summaryrefslogtreecommitdiffstats
path: root/arch/s390/kernel/head.S
blob: fcaefb041364c13f15ddd0c976846b683c626c5a (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
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
/*
 * Copyright IBM Corp. 1999, 2010
 *
 *    Author(s): Hartmut Penner <hp@de.ibm.com>
 *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
 *		 Rob van der Heij <rvdhei@iae.nl>
 *		 Heiko Carstens <heiko.carstens@de.ibm.com>
 *
 * There are 5 different IPL methods
 *  1) load the image directly into ram at address 0 and do an PSW restart
 *  2) linload will load the image from address 0x10000 to memory 0x10000
 *     and start the code thru LPSW 0x0008000080010000 (VM only, deprecated)
 *  3) generate the tape ipl header, store the generated image on a tape
 *     and ipl from it
 *     In case of SL tape you need to IPL 5 times to get past VOL1 etc
 *  4) generate the vm reader ipl header, move the generated image to the
 *     VM reader (use option NOH!) and do a ipl from reader (VM only)
 *  5) direct call of start by the SALIPL loader
 *  We use the cpuid to distinguish between VM and native ipl
 *  params for kernel are pushed to 0x10400 (see setup.h)
 *
 */

#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
#include <asm/facility.h>
#include <asm/page.h>
#include <asm/ptrace.h>

#define ARCH_OFFSET	4

__HEAD

#define IPL_BS	0x730
	.org	0
	.long	0x00080000,0x80000000+iplstart	# The first 24 bytes are loaded
	.long	0x02000018,0x60000050		# by ipl to addresses 0-23.
	.long	0x02000068,0x60000050		# (a PSW and two CCWs).
	.fill	80-24,1,0x40			# bytes 24-79 are discarded !!
	.long	0x020000f0,0x60000050		# The next 160 byte are loaded
	.long	0x02000140,0x60000050		# to addresses 0x18-0xb7
	.long	0x02000190,0x60000050		# They form the continuation
	.long	0x020001e0,0x60000050		# of the CCW program started
	.long	0x02000230,0x60000050		# by ipl and load the range
	.long	0x02000280,0x60000050		# 0x0f0-0x730 from the image
	.long	0x020002d0,0x60000050		# to the range 0x0f0-0x730
	.long	0x02000320,0x60000050		# in memory. At the end of
	.long	0x02000370,0x60000050		# the channel program the PSW
	.long	0x020003c0,0x60000050		# at location 0 is loaded.
	.long	0x02000410,0x60000050		# Initial processing starts
	.long	0x02000460,0x60000050		# at 0x200 = iplstart.
	.long	0x020004b0,0x60000050
	.long	0x02000500,0x60000050
	.long	0x02000550,0x60000050
	.long	0x020005a0,0x60000050
	.long	0x020005f0,0x60000050
	.long	0x02000640,0x60000050
	.long	0x02000690,0x60000050
	.long	0x020006e0,0x20000050

	.org	0x200

#
# subroutine to wait for end I/O
#
.Lirqwait:
	mvc	0x1f0(16),.Lnewpsw	# set up IO interrupt psw
	lpsw	.Lwaitpsw
.Lioint:
	br	%r14
	.align	8
.Lnewpsw:
	.quad	0x0000000080000000,.Lioint
.Lwaitpsw:
	.long	0x020a0000,0x80000000+.Lioint

#
# subroutine for loading cards from the reader
#
.Lloader:
	la	%r4,0(%r14)
	la	%r3,.Lorb		# r2 = address of orb into r2
	la	%r5,.Lirb		# r4 = address of irb
	la	%r6,.Lccws
	la	%r7,20
.Linit:
	st	%r2,4(%r6)		# initialize CCW data addresses
	la	%r2,0x50(%r2)
	la	%r6,8(%r6)
	bct	7,.Linit

	lctl	%c6,%c6,.Lcr6		# set IO subclass mask
	slr	%r2,%r2
.Lldlp:
	ssch	0(%r3)			# load chunk of 1600 bytes
	bnz	.Llderr
.Lwait4irq:
	bas	%r14,.Lirqwait
	c	%r1,0xb8		# compare subchannel number
	bne	.Lwait4irq
	tsch	0(%r5)

	slr	%r0,%r0
	ic	%r0,8(%r5)		# get device status
	chi	%r0,8			# channel end ?
	be	.Lcont
	chi	%r0,12			# channel end + device end ?
	be	.Lcont

	l	%r0,4(%r5)
	s	%r0,8(%r3)		# r0/8 = number of ccws executed
	mhi	%r0,10			# *10 = number of bytes in ccws
	lh	%r3,10(%r5)		# get residual count
	sr	%r0,%r3 		# #ccws*80-residual=#bytes read
	ar	%r2,%r0

	br	%r4			# r2 contains the total size

.Lcont:
	ahi	%r2,0x640		# add 0x640 to total size
	la	%r6,.Lccws
	la	%r7,20
.Lincr:
	l	%r0,4(%r6)		# update CCW data addresses
	ahi	%r0,0x640
	st	%r0,4(%r6)
	ahi	%r6,8
	bct	7,.Lincr

	b	.Lldlp
.Llderr:
	lpsw	.Lcrash

	.align	8
.Lorb:	.long	0x00000000,0x0080ff00,.Lccws
.Lirb:	.long	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
.Lcr6:	.long	0xff000000
.Lloadp:.long	0,0
	.align	8
.Lcrash:.long	0x000a0000,0x00000000

