s390: fix kernel crash due to linkage stack instructions
[pandora-kernel.git] / arch / s390 / kernel / head64.S
1 /*
2  * arch/s390/kernel/head64.S
3  *
4  * Copyright (C) IBM Corp. 1999,2010
5  *
6  *   Author(s): Hartmut Penner <hp@de.ibm.com>
7  *              Martin Schwidefsky <schwidefsky@de.ibm.com>
8  *              Rob van der Heij <rvdhei@iae.nl>
9  *              Heiko Carstens <heiko.carstens@de.ibm.com>
10  *
11  */
12
13 #include <linux/init.h>
14 #include <linux/linkage.h>
15 #include <asm/asm-offsets.h>
16 #include <asm/thread_info.h>
17 #include <asm/page.h>
18
19 __HEAD
20 ENTRY(startup_continue)
21         larl    %r1,sched_clock_base_cc
22         mvc     0(8,%r1),__LC_LAST_UPDATE_CLOCK
23         larl    %r13,.LPG1              # get base
24         lctlg   %c0,%c15,.Lctl-.LPG1(%r13)      # load control registers
25         lg      %r12,.Lparmaddr-.LPG1(%r13)     # pointer to parameter area
26                                         # move IPL device to lowcore
27         lghi    %r0,__LC_PASTE
28         stg     %r0,__LC_VDSO_PER_CPU
29 #
30 # Setup stack
31 #
32         larl    %r15,init_thread_union
33         stg     %r15,__LC_THREAD_INFO   # cache thread info in lowcore
34         lg      %r14,__TI_task(%r15)    # cache current in lowcore
35         stg     %r14,__LC_CURRENT
36         aghi    %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
37         stg     %r15,__LC_KERNEL_STACK  # set end of kernel stack
38         aghi    %r15,-160
39 #
40 # Save ipl parameters, clear bss memory, initialize storage key for kernel pages,
41 # and create a kernel NSS if the SAVESYS= parm is defined
42 #
43         brasl   %r14,startup_init
44         lpswe   .Lentry-.LPG1(13)       # jump to _stext in primary-space,
45                                         # virtual and never return ...
46         .align  16
47 .LPG1:
48 .Lentry:.quad   0x0000000180000000,_stext
49 .Lctl:  .quad   0x04040000              # cr0: AFP registers & secondary space
50         .quad   0                       # cr1: primary space segment table
51         .quad   .Lduct                  # cr2: dispatchable unit control table
52         .quad   0                       # cr3: instruction authorization
53         .quad   0                       # cr4: instruction authorization
54         .quad   .Lduct                  # cr5: primary-aste origin
55         .quad   0                       # cr6:  I/O interrupts
56         .quad   0                       # cr7:  secondary space segment table
57         .quad   0                       # cr8:  access registers translation
58         .quad   0                       # cr9:  tracing off
59         .quad   0                       # cr10: tracing off
60         .quad   0                       # cr11: tracing off
61         .quad   0                       # cr12: tracing off
62         .quad   0                       # cr13: home space segment table
63         .quad   0xc0000000              # cr14: machine check handling off
64         .quad   .Llinkage_stack         # cr15: linkage stack operations
65 .Lpcmsk:.quad   0x0000000180000000
66 .L4malign:.quad 0xffffffffffc00000
67 .Lscan2g:.quad  0x80000000 + 0x20000 - 8        # 2GB + 128K - 8
68 .Lnop:  .long   0x07000700
69 .Lparmaddr:
70         .quad   PARMAREA
71         .align  64
72 .Lduct: .long   0,.Laste,.Laste,0,.Lduald,0,0,0
73         .long   0,0,0,0,0,0,0,0
74 .Laste: .quad   0,0xffffffffffffffff,0,0,0,0,0,0
75         .align  128
76 .Lduald:.rept   8
77         .long   0x80000000,0,0,0        # invalid access-list entries
78         .endr
79 .Llinkage_stack:
80         .long   0,0,0x89000000,0,0,0,0x8a000000,0
81
82 ENTRY(_ehead)
83
84 #ifdef CONFIG_SHARED_KERNEL
85         .org    0x100000 - 0x11000      # head.o ends at 0x11000
86 #endif
87
88 #
89 # startup-code, running in absolute addressing mode
90 #
91 ENTRY(_stext)
92         basr    %r13,0                  # get base
93 .LPG3:
94 # check control registers
95         stctg   %c0,%c15,0(%r15)
96         oi      6(%r15),0x60            # enable sigp emergency & external call
97         oi      4(%r15),0x10            # switch on low address proctection
98         lctlg   %c0,%c15,0(%r15)
99
100         lam     0,15,.Laregs-.LPG3(%r13)        # load acrs needed by uaccess
101         brasl   %r14,start_kernel       # go to C code
102 #
103 # We returned from start_kernel ?!? PANIK
104 #
105         basr    %r13,0
106         lpswe   .Ldw-.(%r13)            # load disabled wait psw
107
108         .align  8
109 .Ldw:   .quad   0x0002000180000000,0x0000000000000000
110 .Laregs:.long   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0