xref: /openbmc/linux/arch/x86/include/asm/irqflags.h (revision f87deada)
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 /* Provide __cpuidle; we can't safely include <linux/cpu.h> */
10 #define __cpuidle __attribute__((__section__(".cpuidle.text")))
11 
12 /*
13  * Interrupt control:
14  */
15 
16 static inline unsigned long native_save_fl(void)
17 {
18 	unsigned long flags;
19 
20 	/*
21 	 * "=rm" is safe here, because "pop" adjusts the stack before
22 	 * it evaluates its effective address -- this is part of the
23 	 * documented behavior of the "pop" instruction.
24 	 */
25 	asm volatile("# __raw_save_flags\n\t"
26 		     "pushf ; pop %0"
27 		     : "=rm" (flags)
28 		     : /* no input */
29 		     : "memory");
30 
31 	return flags;
32 }
33 
34 static inline void native_restore_fl(unsigned long flags)
35 {
36 	asm volatile("push %0 ; popf"
37 		     : /* no output */
38 		     :"g" (flags)
39 		     :"memory", "cc");
40 }
41 
42 static inline void native_irq_disable(void)
43 {
44 	asm volatile("cli": : :"memory");
45 }
46 
47 static inline void native_irq_enable(void)
48 {
49 	asm volatile("sti": : :"memory");
50 }
51 
52 static inline __cpuidle void native_safe_halt(void)
53 {
54 	asm volatile("sti; hlt": : :"memory");
55 }
56 
57 static inline __cpuidle void native_halt(void)
58 {
59 	asm volatile("hlt": : :"memory");
60 }
61 
62 #endif
63 
64 #ifdef CONFIG_PARAVIRT
65 #include <asm/paravirt.h>
66 #else
67 #ifndef __ASSEMBLY__
68 #include <linux/types.h>
69 
70 static inline notrace unsigned long arch_local_save_flags(void)
71 {
72 	return native_save_fl();
73 }
74 
75 static inline notrace void arch_local_irq_restore(unsigned long flags)
76 {
77 	native_restore_fl(flags);
78 }
79 
80 static inline notrace void arch_local_irq_disable(void)
81 {
82 	native_irq_disable();
83 }
84 
85 static inline notrace void arch_local_irq_enable(void)
86 {
87 	native_irq_enable();
88 }
89 
90 /*
91  * Used in the idle loop; sti takes one instruction cycle
92  * to complete:
93  */
94 static inline __cpuidle void arch_safe_halt(void)
95 {
96 	native_safe_halt();
97 }
98 
99 /*
100  * Used when interrupts are already enabled or to
101  * shutdown the processor:
102  */
103 static inline __cpuidle void halt(void)
104 {
105 	native_halt();
106 }
107 
108 /*
109  * For spinlocks, etc:
110  */
111 static inline notrace unsigned long arch_local_irq_save(void)
112 {
113 	unsigned long flags = arch_local_save_flags();
114 	arch_local_irq_disable();
115 	return flags;
116 }
117 #else
118 
119 #define ENABLE_INTERRUPTS(x)	sti
120 #define DISABLE_INTERRUPTS(x)	cli
121 
122 #ifdef CONFIG_X86_64
123 #define SWAPGS	swapgs
124 /*
125  * Currently paravirt can't handle swapgs nicely when we
126  * don't have a stack we can rely on (such as a user space
127  * stack).  So we either find a way around these or just fault
128  * and emulate if a guest tries to call swapgs directly.
129  *
130  * Either way, this is a good way to document that we don't
131  * have a reliable stack. x86_64 only.
132  */
133 #define SWAPGS_UNSAFE_STACK	swapgs
134 
135 #define PARAVIRT_ADJUST_EXCEPTION_FRAME	/*  */
136 
137 #define INTERRUPT_RETURN	jmp native_iret
138 #define USERGS_SYSRET64				\
139 	swapgs;					\
140 	sysretq;
141 #define USERGS_SYSRET32				\
142 	swapgs;					\
143 	sysretl
144 
145 #ifdef CONFIG_DEBUG_ENTRY
146 #define SAVE_FLAGS(x)		pushfq; popq %rax
147 #endif
148 #else
149 #define INTERRUPT_RETURN		iret
150 #define ENABLE_INTERRUPTS_SYSEXIT	sti; sysexit
151 #define GET_CR0_INTO_EAX		movl %cr0, %eax
152 #endif
153 
154 
155 #endif /* __ASSEMBLY__ */
156 #endif /* CONFIG_PARAVIRT */
157 
158 #ifndef __ASSEMBLY__
159 static inline int arch_irqs_disabled_flags(unsigned long flags)
160 {
161 	return !(flags & X86_EFLAGS_IF);
162 }
163 
164 static inline int arch_irqs_disabled(void)
165 {
166 	unsigned long flags = arch_local_save_flags();
167 
168 	return arch_irqs_disabled_flags(flags);
169 }
170 #endif /* !__ASSEMBLY__ */
171 
172 #ifdef __ASSEMBLY__
173 #ifdef CONFIG_TRACE_IRQFLAGS
174 #  define TRACE_IRQS_ON		call trace_hardirqs_on_thunk;
175 #  define TRACE_IRQS_OFF	call trace_hardirqs_off_thunk;
176 #else
177 #  define TRACE_IRQS_ON
178 #  define TRACE_IRQS_OFF
179 #endif
180 #ifdef CONFIG_DEBUG_LOCK_ALLOC
181 #  ifdef CONFIG_X86_64
182 #    define LOCKDEP_SYS_EXIT		call lockdep_sys_exit_thunk
183 #    define LOCKDEP_SYS_EXIT_IRQ \
184 	TRACE_IRQS_ON; \
185 	sti; \
186 	call lockdep_sys_exit_thunk; \
187 	cli; \
188 	TRACE_IRQS_OFF;
189 #  else
190 #    define LOCKDEP_SYS_EXIT \
191 	pushl %eax;				\
192 	pushl %ecx;				\
193 	pushl %edx;				\
194 	call lockdep_sys_exit;			\
195 	popl %edx;				\
196 	popl %ecx;				\
197 	popl %eax;
198 #    define LOCKDEP_SYS_EXIT_IRQ
199 #  endif
200 #else
201 #  define LOCKDEP_SYS_EXIT
202 #  define LOCKDEP_SYS_EXIT_IRQ
203 #endif
204 #endif /* __ASSEMBLY__ */
205 
206 #endif
207