	.align	8
.Lccws: .rept	19
	.long	0x02600050,0x00000000
	.endr
	.long	0x02200050,0x00000000

iplstart:
	mvi	__LC_AR_MODE_ID,1	# set esame flag
	slr	%r0,%r0			# set cpuid to zero
	lhi	%r1,2			# mode 2 = esame (dump)
	sigp	%r1,%r0,0x12		# switch to esame mode
	bras	%r13,0f
	.fill	16,4,0x0
0:	lmh	%r0,%r15,0(%r13)	# clear high-order half of gprs
	sam31				# switch to 31 bit addressing mode
	lh	%r1,0xb8		# test if subchannel number
	bct	%r1,.Lnoload		#  is valid
	l	%r1,0xb8		# load ipl subchannel number
	la	%r2,IPL_BS		# load start address
	bas	%r14,.Lloader		# load rest of ipl image
	l	%r12,.Lparm		# pointer to parameter area
	st	%r1,IPL_DEVICE+ARCH_OFFSET-PARMAREA(%r12) # save ipl device number

#
# load parameter file from ipl device
#
.Lagain1:
	l	%r2,.Linitrd		# ramdisk loc. is temp
	bas	%r14,.Lloader		# load parameter file
	ltr	%r2,%r2 		# got anything ?
	bz	.Lnopf
	chi	%r2,895
	bnh	.Lnotrunc
	la	%r2,895
.Lnotrunc:
	l	%r4,.Linitrd
	clc	0(3,%r4),.L_hdr		# if it is HDRx
	bz	.Lagain1		# skip dataset header
	clc	0(3,%r4),.L_eof		# if it is EOFx
	bz	.Lagain1		# skip dateset trailer
	la	%r5,0(%r4,%r2)
	lr	%r3,%r2
	la	%r3,COMMAND_LINE-PARMAREA(%r12) # load adr. of command line
	mvc	0(256,%r3),0(%r4)
	mvc	256(256,%r3),256(%r4)
	mvc	512(256,%r3),512(%r4)
	mvc	768(122,%r3),768(%r4)
	slr	%r0,%r0
	b	.Lcntlp
.Ldelspc:
	ic	%r0,0(%r2,%r3)
	chi	%r0,0x20		# is it a space ?
	be	.Lcntlp
	ahi	%r2,1
	b	.Leolp
.Lcntlp:
	brct	%r2,.Ldelspc
.Leolp:
	slr	%r0,%r0
	stc	%r0,0(%r2,%r3)		# terminate buffer
.Lnopf:

#
# load ramdisk from ipl device
#
.Lagain2:
	l	%r2,.Linitrd		# addr of ramdisk
	st	%r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12)
	bas	%r14,.Lloader		# load ramdisk
	st	%r2,INITRD_SIZE+ARCH_OFFSET-PARMAREA(%r12) # store size of rd
	ltr	%r2,%r2
	bnz	.Lrdcont
	st	%r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # no ramdisk found
.Lrdcont:
	l	%r2,.Linitrd

	clc	0(3,%r2),.L_hdr		# skip HDRx and EOFx
	bz	.Lagain2
	clc	0(3,%r2),.L_eof
	bz	.Lagain2

#
# reset files in VM reader
#
	stidp	.Lcpuid			# store cpuid
	tm	.Lcpuid,0xff		# running VM ?
	bno	.Lnoreset
	la	%r2,.Lreset
	lhi	%r3,26
	diag	%r2,%r3,8
	la	%r5,.Lirb
	stsch	0(%r5)			# check if irq is pending
	tm	30(%r5),0x0f		# by verifying if any of the
	bnz	.Lwaitforirq		# activity or status control
	tm	31(%r5),0xff		# bits is set in the schib
	bz	.Lnoreset
.Lwaitforirq:
	bas	%r14,.Lirqwait		# wait for IO interrupt
	c	%r1,0xb8		# compare subchannel number
	bne	.Lwaitforirq
	la	%r5,.Lirb
	tsch	0(%r5)
.Lnoreset:
	b	.Lnoload

