xref: /openbmc/linux/arch/parisc/include/asm/bitops.h (revision ee8ec048)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _PARISC_BITOPS_H
3 #define _PARISC_BITOPS_H
4 
5 #ifndef _LINUX_BITOPS_H
6 #error only <linux/bitops.h> can be included directly
7 #endif
8 
9 #include <linux/compiler.h>
10 #include <asm/types.h>
11 #include <asm/byteorder.h>
12 #include <asm/barrier.h>
13 #include <linux/atomic.h>
14 
15 /* See http://marc.theaimsgroup.com/?t=108826637900003 for discussion
16  * on use of volatile and __*_bit() (set/clear/change):
17  *	*_bit() want use of volatile.
18  *	__*_bit() are "relaxed" and don't use spinlock or volatile.
19  */
20 
21 static __inline__ void set_bit(int nr, volatile unsigned long * addr)
22 {
23 	unsigned long mask = BIT_MASK(nr);
24 	unsigned long flags;
25 
26 	addr += BIT_WORD(nr);
27 	_atomic_spin_lock_irqsave(addr, flags);
28 	*addr |= mask;
29 	_atomic_spin_unlock_irqrestore(addr, flags);
30 }
31 
32 static __inline__ void clear_bit(int nr, volatile unsigned long * addr)
33 {
34 	unsigned long mask = BIT_MASK(nr);
35 	unsigned long flags;
36 
37 	addr += BIT_WORD(nr);
38 	_atomic_spin_lock_irqsave(addr, flags);
39 	*addr &= ~mask;
40 	_atomic_spin_unlock_irqrestore(addr, flags);
41 }
42 
43 static __inline__ void change_bit(int nr, volatile unsigned long * addr)
44 {
45 	unsigned long mask = BIT_MASK(nr);
46 	unsigned long flags;
47 
48 	addr += BIT_WORD(nr);
49 	_atomic_spin_lock_irqsave(addr, flags);
50 	*addr ^= mask;
51 	_atomic_spin_unlock_irqrestore(addr, flags);
52 }
53 
54 static __inline__ int test_and_set_bit(int nr, volatile unsigned long * addr)
55 {
56 	unsigned long mask = BIT_MASK(nr);
57 	unsigned long old;
58 	unsigned long flags;
59 	int set;
60 
61 	addr += BIT_WORD(nr);
62 	_atomic_spin_lock_irqsave(addr, flags);
63 	old = *addr;
64 	set = (old & mask) ? 1 : 0;
65 	if (!set)
66 		*addr = old | mask;
67 	_atomic_spin_unlock_irqrestore(addr, flags);
68 
69 	return set;
70 }
71 
72 static __inline__ int test_and_clear_bit(int nr, volatile unsigned long * addr)
73 {
74 	unsigned long mask = BIT_MASK(nr);
75 	unsigned long old;
76 	unsigned long flags;
77 	int set;
78 
79 	addr += BIT_WORD(nr);
80 	_atomic_spin_lock_irqsave(addr, flags);
81 	old = *addr;
82 	set = (old & mask) ? 1 : 0;
83 	if (set)
84 		*addr = old & ~mask;
85 	_atomic_spin_unlock_irqrestore(addr, flags);
86 
87 	return set;
88 }
89 
90 static __inline__ int test_and_change_bit(int nr, volatile unsigned long * addr)
91 {
92 	unsigned long mask = BIT_MASK(nr);
93 	unsigned long oldbit;
94 	unsigned long flags;
95 
96 	addr += BIT_WORD(nr);
97 	_atomic_spin_lock_irqsave(addr, flags);
98 	oldbit = *addr;
99 	*addr = oldbit ^ mask;
100 	_atomic_spin_unlock_irqrestore(addr, flags);
101 
102 	return (oldbit & mask) ? 1 : 0;
103 }
104 
105 #include <asm-generic/bitops/non-atomic.h>
106 
107 /**
108  * __ffs - find first bit in word. returns 0 to "BITS_PER_LONG-1".
109  * @word: The word to search
110  *
111  * __ffs() return is undefined if no bit is set.
112  *
113  * 32-bit fast __ffs by LaMont Jones "lamont At hp com".
114  * 64-bit enhancement by Grant Grundler "grundler At parisc-linux org".
115  * (with help from willy/jejb to get the semantics right)
116  *
117  * This algorithm avoids branches by making use of nullification.
