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-rw-r--r--arch/alpha/include/asm/percpu.h95
1 files changed, 8 insertions, 87 deletions
diff --git a/arch/alpha/include/asm/percpu.h b/arch/alpha/include/asm/percpu.h
index 7f0a9c4f2fd0..2c12378e3aa9 100644
--- a/arch/alpha/include/asm/percpu.h
+++ b/arch/alpha/include/asm/percpu.h
@@ -1,97 +1,18 @@
1#ifndef __ALPHA_PERCPU_H 1#ifndef __ALPHA_PERCPU_H
2#define __ALPHA_PERCPU_H 2#define __ALPHA_PERCPU_H
3 3
4#include <linux/compiler.h>
5#include <linux/threads.h>
6#include <linux/percpu-defs.h>
7
8/* 4/*
9 * Determine the real variable name from the name visible in the 5 * To calculate addresses of locally defined variables, GCC uses
10 * kernel sources. 6 * 32-bit displacement from the GP. Which doesn't work for per cpu
11 */ 7 * variables in modules, as an offset to the kernel per cpu area is
12#define per_cpu_var(var) per_cpu__##var 8 * way above 4G.
13
14#ifdef CONFIG_SMP
15
16/*
17 * per_cpu_offset() is the offset that has to be added to a
18 * percpu variable to get to the instance for a certain processor.
19 */
20extern unsigned long __per_cpu_offset[NR_CPUS];
21
22#define per_cpu_offset(x) (__per_cpu_offset[x])
23
24#define __my_cpu_offset per_cpu_offset(raw_smp_processor_id())
25#ifdef CONFIG_DEBUG_PREEMPT
26#define my_cpu_offset per_cpu_offset(smp_processor_id())
27#else
28#define my_cpu_offset __my_cpu_offset
29#endif
30
31#ifndef MODULE
32#define SHIFT_PERCPU_PTR(var, offset) RELOC_HIDE(&per_cpu_var(var), (offset))
33#else
34/*
35 * To calculate addresses of locally defined variables, GCC uses 32-bit
36 * displacement from the GP. Which doesn't work for per cpu variables in
37 * modules, as an offset to the kernel per cpu area is way above 4G.
38 * 9 *
39 * This forces allocation of a GOT entry for per cpu variable using 10 * Always use weak definitions for percpu variables in modules.
40 * ldq instruction with a 'literal' relocation.
41 */
42#define SHIFT_PERCPU_PTR(var, offset) ({ \
43 extern int simple_identifier_##var(void); \
44 unsigned long __ptr, tmp_gp; \
45 asm ( "br %1, 1f \n\
46 1: ldgp %1, 0(%1) \n\
47 ldq %0, per_cpu__" #var"(%1)\t!literal" \
48 : "=&r"(__ptr), "=&r"(tmp_gp)); \
49 (typeof(&per_cpu_var(var)))(__ptr + (offset)); })
50
51#endif /* MODULE */
52
53/*
54 * A percpu variable may point to a discarded regions. The following are
55 * established ways to produce a usable pointer from the percpu variable
56 * offset.
57 */ 11 */
58#define per_cpu(var, cpu) \ 12#if defined(MODULE) && defined(CONFIG_SMP)
59 (*SHIFT_PERCPU_PTR(var, per_cpu_offset(cpu))) 13#define ARCH_NEEDS_WEAK_PER_CPU
60#define __get_cpu_var(var) \
61 (*SHIFT_PERCPU_PTR(var, my_cpu_offset))
62#define __raw_get_cpu_var(var) \
63 (*SHIFT_PERCPU_PTR(var, __my_cpu_offset))
64
65#else /* ! SMP */
66
67#define per_cpu(var, cpu) (*((void)(cpu), &per_cpu_var(var)))
68#define __get_cpu_var(var) per_cpu_var(var)
69#define __raw_get_cpu_var(var) per_cpu_var(var)
70
71#endif /* SMP */
72
73#ifdef CONFIG_SMP
74#define PER_CPU_BASE_SECTION ".data.percpu"
75#else
76#define PER_CPU_BASE_SECTION ".data"
77#endif
78
79#ifdef CONFIG_SMP
80
81#ifdef MODULE
82#define PER_CPU_SHARED_ALIGNED_SECTION ""
83#else
84#define PER_CPU_SHARED_ALIGNED_SECTION ".shared_aligned"
85#endif
86#define PER_CPU_FIRST_SECTION ".first"
87
88#else
89
90#define PER_CPU_SHARED_ALIGNED_SECTION ""
91#define PER_CPU_FIRST_SECTION ""
92
93#endif 14#endif
94 15
95#define PER_CPU_ATTRIBUTES 16#include <asm-generic/percpu.h>
96 17
97#endif /* __ALPHA_PERCPU_H */ 18#endif /* __ALPHA_PERCPU_H */