xref: /kvm-unit-tests/s390x/cstart64.S (revision 74e79380f900368bf7f8c9aaac5ac1aba962d63e)
1/*
2 * s390x startup code
3 *
4 * Copyright (c) 2017 Red Hat Inc
5 *
6 * Authors:
7 *  Thomas Huth <thuth@redhat.com>
8 *  David Hildenbrand <david@redhat.com>
9 *
10 * This code is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU Library General Public License version 2.
12 */
13#include <asm/asm-offsets.h>
14#include <asm/sigp.h>
15
16.section .init
17
18/*
19 * Short init between 0x10000 and 0x10480 and then jump to 0x11000.
20 * 0x10480 - 0x11000 are written to by bootloader.
21 *
22 * For KVM and TCG kernel boot we are in 64 bit z/Arch mode.
23 * When booting from disk the initial short psw is in 31 bit mode.
24 * When running under LPAR or z/VM, we might start in 31 bit and esam mode.
25 */
26	.globl start
27start:
28	/* Switch to z/Architecture mode and 64-bit */
29	slr     %r0, %r0		# Set cpuid to zero
30	lhi     %r1, 2			# mode 2 = esame
31	sigp    %r1, %r0, SIGP_SET_ARCHITECTURE
32	/* XOR all registers with themselves to clear them fully. */
33	.irp i, 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
34	xgr \i,\i
35	.endr
36	sam64				# Set addressing mode to 64 bit
37	/* setup stack */
38	larl	%r15, stackptr
39	/* setup initial PSW mask + control registers*/
40	larl	%r1, initial_psw
41	lpswe	0(%r1)
42clear_bss_start:
43	larl 	%r2, __bss_start
44	larl 	%r3, __bss_end
45	slgr 	%r3, %r2		# Get sizeof bss
46	aghi 	%r3,-1
47	srlg 	%r4,%r3,8		# Calc number of 256 byte chunks
48	ltgr 	%r4,%r4
49	lgr 	%r1,%r2
50	jz	clear_bss_remainder		# If none, clear remaining bytes
51clear_bss_loop:
52	xc	0(256,%r1), 0(%r1)	# Clear 256 byte chunks via xor
53	la	%r1, 256(%r1)
54	brctg 	%r4, clear_bss_loop
55clear_bss_remainder:
56	larl	%r2, memsetxc
57	ex 	%r3, 0(%r2)
58	/* setup pgm interrupt handler */
59	larl	%r1, pgm_int_psw
60	mvc	GEN_LC_PGM_NEW_PSW(16), 0(%r1)
61	/* setup ext interrupt handler */
62	larl	%r1, ext_int_psw
63	mvc	GEN_LC_EXT_NEW_PSW(16), 0(%r1)
64	/* setup mcck interrupt handler */
65	larl	%r1, mcck_int_psw
66	mvc	GEN_LC_MCCK_NEW_PSW(16), 0(%r1)
67	/* setup io interrupt handler */
68	larl	%r1, io_int_psw
69	mvc	GEN_LC_IO_NEW_PSW(16), 0(%r1)
70	/* setup svc interrupt handler */
71	larl	%r1, svc_int_psw
72	mvc	GEN_LC_SVC_NEW_PSW(16), 0(%r1)
73	/* setup cr0, enabling e.g. AFP-register control */
74	larl	%r1, initial_cr0
75	lctlg	%c0, %c0, 0(%r1)
76	/* call setup() */
77	brasl	%r14, setup
78	/* forward test parameter */
79	larl	%r2, __argc
80	llgf	%r2, 0(%r2)
81	larl	%r3, __argv
82	/* call to main() */
83	brasl	%r14, main
84	/* forward exit code */
85	lgr	%r3, %r2
86	/* call exit() */
87	j exit
88
89memsetxc:
90	xc 0(1,%r1),0(%r1)
91
92	.macro SAVE_REGS
93	/* save grs 0-15 */
94	stmg	%r0, %r15, GEN_LC_SW_INT_GRS
95	/* save crs 0-15 */
96	stctg	%c0, %c15, GEN_LC_SW_INT_CRS
97	/* load a cr0 that has the AFP control bit which enables all FPRs */
98	larl	%r1, initial_cr0
99	lctlg	%c0, %c0, 0(%r1)
