summaryrefslogtreecommitdiff
path: root/include/asm-x86/percpu_32.h
blob: e62ce2fe2c9cc519a8717d5affe79f6f462a6908 (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
#ifndef __ARCH_I386_PERCPU__
#define __ARCH_I386_PERCPU__

#ifdef __ASSEMBLY__

/*
 * PER_CPU finds an address of a per-cpu variable.
 *
 * Args:
 *    var - variable name
 *    reg - 32bit register
 *
 * The resulting address is stored in the "reg" argument.
 *
 * Example:
 *    PER_CPU(cpu_gdt_descr, %ebx)
 */
#ifdef CONFIG_SMP
#define PER_CPU(var, reg)				\
	movl %fs:per_cpu__##this_cpu_off, reg;		\
	lea per_cpu__##var(reg), reg
#define PER_CPU_VAR(var)	%fs:per_cpu__##var
#else /* ! SMP */
#define PER_CPU(var, reg)			\
	movl $per_cpu__##var, reg
#define PER_CPU_VAR(var)	per_cpu__##var
#endif	/* SMP */

#else /* ...!ASSEMBLY */

/*
 * PER_CPU finds an address of a per-cpu variable.
 *
 * Args:
 *    var - variable name
 *    cpu - 32bit register containing the current CPU number
 *
 * The resulting address is stored in the "cpu" argument.
 *
 * Example:
 *    PER_CPU(cpu_gdt_descr, %ebx)
 */
#ifdef CONFIG_SMP

#define __my_cpu_offset x86_read_percpu(this_cpu_off)

/* A macro to avoid #include hell... */
#define percpu_modcopy(pcpudst, src, size)			\
do {								\
	unsigned int __i;					\
	for_each_possible_cpu(__i)				\
		memcpy((pcpudst)+__per_cpu_offset[__i],		\
		       (src), (size));				\
} while (0)

/* fs segment starts at (positive) offset == __per_cpu_offset[cpu] */
#define __percpu_seg "%%fs:"

#else  /* !SMP */

#define __percpu_seg ""

#endif	/* SMP */

#include <asm-generic/percpu.h>

/* We can use this directly for local CPU (faster). */
DECLARE_PER_CPU(unsigned long, this_cpu_off);

/* For arch-specific code, we can use direct single-insn ops (they
 * don't give an lvalue though). */
extern void __bad_percpu_size(void);

#define percpu_to_op(op,var,val)				\
	do {							\
		typedef typeof(var) T__;			\
		if (0) { T__ tmp__; tmp__ = (val); }		\
		switch (sizeof(var)) {				\
		case 1:						\
			asm(op "b %1,"__percpu_seg"%0"		\
			    : "+m" (var)			\
			    :"ri" ((T__)val));			\
			break;					\
		case 2:						\
			asm(op "w %1,"__percpu_seg"%0"		\
			    : "+m" (var)			\
			    :"ri" ((T__)val));			\
			break;					\
		case 4:						\
			asm(op "l %1,"__percpu_seg"%0"		\
			    : "+m" (var)			\
			    :"ri" ((T__)val));			\
			break;					\
		default: __bad_percpu_size();			\
		}						\
	} while (0)

#define percpu_from_op(op,var)					\
	({							\
		typeof(var) ret__;				\
		switch (sizeof(var)) {				\
		case 1:						\
			asm(op "b "__percpu_seg"%1,%0"		\
			    : "=r" (ret__)			\
			    : "m" (var));			\
			break;					\
		case 2:						\
			asm(op "w "__percpu_seg"%1,%0"		\
			    : "=r" (ret__)			\
			    : "m" (var));			\
			break;					\
		case 4:						\
			asm(op "l "__percpu_seg"%1,%0"		\
			    : "=r" (ret__)			\
			    : "m" (var));			\
			break;					\
		default: __bad_percpu_size();			\
		}						\
		ret__; })

#define x86_read_percpu(var) percpu_from_op("mov", per_cpu__##var)
#define x86_write_percpu(var,val) percpu_to_op("mov", per_cpu__##var, val)
#define x86_add_percpu(var,val) percpu_to_op("add", per_cpu__##var, val)
#define x86_sub_percpu(var,val) percpu_to_op("sub", per_cpu__##var, val)
#define x86_or_percpu(var,val) percpu_to_op("or", per_cpu__##var, val)
#endif /* !__ASSEMBLY__ */

#endif /* __ARCH_I386_PERCPU__ */