mm: fix section mismatch warnings
[linux-2.6/mini2440.git] / include / asm-mips / hazards.h
blobd9119f43f9aa1497dbea3e4a2adccdc9a0fa02ba
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.
6 * Copyright (C) 2003, 2004 Ralf Baechle <ralf@linux-mips.org>
7 * Copyright (C) MIPS Technologies, Inc.
8 * written by Ralf Baechle <ralf@linux-mips.org>
9 */
10 #ifndef _ASM_HAZARDS_H
11 #define _ASM_HAZARDS_H
14 #ifdef __ASSEMBLY__
15 #define ASMMACRO(name, code...) .macro name; code; .endm
16 #else
18 #define ASMMACRO(name, code...) \
19 __asm__(".macro " #name "; " #code "; .endm"); \
21 static inline void name(void) \
22 { \
23 __asm__ __volatile__ (#name); \
26 #endif
28 ASMMACRO(_ssnop,
29 sll $0, $0, 1
32 ASMMACRO(_ehb,
33 sll $0, $0, 3
37 * TLB hazards
39 #if defined(CONFIG_CPU_MIPSR2)
42 * MIPSR2 defines ehb for hazard avoidance
45 ASMMACRO(mtc0_tlbw_hazard,
46 _ehb
48 ASMMACRO(tlbw_use_hazard,
49 _ehb
51 ASMMACRO(tlb_probe_hazard,
52 _ehb
54 ASMMACRO(irq_enable_hazard,
55 _ehb
57 ASMMACRO(irq_disable_hazard,
58 _ehb
60 ASMMACRO(back_to_back_c0_hazard,
61 _ehb
64 * gcc has a tradition of misscompiling the previous construct using the
65 * address of a label as argument to inline assembler. Gas otoh has the
66 * annoying difference between la and dla which are only usable for 32-bit
67 * rsp. 64-bit code, so can't be used without conditional compilation.
68 * The alterantive is switching the assembler to 64-bit code which happens
69 * to work right even for 32-bit code ...
71 #define instruction_hazard() \
72 do { \
73 unsigned long tmp; \
75 __asm__ __volatile__( \
76 " .set mips64r2 \n" \
77 " dla %0, 1f \n" \
78 " jr.hb %0 \n" \
79 " .set mips0 \n" \
80 "1: \n" \
81 : "=r" (tmp)); \
82 } while (0)
84 #elif defined(CONFIG_CPU_R10000)
87 * R10000 rocks - all hazards handled in hardware, so this becomes a nobrainer.
90 ASMMACRO(mtc0_tlbw_hazard,
92 ASMMACRO(tlbw_use_hazard,
94 ASMMACRO(tlb_probe_hazard,
96 ASMMACRO(irq_enable_hazard,
98 ASMMACRO(irq_disable_hazard,
100 ASMMACRO(back_to_back_c0_hazard,
102 #define instruction_hazard() do { } while (0)
104 #elif defined(CONFIG_CPU_RM9000)
107 * RM9000 hazards. When the JTLB is updated by tlbwi or tlbwr, a subsequent
108 * use of the JTLB for instructions should not occur for 4 cpu cycles and use
109 * for data translations should not occur for 3 cpu cycles.
112 ASMMACRO(mtc0_tlbw_hazard,
113 _ssnop; _ssnop; _ssnop; _ssnop
115 ASMMACRO(tlbw_use_hazard,
116 _ssnop; _ssnop; _ssnop; _ssnop
118 ASMMACRO(tlb_probe_hazard,
119 _ssnop; _ssnop; _ssnop; _ssnop
121 ASMMACRO(irq_enable_hazard,
123 ASMMACRO(irq_disable_hazard,
125 ASMMACRO(back_to_back_c0_hazard,
127 #define instruction_hazard() do { } while (0)
129 #elif defined(CONFIG_CPU_SB1)
132 * Mostly like R4000 for historic reasons
134 ASMMACRO(mtc0_tlbw_hazard,
136 ASMMACRO(tlbw_use_hazard,
138 ASMMACRO(tlb_probe_hazard,
140 ASMMACRO(irq_enable_hazard,
142 ASMMACRO(irq_disable_hazard,
143 _ssnop; _ssnop; _ssnop
145 ASMMACRO(back_to_back_c0_hazard,
147 #define instruction_hazard() do { } while (0)
149 #else
152 * Finally the catchall case for all other processors including R4000, R4400,
153 * R4600, R4700, R5000, RM7000, NEC VR41xx etc.
155 * The taken branch will result in a two cycle penalty for the two killed
156 * instructions on R4000 / R4400. Other processors only have a single cycle
157 * hazard so this is nice trick to have an optimal code for a range of
158 * processors.
160 ASMMACRO(mtc0_tlbw_hazard,
161 nop; nop
163 ASMMACRO(tlbw_use_hazard,
164 nop; nop; nop
166 ASMMACRO(tlb_probe_hazard,
167 nop; nop; nop
169 ASMMACRO(irq_enable_hazard,
171 ASMMACRO(irq_disable_hazard,
172 nop; nop; nop
174 ASMMACRO(back_to_back_c0_hazard,
175 _ssnop; _ssnop; _ssnop;
177 #define instruction_hazard() do { } while (0)
179 #endif
182 /* FPU hazards */
184 #if defined(CONFIG_CPU_SB1)
185 ASMMACRO(enable_fpu_hazard,
186 .set push;
187 .set mips64;
188 .set noreorder;
189 _ssnop;
190 bnezl $0,.+4;
191 _ssnop;
192 .set pop
194 ASMMACRO(disable_fpu_hazard,
197 #elif defined(CONFIG_CPU_MIPSR2)
198 ASMMACRO(enable_fpu_hazard,
199 _ehb
201 ASMMACRO(disable_fpu_hazard,
202 _ehb
204 #else
205 ASMMACRO(enable_fpu_hazard,
206 nop; nop; nop; nop
208 ASMMACRO(disable_fpu_hazard,
209 _ehb
211 #endif
213 #endif /* _ASM_HAZARDS_H */