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#define DEFINE_PER_CPU_SHARED_ALIGNED(type, name)		\
58    __attribute__((__section__(".data.percpu.shared_aligned"))) \
59    __typeof__(type) per_cpu__##name				\
60    ____cacheline_aligned_in_smp
61
62/* We can use this directly for local CPU (faster). */
63DECLARE_PER_CPU(unsigned long, this_cpu_off);
64
65/* var is in discarded region: offset to particular copy we want */
66#define per_cpu(var, cpu) (*({				\
67	extern int simple_indentifier_##var(void);	\
68	RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]); }))
69
70#define __raw_get_cpu_var(var) (*({					\
71	extern int simple_indentifier_##var(void);			\
72	RELOC_HIDE(&per_cpu__##var, x86_read_percpu(this_cpu_off));	\
73}))
74
75#define __get_cpu_var(var) __raw_get_cpu_var(var)
76
77/* A macro to avoid #include hell... */
78#define percpu_modcopy(pcpudst, src, size)			\
79do {								\
80	unsigned int __i;					\
81	for_each_possible_cpu(__i)				\
82		memcpy((pcpudst)+__per_cpu_offset[__i],		\
83		       (src), (size));				\
84} while (0)
85
86#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
87#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
88
89/* fs segment starts at (positive) offset == __per_cpu_offset[cpu] */
90#define __percpu_seg "%%fs:"
91#else  /* !SMP */
92#include <asm-generic/percpu.h>
93#define __percpu_seg ""
94#endif	/* SMP */
95
96/* For arch-specific code, we can use direct single-insn ops (they
97 * don't give an lvalue though). */
98extern void __bad_percpu_size(void);
99
100#define percpu_to_op(op,var,val)				\
101	do {							\
102		typedef typeof(var) T__;			\
103		if (0) { T__ tmp__; tmp__ = (val); }		\
104		switch (sizeof(var)) {				\
105		case 1:						\
106			asm(op "b %1,"__percpu_seg"%0"		\
107			    : "+m" (var)			\
108			    :"ri" ((T__)val));			\
109			break;					\
110		case 2:						\
111			asm(op "w %1,"__percpu_seg"%0"		\
112			    : "+m" (var)			\
113			    :"ri" ((T__)val));			\
114			break;					\
115		case 4:						\
116			asm(op "l %1,"__percpu_seg"%0"		\
117			    : "+m" (var)			\
118			    :"ri" ((T__)val));			\
119			break;					\
120		default: __bad_percpu_size();			\
121		}						\
122	} while (0)
123
124#define percpu_from_op(op,var)					\
125	({							\
126		typeof(var) ret__;				\
127		switch (sizeof(var)) {				\
128		case 1:						\
129			asm(op "b "__percpu_seg"%1,%0"		\
130			    : "=r" (ret__)			\
131			    : "m" (var));			\
132			break;					\
133		case 2:						\
134			asm(op "w "__percpu_seg"%1,%0"		\
135			    : "=r" (ret__)			\
136			    : "m" (var));			\
137			break;					\
138		case 4:						\
139			asm(op "l "__percpu_seg"%1,%0"		\
140			    : "=r" (ret__)			\
141			    : "m" (var));			\
142			break;					\
143		default: __bad_percpu_size();			\
144		}						\
145		ret__; })
146
147#define x86_read_percpu(var) percpu_from_op("mov", per_cpu__##var)
148#define x86_write_percpu(var,val) percpu_to_op("mov", per_cpu__##var, val)
149#define x86_add_percpu(var,val) percpu_to_op("add", per_cpu__##var, val)
150#define x86_sub_percpu(var,val) percpu_to_op("sub", per_cpu__##var, val)
151#define x86_or_percpu(var,val) percpu_to_op("or", per_cpu__##var, val)
152#endif /* !__ASSEMBLY__ */
153
154#endif /* __ARCH_I386_PERCPU__ */
155