1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
2 | /* |
3 | * HPMC (High Priority Machine Check) handler. |
4 | * |
5 | * Copyright (C) 1999 Philipp Rumpf <prumpf@tux.org> |
6 | * Copyright (C) 1999 Hewlett-Packard (Frank Rowand) |
7 | * Copyright (C) 2000 Hewlett-Packard (John Marvin) |
8 | */ |
9 | |
10 | |
11 | /* |
12 | * This HPMC handler retrieves the HPMC pim data, resets IO and |
13 | * returns to the default trap handler with code set to 1 (HPMC). |
14 | * The default trap handler calls handle interruption, which |
15 | * does a stack and register dump. This at least allows kernel |
16 | * developers to get back to C code in virtual mode, where they |
17 | * have the option to examine and print values from memory that |
18 | * would help in debugging an HPMC caused by a software bug. |
19 | * |
20 | * There is more to do here: |
21 | * |
22 | * 1) On MP systems we need to synchronize processors |
23 | * before calling pdc/iodc. |
24 | * 2) We should be checking the system state and not |
25 | * returning to the fault handler if things are really |
26 | * bad. |
27 | * |
28 | */ |
29 | |
30 | .level 1.1 |
31 | |
32 | #include <asm/assembly.h> |
33 | #include <asm/pdc.h> |
34 | #include <asm/psw.h> |
35 | |
36 | #include <linux/linkage.h> |
37 | #include <linux/init.h> |
38 | |
39 | /* |
40 | * stack for os_hpmc, the HPMC handler. |
41 | * buffer for IODC procedures (for the HPMC handler). |
42 | * |
43 | * IODC requires 7K byte stack. That leaves 1K byte for os_hpmc. |
44 | */ |
45 | |
46 | .import toc_stack,data |
47 | #define hpmc_stack toc_stack /* re-use the TOC stack */ |
48 | |
49 | #define HPMC_IODC_BUF_SIZE 0x8000 |
50 | |
51 | __PAGE_ALIGNED_BSS |
52 | .align 4096 |
53 | hpmc_iodc_buf: |
54 | .block HPMC_IODC_BUF_SIZE |
55 | |
56 | .section .bss |
57 | .align 8 |
58 | hpmc_raddr: |
59 | .block 128 |
60 | |
61 | #define HPMC_PIM_DATA_SIZE 896 /* Enough to hold all architected 2.0 state */ |
62 | |
63 | .section .bss |
64 | .align 8 |
65 | ENTRY(hpmc_pim_data) |
66 | .block HPMC_PIM_DATA_SIZE |
67 | END(hpmc_pim_data) |
68 | |
69 | .text |
70 | |
71 | .import intr_save, code |
72 | .align 16 |
73 | ENTRY(os_hpmc) |
74 | .os_hpmc: |
75 | |
76 | /* |
77 | * registers modified: |
78 | * |
79 | * Using callee saves registers without saving them. The |
80 | * original values are in the pim dump if we need them. |
81 | * |
82 | * r2 (rp) return pointer |
83 | * r3 address of PDCE_PROC |
84 | * r4 scratch |
85 | * r5 scratch |
86 | * r23 (arg3) procedure arg |
87 | * r24 (arg2) procedure arg |
88 | * r25 (arg1) procedure arg |
89 | * r26 (arg0) procedure arg |
90 | * r30 (sp) stack pointer |
91 | * |
92 | * registers read: |
93 | * |
94 | * r26 contains address of PDCE_PROC on entry |
95 | * r28 (ret0) return value from procedure |
