xref: /kvm-unit-tests/s390x/cstart64.S (revision e36a9c28fc8f8f59e0e30db244af0b17c6d04be9)
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 cr0 */
96	stctg	%c0, %c0, GEN_LC_SW_INT_CR0
97	/* load initial cr0 again */
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	std	%f0, 0(%r1)
103	std	%f1, 8(%r1)
104	std	%f2, 16(%r1)
105	std	%f3, 24(%r1)
106	std	%f4, 32(%r1)
107	std	%f5, 40(%r1)
108	std	%f6, 48(%r1)
109	std	%f7, 56(%r1)
110	std	%f8, 64(%r1)
111	std	%f9, 72(%r1)
112	std	%f10, 80(%r1)
113	std	%f11, 88(%r1)
114	std	%f12, 96(%r1)
115	std	%f13, 104(%r1)
116	std	%f14, 112(%r1)
117	std	%f15, 120(%r1)
118	stfpc	GEN_LC_SW_INT_FPC
119	.endm
120
121	.macro RESTORE_REGS
122	/* restore fprs 0-15 + fpc */
123	la	%r1, GEN_LC_SW_INT_FPRS
124	ld	%f0, 0(%r1)
125	ld	%f1, 8(%r1)
126	ld	%f2, 16(%r1)
127	ld	%f3, 24(%r1)
128	ld	%f4, 32(%r1)
129	ld	%f5, 40(%r1)
130	ld	%f6, 48(%r1)
131	ld	%f7, 56(%r1)
132	ld	%f8, 64(%r1)
133	ld	%f9, 72(%r1)
134	ld	%f10, 80(%r1)
135	ld	%f11, 88(%r1)
136	ld	%f12, 96(%r1)
137	ld	%f13, 104(%r1)
138	ld	%f14, 112(%r1)
139	ld	%f15, 120(%r1)
140	lfpc	GEN_LC_SW_INT_FPC
141	/* restore cr0 */
142	lctlg	%c0, %c0, GEN_LC_SW_INT_CR0
143	/* restore grs 0-15 */
144	lmg	%r0, %r15, GEN_LC_SW_INT_GRS
145	.endm
146
147.section .text
148/*
149 * load_reset calling convention:
150 * %r2 subcode (0 or 1)
151 */
152.globl diag308_load_reset
153diag308_load_reset:
154	SAVE_REGS
155	/* Save the first PSW word to the IPL PSW */
156	epsw	%r0, %r1
157	st	%r0, 0
158	/* Store the address and the bit for 31 bit addressing */
159	larl    %r0, 0f
160	oilh    %r0, 0x8000
161	st      %r0, 0x4
162	/* Do the reset */
163	diag    %r0,%r2,0x308
164	/* Failure path */
165	xgr	%r2, %r2
166	br	%r14
167	/* Success path */
168	/* We lost cr0 due to the reset */
1690:	larl	%r1, initial_cr0
170	lctlg	%c0, %c0, 0(%r1)
171	RESTORE_REGS
172	lhi	%r2, 1
173	br	%r14
174
175.globl smp_cpu_setup_state
176smp_cpu_setup_state:
177	xgr	%r1, %r1
178	lmg     %r0, %r15, GEN_LC_SW_INT_GRS
179	lctlg   %c0, %c0, GEN_LC_SW_INT_CR0
180	br	%r14
181
182pgm_int:
183	SAVE_REGS
184	brasl	%r14, handle_pgm_int
185	RESTORE_REGS
186	lpswe	GEN_LC_PGM_OLD_PSW
187
188ext_int:
189	SAVE_REGS
190	brasl	%r14, handle_ext_int
191	RESTORE_REGS
192	lpswe	GEN_LC_EXT_OLD_PSW
193
194mcck_int:
195	SAVE_REGS
196	brasl	%r14, handle_mcck_int
197	RESTORE_REGS
198	lpswe	GEN_LC_MCCK_OLD_PSW
199
200io_int:
201	SAVE_REGS
202	brasl	%r14, handle_io_int
203	RESTORE_REGS
204	lpswe	GEN_LC_IO_OLD_PSW
205
206svc_int:
207	SAVE_REGS
208	brasl	%r14, handle_svc_int
209	RESTORE_REGS
210	lpswe	GEN_LC_SVC_OLD_PSW
211
212	.align	8
213initial_psw:
214	.quad	0x0000000180000000, clear_bss_start
215pgm_int_psw:
216	.quad	0x0000000180000000, pgm_int
217ext_int_psw:
218	.quad	0x0000000180000000, ext_int
219mcck_int_psw:
220	.quad	0x0000000180000000, mcck_int
221io_int_psw:
222	.quad	0x0000000180000000, io_int
223svc_int_psw:
224	.quad	0x0000000180000000, svc_int
225initial_cr0:
226	/* enable AFP-register control, so FP regs (+BFP instr) can be used */
227	.quad	0x0000000000040000
228