1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Code that needs to run below 2 GB.
4 *
5 * Copyright IBM Corp. 2019
6 */
7
8#include <linux/linkage.h>
9#include <asm/asm-extable.h>
10#include <asm/errno.h>
11#include <asm/sigp.h>
12
13 .section .amode31.text,"ax"
14/*
15 * Simplified version of expoline thunk. The normal thunks can not be used here,
16 * because they might be more than 2 GB away, and not reachable by the relative
17 * branch. No comdat, exrl, etc. optimizations used here, because it only
18 * affects a few functions that are not performance-relevant.
19 */
20 .macro BR_EX_AMODE31_r14
21 exrl 0,0f
22 j .
230: br %r14
24 .endm
25
26/*
27 * int _diag14_amode31(unsigned long rx, unsigned long ry1, unsigned long subcode)
28 */
29SYM_FUNC_START(_diag14_amode31)
30 lgr %r1,%r2
31 lgr %r2,%r3
32 lgr %r3,%r4
33 lhi %r5,-EIO
34 sam31
35 diag %r1,%r2,0x14
36.Ldiag14_ex:
37 ipm %r5
38 srl %r5,28
39.Ldiag14_fault:
40 sam64
41 lgfr %r2,%r5
42 BR_EX_AMODE31_r14
43 EX_TABLE_AMODE31(.Ldiag14_ex, .Ldiag14_fault)
44SYM_FUNC_END(_diag14_amode31)
45
46/*
47 * int _diag210_amode31(struct diag210 *addr)
48 */
49SYM_FUNC_START(_diag210_amode31)
50 lgr %r1,%r2
51 lhi %r2,-1
52 sam31
53 diag %r1,%r0,0x210
54.Ldiag210_ex:
55 ipm %r2
56 srl %r2,28
57.Ldiag210_fault:
58 sam64
59 lgfr %r2,%r2
60 BR_EX_AMODE31_r14
61 EX_TABLE_AMODE31(.Ldiag210_ex, .Ldiag210_fault)
62SYM_FUNC_END(_diag210_amode31)
63
64/*
65 * int diag8c(struct diag8c *addr, struct ccw_dev_id *devno, size_t len)
66*/
67SYM_FUNC_START(_diag8c_amode31)
68 llgf %r3,0(%r3)
69 sam31
70 diag %r2,%r4,0x8c
71.Ldiag8c_ex:
72 sam64
73 lgfr %r2,%r3
74 BR_EX_AMODE31_r14
75 EX_TABLE_AMODE31(.Ldiag8c_ex, .Ldiag8c_ex)
76SYM_FUNC_END(_diag8c_amode31)
77/*
78 * int _diag26c_amode31(void *req, void *resp, enum diag26c_sc subcode)
79 */
80SYM_FUNC_START(_diag26c_amode31)
81 lghi %r5,-EOPNOTSUPP
82 sam31
83 diag %r2,%r4,0x26c
84.Ldiag26c_ex:
85 sam64
86 lgfr %r2,%r5
87 BR_EX_AMODE31_r14
88 EX_TABLE_AMODE31(.Ldiag26c_ex, .Ldiag26c_ex)
89SYM_FUNC_END(_diag26c_amode31)
90
91/*
92 * void _diag0c_amode31(unsigned long rx)
93 */
94SYM_FUNC_START(_diag0c_amode31)
95 sam31
96 diag %r2,%r2,0x0c
97 sam64
98 BR_EX_AMODE31_r14
99SYM_FUNC_END(_diag0c_amode31)
100
101/*
102 * void _diag308_reset_amode31(void)
103 *
104 * Calls diag 308 subcode 1 and continues execution
105 */
106SYM_FUNC_START(_diag308_reset_amode31)
107 larl %r4,ctlregs # Save control registers
108 stctg %c0,%c15,0(%r4)
109 lg %r2,0(%r4) # Disable lowcore protection
110 nilh %r2,0xefff
111 larl %r4,ctlreg0
112 stg %r2,0(%r4)
113 lctlg %c0,%c0,0(%r4)
114 larl %r4,fpctl # Floating point control register
115 stfpc 0(%r4)
116 larl %r4,prefix # Save prefix register
117 stpx 0(%r4)
118 larl %r4,prefix_zero # Set prefix register to 0
119 spx 0(%r4)
120 larl %r4,continue_psw # Save PSW flags
121 epsw %r2,%r3
122 stm %r2,%r3,0(%r4)
123 larl %r4,.Lrestart_part2 # Setup restart PSW at absolute 0
124 larl %r3,restart_diag308_psw
125 og %r4,0(%r3) # Save PSW
126 lghi %r3,0
127 sturg %r4,%r3 # Use sturg, because of large pages
128 lghi %r1,1
129 lghi %r0,0
130 diag %r0,%r1,0x308
131.Lrestart_part2:
132 lhi %r0,0 # Load r0 with zero
133 lhi %r1,2 # Use mode 2 = ESAME (dump)
134 sigp %r1,%r0,SIGP_SET_ARCHITECTURE # Switch to ESAME mode
135 sam64 # Switch to 64 bit addressing mode
136 larl %r4,ctlregs # Restore control registers
137 lctlg %c0,%c15,0(%r4)
138 larl %r4,fpctl # Restore floating point ctl register
139 lfpc 0(%r4)
140 larl %r4,prefix # Restore prefix register
141 spx 0(%r4)
142 larl %r4,continue_psw # Restore PSW flags
143 larl %r2,.Lcontinue
144 stg %r2,8(%r4)
145 lpswe 0(%r4)
146.Lcontinue:
147 BR_EX_AMODE31_r14
148SYM_FUNC_END(_diag308_reset_amode31)
149
150 .section .amode31.data,"aw",@progbits
151 .balign 8
152SYM_DATA_LOCAL(restart_diag308_psw, .long 0x00080000,0x80000000)
153SYM_DATA_LOCAL(continue_psw, .quad 0,0)
154SYM_DATA_LOCAL(ctlreg0, .quad 0)
155SYM_DATA_LOCAL(ctlregs, .fill 16,8,0)
156SYM_DATA_LOCAL(fpctl, .long 0)
157SYM_DATA_LOCAL(prefix, .long 0)
158SYM_DATA_LOCAL(prefix_zero, .long 0)
159

source code of linux/arch/s390/kernel/text_amode31.S