96 | */ |
97 | |
98 | copy arg0, %r3 /* save address of PDCE_PROC */ |
99 | |
100 | /* |
101 | * disable nested HPMCs |
102 | * |
103 | * Increment os_hpmc checksum to invalidate it. |
104 | * Do this before turning the PSW M bit off. |
105 | */ |
106 | |
107 | mfctl %cr14, %r4 |
108 | ldw 52(%r4),%r5 |
109 | addi 1,%r5,%r5 |
110 | stw %r5,52(%r4) |
111 | |
112 | /* MP_FIXME: synchronize all processors. */ |
113 | |
114 | /* Setup stack pointer. */ |
115 | |
116 | load32 PA(hpmc_stack),sp |
117 | |
118 | ldo 128(sp),sp /* leave room for arguments */ |
119 | |
120 | /* |
121 | * Most PDC routines require that the M bit be off. |
122 | * So turn on the Q bit and turn off the M bit. |
123 | */ |
124 | |
125 | ldi PSW_SM_Q,%r4 /* PSW Q on, PSW M off */ |
126 | mtctl %r4,ipsw |
127 | mtctl %r0,pcsq |
128 | mtctl %r0,pcsq |
129 | load32 PA(os_hpmc_1),%r4 |
130 | mtctl %r4,pcoq |
131 | ldo 4(%r4),%r4 |
132 | mtctl %r4,pcoq |
133 | rfi |
134 | nop |
135 | |
136 | os_hpmc_1: |
137 | |
138 | /* Call PDC_PIM to get HPMC pim info */ |
139 | |
140 | /* |
141 | * Note that on some newer boxes, PDC_PIM must be called |
142 | * before PDC_IO if you want IO to be reset. PDC_PIM sets |
143 | * a flag that PDC_IO examines. |
144 | */ |
145 | |
146 | ldo PDC_PIM(%r0), arg0 |
147 | ldo PDC_PIM_HPMC(%r0),arg1 /* Transfer HPMC data */ |
148 | load32 PA(hpmc_raddr),arg2 |
149 | load32 PA(hpmc_pim_data),arg3 |
150 | load32 HPMC_PIM_DATA_SIZE,%r4 |
151 | stw %r4,-52(sp) |
152 | |
153 | ldil L%PA(os_hpmc_2), rp |
154 | bv (r3) /* call pdce_proc */ |
155 | ldo R%PA(os_hpmc_2)(rp), rp |
156 | |
157 | os_hpmc_2: |
158 | comib,<> 0,ret0, os_hpmc_fail |
159 | |
160 | /* Reset IO by calling the hversion dependent PDC_IO routine */ |
161 | |
162 | ldo PDC_IO(%r0),arg0 |
163 | ldo 0(%r0),arg1 /* log IO errors */ |
164 | ldo 0(%r0),arg2 /* reserved */ |
165 | ldo 0(%r0),arg3 /* reserved */ |
166 | stw %r0,-52(sp) /* reserved */ |
167 | |
168 | ldil L%PA(os_hpmc_3),rp |
169 | bv (%r3) /* call pdce_proc */ |
170 | ldo R%PA(os_hpmc_3)(rp),rp |
171 | |
172 | os_hpmc_3: |
173 | |
174 | /* FIXME? Check for errors from PDC_IO (-1 might be OK) */ |
175 | |
176 | /* |
177 | * Initialize the IODC console device (HPA,SPA, path etc. |
178 | * are stored on page 0. |
179 | */ |
180 | |
181 | /* |
182 | * Load IODC into hpmc_iodc_buf by calling PDC_IODC. |
183 | * Note that PDC_IODC handles flushing the appropriate |
184 | * data and instruction cache lines. |
185 | */ |
186 | |
187 | ldo PDC_IODC(%r0),arg0 |
188 | ldo PDC_IODC_READ(%r0),arg1 |
189 | load32 PA(hpmc_raddr),arg2 |
190 | ldw BOOT_CONSOLE_HPA_OFFSET(%r0),arg3 /* console hpa */ |
191 | ldo PDC_IODC_RI_INIT(%r0),%r4 |
192 | stw %r4,-52(sp) |
193 | load32 PA(hpmc_iodc_buf),%r4 |
194 | stw %r4,-56(sp) |
