xref: /openbmc/linux/arch/parisc/include/asm/bitops.h (revision f71a261a)
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 /* compiler build environment sanity checks: */
16 #if !defined(CONFIG_64BIT) && defined(__LP64__)
17 #error "Please use 'ARCH=parisc' to build the 32-bit kernel."
18 #endif
19 #if defined(CONFIG_64BIT) && !defined(__LP64__)
20 #error "Please use 'ARCH=parisc64' to build the 64-bit kernel."
21 #endif
22 
23 /* See http://marc.theaimsgroup.com/?t=108826637900003 for discussion
24  * on use of volatile and __*_bit() (set/clear/change):
25  *	*_bit() want use of volatile.
26  *	__*_bit() are "relaxed" and don't use spinlock or volatile.
27  */
28 
29 static __inline__ void set_bit(int nr, volatile unsigned long * addr)
30 {
31 	unsigned long mask = BIT_MASK(nr);
32 	unsigned long flags;
33 
34 	addr += BIT_WORD(nr);
35 	_atomic_spin_lock_irqsave(addr, flags);
36 	*addr |= mask;
37 	_atomic_spin_unlock_irqrestore(addr, flags);
38 }
39 
40 static __inline__ void clear_bit(int nr, volatile unsigned long * addr)
41 {
42 	unsigned long mask = BIT_MASK(nr);
43 	unsigned long flags;
44 
45 	addr += BIT_WORD(nr);
46 	_atomic_spin_lock_irqsave(addr, flags);
47 	*addr &= ~mask;
48 	_atomic_spin_unlock_irqrestore(addr, flags);
49 }
50 
51 static __inline__ void change_bit(int nr, volatile unsigned long * addr)
52 {
53 	unsigned long mask = BIT_MASK(nr);
54 	unsigned long flags;
55 
56 	addr += BIT_WORD(nr);
57 	_atomic_spin_lock_irqsave(addr, flags);
58 	*addr ^= mask;
59 	_atomic_spin_unlock_irqrestore(addr, flags);
60 }
61 
62 static __inline__ int test_and_set_bit(int nr, volatile unsigned long * addr)
63 {
64 	unsigned long mask = BIT_MASK(nr);
65 	unsigned long old;
66 	unsigned long flags;
67 	int set;
68 
69 	addr += BIT_WORD(nr);
70 	_atomic_spin_lock_irqsave(addr, flags);
71 	old = *addr;
72 	set = (old & mask) ? 1 : 0;
73 	if (!set)
74 		*addr = old | mask;
75 	_atomic_spin_unlock_irqrestore(addr, flags);
76 
77 	return set;
78 }
79 
80 static __inline__ int test_and_clear_bit(int nr, volatile unsigned long * addr)
81 {
82 	unsigned long mask = BIT_MASK(nr);
83 	unsigned long old;
84 	unsigned long flags;
85 	int set;
86 
87 	addr += BIT_WORD(nr);
88 	_atomic_spin_lock_irqsave(addr, flags);
89 	old = *addr;
90 	set = (old & mask) ? 1 : 0;
91 	if (set)
92 		*addr = old & ~mask;
93 	_atomic_spin_unlock_irqrestore(addr, flags);
94 
95 	return set;
96 }
97 
98 static __inline__ int test_and_change_bit(int nr, volatile unsigned long * addr)
99 {
100 	unsigned long mask = BIT_MASK(nr);
101 	unsigned long oldbit;
102 	unsigned long flags;
103 
104 	addr += BIT_WORD(nr);
105 	_atomic_spin_lock_irqsave(addr, flags);
106 	oldbit = *addr;
107 	*addr = oldbit ^ mask;
108 	_atomic_spin_unlock_irqrestore(addr, flags);
109 
110 	return (oldbit & mask) ? 1 : 0;
111 }
112 
113 #include <asm-generic/bitops/non-atomic.h>
114 
115 /**
116  * __ffs - find first bit in word. returns 0 to "BITS_PER_LONG-1".
117  * @word: The word to search
118  *
119  * __ffs() return is undefined if no bit is set.
120  *
121  * 32-bit fast __ffs by LaMont Jones "lamont At hp com".
122  * 64-bit enhancement by Grant Grundler "grundler At parisc-linux org".
123  * (with help from willy/jejb to get the semantics right)
124  *
125  * This algorithm avoids branches by making use of nullification.
