xref: /openbmc/linux/arch/xtensa/include/asm/asmmacro.h (revision 6a551c11)
1 /*
2  * include/asm-xtensa/asmmacro.h
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file "COPYING" in the main directory of this archive
6  * for more details.
7  *
8  * Copyright (C) 2005 Tensilica Inc.
9  */
10 
11 #ifndef _XTENSA_ASMMACRO_H
12 #define _XTENSA_ASMMACRO_H
13 
14 #include <variant/core.h>
15 
16 /*
17  * Some little helpers for loops. Use zero-overhead-loops
18  * where applicable and if supported by the processor.
19  *
20  * __loopi ar, at, size, inc
21  *         ar	register initialized with the start address
22  *	   at	scratch register used by macro
23  *	   size	size immediate value
24  *	   inc	increment
25  *
26  * __loops ar, as, at, inc_log2[, mask_log2][, cond][, ncond]
27  *	   ar	register initialized with the start address
28  *	   as	register initialized with the size
29  *	   at	scratch register use by macro
30  *	   inc_log2	increment [in log2]
31  *	   mask_log2	mask [in log2]
32  *	   cond		true condition (used in loop'cond')
33  *	   ncond	false condition (used in b'ncond')
34  *
35  * __loop  as
36  *	   restart loop. 'as' register must not have been modified!
37  *
38  * __endla ar, as, incr
39  *	   ar	start address (modified)
40  *	   as	scratch register used by __loops/__loopi macros or
41  *		end address used by __loopt macro
42  *	   inc	increment
43  */
44 
45 /*
46  * loop for given size as immediate
47  */
48 
49 	.macro	__loopi ar, at, size, incr
50 
51 #if XCHAL_HAVE_LOOPS
52 		movi	\at, ((\size + \incr - 1) / (\incr))
53 		loop	\at, 99f
54 #else
55 		addi	\at, \ar, \size
56 		98:
57 #endif
58 
59 	.endm
60 
61 /*
62  * loop for given size in register
63  */
64 
65 	.macro	__loops	ar, as, at, incr_log2, mask_log2, cond, ncond
66 
67 #if XCHAL_HAVE_LOOPS
68 		.ifgt \incr_log2 - 1
69 			addi	\at, \as, (1 << \incr_log2) - 1
70 			.ifnc \mask_log2,
71 				extui	\at, \at, \incr_log2, \mask_log2
72 			.else
73 				srli	\at, \at, \incr_log2
74 			.endif
75 		.endif
76 		loop\cond	\at, 99f
77 #else
78 		.ifnc \mask_log2,
79 			extui	\at, \as, \incr_log2, \mask_log2
80 		.else
81 			.ifnc \ncond,
82 				srli	\at, \as, \incr_log2
83 			.endif
84 		.endif
85 		.ifnc \ncond,
86 			b\ncond	\at, 99f
87 
88 		.endif
89 		.ifnc \mask_log2,
90 			slli	\at, \at, \incr_log2
91 			add	\at, \ar, \at
92 		.else
93 			add	\at, \ar, \as
94 		.endif
95 #endif
96 		98:
97 
98 	.endm
99 
100 /*
101  * loop from ar to as
102  */
103 
104 	.macro	__loopt	ar, as, at, incr_log2
105 
106 #if XCHAL_HAVE_LOOPS
107 		sub	\at, \as, \ar
108 		.ifgt	\incr_log2 - 1
109 			addi	\at, \at, (1 << \incr_log2) - 1
110 			srli	\at, \at, \incr_log2
111 		.endif
112 		loop	\at, 99f
113 #else
114 		98:
115 #endif
116 
117 	.endm
118 
119 /*
120  * restart loop. registers must be unchanged
121  */
122 
123 	.macro	__loop	as
124 
125 #if XCHAL_HAVE_LOOPS
126 		loop	\as, 99f
127 #else
128 		98:
129 #endif
130 
131 	.endm
132 
133 /*
134  * end of loop with no increment of the address.
135  */
136 
137 	.macro	__endl	ar, as
138 #if !XCHAL_HAVE_LOOPS
139 		bltu	\ar, \as, 98b
140 #endif
141 		99:
142 	.endm
143 
144 /*
145  * end of loop with increment of the address.
146  */
147 
148 	.macro	__endla	ar, as, incr
149 		addi	\ar, \ar, \incr
150 		__endl	\ar \as
151 	.endm
152 
153 
154 #endif /* _XTENSA_ASMMACRO_H */
155