1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2002
4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 */
6
7 #include <common.h>
8
9 /*
10 * CPU test
11 * Branch instructions: b, bl, bc
12 *
13 * The first 2 instructions (b, bl) are verified by jumping
14 * to a fixed address and checking whether control was transferred
15 * to that very point. For the bl instruction the value of the
16 * link register is checked as well (using mfspr).
17 * To verify the bc instruction various combinations of the BI/BO
18 * fields, the CTR and the condition register values are
19 * checked. The list of such combinations is pre-built and
20 * linked in U-Boot at build time.
21 */
22
23 #include <post.h>
24 #include "cpu_asm.h"
25
26 #if CONFIG_POST & CONFIG_SYS_POST_CPU
27
28 extern void cpu_post_exec_11 (ulong *code, ulong *res, ulong op1);
29 extern void cpu_post_exec_31 (ulong *code, ulong *ctr, ulong *lr, ulong *jump,
30 ulong cr);
31
cpu_post_test_bc(ulong cmd,ulong bo,ulong bi,int pjump,int decr,int link,ulong pctr,ulong cr)32 static int cpu_post_test_bc (ulong cmd, ulong bo, ulong bi,
33 int pjump, int decr, int link, ulong pctr, ulong cr)
34 {
35 int ret = 0;
36 ulong lr = 0;
37 ulong ctr = pctr;
38 ulong jump;
39
40 unsigned long code[] =
41 {
42 ASM_MTCR(6),
43 ASM_MFLR(6),
44 ASM_MTCTR(3),
45 ASM_MTLR(4),
46 ASM_LI(5, 1),
47 ASM_3O(cmd, bo, bi, 8),
48 ASM_LI(5, 0),
49 ASM_MFCTR(3),
50 ASM_MFLR(4),
51 ASM_MTLR(6),
52 ASM_BLR,
53 };
54
55 cpu_post_exec_31 (code, &ctr, &lr, &jump, cr);
56
57 if (ret == 0)
58 ret = pjump == jump ? 0 : -1;
59 if (ret == 0)
60 {
61 if (decr)
62 ret = pctr == ctr + 1 ? 0 : -1;
63 else
64 ret = pctr == ctr ? 0 : -1;
65 }
66 if (ret == 0)
67 {
68 if (link)
69 ret = lr == (ulong) code + 24 ? 0 : -1;
70 else
71 ret = lr == 0 ? 0 : -1;
72 }
73
74 return ret;
75 }
76
cpu_post_test_b(void)77 int cpu_post_test_b (void)
78 {
79 int ret = 0;
80 unsigned int i;
81 int flag = disable_interrupts();
82
83 if (ret == 0)
84 {
85 ulong code[] =
86 {
87 ASM_MFLR(4),
88 ASM_MTLR(3),
89 ASM_B(4),
90 ASM_MFLR(3),
91 ASM_MTLR(4),
92 ASM_BLR,
93 };
94 ulong res;
95
96 cpu_post_exec_11 (code, &res, 0);
97
98 ret = res == 0 ? 0 : -1;
99
100 if (ret != 0)
101 {
102 post_log ("Error at b1 test !\n");
103 }
104 }
105
106 if (ret == 0)
107 {
108 ulong code[] =
109 {
110 ASM_MFLR(4),
111 ASM_MTLR(3),
112 ASM_BL(4),
113 ASM_MFLR(3),
114 ASM_MTLR(4),
115 ASM_BLR,
116 };
117 ulong res;
118
119 cpu_post_exec_11 (code, &res, 0);
120
121 ret = res == (ulong)code + 12 ? 0 : -1;
122
123 if (ret != 0)
124 {
125 post_log ("Error at b2 test !\n");
126 }
127 }
128
129 if (ret == 0)
130 {
131 ulong cc, cd;
132 int cond;
133 ulong ctr;
134 int link;
135
136 i = 0;
137
138 for (cc = 0; cc < 4 && ret == 0; cc++)
139 {
140 for (cd = 0; cd < 4 && ret == 0; cd++)
141 {
142 for (link = 0; link <= 1 && ret == 0; link++)
143 {
144 for (cond = 0; cond <= 1 && ret == 0; cond++)
145 {
146 for (ctr = 1; ctr <= 2 && ret == 0; ctr++)
147 {
148 int decr = cd < 2;
149 int cr = cond ? 0x80000000 : 0x00000000;
150 int jumpc = cc >= 2 ||
151 (cc == 0 && !cond) ||
152 (cc == 1 && cond);
153 int jumpd = cd >= 2 ||
154 (cd == 0 && ctr != 1) ||
155 (cd == 1 && ctr == 1);
156 int jump = jumpc && jumpd;
157
158 ret = cpu_post_test_bc (link ? OP_BCL : OP_BC,
159 (cc << 3) + (cd << 1), 0, jump, decr, link,
160 ctr, cr);
161
162 if (ret != 0)
163 {
164 post_log ("Error at b3 test %d !\n", i);
165 }
166
167 i++;
168 }
169 }
170 }
171 }
172 }
173 }
174
175 if (flag)
176 enable_interrupts();
177
178 return ret;
179 }
180
181 #endif
182