1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun #ifndef _ASM_WORD_AT_A_TIME_H
3*4882a593Smuzhiyun #define _ASM_WORD_AT_A_TIME_H
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun #include <asm/compiler.h>
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun /*
8*4882a593Smuzhiyun * word-at-a-time interface for Alpha.
9*4882a593Smuzhiyun */
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun /*
12*4882a593Smuzhiyun * We do not use the word_at_a_time struct on Alpha, but it needs to be
13*4882a593Smuzhiyun * implemented to humour the generic code.
14*4882a593Smuzhiyun */
15*4882a593Smuzhiyun struct word_at_a_time {
16*4882a593Smuzhiyun const unsigned long unused;
17*4882a593Smuzhiyun };
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun #define WORD_AT_A_TIME_CONSTANTS { 0 }
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun /* Return nonzero if val has a zero */
has_zero(unsigned long val,unsigned long * bits,const struct word_at_a_time * c)22*4882a593Smuzhiyun static inline unsigned long has_zero(unsigned long val, unsigned long *bits, const struct word_at_a_time *c)
23*4882a593Smuzhiyun {
24*4882a593Smuzhiyun unsigned long zero_locations = __kernel_cmpbge(0, val);
25*4882a593Smuzhiyun *bits = zero_locations;
26*4882a593Smuzhiyun return zero_locations;
27*4882a593Smuzhiyun }
28*4882a593Smuzhiyun
prep_zero_mask(unsigned long val,unsigned long bits,const struct word_at_a_time * c)29*4882a593Smuzhiyun static inline unsigned long prep_zero_mask(unsigned long val, unsigned long bits, const struct word_at_a_time *c)
30*4882a593Smuzhiyun {
31*4882a593Smuzhiyun return bits;
32*4882a593Smuzhiyun }
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun #define create_zero_mask(bits) (bits)
35*4882a593Smuzhiyun
find_zero(unsigned long bits)36*4882a593Smuzhiyun static inline unsigned long find_zero(unsigned long bits)
37*4882a593Smuzhiyun {
38*4882a593Smuzhiyun #if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
39*4882a593Smuzhiyun /* Simple if have CIX instructions */
40*4882a593Smuzhiyun return __kernel_cttz(bits);
41*4882a593Smuzhiyun #else
42*4882a593Smuzhiyun unsigned long t1, t2, t3;
43*4882a593Smuzhiyun /* Retain lowest set bit only */
44*4882a593Smuzhiyun bits &= -bits;
45*4882a593Smuzhiyun /* Binary search for lowest set bit */
46*4882a593Smuzhiyun t1 = bits & 0xf0;
47*4882a593Smuzhiyun t2 = bits & 0xcc;
48*4882a593Smuzhiyun t3 = bits & 0xaa;
49*4882a593Smuzhiyun if (t1) t1 = 4;
50*4882a593Smuzhiyun if (t2) t2 = 2;
51*4882a593Smuzhiyun if (t3) t3 = 1;
52*4882a593Smuzhiyun return t1 + t2 + t3;
53*4882a593Smuzhiyun #endif
54*4882a593Smuzhiyun }
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun #define zero_bytemask(mask) ((2ul << (find_zero(mask) * 8)) - 1)
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun #endif /* _ASM_WORD_AT_A_TIME_H */
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