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 /* Declaration required for gcc < 4.9 to prevent -Werror=missing-prototypes */
17 extern inline unsigned long native_save_fl(void);
native_save_fl(void)18 extern inline unsigned long native_save_fl(void)
19 {
20 	unsigned long flags;
21 
22 	/*
23 	 * "=rm" is safe here, because "pop" adjusts the stack before
24 	 * it evaluates its effective address -- this is part of the
25 	 * documented behavior of the "pop" instruction.
26 	 */
27 	asm volatile("# __raw_save_flags\n\t"
28 		     "pushf ; pop %0"
29 		     : "=rm" (flags)
30 		     : /* no input */
31 		     : "memory");
32 
33 	return flags;
34 }
35 
36 extern inline void native_restore_fl(unsigned long flags);
native_restore_fl(unsigned long flags)37 extern inline void native_restore_fl(unsigned long flags)
38 {
39 	asm volatile("push %0 ; popf"
40 		     : /* no output */
41 		     :"g" (flags)
42 		     :"memory", "cc");
43 }
44 
native_irq_disable(void)45 static inline void native_irq_disable(void)
46 {
47 	asm volatile("cli": : :"memory");
48 }
49 
native_irq_enable(void)50 static inline void native_irq_enable(void)
51 {
52 	asm volatile("sti": : :"memory");
53 }
54 
native_safe_halt(void)55 static inline __cpuidle void native_safe_halt(void)
56 {
57 	asm volatile("sti; hlt": : :"memory");
58 }
59 
native_halt(void)60 static inline __cpuidle void native_halt(void)
61 {
62 	asm volatile("hlt": : :"memory");
63 }
64 
65 #endif
66 
67 #ifdef CONFIG_PARAVIRT
68 #include <asm/paravirt.h>
69 #else
70 #ifndef __ASSEMBLY__
71 #include <linux/types.h>
72 
arch_local_save_flags(void)73 static inline notrace unsigned long arch_local_save_flags(void)
74 {
75 	return native_save_fl();
76 }
77 
arch_local_irq_restore(unsigned long flags)78 static inline notrace void arch_local_irq_restore(unsigned long flags)
79 {
80 	native_restore_fl(flags);
81 }
82 
arch_local_irq_disable(void)83 static inline notrace void arch_local_irq_disable(void)
84 {
85 	native_irq_disable();
86 }
87 
arch_local_irq_enable(void)88 static inline notrace void arch_local_irq_enable(void)
89 {
90 	native_irq_enable();
91 }
92 
93 /*
94  * Used in the idle loop; sti takes one instruction cycle
95  * to complete:
96  */
arch_safe_halt(void)97 static inline __cpuidle void arch_safe_halt(void)
98 {
99 	native_safe_halt();
100 }
101 
102 /*
103  * Used when interrupts are already enabled or to
104  * shutdown the processor:
105  */
halt(void)106 static inline __cpuidle void halt(void)
107 {
108 	native_halt();
109 }
110 
111 /*
112  * For spinlocks, etc:
113  */
arch_local_irq_save(void)114 static inline notrace unsigned long arch_local_irq_save(void)
115 {
116 	unsigned long flags = arch_local_save_flags();
117 	arch_local_irq_disable();
118 	return flags;
119 }
120 #else
121 
122 #define ENABLE_INTERRUPTS(x)	sti
123 #define DISABLE_INTERRUPTS(x)	cli
124 
125 #ifdef CONFIG_X86_64
126 #define SWAPGS	swapgs
127 /*
128  * Currently paravirt can't handle swapgs nicely when we
129  * don't have a stack we can rely on (such as a user space
130  * stack).  So we either find a way around these or just fault
131  * and emulate if a guest tries to call swapgs directly.
132  *
133  * Either way, this is a good way to document that we don't
134  * have a reliable stack. x86_64 only.
135  */
136 #define SWAPGS_UNSAFE_STACK	swapgs
137 
138 #define PARAVIRT_ADJUST_EXCEPTION_FRAME	/*  */
139 
140 #define INTERRUPT_RETURN	jmp native_iret
141 #define USERGS_SYSRET64				\
142 	swapgs;					\
143 	sysretq;
144 #define USERGS_SYSRET32				\
145 	swapgs;					\
146 	sysretl
147 
148 #ifdef CONFIG_DEBUG_ENTRY
149 #define SAVE_FLAGS(x)		pushfq; popq %rax
150 #endif
151 #else
152 #define INTERRUPT_RETURN		iret
153 #define ENABLE_INTERRUPTS_SYSEXIT	sti; sysexit
154 #define GET_CR0_INTO_EAX		movl %cr0, %eax
155 #endif
156 
157 
158 #endif /* __ASSEMBLY__ */
159 #endif /* CONFIG_PARAVIRT */
160 
161 #ifndef __ASSEMBLY__
arch_irqs_disabled_flags(unsigned long flags)162 static inline int arch_irqs_disabled_flags(unsigned long flags)
163 {
164 	return !(flags & X86_EFLAGS_IF);
165 }
166 
arch_irqs_disabled(void)167 static inline int arch_irqs_disabled(void)
168 {
169 	unsigned long flags = arch_local_save_flags();
170 
171 	return arch_irqs_disabled_flags(flags);
172 }
173 #endif /* !__ASSEMBLY__ */
174 
175 #ifdef __ASSEMBLY__
176 #ifdef CONFIG_TRACE_IRQFLAGS
177 #  define TRACE_IRQS_ON		call trace_hardirqs_on_thunk;
178 #  define TRACE_IRQS_OFF	call trace_hardirqs_off_thunk;
179 #else
180 #  define TRACE_IRQS_ON
181 #  define TRACE_IRQS_OFF
182 #endif
183 #ifdef CONFIG_DEBUG_LOCK_ALLOC
184 #  ifdef CONFIG_X86_64
185 #    define LOCKDEP_SYS_EXIT		call lockdep_sys_exit_thunk
186 #    define LOCKDEP_SYS_EXIT_IRQ \
187 	TRACE_IRQS_ON; \
188 	sti; \
189 	call lockdep_sys_exit_thunk; \
190 	cli; \
191 	TRACE_IRQS_OFF;
192 #  else
193 #    define LOCKDEP_SYS_EXIT \
194 	pushl %eax;				\
195 	pushl %ecx;				\
196 	pushl %edx;				\
197 	call lockdep_sys_exit;			\
198 	popl %edx;				\
199 	popl %ecx;				\
200 	popl %eax;
201 #    define LOCKDEP_SYS_EXIT_IRQ
202 #  endif
203 #else
204 #  define LOCKDEP_SYS_EXIT
205 #  define LOCKDEP_SYS_EXIT_IRQ
206 #endif
207 #endif /* __ASSEMBLY__ */
208 
209 #endif
210