aboutsummaryrefslogtreecommitdiffstats
path: root/arch/parisc/kernel/hpmc.S
blob: 2cbf13b3ef11d0a1ff62f7eb5cec9b1c96333371 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
/* 
 * HPMC (High Priority Machine Check) handler.
 *
 * Copyright (C) 1999 Philipp Rumpf <prumpf@tux.org>
 * Copyright (C) 1999 Hewlett-Packard (Frank Rowand)
 * Copyright (C) 2000 Hewlett-Packard (John Marvin)
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


/*
 * This HPMC handler retrieves the HPMC pim data, resets IO and
 * returns to the default trap handler with code set to 1 (HPMC).
 * The default trap handler calls handle interruption, which
 * does a stack and register dump. This at least allows kernel
 * developers to get back to C code in virtual mode, where they
 * have the option to examine and print values from memory that
 * would help in debugging an HPMC caused by a software bug.
 *
 * There is more to do here:
 *
 *      1) On MP systems we need to synchronize processors
 *         before calling pdc/iodc.
 *      2) We should be checking the system state and not
 *         returning to the fault handler if things are really
 *         bad.
 *
 */

	.level		1.1
	.data

#include <asm/assembly.h>
#include <asm/pdc.h>

#include <linux/linkage.h>

	/*
	 * stack for os_hpmc, the HPMC handler.
	 * buffer for IODC procedures (for the HPMC handler).
	 *
	 * IODC requires 7K byte stack.  That leaves 1K byte for os_hpmc.
	 */

	.align	PAGE_SIZE
hpmc_stack:
	.block 16384

#define HPMC_IODC_BUF_SIZE 0x8000

	.align	PAGE_SIZE
hpmc_iodc_buf:
	.block HPMC_IODC_BUF_SIZE

	.align 8
hpmc_raddr:
	.block 128

#define HPMC_PIM_DATA_SIZE 896 /* Enough to hold all architected 2.0 state */

	.align 8
ENTRY(hpmc_pim_data)
	.block HPMC_PIM_DATA_SIZE
END(hpmc_pim_data)

	.text

	.import intr_save, code
ENTRY(os_hpmc)

	/*
	 * registers modified:
	 *
	 *   Using callee saves registers without saving them.  The
	 *   original values are in the pim dump if we need them.
	 *
	 *   r2   (rp)  return pointer
	 *   r3   address of PDCE_PROC
	 *   r4   scratch
	 *   r5   scratch
	 *   r23  (arg3) procedure arg
	 *   r24  (arg2) procedure arg
	 *   r25  (arg1) procedure arg
	 *   r26  (arg0) procedure arg
	 *   r30  (sp)   stack pointer
	 *
	 * registers read:
	 *
	 *   r26  contains address of PDCE_PROC on entry
	 *   r28  (ret0) return value from procedure
	 */

	copy    arg0, %r3       /* save address of PDCE_PROC */

	/*
	 *  disable nested HPMCs
	 *
	 * Increment os_hpmc checksum to invalidate it.
	 * Do this before turning the PSW M bit off.
	 */

	mfctl   %cr14, %r4
	ldw     52(%r4),%r5
	addi    1,%r5,%r5
	stw     %r5,52(%r4)

	/* MP_FIXME: synchronize all processors. */

	/* Setup stack pointer. */

	load32	PA(hpmc_stack),sp
	
	ldo     128(sp),sp /* leave room for arguments */

	/*
	 * Most PDC routines require that the M bit be off.
	 * So turn on the Q bit and turn off the M bit.
	 */

	ldo     8(%r0),%r4                       /* PSW Q on, PSW M off */
	mtctl   %r4,ipsw
	mtctl   %r0,pcsq
	mtctl   %r0,pcsq
	load32	PA(os_hpmc_1),%r4
	mtctl   %r4,pcoq
	ldo     4(%r4),%r4
	mtctl   %r4,pcoq
	rfi
	nop

os_hpmc_1:

	/* Call PDC_PIM to get HPMC pim info */

	/*
	 * Note that on some newer boxes, PDC_PIM must be called
	 * before PDC_IO if you want IO to be reset. PDC_PIM sets
	 * a flag that PDC_IO examines.
	 */

	ldo     PDC_PIM(%r0), arg0
	ldo     PDC_PIM_HPMC(%r0),arg1          /* Transfer HPMC data */
	load32	PA(hpmc_raddr),arg2
	load32	PA(hpmc_pim_data),arg3
	load32	HPMC_PIM_DATA_SIZE,%r4
	stw     %r4,-52(sp)

	ldil    L%PA(os_hpmc_2), rp
	bv      (r3)                            /* call pdce_proc */
	ldo     R%PA(os_hpmc_2)(rp), rp

os_hpmc_2:
	comib,<>  0,ret0, os_hpmc_fail

	/* Reset IO by calling the hversion dependent PDC_IO routine */

	ldo     PDC_IO(%r0),arg0
	ldo     0(%r0),arg1                     /* log IO errors */
	ldo     0(%r0),arg2                     /* reserved */
	ldo     0(%r0),arg3                     /* reserved */
	stw     %r0,-52(sp)                     /* reserved */

	ldil    L%PA(os_hpmc_3),rp
	bv      (%r3)                           /* call pdce_proc */
	ldo     R%PA(os_hpmc_3)(rp),rp

os_hpmc_3:

