summaryrefslogtreecommitdiff
path: root/arch/parisc/kernel/real2.S
blob: 7a92695d95a6bf814a72803da7d02403953eacd4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
/*
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2000 Hewlett Packard (Paul Bame bame@puffin.external.hp.com)
 *
 */

#include <asm/psw.h>
#include <asm/assembly.h>

#include <linux/linkage.h>

	.section	.bss
	.export real_stack
	.export real32_stack
	.export real64_stack
	.align	64
real_stack:
real32_stack:
real64_stack:
	.block	8192

#ifdef CONFIG_64BIT
#  define REG_SZ 8
#else
#  define REG_SZ 4
#endif

#define N_SAVED_REGS 9

save_cr_space:
	.block	REG_SZ * N_SAVED_REGS
save_cr_end:


/************************ 32-bit real-mode calls ***********************/
/* This can be called in both narrow and wide kernels */

	.text

	/* unsigned long real32_call_asm(unsigned int *sp,
	 *		unsigned int *arg0p,
	 *		unsigned int iodc_fn)
	 *	sp is value of stack pointer to adopt before calling PDC (virt)
	 *	arg0p points to where saved arg values may be found
	 *	iodc_fn is the IODC function to call
	 */

ENTRY(real32_call_asm)
	STREG	%rp, -RP_OFFSET(%sp)	/* save RP */
#ifdef CONFIG_64BIT
	callee_save
	ldo	2*REG_SZ(%sp), %sp	/* room for a couple more saves */
	STREG	%r27, -1*REG_SZ(%sp)
	STREG	%r29, -2*REG_SZ(%sp)
#endif
	STREG	%sp, -REG_SZ(%arg0)	/* save SP on real-mode stack */
	copy	%arg0, %sp		/* adopt the real-mode SP */

	/* save iodc_fn */
	copy	%arg2, %r31

	/* load up the arg registers from the saved arg area */
	/* 32-bit calling convention passes first 4 args in registers */
	ldw	0(%arg1), %arg0		/* note overwriting arg0 */
	ldw	-8(%arg1), %arg2
	ldw	-12(%arg1), %arg3
	ldw	-4(%arg1), %arg1	/* obviously must do this one last! */

	tophys_r1  %sp

	b,l	rfi_virt2real,%r2
	nop

	b,l	save_control_regs,%r2		/* modifies r1, r2, r28 */
	nop

#ifdef CONFIG_64BIT
	rsm	PSW_SM_W, %r0		/* go narrow */
#endif

	load32	PA(ric_ret), %r2
	bv	0(%r31)
	nop
ric_ret:
#ifdef CONFIG_64BIT
	ssm	PSW_SM_W, %r0		/* go wide */
#endif
	/* restore CRs before going virtual in case we page fault */
	b,l	restore_control_regs, %r2	/* modifies r1, r2, r26 */
	nop

	b,l	rfi_real2virt,%r2
	nop

	tovirt_r1 %sp
	LDREG	-REG_SZ(%sp), %sp	/* restore SP */
#ifdef CONFIG_64BIT
	LDREG	-1*REG_SZ(%sp), %r27
	LDREG	-2*REG_SZ(%sp), %r29
	ldo	-2*REG_SZ(%sp), %sp
	callee_rest
#endif
	LDREG	-RP_OFFSET(%sp), %rp	/* restore RP */
	bv	0(%rp)
	nop
ENDPROC(real32_call_asm)


#  define PUSH_CR(r, where) mfctl r, %r1 ! STREG,ma %r1, REG_SZ(where)
#  define POP_CR(r, where) LDREG,mb -REG_SZ(where), %r1 ! mtctl %r1, r

	.text
save_control_regs:
	load32	PA(save_cr_space), %r28
	PUSH_CR(%cr24, %r28)
	PUSH_CR(%cr25, %r28)
	PUSH_CR(%cr26, %r28)
	PUSH_CR(%cr27, %r28)
	PUSH_CR(%cr28, %r28)
	PUSH_CR(%cr29, %r28)
	PUSH_CR(%cr30, %r28)
	PUSH_CR(%cr31, %r28)
	PUSH_CR(%cr15, %r28)
	bv 0(%r2)
	nop

restore_control_regs:
	load32	PA(save_cr_end), %r26
	POP_CR(%cr15, %r26)
	POP_CR(%cr31, %r26)
	POP_CR(%cr30, %r26)
	POP_CR(%cr29, %r26)
	POP_CR(%cr28, %r26)
	POP_CR(%cr27, %r26)
	POP_CR(%cr26, %r26)
	POP_CR(%cr25, %r26)
	POP_CR(%cr24, %r26)
	bv 0(%r2)
	nop

