xref: /linux/arch/x86/include/asm/irqflags.h (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800) 
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 
native_irqs_disabled_flags(unsigned long flags)57 static __always_inline int native_irqs_disabled_flags(unsigned long flags)
58 {
59 	return !(flags & X86_EFLAGS_IF);
60 }
61 
native_local_irq_save(void)62 static __always_inline unsigned long native_local_irq_save(void)
63 {
64 	unsigned long flags = native_save_fl();
65 
66 	native_irq_disable();
67 
68 	return flags;
69 }
70 
native_local_irq_restore(unsigned long flags)71 static __always_inline void native_local_irq_restore(unsigned long flags)
72 {
73 	if (!native_irqs_disabled_flags(flags))
74 		native_irq_enable();
75 }
76 
77 #endif
78 
79 #ifdef CONFIG_PARAVIRT_XXL
80 #include <asm/paravirt.h>
81 #else
82 #ifndef __ASSEMBLY__
83 #include <linux/types.h>
84 
arch_local_save_flags(void)85 static __always_inline unsigned long arch_local_save_flags(void)
86 {
87 	return native_save_fl();
88 }
89 
arch_local_irq_disable(void)90 static __always_inline void arch_local_irq_disable(void)
91 {
92 	native_irq_disable();
93 }
94 
arch_local_irq_enable(void)95 static __always_inline void arch_local_irq_enable(void)
96 {
97 	native_irq_enable();
98 }
99 
100 /*
101  * Used in the idle loop; sti takes one instruction cycle
102  * to complete:
103  */
arch_safe_halt(void)104 static __always_inline void arch_safe_halt(void)
105 {
106 	native_safe_halt();
107 }
108 
109 /*
110  * Used when interrupts are already enabled or to
111  * shutdown the processor:
112  */
halt(void)113 static __always_inline void halt(void)
114 {
115 	native_halt();
116 }
117 
118 /*
119  * For spinlocks, etc:
120  */
arch_local_irq_save(void)121 static __always_inline unsigned long arch_local_irq_save(void)
122 {
123 	unsigned long flags = arch_local_save_flags();
124 	arch_local_irq_disable();
125 	return flags;
126 }
127 #else
128 
129 #ifdef CONFIG_X86_64
130 #ifdef CONFIG_DEBUG_ENTRY
131 #define SAVE_FLAGS		pushfq; popq %rax
132 #endif
133 
134 #endif
135 
136 #endif /* __ASSEMBLY__ */
137 #endif /* CONFIG_PARAVIRT_XXL */
138 
139 #ifndef __ASSEMBLY__
arch_irqs_disabled_flags(unsigned long flags)140 static __always_inline int arch_irqs_disabled_flags(unsigned long flags)
141 {
142 	return !(flags & X86_EFLAGS_IF);
143 }
144 
arch_irqs_disabled(void)145 static __always_inline int arch_irqs_disabled(void)
146 {
147 	unsigned long flags = arch_local_save_flags();
148 
149 	return arch_irqs_disabled_flags(flags);
150 }
151 
arch_local_irq_restore(unsigned long flags)152 static __always_inline void arch_local_irq_restore(unsigned long flags)
153 {
154 	if (!arch_irqs_disabled_flags(flags))
155 		arch_local_irq_enable();
156 }
157 #endif /* !__ASSEMBLY__ */
158 
159 #endif
160