195 | load32 HPMC_IODC_BUF_SIZE,%r4 |
196 | stw %r4,-60(sp) |
197 | |
198 | ldil L%PA(os_hpmc_4),rp |
199 | bv (%r3) /* call pdce_proc */ |
200 | ldo R%PA(os_hpmc_4)(rp),rp |
201 | |
202 | os_hpmc_4: |
203 | comib,<> 0,ret0,os_hpmc_fail |
204 | |
205 | /* Call the entry init (just loaded by PDC_IODC) */ |
206 | |
207 | ldw BOOT_CONSOLE_HPA_OFFSET(%r0),arg0 /* console hpa */ |
208 | ldo ENTRY_INIT_MOD_DEV(%r0), arg1 |
209 | ldw BOOT_CONSOLE_SPA_OFFSET(%r0),arg2 /* console spa */ |
210 | depi 0,31,11,arg2 /* clear bits 21-31 */ |
211 | ldo BOOT_CONSOLE_PATH_OFFSET(%r0),arg3 /* console path */ |
212 | load32 PA(hpmc_raddr),%r4 |
213 | stw %r4, -52(sp) |
214 | stw %r0, -56(sp) /* HV */ |
215 | stw %r0, -60(sp) /* HV */ |
216 | stw %r0, -64(sp) /* HV */ |
217 | stw %r0, -68(sp) /* lang, must be zero */ |
218 | |
219 | load32 PA(hpmc_iodc_buf),%r5 |
220 | ldil L%PA(os_hpmc_5),rp |
221 | bv (%r5) |
222 | ldo R%PA(os_hpmc_5)(rp),rp |
223 | |
224 | os_hpmc_5: |
225 | comib,<> 0,ret0,os_hpmc_fail |
226 | |
227 | /* Prepare to call intr_save */ |
228 | |
229 | /* |
230 | * Load kernel page directory (load into user also, since |
231 | * we don't intend to ever return to user land anyway) |
232 | */ |
233 | |
234 | load32 PA(swapper_pg_dir),%r4 |
235 | mtctl %r4,%cr24 /* Initialize kernel root pointer */ |
236 | mtctl %r4,%cr25 /* Initialize user root pointer */ |
237 | |
238 | /* Clear sr4-sr7 */ |
239 | |
240 | mtsp %r0, %sr4 |
241 | mtsp %r0, %sr5 |
242 | mtsp %r0, %sr6 |
243 | mtsp %r0, %sr7 |
244 | |
245 | tovirt_r1 %r30 /* make sp virtual */ |
246 | |
247 | rsm PSW_SM_Q,%r0 /* Clear Q bit */ |
248 | ldi 1,%r8 /* Set trap code to "1" for HPMC */ |
249 | load32 PA(intr_save),%r1 |
250 | be 0(%sr7,%r1) |
251 | nop |
252 | |
253 | os_hpmc_fail: |
254 | |
255 | /* |
256 | * Reset the system |
257 | * |
258 | * Some systems may lockup from a broadcast reset, so try the |
259 | * hversion PDC_BROADCAST_RESET() first. |
260 | * MP_FIXME: reset all processors if more than one central bus. |
261 | */ |
262 | |
263 | /* PDC_BROADCAST_RESET() */ |
264 | |
265 | ldo PDC_BROADCAST_RESET(%r0),arg0 |
266 | ldo 0(%r0),arg1 /* do reset */ |
267 | |
268 | ldil L%PA(os_hpmc_6),rp |
269 | bv (%r3) /* call pdce_proc */ |
270 | ldo R%PA(os_hpmc_6)(rp),rp |
271 | |
272 | os_hpmc_6: |
273 | |
274 | /* |
275 | * possible return values: |
276 | * -1 non-existent procedure |
277 | * -2 non-existent option |
278 | * -16 unaligned stack |
279 | * |
280 | * If call returned, do a broadcast reset. |
281 | */ |
282 | |
283 | ldil L%0xfffc0000,%r4 /* IO_BROADCAST */ |
284 | ldo 5(%r0),%r5 |
285 | stw %r5,48(%r4) /* CMD_RESET to IO_COMMAND offset */ |
286 | |
287 | b . |
288 | nop |
289 | .align 16 /* make function length multiple of 16 bytes */ |
290 | |