100	/* save fprs 0-15 + fpc */
101	la	%r1, GEN_LC_SW_INT_FPRS
102	.irp i, 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
103	std	\i, \i * 8(%r1)
104	.endr
105	stfpc	GEN_LC_SW_INT_FPC
106	.endm
107
108	.macro RESTORE_REGS
109	/* restore fprs 0-15 + fpc */
110	la	%r1, GEN_LC_SW_INT_FPRS
111	.irp i, 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
112	ld	\i, \i * 8(%r1)
113	.endr
114	lfpc	GEN_LC_SW_INT_FPC
115	/* restore crs 0-15 */
116	lctlg	%c0, %c15, GEN_LC_SW_INT_CRS
117	/* restore grs 0-15 */
118	lmg	%r0, %r15, GEN_LC_SW_INT_GRS
119	.endm
120
121.section .text
122/*
123 * load_reset calling convention:
124 * %r2 subcode (0 or 1)
125 */
126.globl diag308_load_reset
127diag308_load_reset:
128	SAVE_REGS
129	/* Backup current PSW mask, as we have to restore it on success */
130	epsw	%r0, %r1
131	st	%r0, GEN_LC_SW_INT_PSW
132	st	%r1, GEN_LC_SW_INT_PSW + 4
133	/* Load reset psw mask (short psw, 64 bit) */
134	lg	%r0, reset_psw
135	/* Load the success label address */
136	larl    %r1, 0f
137	/* Or it to the mask */
138	ogr	%r0, %r1
139	/* Store it at the reset PSW location (real 0x0) */
140	stg	%r0, 0
141	/* Do the reset */
142	diag    %r0,%r2,0x308
143	/* Failure path */
144	xgr	%r2, %r2
145	br	%r14
146	/* Success path */
147	/* load a cr0 that has the AFP control bit which enables all FPRs */
1480:	larl	%r1, initial_cr0
149	lctlg	%c0, %c0, 0(%r1)
150	RESTORE_REGS
151	lhi	%r2, 1
152	larl	%r0, 1f
153	stg	%r0, GEN_LC_SW_INT_PSW + 8
154	lpswe	GEN_LC_SW_INT_PSW
1551:	br	%r14
156
157.globl smp_cpu_setup_state
158smp_cpu_setup_state:
159	xgr	%r1, %r1
160	lmg     %r0, %r15, GEN_LC_SW_INT_GRS
161	lctlg   %c0, %c0, GEN_LC_SW_INT_CRS
162	/* We should only go once through cpu setup and not for every restart */
163	stg	%r14, GEN_LC_RESTART_NEW_PSW + 8
164	larl	%r14, 0f
165	lpswe	GEN_LC_SW_INT_PSW
166	/* If the function returns, just loop here */
1670:	j	0
168
169pgm_int:
170	SAVE_REGS
171	brasl	%r14, handle_pgm_int
172	RESTORE_REGS
173	lpswe	GEN_LC_PGM_OLD_PSW
174
175ext_int:
176	SAVE_REGS
177	brasl	%r14, handle_ext_int
178	RESTORE_REGS
179	lpswe	GEN_LC_EXT_OLD_PSW
180
181mcck_int:
182	SAVE_REGS
183	brasl	%r14, handle_mcck_int
184	RESTORE_REGS
185	lpswe	GEN_LC_MCCK_OLD_PSW
186
187io_int:
188	SAVE_REGS
189	brasl	%r14, handle_io_int
190	RESTORE_REGS
191	lpswe	GEN_LC_IO_OLD_PSW
192
193svc_int:
194	SAVE_REGS
195	brasl	%r14, handle_svc_int
196	RESTORE_REGS
197	lpswe	GEN_LC_SVC_OLD_PSW
198
199	.align	8
200reset_psw:
201	.quad	0x0008000180000000
202initial_psw:
203	.quad	0x0000000180000000, clear_bss_start
204pgm_int_psw:
205	.quad	0x0000000180000000, pgm_int
206ext_int_psw:
207	.quad	0x0000000180000000, ext_int
208mcck_int_psw:
209	.quad	0x0000000180000000, mcck_int
210io_int_psw:
211	.quad	0x0000000180000000, io_int
212svc_int_psw:
213	.quad	0x0000000180000000, svc_int
214initial_cr0:
215	/* enable AFP-register control, so FP regs (+BFP instr) can be used */
216	.quad	0x0000000000040000
217