xref: /openbmc/linux/arch/x86/include/asm/irqflags.h (revision 4800cd83)
1 #ifndef _X86_IRQFLAGS_H_
2 #define _X86_IRQFLAGS_H_
3 
4 #include <asm/processor-flags.h>
5 
6 #ifndef __ASSEMBLY__
7 /*
8  * Interrupt control:
9  */
10 
11 static inline unsigned long native_save_fl(void)
12 {
13 	unsigned long flags;
14 
15 	/*
16 	 * "=rm" is safe here, because "pop" adjusts the stack before
17 	 * it evaluates its effective address -- this is part of the
18 	 * documented behavior of the "pop" instruction.
19 	 */
20 	asm volatile("# __raw_save_flags\n\t"
21 		     "pushf ; pop %0"
22 		     : "=rm" (flags)
23 		     : /* no input */
24 		     : "memory");
25 
26 	return flags;
27 }
28 
29 static inline void native_restore_fl(unsigned long flags)
30 {
31 	asm volatile("push %0 ; popf"
32 		     : /* no output */
33 		     :"g" (flags)
34 		     :"memory", "cc");
35 }
36 
37 static inline void native_irq_disable(void)
38 {
39 	asm volatile("cli": : :"memory");
40 }
41 
42 static inline void native_irq_enable(void)
43 {
44 	asm volatile("sti": : :"memory");
45 }
46 
47 static inline void native_safe_halt(void)
48 {
49 	asm volatile("sti; hlt": : :"memory");
50 }
51 
52 static inline void native_halt(void)
53 {
54 	asm volatile("hlt": : :"memory");
55 }
56 
57 #endif
58 
59 #ifdef CONFIG_PARAVIRT
60 #include <asm/paravirt.h>
61 #else
62 #ifndef __ASSEMBLY__
63 
64 static inline unsigned long arch_local_save_flags(void)
65 {
66 	return native_save_fl();
67 }
68 
69 static inline void arch_local_irq_restore(unsigned long flags)
70 {
71 	native_restore_fl(flags);
72 }
73 
74 static inline void arch_local_irq_disable(void)
75 {
76 	native_irq_disable();
77 }
78 
79 static inline void arch_local_irq_enable(void)
80 {
81 	native_irq_enable();
82 }
83 
84 /*
85  * Used in the idle loop; sti takes one instruction cycle
86  * to complete:
87  */
88 static inline void arch_safe_halt(void)
89 {
90 	native_safe_halt();
91 }
92 
93 /*
94  * Used when interrupts are already enabled or to
95  * shutdown the processor:
96  */
97 static inline void halt(void)
98 {
99 	native_halt();
100 }
101 
102 /*
103  * For spinlocks, etc:
104  */
105 static inline unsigned long arch_local_irq_save(void)
106 {
107 	unsigned long flags = arch_local_save_flags();
108 	arch_local_irq_disable();
109 	return flags;
110 }
111 #else
112 
113 #define ENABLE_INTERRUPTS(x)	sti
114 #define DISABLE_INTERRUPTS(x)	cli
115 
116 #ifdef CONFIG_X86_64
117 #define SWAPGS	swapgs
118 /*
119  * Currently paravirt can't handle swapgs nicely when we
120  * don't have a stack we can rely on (such as a user space
121  * stack).  So we either find a way around these or just fault
122  * and emulate if a guest tries to call swapgs directly.
123  *
124  * Either way, this is a good way to document that we don't
125  * have a reliable stack. x86_64 only.
126  */
127 #define SWAPGS_UNSAFE_STACK	swapgs
128 
129 #define PARAVIRT_ADJUST_EXCEPTION_FRAME	/*  */
130 
131 #define INTERRUPT_RETURN	iretq
132 #define USERGS_SYSRET64				\
133 	swapgs;					\
134 	sysretq;
135 #define USERGS_SYSRET32				\
136 	swapgs;					\
137 	sysretl
138 #define ENABLE_INTERRUPTS_SYSEXIT32		\
139 	swapgs;					\
140 	sti;					\
141 	sysexit
142 
143 #else
144 #define INTERRUPT_RETURN		iret
145 #define ENABLE_INTERRUPTS_SYSEXIT	sti; sysexit
146 #define GET_CR0_INTO_EAX		movl %cr0, %eax
147 #endif
148 
149 
150 #endif /* __ASSEMBLY__ */
151 #endif /* CONFIG_PARAVIRT */
152 
153 #ifndef __ASSEMBLY__
154 static inline int arch_irqs_disabled_flags(unsigned long flags)
155 {
156 	return !(flags & X86_EFLAGS_IF);
157 }
158 
159 static inline int arch_irqs_disabled(void)
160 {
161 	unsigned long flags = arch_local_save_flags();
162 
163 	return arch_irqs_disabled_flags(flags);
164 }
165 
166 #else
167 
168 #ifdef CONFIG_X86_64
169 #define ARCH_LOCKDEP_SYS_EXIT		call lockdep_sys_exit_thunk
170 #define ARCH_LOCKDEP_SYS_EXIT_IRQ	\
171 	TRACE_IRQS_ON; \
172 	sti; \
173 	SAVE_REST; \
174 	LOCKDEP_SYS_EXIT; \
175 	RESTORE_REST; \
176 	cli; \
177 	TRACE_IRQS_OFF;
178 
179 #else
180 #define ARCH_LOCKDEP_SYS_EXIT			\
181 	pushl %eax;				\
182 	pushl %ecx;				\
183 	pushl %edx;				\
184 	call lockdep_sys_exit;			\
185 	popl %edx;				\
186 	popl %ecx;				\
187 	popl %eax;
188 
189 #define ARCH_LOCKDEP_SYS_EXIT_IRQ
190 #endif
191 
192 #ifdef CONFIG_TRACE_IRQFLAGS
193 #  define TRACE_IRQS_ON		call trace_hardirqs_on_thunk;
194 #  define TRACE_IRQS_OFF	call trace_hardirqs_off_thunk;
195 #else
196 #  define TRACE_IRQS_ON
197 #  define TRACE_IRQS_OFF
198 #endif
199 #ifdef CONFIG_DEBUG_LOCK_ALLOC
200 #  define LOCKDEP_SYS_EXIT	ARCH_LOCKDEP_SYS_EXIT
201 #  define LOCKDEP_SYS_EXIT_IRQ	ARCH_LOCKDEP_SYS_EXIT_IRQ
202 # else
203 #  define LOCKDEP_SYS_EXIT
204 #  define LOCKDEP_SYS_EXIT_IRQ
205 # endif
206 
207 #endif /* __ASSEMBLY__ */
208 #endif
209