xref: /openbmc/linux/arch/arm/include/asm/assembler.h (revision 6f6f6a70)
1 /*
2  *  arch/arm/include/asm/assembler.h
3  *
4  *  Copyright (C) 1996-2000 Russell King
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  *  This file contains arm architecture specific defines
11  *  for the different processors.
12  *
13  *  Do not include any C declarations in this file - it is included by
14  *  assembler source.
15  */
16 #ifndef __ASM_ASSEMBLER_H__
17 #define __ASM_ASSEMBLER_H__
18 
19 #ifndef __ASSEMBLY__
20 #error "Only include this from assembly code"
21 #endif
22 
23 #include <asm/ptrace.h>
24 #include <asm/domain.h>
25 
26 #define IOMEM(x)	(x)
27 
28 /*
29  * Endian independent macros for shifting bytes within registers.
30  */
31 #ifndef __ARMEB__
32 #define pull            lsr
33 #define push            lsl
34 #define get_byte_0      lsl #0
35 #define get_byte_1	lsr #8
36 #define get_byte_2	lsr #16
37 #define get_byte_3	lsr #24
38 #define put_byte_0      lsl #0
39 #define put_byte_1	lsl #8
40 #define put_byte_2	lsl #16
41 #define put_byte_3	lsl #24
42 #else
43 #define pull            lsl
44 #define push            lsr
45 #define get_byte_0	lsr #24
46 #define get_byte_1	lsr #16
47 #define get_byte_2	lsr #8
48 #define get_byte_3      lsl #0
49 #define put_byte_0	lsl #24
50 #define put_byte_1	lsl #16
51 #define put_byte_2	lsl #8
52 #define put_byte_3      lsl #0
53 #endif
54 
55 /*
56  * Data preload for architectures that support it
57  */
58 #if __LINUX_ARM_ARCH__ >= 5
59 #define PLD(code...)	code
60 #else
61 #define PLD(code...)
62 #endif
63 
64 /*
65  * This can be used to enable code to cacheline align the destination
66  * pointer when bulk writing to memory.  Experiments on StrongARM and
67  * XScale didn't show this a worthwhile thing to do when the cache is not
68  * set to write-allocate (this would need further testing on XScale when WA
69  * is used).
70  *
71  * On Feroceon there is much to gain however, regardless of cache mode.
72  */
73 #ifdef CONFIG_CPU_FEROCEON
74 #define CALGN(code...) code
75 #else
76 #define CALGN(code...)
77 #endif
78 
79 /*
80  * Enable and disable interrupts
81  */
82 #if __LINUX_ARM_ARCH__ >= 6
83 	.macro	disable_irq_notrace
84 	cpsid	i
85 	.endm
86 
87 	.macro	enable_irq_notrace
88 	cpsie	i
89 	.endm
90 #else
91 	.macro	disable_irq_notrace
92 	msr	cpsr_c, #PSR_I_BIT | SVC_MODE
93 	.endm
94 
95 	.macro	enable_irq_notrace
96 	msr	cpsr_c, #SVC_MODE
97 	.endm
98 #endif
99 
100 	.macro asm_trace_hardirqs_off
101 #if defined(CONFIG_TRACE_IRQFLAGS)
102 	stmdb   sp!, {r0-r3, ip, lr}
103 	bl	trace_hardirqs_off
104 	ldmia	sp!, {r0-r3, ip, lr}
105 #endif
106 	.endm
107 
108 	.macro asm_trace_hardirqs_on_cond, cond
109 #if defined(CONFIG_TRACE_IRQFLAGS)
110 	/*
111 	 * actually the registers should be pushed and pop'd conditionally, but
112 	 * after bl the flags are certainly clobbered
113 	 */
114 	stmdb   sp!, {r0-r3, ip, lr}
115 	bl\cond	trace_hardirqs_on
116 	ldmia	sp!, {r0-r3, ip, lr}
117 #endif
118 	.endm
119 
120 	.macro asm_trace_hardirqs_on
121 	asm_trace_hardirqs_on_cond al
122 	.endm
123 
124 	.macro disable_irq
125 	disable_irq_notrace
126 	asm_trace_hardirqs_off
127 	.endm
128 
129 	.macro enable_irq
130 	asm_trace_hardirqs_on
131 	enable_irq_notrace
132 	.endm
133 /*
134  * Save the current IRQ state and disable IRQs.  Note that this macro
135  * assumes FIQs are enabled, and that the processor is in SVC mode.
136  */
137 	.macro	save_and_disable_irqs, oldcpsr
138 	mrs	\oldcpsr, cpsr
139 	disable_irq
140 	.endm
141 
142 /*
143  * Restore interrupt state previously stored in a register.  We don't
144  * guarantee that this will preserve the flags.
