[PATCH] s390: kexec fixes and improvements.
[linux-2.6.git] / arch / s390 / kernel / relocate_kernel.S
1 /*
2  * arch/s390/kernel/relocate_kernel.S
3  *
4  * (C) Copyright IBM Corp. 2005
5  *
6  * Author(s): Rolf Adelsberger <adelsberger@de.ibm.com>
7  *            Heiko Carstens <heiko.carstens@de.ibm.com>
8  *
9  */
10
11 /*
12  * moves the new kernel to its destination...
13  * %r2 = pointer to first kimage_entry_t
14  * %r3 = start address - where to jump to after the job is done...
15  *
16  * %r5 will be used as temp. storage
17  * %r6 holds the destination address
18  * %r7 = PAGE_SIZE
19  * %r8 holds the source address
20  * %r9 = PAGE_SIZE
21  * %r10 is a page mask
22  */
23
24         .text
25         .globl          relocate_kernel
26         relocate_kernel:
27                 basr    %r13,0          #base address
28         .base:
29                 stnsm   sys_msk-.base(%r13),0xf8        #disable DAT and IRQ (external)
30                 spx     zero64-.base(%r13)      #absolute addressing mode
31                 stctl   %c0,%c15,ctlregs-.base(%r13)
32                 stm     %r0,%r15,gprregs-.base(%r13)
33                 la      %r1,load_psw-.base(%r13)
34                 mvc     0(8,%r0),0(%r1)
35                 la      %r0,.back-.base(%r13)
36                 st      %r0,4(%r0)
37                 oi      4(%r0),0x80
38                 mvc     0x68(8,%r0),0(%r1)
39                 la      %r0,.back_pgm-.base(%r13)
40                 st      %r0,0x6c(%r0)
41                 oi      0x6c(%r0),0x80
42                 lhi     %r0,0
43                 diag    %r0,%r0,0x308
44         .back:
45                 basr    %r13,0
46         .back_base:
47                 oi      have_diag308-.back_base(%r13),0x01
48                 lctl    %c0,%c15,ctlregs-.back_base(%r13)
49                 lm      %r0,%r15,gprregs-.back_base(%r13)
50                 j       .start_reloc
51         .back_pgm:
52                 lm      %r0,%r15,gprregs-.base(%r13)
53         .start_reloc:
54                 lhi     %r10,-1         #preparing the mask
55                 sll     %r10,12         #shift it such that it becomes 0xf000
56         .top:
57                 lhi     %r7,4096        #load PAGE_SIZE in r7
58                 lhi     %r9,4096        #load PAGE_SIZE in r9
59                 l       %r5,0(%r2)      #read another word for indirection page
60                 ahi     %r2,4           #increment pointer
61                 tml     %r5,0x1         #is it a destination page?
62                 je      .indir_check    #NO, goto "indir_check"
63                 lr      %r6,%r5         #r6 = r5
64                 nr      %r6,%r10        #mask it out and...
65                 j       .top            #...next iteration
66         .indir_check:
67                 tml     %r5,0x2         #is it a indirection page?
68                 je      .done_test      #NO, goto "done_test"
69                 nr      %r5,%r10        #YES, mask out,
70                 lr      %r2,%r5         #move it into the right register,
71                 j       .top            #and read next...
72         .done_test:
73                 tml     %r5,0x4         #is it the done indicator?
74                 je      .source_test    #NO! Well, then it should be the source indicator...
75                 j       .done           #ok, lets finish it here...
76         .source_test:
77                 tml     %r5,0x8         #it should be a source indicator...
78                 je      .top            #NO, ignore it...
79                 lr      %r8,%r5         #r8 = r5
80                 nr      %r8,%r10        #masking
81         0:      mvcle   %r6,%r8,0x0     #copy PAGE_SIZE bytes from r8 to r6 - pad with 0
82                 jo      0b
83                 j       .top
84         .done:
85                 sr      %r0,%r0         #clear register r0
86                 la      %r4,load_psw-.base(%r13)        #load psw-address into the register
87                 o       %r3,4(%r4)      #or load address into psw
88                 st      %r3,4(%r4)
89                 mvc     0(8,%r0),0(%r4) #copy psw to absolute address 0
90                 tm      have_diag308-.base(%r13),0x01
91                 jno     .no_diag308
92                 diag    %r0,%r0,0x308
93         .no_diag308:
94                 sr      %r1,%r1         #clear %r1
95                 sr      %r2,%r2         #clear %r2
96                 sigp    %r1,%r2,0x12    #set cpuid to zero
97                 lpsw    0               #hopefully start new kernel...
98
99                 .align  8
100         zero64:
101                 .quad   0
102         load_psw:
103                 .long   0x00080000,0x80000000
104         sys_msk:
105                 .quad   0
106         ctlregs:
107                 .rept   16
108                 .long   0
109                 .endr
110         gprregs:
111                 .rept   16
112                 .long   0
113                 .endr
114         have_diag308:
115                 .byte   0
116                 .align  8
117         relocate_kernel_end:
118         .globl  relocate_kernel_len
119         relocate_kernel_len:
120                 .quad   relocate_kernel_end - relocate_kernel