	/* FIXME? Check for errors from PDC_IO (-1 might be OK) */

	/*
	 * Initialize the IODC console device (HPA,SPA, path etc.
	 * are stored on page 0.
	 */

	/*
	 * Load IODC into hpmc_iodc_buf by calling PDC_IODC.
	 * Note that PDC_IODC handles flushing the appropriate
	 * data and instruction cache lines.
	 */

	ldo     PDC_IODC(%r0),arg0
	ldo     PDC_IODC_READ(%r0),arg1
	load32	PA(hpmc_raddr),arg2
	ldw     BOOT_CONSOLE_HPA_OFFSET(%r0),arg3 /* console hpa */
	ldo     PDC_IODC_RI_INIT(%r0),%r4
	stw     %r4,-52(sp)
	load32	PA(hpmc_iodc_buf),%r4
	stw     %r4,-56(sp)
	load32	HPMC_IODC_BUF_SIZE,%r4
	stw     %r4,-60(sp)

	ldil    L%PA(os_hpmc_4),rp
	bv      (%r3)                            /* call pdce_proc */
	ldo     R%PA(os_hpmc_4)(rp),rp

os_hpmc_4:
	comib,<>  0,ret0,os_hpmc_fail

	/* Call the entry init (just loaded by PDC_IODC) */

	ldw     BOOT_CONSOLE_HPA_OFFSET(%r0),arg0  /* console hpa */
	ldo     ENTRY_INIT_MOD_DEV(%r0), arg1
	ldw     BOOT_CONSOLE_SPA_OFFSET(%r0),arg2  /* console spa */
	depi    0,31,11,arg2                       /* clear bits 21-31    */
	ldo     BOOT_CONSOLE_PATH_OFFSET(%r0),arg3 /* console path */
	load32	PA(hpmc_raddr),%r4
	stw     %r4, -52(sp)
	stw     %r0, -56(sp)                    /* HV                  */
	stw     %r0, -60(sp)                    /* HV                  */
	stw     %r0, -64(sp)                    /* HV                  */
	stw     %r0, -68(sp)                    /* lang, must be zero  */

	load32	PA(hpmc_iodc_buf),%r5
	ldil    L%PA(os_hpmc_5),rp
	bv      (%r5)
	ldo     R%PA(os_hpmc_5)(rp),rp

os_hpmc_5:
	comib,<>  0,ret0,os_hpmc_fail

	/* Prepare to call intr_save */

	/*
	 * Load kernel page directory (load into user also, since
	 * we don't intend to ever return to user land anyway)
	 */

	load32		PA(swapper_pg_dir),%r4
	mtctl		%r4,%cr24	/* Initialize kernel root pointer */
	mtctl		%r4,%cr25	/* Initialize user root pointer */

	/* Clear sr4-sr7 */

	mtsp	%r0, %sr4
	mtsp	%r0, %sr5
	mtsp	%r0, %sr6
	mtsp	%r0, %sr7

	tovirt_r1 %r30      /* make sp virtual */

	rsm 8,%r0           /* Clear Q bit */
	ldi     1,%r8       /* Set trap code to "1" for HPMC */
	load32	PA(intr_save),%r1
	be      0(%sr7,%r1)
	nop

os_hpmc_fail:

	/*
	 * Reset the system
	 *
	 * Some systems may lockup from a broadcast reset, so try the
	 * hversion PDC_BROADCAST_RESET() first.
	 * MP_FIXME: reset all processors if more than one central bus.
	 */

	/* PDC_BROADCAST_RESET() */

	ldo     PDC_BROADCAST_RESET(%r0),arg0
	ldo     0(%r0),arg1                     /* do reset */

	ldil    L%PA(os_hpmc_6),rp
	bv      (%r3)                           /* call pdce_proc */
	ldo     R%PA(os_hpmc_6)(rp),rp

os_hpmc_6:

	/*
	 * possible return values:
	 *  -1  non-existent procedure
	 *  -2  non-existent option
	 *  -16 unaligned stack
	 *
	 * If call returned, do a broadcast reset.
	 */

	ldil    L%0xfffc0000,%r4        /* IO_BROADCAST */
	ldo     5(%r0),%r5
	stw     %r5,48(%r4)             /*  CMD_RESET to IO_COMMAND offset */

	b .
	nop
ENDPROC(os_hpmc)
ENTRY(os_hpmc_end)	/* this label used to compute os_hpmc checksum */
	nop