145  */
146 	.macro	restore_irqs_notrace, oldcpsr
147 	msr	cpsr_c, \oldcpsr
148 	.endm
149 
150 	.macro restore_irqs, oldcpsr
151 	tst	\oldcpsr, #PSR_I_BIT
152 	asm_trace_hardirqs_on_cond eq
153 	restore_irqs_notrace \oldcpsr
154 	.endm
155 
156 #define USER(x...)				\
157 9999:	x;					\
158 	.pushsection __ex_table,"a";		\
159 	.align	3;				\
160 	.long	9999b,9001f;			\
161 	.popsection
162 
163 #ifdef CONFIG_SMP
164 #define ALT_SMP(instr...)					\
165 9998:	instr
166 /*
167  * Note: if you get assembler errors from ALT_UP() when building with
168  * CONFIG_THUMB2_KERNEL, you almost certainly need to use
169  * ALT_SMP( W(instr) ... )
170  */
171 #define ALT_UP(instr...)					\
172 	.pushsection ".alt.smp.init", "a"			;\
173 	.long	9998b						;\
174 9997:	instr							;\
175 	.if . - 9997b != 4					;\
176 		.error "ALT_UP() content must assemble to exactly 4 bytes";\
177 	.endif							;\
178 	.popsection
179 #define ALT_UP_B(label)					\
180 	.equ	up_b_offset, label - 9998b			;\
181 	.pushsection ".alt.smp.init", "a"			;\
182 	.long	9998b						;\
183 	W(b)	. + up_b_offset					;\
184 	.popsection
185 #else
186 #define ALT_SMP(instr...)
187 #define ALT_UP(instr...) instr
188 #define ALT_UP_B(label) b label
189 #endif
190 
191 /*
192  * Instruction barrier
193  */
194 	.macro	instr_sync
195 #if __LINUX_ARM_ARCH__ >= 7
196 	isb
197 #elif __LINUX_ARM_ARCH__ == 6
198 	mcr	p15, 0, r0, c7, c5, 4
199 #endif
200 	.endm
201 
202 /*
203  * SMP data memory barrier
204  */
205 	.macro	smp_dmb mode
206 #ifdef CONFIG_SMP
207 #if __LINUX_ARM_ARCH__ >= 7
208 	.ifeqs "\mode","arm"
209 	ALT_SMP(dmb)
210 	.else
211 	ALT_SMP(W(dmb))
212 	.endif
213 #elif __LINUX_ARM_ARCH__ == 6
214 	ALT_SMP(mcr	p15, 0, r0, c7, c10, 5)	@ dmb
215 #else
216 #error Incompatible SMP platform
217 #endif
218 	.ifeqs "\mode","arm"
219 	ALT_UP(nop)
220 	.else
221 	ALT_UP(W(nop))
222 	.endif
223 #endif
224 	.endm
225 
226 #ifdef CONFIG_THUMB2_KERNEL
227 	.macro	setmode, mode, reg
228 	mov	\reg, #\mode
229 	msr	cpsr_c, \reg
230 	.endm
231 #else
232 	.macro	setmode, mode, reg
233 	msr	cpsr_c, #\mode
234 	.endm
235 #endif
236 
237 /*
238  * STRT/LDRT access macros with ARM and Thumb-2 variants
239  */
240 #ifdef CONFIG_THUMB2_KERNEL
241 
242 	.macro	usraccoff, instr, reg, ptr, inc, off, cond, abort, t=TUSER()
243 9999:
244 	.if	\inc == 1
245 	\instr\cond\()b\()\t\().w \reg, [\ptr, #\off]
246 	.elseif	\inc == 4
247 	\instr\cond\()\t\().w \reg, [\ptr, #\off]
248 	.else
249 	.error	"Unsupported inc macro argument"
250 	.endif
251 
252 	.pushsection __ex_table,"a"
253 	.align	3
254 	.long	9999b, \abort
255 	.popsection
256 	.endm
257 
258 	.macro	usracc, instr, reg, ptr, inc, cond, rept, abort
259 	@ explicit IT instruction needed because of the label
260 	@ introduced by the USER macro
261 	.ifnc	\cond,al
262 	.if	\rept == 1
263 	itt	\cond
264 	.elseif	\rept == 2
265 	ittt	\cond
266 	.else
267 	.error	"Unsupported rept macro argument"
268 	.endif
269 	.endif
270 
271 	@ Slightly optimised to avoid incrementing the pointer twice
272 	usraccoff \instr, \reg, \ptr, \inc, 0, \cond, \abort
273 	.if	\rept == 2
274 	usraccoff \instr, \reg, \ptr, \inc, \inc, \cond, \abort
275 	.endif
276 
277 	add\cond \ptr, #\rept * \inc
278 	.endm
279 
280 #else	/* !CONFIG_THUMB2_KERNEL */
281 
282 	.macro	usracc, instr, reg, ptr, inc, cond, rept, abort, t=TUSER()
283 	.rept	\rept
284 9999:
285 	.if	\inc == 1
286 	\instr\cond\()b\()\t \reg, [\ptr], #\inc
287 	.elseif	\inc == 4
288 	\instr\cond\()\t \reg, [\ptr], #\inc
289 	.else
290 	.error	"Unsupported inc macro argument"
291 	.endif
292 
293 	.pushsection __ex_table,"a"
294 	.align	3
295 	.long	9999b, \abort
296 	.popsection
297 	.endr
298 	.endm
299 
300 #endif	/* CONFIG_THUMB2_KERNEL */
301 
302 	.macro	strusr, reg, ptr, inc, cond=al, rept=1, abort=9001f
303 	usracc	str, \reg, \ptr, \inc, \cond, \rept, \abort
304 	.endm
305 
306 	.macro	ldrusr, reg, ptr, inc, cond=al, rept=1, abort=9001f
307 	usracc	ldr, \reg, \ptr, \inc, \cond, \rept, \abort
308 	.endm
309 
310 /* Utility macro for declaring string literals */
311 	.macro	string name:req, string
312 	.type \name , #object
313 \name:
314 	.asciz "\string"
315 	.size \name , . - \name
316 	.endm
317 
318 #endif /* __ASM_ASSEMBLER_H__ */
319