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 #ifndef CONFIG_PARAVIRT
80 #ifndef __ASSEMBLY__
81 /*
82  * Used in the idle loop; sti takes one instruction cycle
83  * to complete:
84  */
arch_safe_halt(void)85 static __always_inline void arch_safe_halt(void)
86 {
87 	native_safe_halt();
88 }
89 
90 /*
91  * Used when interrupts are already enabled or to
92  * shutdown the processor:
93  */
halt(void)94 static __always_inline void halt(void)
95 {
96 	native_halt();
97 }
98 #endif /* __ASSEMBLY__ */
99 #endif /* CONFIG_PARAVIRT */
100 
101 #ifdef CONFIG_PARAVIRT_XXL
102 #include <asm/paravirt.h>
103 #else
104 #ifndef __ASSEMBLY__
105 #include <linux/types.h>
106 
arch_local_save_flags(void)107 static __always_inline unsigned long arch_local_save_flags(void)
108 {
109 	return native_save_fl();
110 }
111 
arch_local_irq_disable(void)112 static __always_inline void arch_local_irq_disable(void)
113 {
114 	native_irq_disable();
115 }
116 
arch_local_irq_enable(void)117 static __always_inline void arch_local_irq_enable(void)
118 {
119 	native_irq_enable();
120 }
121 
122 /*
123  * For spinlocks, etc:
124  */
arch_local_irq_save(void)125 static __always_inline unsigned long arch_local_irq_save(void)
126 {
127 	unsigned long flags = arch_local_save_flags();
128 	arch_local_irq_disable();
129 	return flags;
130 }
131 #else
132 
133 #ifdef CONFIG_X86_64
134 #ifdef CONFIG_DEBUG_ENTRY
135 #define SAVE_FLAGS		pushfq; popq %rax
136 #endif
137 
138 #endif
139 
140 #endif /* __ASSEMBLY__ */
141 #endif /* CONFIG_PARAVIRT_XXL */
142 
143 #ifndef __ASSEMBLY__
arch_irqs_disabled_flags(unsigned long flags)144 static __always_inline int arch_irqs_disabled_flags(unsigned long flags)
145 {
146 	return !(flags & X86_EFLAGS_IF);
147 }
148 
arch_irqs_disabled(void)149 static __always_inline int arch_irqs_disabled(void)
150 {
151 	unsigned long flags = arch_local_save_flags();
152 
153 	return arch_irqs_disabled_flags(flags);
154 }
155 
arch_local_irq_restore(unsigned long flags)156 static __always_inline void arch_local_irq_restore(unsigned long flags)
157 {
158 	if (!arch_irqs_disabled_flags(flags))
159 		arch_local_irq_enable();
160 }
161 #endif /* !__ASSEMBLY__ */
162 
163 #endif
164