#
# everything loaded, go for it
#
.Lnoload:
	l	%r1,.Lstartup
	br	%r1

.Linitrd:.long _end			# default address of initrd
.Lparm:	.long  PARMAREA
.Lstartup: .long startup
.Lreset:.byte	0xc3,0xc8,0xc1,0xd5,0xc7,0xc5,0x40,0xd9,0xc4,0xd9,0x40
	.byte	0xc1,0xd3,0xd3,0x40,0xd2,0xc5,0xc5,0xd7,0x40,0xd5,0xd6
	.byte	0xc8,0xd6,0xd3,0xc4	# "change rdr all keep nohold"
.L_eof: .long	0xc5d6c600	 /* C'EOF' */
.L_hdr: .long	0xc8c4d900	 /* C'HDR' */
	.align	8
.Lcpuid:.fill	8,1,0

#
# startup-code at 0x10000, running in absolute addressing mode
# this is called either by the ipl loader or directly by PSW restart
# or linload or SALIPL
#
	.org	0x10000
ENTRY(startup)
	j	.Lep_startup_normal
	.org	0x10008
#
# This is a list of s390 kernel entry points. At address 0x1000f the number of
# valid entry points is stored.
#
# IMPORTANT: Do not change this table, it is s390 kernel ABI!
#
	.ascii	"S390EP"
	.byte	0x00,0x01
#
# kdump startup-code at 0x10010, running in 64 bit absolute addressing mode
#
	.org	0x10010
ENTRY(startup_kdump)
	j	.Lep_startup_kdump
.Lep_startup_normal:
	mvi	__LC_AR_MODE_ID,1	# set esame flag
	slr	%r0,%r0 		# set cpuid to zero
	lhi	%r1,2			# mode 2 = esame (dump)
	sigp	%r1,%r0,0x12		# switch to esame mode
	bras	%r13,0f
	.fill	16,4,0x0
0:	lmh	%r0,%r15,0(%r13)	# clear high-order half of gprs
	sam64				# switch to 64 bit addressing mode
	basr	%r13,0			# get base
.LPG0:
	xc	0x200(256),0x200	# partially clear lowcore
	xc	0x300(256),0x300
	xc	0xe00(256),0xe00
	xc	0xf00(256),0xf00
	lctlg	%c0,%c15,0x200(%r0)	# initialize control registers
	stck	__LC_LAST_UPDATE_CLOCK
	spt	6f-.LPG0(%r13)
	mvc	__LC_LAST_UPDATE_TIMER(8),6f-.LPG0(%r13)
	stfl	0(%r0)			# store facilities @ __LC_STFL_FAC_LIST
	mvc	__LC_STFLE_FAC_LIST(4),__LC_STFL_FAC_LIST
	tm	__LC_STFLE_FAC_LIST,0x01	# stfle available ?
	jz	0f
	lghi	%r0,FACILITIES_ALS_DWORDS-1
	.insn	s,0xb2b00000,__LC_STFLE_FAC_LIST # store facility list extended
	# verify if all required facilities are supported by the machine
0:	la	%r1,__LC_STFLE_FAC_LIST
	la	%r2,3f+8-.LPG0(%r13)
	lhi	%r3,FACILITIES_ALS_DWORDS
1:	lg	%r0,0(%r1)
	ng	%r0,0(%r2)
	clg	%r0,0(%r2)
	jne	2f
	la	%r1,8(%r1)
	la	%r2,8(%r2)
	ahi	%r3,-1
	jnz	1b
	j	4f
2:	l	%r15,.Lstack-.LPG0(%r13)
	ahi	%r15,-STACK_FRAME_OVERHEAD
	la	%r2,.Lals_string-.LPG0(%r13)
	l	%r3,.Lsclp_print-.LPG0(%r13)
	basr	%r14,%r3
	lpsw	3f-.LPG0(%r13)		# machine type not good enough, crash
.Lals_string:
	.asciz	"The Linux kernel requires more recent processor hardware"
.Lsclp_print:
	.long	_sclp_print_early
.Lstack:
	.long	0x8000 + (1<<(PAGE_SHIFT+THREAD_ORDER))
	.align 16
3:	.long	0x000a0000,0x8badcccc

# List of facilities that are required. If not all facilities are present
# the kernel will crash.

	.quad FACILITIES_ALS

4:
	/* Continue with startup code in head64.S */
	jg	startup_continue

	.align	8
6:	.long	0x7fffffff,0xffffffff

#include "head_kdump.S"

#
# params at 10400 (setup.h)
#
	.org	PARMAREA
	.long	0,0			# IPL_DEVICE
	.long	0,0			# INITRD_START
	.long	0,0			# INITRD_SIZE
	.long	0,0			# OLDMEM_BASE
	.long	0,0			# OLDMEM_SIZE

	.org	COMMAND_LINE
	.byte	"root=/dev/ram0 ro"
	.byte	0

	.org	0x11000