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-rw-r--r--arch/mips/lib/mips-atomic.c176
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diff --git a/arch/mips/lib/mips-atomic.c b/arch/mips/lib/mips-atomic.c
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1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2003 by Ralf Baechle
7 * Copyright (C) 1996 by Paul M. Antoine
8 * Copyright (C) 1999 Silicon Graphics
9 * Copyright (C) 2000 MIPS Technologies, Inc.
10 */
11#include <asm/irqflags.h>
12#include <asm/hazards.h>
13#include <linux/compiler.h>
14#include <linux/preempt.h>
15#include <linux/export.h>
16
17#if !defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_MIPS_MT_SMTC)
18
19/*
20 * For cli() we have to insert nops to make sure that the new value
21 * has actually arrived in the status register before the end of this
22 * macro.
23 * R4000/R4400 need three nops, the R4600 two nops and the R10000 needs
24 * no nops at all.
25 */
26/*
27 * For TX49, operating only IE bit is not enough.
28 *
29 * If mfc0 $12 follows store and the mfc0 is last instruction of a
30 * page and fetching the next instruction causes TLB miss, the result
31 * of the mfc0 might wrongly contain EXL bit.
32 *
33 * ERT-TX49H2-027, ERT-TX49H3-012, ERT-TX49HL3-006, ERT-TX49H4-008
34 *
35 * Workaround: mask EXL bit of the result or place a nop before mfc0.
36 */
37__asm__(
38 " .macro arch_local_irq_disable\n"
39 " .set push \n"
40 " .set noat \n"
41#ifdef CONFIG_MIPS_MT_SMTC
42 " mfc0 $1, $2, 1 \n"
43 " ori $1, 0x400 \n"
44 " .set noreorder \n"
45 " mtc0 $1, $2, 1 \n"
46#elif defined(CONFIG_CPU_MIPSR2)
47 /* see irqflags.h for inline function */
48#else
49 " mfc0 $1,$12 \n"
50 " ori $1,0x1f \n"
51 " xori $1,0x1f \n"
52 " .set noreorder \n"
53 " mtc0 $1,$12 \n"
54#endif
55 " irq_disable_hazard \n"
56 " .set pop \n"
57 " .endm \n");
58
59notrace void arch_local_irq_disable(void)
60{
61 preempt_disable();
62 __asm__ __volatile__(
63 "arch_local_irq_disable"
64 : /* no outputs */
65 : /* no inputs */
66 : "memory");
67 preempt_enable();
68}
69EXPORT_SYMBOL(arch_local_irq_disable);
70
71
72__asm__(
73 " .macro arch_local_irq_save result \n"
74 " .set push \n"
75 " .set reorder \n"
76 " .set noat \n"
77#ifdef CONFIG_MIPS_MT_SMTC
78 " mfc0 \\result, $2, 1 \n"
79 " ori $1, \\result, 0x400 \n"
80 " .set noreorder \n"
81 " mtc0 $1, $2, 1 \n"
82 " andi \\result, \\result, 0x400 \n"
83#elif defined(CONFIG_CPU_MIPSR2)
84 /* see irqflags.h for inline function */
85#else
86 " mfc0 \\result, $12 \n"
87 " ori $1, \\result, 0x1f \n"
88 " xori $1, 0x1f \n"
89 " .set noreorder \n"
90 " mtc0 $1, $12 \n"
91#endif
92 " irq_disable_hazard \n"
93 " .set pop \n"
94 " .endm \n");
95
96notrace unsigned long arch_local_irq_save(void)
97{
98 unsigned long flags;
99 preempt_disable();
100 asm volatile("arch_local_irq_save\t%0"
101 : "=r" (flags)
102 : /* no inputs */
103 : "memory");
104 preempt_enable();
105 return flags;
106}
107EXPORT_SYMBOL(arch_local_irq_save);
108
109
110__asm__(
111 " .macro arch_local_irq_restore flags \n"
112 " .set push \n"
113 " .set noreorder \n"
114 " .set noat \n"
115#ifdef CONFIG_MIPS_MT_SMTC
116 "mfc0 $1, $2, 1 \n"
117 "andi \\flags, 0x400 \n"
118 "ori $1, 0x400 \n"
119 "xori $1, 0x400 \n"
120 "or \\flags, $1 \n"
121 "mtc0 \\flags, $2, 1 \n"
122#elif defined(CONFIG_CPU_MIPSR2) && defined(CONFIG_IRQ_CPU)
123 /* see irqflags.h for inline function */
124#elif defined(CONFIG_CPU_MIPSR2)
125 /* see irqflags.h for inline function */
126#else
127 " mfc0 $1, $12 \n"
128 " andi \\flags, 1 \n"
129 " ori $1, 0x1f \n"
130 " xori $1, 0x1f \n"
131 " or \\flags, $1 \n"
132 " mtc0 \\flags, $12 \n"
133#endif
134 " irq_disable_hazard \n"
135 " .set pop \n"
136 " .endm \n");
137
138notrace void arch_local_irq_restore(unsigned long flags)
139{
140 unsigned long __tmp1;
141
142#ifdef CONFIG_MIPS_MT_SMTC
143 /*
144 * SMTC kernel needs to do a software replay of queued
145 * IPIs, at the cost of branch and call overhead on each
146 * local_irq_restore()
147 */
148 if (unlikely(!(flags & 0x0400)))
149 smtc_ipi_replay();
150#endif
151 preempt_disable();
152 __asm__ __volatile__(
153 "arch_local_irq_restore\t%0"
154 : "=r" (__tmp1)
155 : "0" (flags)
156 : "memory");
157 preempt_enable();
158}
159EXPORT_SYMBOL(arch_local_irq_restore);
160
161
162notrace void __arch_local_irq_restore(unsigned long flags)
163{
164 unsigned long __tmp1;
165
166 preempt_disable();
167 __asm__ __volatile__(
168 "arch_local_irq_restore\t%0"
169 : "=r" (__tmp1)
170 : "0" (flags)
171 : "memory");
172 preempt_enable();
173}
174EXPORT_SYMBOL(__arch_local_irq_restore);
175
176#endif /* !defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_MIPS_MT_SMTC) */
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