1#ifndef __ARCH_I386_PERCPU__
2#define __ARCH_I386_PERCPU__
3
4#ifdef __ASSEMBLY__
5
6/*
7 * PER_CPU finds an address of a per-cpu variable.
8 *
9 * Args:
10 *    var - variable name
11 *    reg - 32bit register
12 *
13 * The resulting address is stored in the "reg" argument.
14 *
15 * Example:
16 *    PER_CPU(cpu_gdt_descr, %ebx)
17 */
18#ifdef CONFIG_SMP
19#define PER_CPU(var, reg)				\
20	movl %fs:per_cpu__##this_cpu_off, reg;		\
21	lea per_cpu__##var(reg), reg
22#define PER_CPU_VAR(var)	%fs:per_cpu__##var
23#else /* ! SMP */
24#define PER_CPU(var, reg)			\
25	movl $per_cpu__##var, reg
26#define PER_CPU_VAR(var)	per_cpu__##var
27#endif	/* SMP */
28
29#else /* ...!ASSEMBLY */
30
31/*
32 * PER_CPU finds an address of a per-cpu variable.
33 *
34 * Args:
35 *    var - variable name
36 *    cpu - 32bit register containing the current CPU number
37 *
38 * The resulting address is stored in the "cpu" argument.
39 *
40 * Example:
41 *    PER_CPU(cpu_gdt_descr, %ebx)
42 */
43#ifdef CONFIG_SMP
44/* Same as generic implementation except for optimized local access. */
45#define __GENERIC_PER_CPU
46
47/* This is used for other cpus to find our section. */
48extern unsigned long __per_cpu_offset[];
49
50#define per_cpu_offset(x) (__per_cpu_offset[x])
51
52/* Separate out the type, so (int[3], foo) works. */
53#define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name
54#define DEFINE_PER_CPU(type, name) \
55    __attribute__((__section__(".data.percpu"))) __typeof__(type) per_cpu__##name
56
57/* We can use this directly for local CPU (faster). */
58DECLARE_PER_CPU(unsigned long, this_cpu_off);
59
60/* var is in discarded region: offset to particular copy we want */
61#define per_cpu(var, cpu) (*({				\
62	extern int simple_indentifier_##var(void);	\
63	RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]); }))
64
65#define __raw_get_cpu_var(var) (*({					\
66	extern int simple_indentifier_##var(void);			\
67	RELOC_HIDE(&per_cpu__##var, x86_read_percpu(this_cpu_off));	\
68}))
69
70#define __get_cpu_var(var) __raw_get_cpu_var(var)
71
72/* A macro to avoid #include hell... */
73#define percpu_modcopy(pcpudst, src, size)			\
74do {								\
75	unsigned int __i;					\
76	for_each_possible_cpu(__i)				\
77		memcpy((pcpudst)+__per_cpu_offset[__i],		\
78		       (src), (size));				\
79} while (0)
80
81#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
82#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
83
84/* fs segment starts at (positive) offset == __per_cpu_offset[cpu] */
85#define __percpu_seg "%%fs:"
86#else  /* !SMP */
87#include <asm-generic/percpu.h>
88#define __percpu_seg ""
89#endif	/* SMP */
90
91/* For arch-specific code, we can use direct single-insn ops (they
92 * don't give an lvalue though). */
93extern void __bad_percpu_size(void);
94
95#define percpu_to_op(op,var,val)				\
96	do {							\
97		typedef typeof(var) T__;			\
98		if (0) { T__ tmp__; tmp__ = (val); }		\
99		switch (sizeof(var)) {				\
100		case 1:						\
101			asm(op "b %1,"__percpu_seg"%0"		\
102			    : "+m" (var)			\
103			    :"ri" ((T__)val));			\
104			break;					\
105		case 2:						\
106			asm(op "w %1,"__percpu_seg"%0"		\
107			    : "+m" (var)			\
108			    :"ri" ((T__)val));			\
109			break;					\
110		case 4:						\
111			asm(op "l %1,"__percpu_seg"%0"		\
112			    : "+m" (var)			\
113			    :"ri" ((T__)val));			\
114			break;					\
115		default: __bad_percpu_size();			\
116		}						\
117	} while (0)
118
119#define percpu_from_op(op,var)					\
120	({							\
121		typeof(var) ret__;				\
122		switch (sizeof(var)) {				\
123		case 1:						\
124			asm(op "b "__percpu_seg"%1,%0"		\
125			    : "=r" (ret__)			\
126			    : "m" (var));			\
127			break;					\
128		case 2:						\
129			asm(op "w "__percpu_seg"%1,%0"		\
130			    : "=r" (ret__)			\
131			    : "m" (var));			\
132			break;					\
133		case 4:						\
134			asm(op "l "__percpu_seg"%1,%0"		\
135			    : "=r" (ret__)			\
136			    : "m" (var));			\
137			break;					\
138		default: __bad_percpu_size();			\
139		}						\
140		ret__; })
141
142#define x86_read_percpu(var) percpu_from_op("mov", per_cpu__##var)
143#define x86_write_percpu(var,val) percpu_to_op("mov", per_cpu__##var, val)
144#define x86_add_percpu(var,val) percpu_to_op("add", per_cpu__##var, val)
145#define x86_sub_percpu(var,val) percpu_to_op("sub", per_cpu__##var, val)
146#define x86_or_percpu(var,val) percpu_to_op("or", per_cpu__##var, val)
147#endif /* !__ASSEMBLY__ */
148
149#endif /* __ARCH_I386_PERCPU__ */
150