/* rfi_virt2real() and rfi_real2virt() could perhaps be adapted for
 * more general-purpose use by the several places which need RFIs
 */
	.text
	.align 128
rfi_virt2real:
	/* switch to real mode... */
	rsm		PSW_SM_I,%r0
	load32		PA(rfi_v2r_1), %r1
	nop
	nop
	nop
	nop
	nop
	
	rsm             PSW_SM_Q,%r0  /* disable Q & I bits to load iia queue */
	mtctl		%r0, %cr17	/* Clear IIASQ tail */
	mtctl		%r0, %cr17	/* Clear IIASQ head */
	mtctl		%r1, %cr18	/* IIAOQ head */
	ldo		4(%r1), %r1
	mtctl		%r1, %cr18	/* IIAOQ tail */
	load32          REAL_MODE_PSW, %r1
	mtctl		%r1, %cr22
	rfi
	
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop
rfi_v2r_1:
	tophys_r1 %r2
	bv	0(%r2)
	nop

	.text
	.align 128
rfi_real2virt:
	rsm		PSW_SM_I,%r0
	load32		(rfi_r2v_1), %r1
	nop
	nop
	nop
	nop
	nop
	
	rsm             PSW_SM_Q,%r0    /* disable Q bit to load iia queue */
	mtctl		%r0, %cr17	/* Clear IIASQ tail */
	mtctl		%r0, %cr17	/* Clear IIASQ head */
	mtctl		%r1, %cr18	/* IIAOQ head */
	ldo		4(%r1), %r1
	mtctl		%r1, %cr18	/* IIAOQ tail */
	load32		KERNEL_PSW, %r1
	mtctl		%r1, %cr22
	rfi
	
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop
rfi_r2v_1:
	tovirt_r1 %r2
	bv	0(%r2)
	nop

#ifdef CONFIG_64BIT

/************************ 64-bit real-mode calls ***********************/
/* This is only usable in wide kernels right now and will probably stay so */
	.text
	/* unsigned long real64_call_asm(unsigned long *sp,
	 *		unsigned long *arg0p,
	 *		unsigned long fn)
	 *	sp is value of stack pointer to adopt before calling PDC (virt)
	 *	arg0p points to where saved arg values may be found
	 *	iodc_fn is the IODC function to call
	 */
ENTRY(real64_call_asm)
	std	%rp, -0x10(%sp)		/* save RP */
	std	%sp, -8(%arg0)		/* save SP on real-mode stack */
	copy	%arg0, %sp		/* adopt the real-mode SP */

	/* save fn */
	copy	%arg2, %r31

	/* set up the new ap */
	ldo	64(%arg1), %r29

	/* load up the arg registers from the saved arg area */
	/* 32-bit calling convention passes first 4 args in registers */
	ldd	0*REG_SZ(%arg1), %arg0		/* note overwriting arg0 */
	ldd	2*REG_SZ(%arg1), %arg2
	ldd	3*REG_SZ(%arg1), %arg3
	ldd	4*REG_SZ(%arg1), %r22
	ldd	5*REG_SZ(%arg1), %r21
	ldd	6*REG_SZ(%arg1), %r20
	ldd	7*REG_SZ(%arg1), %r19
	ldd	1*REG_SZ(%arg1), %arg1		/* do this one last! */

	tophys_r1 %sp

	b,l	rfi_virt2real,%r2
	nop

	b,l	save_control_regs,%r2		/* modifies r1, r2, r28 */
	nop

	load32	PA(r64_ret), %r2
	bv	0(%r31)
	nop
r64_ret:
	/* restore CRs before going virtual in case we page fault */
	b,l	restore_control_regs, %r2	/* modifies r1, r2, r26 */
	nop

	b,l	rfi_real2virt,%r2
	nop

	tovirt_r1 %sp
	ldd	-8(%sp), %sp		/* restore SP */
	ldd	-0x10(%sp), %rp		/* restore RP */
	bv	0(%rp)
	nop
ENDPROC(real64_call_asm)

#endif

	.text
	/* http://lists.parisc-linux.org/hypermail/parisc-linux/10916.html
	**	GCC 3.3 and later has a new function in libgcc.a for
	**	comparing function pointers.
	*/
ENTRY(__canonicalize_funcptr_for_compare)
#ifdef CONFIG_64BIT
	bve (%r2)
#else
	bv %r0(%r2)
#endif
	copy %r26,%r28
ENDPROC(__canonicalize_funcptr_for_compare)