summaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/irqflags.h
blob: c14f2a74b2be7495f1ee00c92322a58cc43d10a6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _X86_IRQFLAGS_H_
#define _X86_IRQFLAGS_H_

#include <asm/processor-flags.h>

#ifndef __ASSEMBLY__

/* Provide __cpuidle; we can't safely include <linux/cpu.h> */
#define __cpuidle __attribute__((__section__(".cpuidle.text")))

/*
 * Interrupt control:
 */

/* Declaration required for gcc < 4.9 to prevent -Werror=missing-prototypes */
extern inline unsigned long native_save_fl(void);
extern inline unsigned long native_save_fl(void)
{
	unsigned long flags;

	/*
	 * "=rm" is safe here, because "pop" adjusts the stack before
	 * it evaluates its effective address -- this is part of the
	 * documented behavior of the "pop" instruction.
	 */
	asm volatile("# __raw_save_flags\n\t"
		     "pushf ; pop %0"
		     : "=rm" (flags)
		     : /* no input */
		     : "memory");

	return flags;
}

static inline void native_restore_fl(unsigned long flags)
{
	asm volatile("push %0 ; popf"
		     : /* no output */
		     :"g" (flags)
		     :"memory", "cc");
}

static inline void native_irq_disable(void)
{
	asm volatile("cli": : :"memory");
}

static inline void native_irq_enable(void)
{
	asm volatile("sti": : :"memory");
}

static inline __cpuidle void native_safe_halt(void)
{
	asm volatile("sti; hlt": : :"memory");
}

static inline __cpuidle void native_halt(void)
{
	asm volatile("hlt": : :"memory");
}

#endif

#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#else
#ifndef __ASSEMBLY__
#include <linux/types.h>

static inline notrace unsigned long arch_local_save_flags(void)
{
	return native_save_fl();
}

static inline notrace void arch_local_irq_restore(unsigned long flags)
{
	native_restore_fl(flags);
}

static inline notrace void arch_local_irq_disable(void)
{
	native_irq_disable();
}

static inline notrace void arch_local_irq_enable(void)
{
	native_irq_enable();
}

/*
 * Used in the idle loop; sti takes one instruction cycle
 * to complete:
 */
static inline __cpuidle void arch_safe_halt(void)
{
	native_safe_halt();
}

/*
 * Used when interrupts are already enabled or to
 * shutdown the processor:
 */
static inline __cpuidle void halt(void)
{
	native_halt();
}

/*
 * For spinlocks, etc:
 */
static inline notrace unsigned long arch_local_irq_save(void)
{
	unsigned long flags = arch_local_save_flags();
	arch_local_irq_disable();
	return flags;
}
#else

#define ENABLE_INTERRUPTS(x)	sti
#define DISABLE_INTERRUPTS(x)	cli

#ifdef CONFIG_X86_64
#define SWAPGS	swapgs
/*
 * Currently paravirt can't handle swapgs nicely when we
 * don't have a stack we can rely on (such as a user space
 * stack).  So we either find a way around these or just fault
 * and emulate if a guest tries to call swapgs directly.
 *
 * Either way, this is a good way to document that we don't
 * have a reliable stack. x86_64 only.
 */
#define SWAPGS_UNSAFE_STACK	swapgs

#define PARAVIRT_ADJUST_EXCEPTION_FRAME	/*  */

#define INTERRUPT_RETURN	jmp native_iret
#define USERGS_SYSRET64				\
	swapgs;					\
	sysretq;
#define USERGS_SYSRET32				\
	swapgs;					\
	sysretl

#ifdef CONFIG_DEBUG_ENTRY
#define SAVE_FLAGS(x)		pushfq; popq %rax
#endif
#else
#define INTERRUPT_RETURN		iret
#define ENABLE_INTERRUPTS_SYSEXIT	sti; sysexit
#define GET_CR0_INTO_EAX		movl %cr0, %eax
#endif


#endif /* __ASSEMBLY__ */
#endif /* CONFIG_PARAVIRT */

#ifndef __ASSEMBLY__
static inline int arch_irqs_disabled_flags(unsigned long flags)
{
	return !(flags & X86_EFLAGS_IF);
}

static inline int arch_irqs_disabled(void)
{
	unsigned long flags = arch_local_save_flags();

	return arch_irqs_disabled_flags(flags);
}
#endif /* !__ASSEMBLY__ */

#ifdef __ASSEMBLY__
#ifdef CONFIG_TRACE_IRQFLAGS
#  define TRACE_IRQS_ON		call trace_hardirqs_on_thunk;
#  define TRACE_IRQS_OFF	call trace_hardirqs_off_thunk;
#else
#  define TRACE_IRQS_ON
#  define TRACE_IRQS_OFF
#endif
#ifdef CONFIG_DEBUG_LOCK_ALLOC
#  ifdef CONFIG_X86_64
#    define LOCKDEP_SYS_EXIT		call lockdep_sys_exit_thunk
#    define LOCKDEP_SYS_EXIT_IRQ \
	TRACE_IRQS_ON; \
	sti; \
	call lockdep_sys_exit_thunk; \
	cli; \
	TRACE_IRQS_OFF;
#  else
#    define LOCKDEP_SYS_EXIT \
	pushl %eax;				\
	pushl %ecx;				\
	pushl %edx;				\
	call lockdep_sys_exit;			\
	popl %edx;				\
	popl %ecx;				\
	popl %eax;
#    define LOCKDEP_SYS_EXIT_IRQ
#  endif
#else
#  define LOCKDEP_SYS_EXIT
#  define LOCKDEP_SYS_EXIT_IRQ
#endif
#endif /* __ASSEMBLY__ */

#endif