126  * One side effect of "extr" instructions is it sets PSW[N] bit.
127  * How PSW[N] (nullify next insn) gets set is determined by the
128  * "condition" field (eg "<>" or "TR" below) in the extr* insn.
129  * Only the 1st and one of either the 2cd or 3rd insn will get executed.
130  * Each set of 3 insn will get executed in 2 cycles on PA8x00 vs 16 or so
131  * cycles for each mispredicted branch.
132  */
133 
134 static __inline__ unsigned long __ffs(unsigned long x)
135 {
136 	unsigned long ret;
137 
138 	__asm__(
139 #ifdef CONFIG_64BIT
140 		" ldi       63,%1\n"
141 		" extrd,u,*<>  %0,63,32,%%r0\n"
142 		" extrd,u,*TR  %0,31,32,%0\n"	/* move top 32-bits down */
143 		" addi    -32,%1,%1\n"
144 #else
145 		" ldi       31,%1\n"
146 #endif
147 		" extru,<>  %0,31,16,%%r0\n"
148 		" extru,TR  %0,15,16,%0\n"	/* xxxx0000 -> 0000xxxx */
149 		" addi    -16,%1,%1\n"
150 		" extru,<>  %0,31,8,%%r0\n"
151 		" extru,TR  %0,23,8,%0\n"	/* 0000xx00 -> 000000xx */
152 		" addi    -8,%1,%1\n"
153 		" extru,<>  %0,31,4,%%r0\n"
154 		" extru,TR  %0,27,4,%0\n"	/* 000000x0 -> 0000000x */
155 		" addi    -4,%1,%1\n"
156 		" extru,<>  %0,31,2,%%r0\n"
157 		" extru,TR  %0,29,2,%0\n"	/* 0000000y, 1100b -> 0011b */
158 		" addi    -2,%1,%1\n"
159 		" extru,=  %0,31,1,%%r0\n"	/* check last bit */
160 		" addi    -1,%1,%1\n"
161 			: "+r" (x), "=r" (ret) );
162 	return ret;
163 }
164 
165 #include <asm-generic/bitops/ffz.h>
166 
167 /*
168  * ffs: find first bit set. returns 1 to BITS_PER_LONG or 0 (if none set)
169  * This is defined the same way as the libc and compiler builtin
170  * ffs routines, therefore differs in spirit from the above ffz (man ffs).
171  */
172 static __inline__ int ffs(int x)
173 {
174 	return x ? (__ffs((unsigned long)x) + 1) : 0;
175 }
176 
177 /*
178  * fls: find last (most significant) bit set.
179  * fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
180  */
181 
182 static __inline__ int fls(unsigned int x)
183 {
184 	int ret;
185 	if (!x)
186 		return 0;
187 
188 	__asm__(
189 	"	ldi		1,%1\n"
190 	"	extru,<>	%0,15,16,%%r0\n"
191 	"	zdep,TR		%0,15,16,%0\n"		/* xxxx0000 */
192 	"	addi		16,%1,%1\n"
193 	"	extru,<>	%0,7,8,%%r0\n"
194 	"	zdep,TR		%0,23,24,%0\n"		/* xx000000 */
195 	"	addi		8,%1,%1\n"
196 	"	extru,<>	%0,3,4,%%r0\n"
197 	"	zdep,TR		%0,27,28,%0\n"		/* x0000000 */
198 	"	addi		4,%1,%1\n"
199 	"	extru,<>	%0,1,2,%%r0\n"
200 	"	zdep,TR		%0,29,30,%0\n"		/* y0000000 (y&3 = 0) */
201 	"	addi		2,%1,%1\n"
202 	"	extru,=		%0,0,1,%%r0\n"
203 	"	addi		1,%1,%1\n"		/* if y & 8, add 1 */
204 		: "+r" (x), "=r" (ret) );
205 
206 	return ret;
207 }
208 
209 #include <asm-generic/bitops/__fls.h>
210 #include <asm-generic/bitops/fls64.h>
211 #include <asm-generic/bitops/hweight.h>
212 #include <asm-generic/bitops/lock.h>
213 #include <asm-generic/bitops/sched.h>
214 #include <asm-generic/bitops/le.h>
215 #include <asm-generic/bitops/ext2-atomic-setbit.h>
216 
217 #endif /* _PARISC_BITOPS_H */
218