevent -Werror=missing-prototypes */
16 extern inline unsigned long native_save_fl(void);
native_save_fl(void)17 extern __always_inline unsigned long native_save_fl(void)
18 {
19 	unsigned long flags;
20 
21 	/*
22 	 * "=rm" is safe here, because "pop" adjusts the stack before
23 	 * it evaluates its effective address -- this is part of the
24 	 * documented behavior of the "pop" instruction.
25 	 */
26 	asm volatile("# __raw_save_flags\n\t"
27 		     "pushf ; pop %0"
28 		     : "=rm" (flags)
29 		     : /* no input */
30 		     : "memory");
31 
32 	return flags;
33 }
34 
native_irq_disable(void)35 static __always_inline void native_irq_disable(void)
36 {
37 	asm volatile("cli": : :"memory");
38 }
39 
native_irq_enable(void)40 static __always_inline void native_irq_enable(void)
41 {
42 	asm volatile("sti": : :"memory");
43 }
44 
native_safe_halt(void)45 static __always_inline void native_safe_halt(void)
46 {
47 	mds_idle_clear_cpu_buffers();
48 	asm volatile("sti; hlt": : :"memory");
49 }
50 
native_halt(void)51 static __always_inline void native_halt(void)
52 {
53 	mds_idle_clear_cpu_buffers();
54 	asm volatile("hlt": : :"memory");
55 }
56 
57 #endif
58 
59 #ifdef CONFIG_PARAVIRT_XXL
60 #include <asm/paravirt.h>
61 #else
62 #ifndef __ASSEMBLY__
63 #include <linux/types.h>
64 
arch_local_save_flags(void)65 static __always_inline unsigned long arch_local_save_flags(void)
66 {
67 	return native_save_fl();
68 }
69 
arch_local_irq_disable(void)70 static __always_inline void arch_local_irq_disable(void)
71 {
72 	native_irq_disable();
73 }
74 
arch_local_irq_enable(void)75 static __always_inline void arch_local_irq_enable(void)
76 {
77 	native_irq_enable();
78 }
79 
80 /*
81  * Used in the idle loop; sti takes one instruction cycle
82  * to complete:
83  */
arch_safe_halt(void)84 static __always_inline void arch_safe_halt(void)
85 {
86 	native_safe_halt();
87 }
88 
89 /*
90  * Used when interrupts are already enabled or to
91  * shutdown the processor:
92  */
halt(void)93 static __always_inline void halt(void)
94 {
95 	native_halt();
96 }
97 
98 /*
99  * For spinlocks, etc:
100  */
arch_local_irq_save(void)101 static __always_inline unsigned long arch_local_irq_save(void)
102 {
103 	unsigned long flags = arch_local_save_flags();
104 	arch_local_irq_disable();
105 	return flags;
106 }
107 #else
108 
109 #ifdef CONFIG_X86_64
110 #ifdef CONFIG_DEBUG_ENTRY
111 #define SAVE_FLAGS		pushfq; popq %rax
112 #endif
113 
114 #endif
115 
116 #endif /* __ASSEMBLY__ */
117 #endif /* CONFIG_PARAVIRT_XXL */
118 
119 #ifndef __ASSEMBLY__
arch_irqs_disabled_flags(unsigned long flags)120 static __always_inline int arch_irqs_disabled_flags(unsigned long flags)
121 {
122 	return !(flags & X86_EFLAGS_IF);
123 }
124 
arch_irqs_disabled(void)125 static __always_inline int arch_irqs_disabled(void)
126 {
127 	unsigned long flags = arch_local_save_flags();
128 
129 	return arch_irqs_disabled_flags(flags);
130 }
131 
arch_local_irq_restore(unsigned long flags)132 static __always_inline void arch_local_irq_restore(unsigned long flags)
133 {
134 	if (!arch_irqs_disabled_flags(flags))
135 		arch_local_irq_enable();
136 }
137 #endif /* !__ASSEMBLY__ */
138 
139 #endif
140