xref: /linux/lib/zlib_dfltcc/dfltcc_util.h (revision 24bce201d79807b668bf9d9e0aca801c5c0d5f78)
1 // SPDX-License-Identifier: Zlib
2 #ifndef DFLTCC_UTIL_H
3 #define DFLTCC_UTIL_H
4 
5 #include <linux/zutil.h>
6 
7 /*
8  * C wrapper for the DEFLATE CONVERSION CALL instruction.
9  */
10 typedef enum {
11     DFLTCC_CC_OK = 0,
12     DFLTCC_CC_OP1_TOO_SHORT = 1,
13     DFLTCC_CC_OP2_TOO_SHORT = 2,
14     DFLTCC_CC_OP2_CORRUPT = 2,
15     DFLTCC_CC_AGAIN = 3,
16 } dfltcc_cc;
17 
18 #define DFLTCC_QAF 0
19 #define DFLTCC_GDHT 1
20 #define DFLTCC_CMPR 2
21 #define DFLTCC_XPND 4
22 #define HBT_CIRCULAR (1 << 7)
23 #define HB_BITS 15
24 #define HB_SIZE (1 << HB_BITS)
25 
26 static inline dfltcc_cc dfltcc(
27     int fn,
28     void *param,
29     Byte **op1,
30     size_t *len1,
31     const Byte **op2,
32     size_t *len2,
33     void *hist
34 )
35 {
36     Byte *t2 = op1 ? *op1 : NULL;
37     size_t t3 = len1 ? *len1 : 0;
38     const Byte *t4 = op2 ? *op2 : NULL;
39     size_t t5 = len2 ? *len2 : 0;
40     register int r0 __asm__("r0") = fn;
41     register void *r1 __asm__("r1") = param;
42     register Byte *r2 __asm__("r2") = t2;
43     register size_t r3 __asm__("r3") = t3;
44     register const Byte *r4 __asm__("r4") = t4;
45     register size_t r5 __asm__("r5") = t5;
46     int cc;
47 
48     __asm__ volatile(
49                      ".insn rrf,0xb9390000,%[r2],%[r4],%[hist],0\n"
50                      "ipm %[cc]\n"
51                      : [r2] "+r" (r2)
52                      , [r3] "+r" (r3)
53                      , [r4] "+r" (r4)
54                      , [r5] "+r" (r5)
55                      , [cc] "=r" (cc)
56                      : [r0] "r" (r0)
57                      , [r1] "r" (r1)
58                      , [hist] "r" (hist)
59                      : "cc", "memory");
60     t2 = r2; t3 = r3; t4 = r4; t5 = r5;
61 
62     if (op1)
63         *op1 = t2;
64     if (len1)
65         *len1 = t3;
66     if (op2)
67         *op2 = t4;
68     if (len2)
69         *len2 = t5;
70     return (cc >> 28) & 3;
71 }
72 
73 static inline int is_bit_set(
74     const char *bits,
75     int n
76 )
77 {
78     return bits[n / 8] & (1 << (7 - (n % 8)));
79 }
80 
81 static inline void turn_bit_off(
82     char *bits,
83     int n
84 )
85 {
86     bits[n / 8] &= ~(1 << (7 - (n % 8)));
87 }
88 
89 static inline int dfltcc_are_params_ok(
90     int level,
91     uInt window_bits,
92     int strategy,
93     uLong level_mask
94 )
95 {
96     return (level_mask & (1 << level)) != 0 &&
97         (window_bits == HB_BITS) &&
98         (strategy == Z_DEFAULT_STRATEGY);
99 }
100 
101 char *oesc_msg(char *buf, int oesc);
102 
103 #endif /* DFLTCC_UTIL_H */
104