xref: /openbmc/linux/arch/xtensa/include/asm/asmmacro.h (revision b627b4ed)
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, at, incr
39  *	   ar	start address (modified)
40  *	   as	scratch register used by macro
41  *	   inc	increment
42  */
43 
44 /*
45  * loop for given size as immediate
46  */
47 
48 	.macro	__loopi ar, at, size, incr
49 
50 #if XCHAL_HAVE_LOOPS
51 		movi	\at, ((\size + \incr - 1) / (\incr))
52 		loop	\at, 99f
53 #else
54 		addi	\at, \ar, \size
55 		98:
56 #endif
57 
58 	.endm
59 
60 /*
61  * loop for given size in register
62  */
63 
64 	.macro	__loops	ar, as, at, incr_log2, mask_log2, cond, ncond
65 
66 #if XCHAL_HAVE_LOOPS
67 		.ifgt \incr_log2 - 1
68 			addi	\at, \as, (1 << \incr_log2) - 1
69 			.ifnc \mask_log2,
70 				extui	\at, \at, \incr_log2, \mask_log2
71 			.else
72 				srli	\at, \at, \incr_log2
73 			.endif
74 		.endif
75 		loop\cond	\at, 99f
76 #else
77 		.ifnc \mask_log2,
78 			extui	\at, \as, \incr_log2, \mask_log2
79 		.else
80 			.ifnc \ncond,
81 				srli	\at, \as, \incr_log2
82 			.endif
83 		.endif
84 		.ifnc \ncond,
85 			b\ncond	\at, 99f
86 
87 		.endif
88 		.ifnc \mask_log2,
89 			slli	\at, \at, \incr_log2
90 			add	\at, \ar, \at
91 		.else
92 			add	\at, \ar, \as
93 		.endif
94 #endif
95 		98:
96 
97 	.endm
98 
99 /*
100  * loop from ar to ax
101  */
102 
103 	.macro	__loopt	ar, as, at, incr_log2
104 
105 #if XCHAL_HAVE_LOOPS
106 		sub	\at, \as, \ar
107 		.ifgt	\incr_log2 - 1
108 			addi	\at, \at, (1 << \incr_log2) - 1
109 			srli	\at, \at, \incr_log2
110 		.endif
111 		loop	\at, 99f
112 #else
113 		98:
114 #endif
115 
116 	.endm
117 
118 /*
119  * restart loop. registers must be unchanged
120  */
121 
122 	.macro	__loop	as
123 
124 #if XCHAL_HAVE_LOOPS
125 		loop	\as, 99f
126 #else
127 		98:
128 #endif
129 
130 	.endm
131 
132 /*
133  * end of loop with no increment of the address.
134  */
135 
136 	.macro	__endl	ar, as
137 #if !XCHAL_HAVE_LOOPS
138 		bltu	\ar, \as, 98b
139 #endif
140 		99:
141 	.endm
142 
143 /*
144  * end of loop with increment of the address.
145  */
146 
147 	.macro	__endla	ar, as, incr
148 		addi	\ar, \ar, \incr
149 		__endl	\ar \as
150 	.endm
151 
152 
153 #endif /* _XTENSA_ASMMACRO_H */
154