1 /* Copyright (C) 2004-2023 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library. If not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <assert.h>
19 #include <stdbool.h>
20 #include <stdlib.h>
21 #include <unistd.h>
22
23
24 static long int linux_sysconf (int name);
25
26 #define CSHAPE(totalsize, linesize, assoc) \
27 ((totalsize & ~0xff) | (linesize << 4) | assoc)
28
29 extern long __libc_alpha_cache_shape[4];
30
31 /* Get the value of the system variable NAME. */
32 long int
33 __sysconf (int name)
34 {
35 long shape, index;
36
37 /* We only handle the cache information here (for now). */
38 if (name < _SC_LEVEL1_ICACHE_SIZE || name > _SC_LEVEL4_CACHE_LINESIZE)
39 return linux_sysconf (name);
40
41 /* No Alpha has L4 caches. */
42 if (name >= _SC_LEVEL4_CACHE_SIZE)
43 return -1;
44
45 index = (name - _SC_LEVEL1_ICACHE_SIZE) / 3;
46 shape = __libc_alpha_cache_shape[index];
47 if (shape == -2)
48 {
49 long shape_l1i, shape_l1d, shape_l2, shape_l3 = -1;
50
51 /* ??? In the cases below for which we do not know L1 cache sizes,
52 we could do timings to measure sizes. But for the Bcache, it's
53 generally big enough that (without additional help) TLB effects
54 get in the way. We'd either need to be able to allocate large
55 pages or have the kernel do the timings from KSEG. Fortunately,
56 kernels beginning with 2.6.5 will pass us this info in auxvec. */
57
58 switch (__builtin_alpha_implver ())
59 {
60 case 0: /* EV4 */
61 /* EV4/LCA45 had 8k L1 caches; EV45 had 16k L1 caches. */
62 /* EV4/EV45 had 128k to 16M 32-byte direct Bcache. LCA45
63 had 64k to 8M 8-byte direct Bcache. Can't tell. */
64 shape_l1i = shape_l1d = shape_l2 = CSHAPE (0, 5, 1);
65 break;
66
67 case 1: /* EV5 */
68 if (__builtin_alpha_amask (1 << 8))
69 {
70 /* MAX insns not present; either EV5 or EV56. */
71 shape_l1i = shape_l1d = CSHAPE(8*1024, 5, 1);
72 /* ??? L2 and L3 *can* be configured as 32-byte line. */
73 shape_l2 = CSHAPE (96*1024, 6, 3);
74 /* EV5/EV56 has 1M to 16M Bcache. */
75 shape_l3 = CSHAPE (0, 6, 1);
76 }
77 else
78 {
79 /* MAX insns present; either PCA56 or PCA57. */
80 /* PCA56 had 16k 64-byte cache; PCA57 had 32k Icache. */
81 /* PCA56 had 8k 64-byte cache; PCA57 had 16k Dcache. */
82 /* PCA5[67] had 512k to 4M Bcache. */
83 shape_l1i = shape_l1d = shape_l2 = CSHAPE (0, 6, 1);
84 }
85 break;
86
87 case 2: /* EV6 */
88 shape_l1i = shape_l1d = CSHAPE(64*1024, 6, 2);
89 /* EV6/EV67/EV68* had 1M to 16M Bcache. */
90 shape_l2 = CSHAPE (0, 6, 1);
91 break;
92
93 case 3: /* EV7 */
94 shape_l1i = shape_l1d = CSHAPE(64*1024, 6, 2);
95 shape_l2 = CSHAPE(7*1024*1024/4, 6, 7);
96 break;
97
98 default:
99 shape_l1i = shape_l1d = shape_l2 = 0;
100 break;
101 }
102
103 __libc_alpha_cache_shape[0] = shape_l1i;
104 __libc_alpha_cache_shape[1] = shape_l1d;
105 __libc_alpha_cache_shape[2] = shape_l2;
106 __libc_alpha_cache_shape[3] = shape_l3;
107 shape = __libc_alpha_cache_shape[index];
108 }
109
110 if (shape <= 0)
111 return shape;
112
113 switch ((name - _SC_LEVEL1_ICACHE_SIZE) % 3)
114 {
115 case 0: /* total size */
116 return shape & -0x100;
117 case 1: /* associativity */
118 return shape & 0xf;
119 default: /* line size */
120 return 1L << ((shape >> 4) & 0xf);
121 }
122 }
123
124 /* Now the generic Linux version. */
125 #undef __sysconf
126 #define __sysconf static linux_sysconf
127 #include <sysdeps/unix/sysv/linux/sysconf.c>