xref: /openbmc/linux/arch/parisc/kernel/real2.S (revision 732a675a)
1/*
2 *
3 * This file is subject to the terms and conditions of the GNU General Public
4 * License.  See the file "COPYING" in the main directory of this archive
5 * for more details.
6 *
7 * Copyright (C) 2000 Hewlett Packard (Paul Bame bame@puffin.external.hp.com)
8 *
9 */
10
11#include <asm/psw.h>
12#include <asm/assembly.h>
13
14#include <linux/linkage.h>
15#include <linux/init.h>
16
17	.section	.bss
18	.export real_stack
19	.export real32_stack
20	.export real64_stack
21	.align	64
22real_stack:
23real32_stack:
24real64_stack:
25	.block	8192
26
27#ifdef CONFIG_64BIT
28#  define REG_SZ 8
29#else
30#  define REG_SZ 4
31#endif
32
33#define N_SAVED_REGS 9
34
35save_cr_space:
36	.block	REG_SZ * N_SAVED_REGS
37save_cr_end:
38
39
40/************************ 32-bit real-mode calls ***********************/
41/* This can be called in both narrow and wide kernels */
42
43	__HEAD
44
45	/* unsigned long real32_call_asm(unsigned int *sp,
46	 *		unsigned int *arg0p,
47	 *		unsigned int iodc_fn)
48	 *	sp is value of stack pointer to adopt before calling PDC (virt)
49	 *	arg0p points to where saved arg values may be found
50	 *	iodc_fn is the IODC function to call
51	 */
52
53ENTRY(real32_call_asm)
54	STREG	%rp, -RP_OFFSET(%sp)	/* save RP */
55#ifdef CONFIG_64BIT
56	callee_save
57	ldo	2*REG_SZ(%sp), %sp	/* room for a couple more saves */
58	STREG	%r27, -1*REG_SZ(%sp)
59	STREG	%r29, -2*REG_SZ(%sp)
60#endif
61	STREG	%sp, -REG_SZ(%arg0)	/* save SP on real-mode stack */
62	copy	%arg0, %sp		/* adopt the real-mode SP */
63
64	/* save iodc_fn */
65	copy	%arg2, %r31
66
67	/* load up the arg registers from the saved arg area */
68	/* 32-bit calling convention passes first 4 args in registers */
69	ldw	0(%arg1), %arg0		/* note overwriting arg0 */
70	ldw	-8(%arg1), %arg2
71	ldw	-12(%arg1), %arg3
72	ldw	-4(%arg1), %arg1	/* obviously must do this one last! */
73
74	tophys_r1  %sp
75
76	b,l	rfi_virt2real,%r2
77	nop
78
79	b,l	save_control_regs,%r2		/* modifies r1, r2, r28 */
80	nop
81
82#ifdef CONFIG_64BIT
83	rsm	PSW_SM_W, %r0		/* go narrow */
84#endif
85
86	load32	PA(ric_ret), %r2
87	bv	0(%r31)
88	nop
89ric_ret:
90#ifdef CONFIG_64BIT
91	ssm	PSW_SM_W, %r0		/* go wide */
92#endif
93	/* restore CRs before going virtual in case we page fault */
94	b,l	restore_control_regs, %r2	/* modifies r1, r2, r26 */
95	nop
96
97	b,l	rfi_real2virt,%r2
98	nop
99
100	tovirt_r1 %sp
101	LDREG	-REG_SZ(%sp), %sp	/* restore SP */
102#ifdef CONFIG_64BIT
103	LDREG	-1*REG_SZ(%sp), %r27
104	LDREG	-2*REG_SZ(%sp), %r29
105	ldo	-2*REG_SZ(%sp), %sp
106	callee_rest
107#endif
108	LDREG	-RP_OFFSET(%sp), %rp	/* restore RP */
109	bv	0(%rp)
110	nop
111ENDPROC(real32_call_asm)
112
113
114#  define PUSH_CR(r, where) mfctl r, %r1 ! STREG,ma %r1, REG_SZ(where)
115#  define POP_CR(r, where) LDREG,mb -REG_SZ(where), %r1 ! mtctl %r1, r
116
117	__HEAD
118save_control_regs:
119	load32	PA(save_cr_space), %r28
120	PUSH_CR(%cr24, %r28)
121	PUSH_CR(%cr25, %r28)
122	PUSH_CR(%cr26, %r28)
123	PUSH_CR(%cr27, %r28)
124	PUSH_CR(%cr28, %r28)
125	PUSH_CR(%cr29, %r28)
126	PUSH_CR(%cr30, %r28)
127	PUSH_CR(%cr31, %r28)
128	PUSH_CR(%cr15, %r28)
129	bv 0(%r2)
130	nop
131
132restore_control_regs:
133	load32	PA(save_cr_end), %r26
134	POP_CR(%cr15, %r26)
135	POP_CR(%cr31, %r26)
136	POP_CR(%cr30, %r26)
137	POP_CR(%cr29, %r26)
138	POP_CR(%cr28, %r26)
139	POP_CR(%cr27, %r26)
140	POP_CR(%cr26, %r26)
141	POP_CR(%cr25, %r26)
142	POP_CR(%cr24, %r26)
143	bv 0(%r2)