118  * One side effect of "extr" instructions is it sets PSW[N] bit.
119  * How PSW[N] (nullify next insn) gets set is determined by the
120  * "condition" field (eg "<>" or "TR" below) in the extr* insn.
121  * Only the 1st and one of either the 2cd or 3rd insn will get executed.
122  * Each set of 3 insn will get executed in 2 cycles on PA8x00 vs 16 or so
123  * cycles for each mispredicted branch.
124  */
125 
126 static __inline__ unsigned long __ffs(unsigned long x)
127 {
128 	unsigned long ret;
129 
130 	__asm__(
131 #ifdef CONFIG_64BIT
132 		" ldi       63,%1\n"
133 		" extrd,u,*<>  %0,63,32,%%r0\n"
134 		" extrd,u,*TR  %0,31,32,%0\n"	/* move top 32-bits down */
135 		" addi    -32,%1,%1\n"
136 #else
137 		" ldi       31,%1\n"
138 #endif
139 		" extru,<>  %0,31,16,%%r0\n"
140 		" extru,TR  %0,15,16,%0\n"	/* xxxx0000 -> 0000xxxx */
141 		" addi    -16,%1,%1\n"
142 		" extru,<>  %0,31,8,%%r0\n"
143 		" extru,TR  %0,23,8,%0\n"	/* 0000xx00 -> 000000xx */
144 		" addi    -8,%1,%1\n"
145 		" extru,<>  %0,31,4,%%r0\n"
146 		" extru,TR  %0,27,4,%0\n"	/* 000000x0 -> 0000000x */
147 		" addi    -4,%1,%1\n"
148 		" extru,<>  %0,31,2,%%r0\n"
149 		" extru,TR  %0,29,2,%0\n"	/* 0000000y, 1100b -> 0011b */
150 		" addi    -2,%1,%1\n"
151 		" extru,=  %0,31,1,%%r0\n"	/* check last bit */
152 		" addi    -1,%1,%1\n"
153 			: "+r" (x), "=r" (ret) );
154 	return ret;
155 }
156 
157 #include <asm-generic/bitops/ffz.h>
158 
159 /*
160  * ffs: find first bit set. returns 1 to BITS_PER_LONG or 0 (if none set)
161  * This is defined the same way as the libc and compiler builtin
162  * ffs routines, therefore differs in spirit from the above ffz (man ffs).
163  */
164 static __inline__ int ffs(int x)
165 {
166 	return x ? (__ffs((unsigned long)x) + 1) : 0;
167 }
168 
169 /*
170  * fls: find last (most significant) bit set.
171  * fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
172  */
173 
174 static __inline__ int fls(unsigned int x)
175 {
176 	int ret;
177 	if (!x)
178 		return 0;
179 
180 	__asm__(
181 	"	ldi		1,%1\n"
182 	"	extru,<>	%0,15,16,%%r0\n"
183 	"	zdep,TR		%0,15,16,%0\n"		/* xxxx0000 */
184 	"	addi		16,%1,%1\n"
185 	"	extru,<>	%0,7,8,%%r0\n"
186 	"	zdep,TR		%0,23,24,%0\n"		/* xx000000 */
187 	"	addi		8,%1,%1\n"
188 	"	extru,<>	%0,3,4,%%r0\n"
189 	"	zdep,TR		%0,27,28,%0\n"		/* x0000000 */
190 	"	addi		4,%1,%1\n"
191 	"	extru,<>	%0,1,2,%%r0\n"
192 	"	zdep,TR		%0,29,30,%0\n"		/* y0000000 (y&3 = 0) */
193 	"	addi		2,%1,%1\n"
194 	"	extru,=		%0,0,1,%%r0\n"
195 	"	addi		1,%1,%1\n"		/* if y & 8, add 1 */
196 		: "+r" (x), "=r" (ret) );
197 
198 	return ret;
199 }
200 
201 #include <asm-generic/bitops/__fls.h>
202 #include <asm-generic/bitops/fls64.h>
203 #include <asm-generic/bitops/hweight.h>
204 #include <asm-generic/bitops/lock.h>
205 #include <asm-generic/bitops/sched.h>
206 #include <asm-generic/bitops/find.h>
207 #include <asm-generic/bitops/le.h>
208 #include <asm-generic/bitops/ext2-atomic-setbit.h>
209 
210 #endif /* _PARISC_BITOPS_H */
211