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/errno.h>
 10#include <asm/sigp.h>
 11
 12#ifdef CC_USING_EXPOLINE
 13	.pushsection .dma.text.__s390_indirect_jump_r14,"axG"
 14__dma__s390_indirect_jump_r14:
 15	larl	%r1,0f
 16	ex	0,0(%r1)
 17	j	.
 180:	br	%r14
 19	.popsection
 20#endif
 21
 22	.section .dma.text,"ax"
 23/*
 24 * Simplified version of expoline thunk. The normal thunks can not be used here,
 25 * because they might be more than 2 GB away, and not reachable by the relative
 26 * branch. No comdat, exrl, etc. optimizations used here, because it only
 27 * affects a few functions that are not performance-relevant.
 28 */
 29	.macro BR_EX_DMA_r14
 30#ifdef CC_USING_EXPOLINE
 31	jg	__dma__s390_indirect_jump_r14
 32#else
 33	br	%r14
 34#endif
 35	.endm
 36
 37/*
 38 * int _diag14_dma(unsigned long rx, unsigned long ry1, unsigned long subcode)
 39 */
 40ENTRY(_diag14_dma)
 41	lgr	%r1,%r2
 42	lgr	%r2,%r3
 43	lgr	%r3,%r4
 44	lhi	%r5,-EIO
 45	sam31
 46	diag	%r1,%r2,0x14
 47.Ldiag14_ex:
 48	ipm	%r5
 49	srl	%r5,28
 50.Ldiag14_fault:
 51	sam64
 52	lgfr	%r2,%r5
 53	BR_EX_DMA_r14
 54	EX_TABLE_DMA(.Ldiag14_ex, .Ldiag14_fault)
 55ENDPROC(_diag14_dma)
 56
 57/*
 58 * int _diag210_dma(struct diag210 *addr)
 59 */
 60ENTRY(_diag210_dma)
 61	lgr	%r1,%r2
 62	lhi	%r2,-1
 63	sam31
 64	diag	%r1,%r0,0x210
 65.Ldiag210_ex:
 66	ipm	%r2
 67	srl	%r2,28
 68.Ldiag210_fault:
 69	sam64
 70	lgfr	%r2,%r2
 71	BR_EX_DMA_r14
 72	EX_TABLE_DMA(.Ldiag210_ex, .Ldiag210_fault)
 73ENDPROC(_diag210_dma)
 74
 75/*
 76 * int _diag26c_dma(void *req, void *resp, enum diag26c_sc subcode)
 77 */
 78ENTRY(_diag26c_dma)
 79	lghi	%r5,-EOPNOTSUPP
 80	sam31
 81	diag	%r2,%r4,0x26c
 82.Ldiag26c_ex:
 83	sam64
 84	lgfr	%r2,%r5
 85	BR_EX_DMA_r14
 86	EX_TABLE_DMA(.Ldiag26c_ex, .Ldiag26c_ex)
 87ENDPROC(_diag26c_dma)
 88
 89/*
 90 * void _diag0c_dma(struct hypfs_diag0c_entry *entry)
 91 */
 92ENTRY(_diag0c_dma)
 93	sam31
 94	diag	%r2,%r2,0x0c
 95	sam64
 96	BR_EX_DMA_r14
 97ENDPROC(_diag0c_dma)
 98
 99/*
100 * void _swsusp_reset_dma(void)
101 */
102ENTRY(_swsusp_reset_dma)
103	larl	%r1,restart_entry
104	larl	%r2,.Lrestart_diag308_psw
105	og	%r1,0(%r2)
106	stg	%r1,0(%r0)
107	lghi	%r0,0
108	diag	%r0,%r0,0x308
109restart_entry:
110	lhi	%r1,1
111	sigp	%r1,%r0,SIGP_SET_ARCHITECTURE
112	sam64
113	BR_EX_DMA_r14
114ENDPROC(_swsusp_reset_dma)
115
116/*
117 * void _diag308_reset_dma(void)
118 *
119 * Calls diag 308 subcode 1 and continues execution
120 */
121ENTRY(_diag308_reset_dma)
122	larl	%r4,.Lctlregs		# Save control registers
123	stctg	%c0,%c15,0(%r4)
124	lg	%r2,0(%r4)		# Disable lowcore protection
125	nilh	%r2,0xefff
126	larl	%r4,.Lctlreg0
127	stg	%r2,0(%r4)
128	lctlg	%c0,%c0,0(%r4)
129	larl	%r4,.Lfpctl		# Floating point control register
130	stfpc	0(%r4)
131	larl	%r4,.Lprefix		# Save prefix register
132	stpx	0(%r4)
133	larl	%r4,.Lprefix_zero	# Set prefix register to 0
134	spx	0(%r4)
135	larl	%r4,.Lcontinue_psw	# Save PSW flags
136	epsw	%r2,%r3
137	stm	%r2,%r3,0(%r4)
138	larl	%r4,restart_part2	# Setup restart PSW at absolute 0
139	larl	%r3,.Lrestart_diag308_psw
140	og	%r4,0(%r3)		# Save PSW
141	lghi	%r3,0
142	sturg	%r4,%r3			# Use sturg, because of large pages
143	lghi	%r1,1
144	lghi	%r0,0
145	diag	%r0,%r1,0x308
146restart_part2:
147	lhi	%r0,0			# Load r0 with zero
148	lhi	%r1,2			# Use mode 2 = ESAME (dump)
149	sigp	%r1,%r0,SIGP_SET_ARCHITECTURE	# Switch to ESAME mode
150	sam64				# Switch to 64 bit addressing mode
151	larl	%r4,.Lctlregs		# Restore control registers
152	lctlg	%c0,%c15,0(%r4)
153	larl	%r4,.Lfpctl		# Restore floating point ctl register
154	lfpc	0(%r4)
155	larl	%r4,.Lprefix		# Restore prefix register
156	spx	0(%r4)
157	larl	%r4,.Lcontinue_psw	# Restore PSW flags
158	lpswe	0(%r4)
159.Lcontinue:
160	BR_EX_DMA_r14
161ENDPROC(_diag308_reset_dma)
162
163	.section .dma.data,"aw",@progbits
164.align	8
165.Lrestart_diag308_psw:
166	.long	0x00080000,0x80000000
167
168.align 8
169.Lcontinue_psw:
170	.quad	0,.Lcontinue
171
172.align 8
173.Lctlreg0:
174	.quad	0
175.Lctlregs:
176	.rept	16
177	.quad	0
178	.endr
179.Lfpctl:
180	.long	0
181.Lprefix:
182	.long	0
183.Lprefix_zero:
184	.long	0