144	nop
145
146/* rfi_virt2real() and rfi_real2virt() could perhaps be adapted for
147 * more general-purpose use by the several places which need RFIs
148 */
149	__HEAD
150	.align 128
151rfi_virt2real:
152	/* switch to real mode... */
153	rsm		PSW_SM_I,%r0
154	load32		PA(rfi_v2r_1), %r1
155	nop
156	nop
157	nop
158	nop
159	nop
160
161	rsm             PSW_SM_Q,%r0  /* disable Q & I bits to load iia queue */
162	mtctl		%r0, %cr17	/* Clear IIASQ tail */
163	mtctl		%r0, %cr17	/* Clear IIASQ head */
164	mtctl		%r1, %cr18	/* IIAOQ head */
165	ldo		4(%r1), %r1
166	mtctl		%r1, %cr18	/* IIAOQ tail */
167	load32          REAL_MODE_PSW, %r1
168	mtctl		%r1, %cr22
169	rfi
170
171	nop
172	nop
173	nop
174	nop
175	nop
176	nop
177	nop
178	nop
179rfi_v2r_1:
180	tophys_r1 %r2
181	bv	0(%r2)
182	nop
183
184	__HEAD
185	.align 128
186rfi_real2virt:
187	rsm		PSW_SM_I,%r0
188	load32		(rfi_r2v_1), %r1
189	nop
190	nop
191	nop
192	nop
193	nop
194
195	rsm             PSW_SM_Q,%r0    /* disable Q bit to load iia queue */
196	mtctl		%r0, %cr17	/* Clear IIASQ tail */
197	mtctl		%r0, %cr17	/* Clear IIASQ head */
198	mtctl		%r1, %cr18	/* IIAOQ head */
199	ldo		4(%r1), %r1
200	mtctl		%r1, %cr18	/* IIAOQ tail */
201	load32		KERNEL_PSW, %r1
202	mtctl		%r1, %cr22
203	rfi
204
205	nop
206	nop
207	nop
208	nop
209	nop
210	nop
211	nop
212	nop
213rfi_r2v_1:
214	tovirt_r1 %r2
215	bv	0(%r2)
216	nop
217
218#ifdef CONFIG_64BIT
219
220/************************ 64-bit real-mode calls ***********************/
221/* This is only usable in wide kernels right now and will probably stay so */
222	__HEAD
223	/* unsigned long real64_call_asm(unsigned long *sp,
224	 *		unsigned long *arg0p,
225	 *		unsigned long fn)
226	 *	sp is value of stack pointer to adopt before calling PDC (virt)
227	 *	arg0p points to where saved arg values may be found
228	 *	iodc_fn is the IODC function to call
229	 */
230ENTRY(real64_call_asm)
231	std	%rp, -0x10(%sp)		/* save RP */
232	std	%sp, -8(%arg0)		/* save SP on real-mode stack */
233	copy	%arg0, %sp		/* adopt the real-mode SP */
234
235	/* save fn */
236	copy	%arg2, %r31
237
238	/* set up the new ap */
239	ldo	64(%arg1), %r29
240
241	/* load up the arg registers from the saved arg area */
242	/* 32-bit calling convention passes first 4 args in registers */
243	ldd	0*REG_SZ(%arg1), %arg0		/* note overwriting arg0 */
244	ldd	2*REG_SZ(%arg1), %arg2
245	ldd	3*REG_SZ(%arg1), %arg3
246	ldd	4*REG_SZ(%arg1), %r22
247	ldd	5*REG_SZ(%arg1), %r21
248	ldd	6*REG_SZ(%arg1), %r20
249	ldd	7*REG_SZ(%arg1), %r19
250	ldd	1*REG_SZ(%arg1), %arg1		/* do this one last! */
251
252	tophys_r1 %sp
253
254	b,l	rfi_virt2real,%r2
255	nop
256
257	b,l	save_control_regs,%r2		/* modifies r1, r2, r28 */
258	nop
259
260	load32	PA(r64_ret), %r2
261	bv	0(%r31)
262	nop
263r64_ret:
264	/* restore CRs before going virtual in case we page fault */
265	b,l	restore_control_regs, %r2	/* modifies r1, r2, r26 */
266	nop
267
268	b,l	rfi_real2virt,%r2
269	nop
270
271	tovirt_r1 %sp
272	ldd	-8(%sp), %sp		/* restore SP */
273	ldd	-0x10(%sp), %rp		/* restore RP */
274	bv	0(%rp)
275	nop
276ENDPROC(real64_call_asm)
277
278#endif
279
280	__HEAD
281	/* http://lists.parisc-linux.org/hypermail/parisc-linux/10916.html
282	**	GCC 3.3 and later has a new function in libgcc.a for
283	**	comparing function pointers.
284	*/
285ENTRY(__canonicalize_funcptr_for_compare)
286#ifdef CONFIG_64BIT
287	bve (%r2)
288#else
289	bv %r0(%r2)
290#endif
291	copy %r26,%r28
292ENDPROC(__canonicalize_funcptr_for_compare)
293
294