xref: /openbmc/linux/arch/parisc/kernel/real2.S (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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#include <asm/assembly.h>
11#include <asm/psw.h>
12
13	.section	.bss
14	.export real_stack
15	.export real32_stack
16	.export real64_stack
17	.align	64
18real_stack:
19real32_stack:
20real64_stack:
21	.block	8192
22
23#ifdef __LP64__
24#  define REG_SZ 8
25#else
26#  define REG_SZ 4
27#endif
28
29#define N_SAVED_REGS 9
30
31save_cr_space:
32	.block	REG_SZ * N_SAVED_REGS
33save_cr_end:
34
35
36/************************ 32-bit real-mode calls ***********************/
37/* This can be called in both narrow and wide kernels */
38
39	.text
40
41	.export real32_call_asm
42
43	/* unsigned long real32_call_asm(unsigned int *sp,
44	 *		unsigned int *arg0p,
45	 *		unsigned int iodc_fn)
46	 *	sp is value of stack pointer to adopt before calling PDC (virt)
47	 *	arg0p points to where saved arg values may be found
48	 *	iodc_fn is the IODC function to call
49	 */
50
51real32_call_asm:
52	STREG	%rp, -RP_OFFSET(%sp)	/* save RP */
53#ifdef __LP64__
54	callee_save
55	ldo	2*REG_SZ(%sp), %sp	/* room for a couple more saves */
56	STREG	%r27, -1*REG_SZ(%sp)
57	STREG	%r29, -2*REG_SZ(%sp)
58#endif
59	STREG	%sp, -REG_SZ(%arg0)	/* save SP on real-mode stack */
60	copy	%arg0, %sp		/* adopt the real-mode SP */
61
62	/* save iodc_fn */
63	copy	%arg2, %r31
64
65	/* load up the arg registers from the saved arg area */
66	/* 32-bit calling convention passes first 4 args in registers */
67	ldw	0(%arg1), %arg0		/* note overwriting arg0 */
68	ldw	-8(%arg1), %arg2
69	ldw	-12(%arg1), %arg3
70	ldw	-4(%arg1), %arg1	/* obviously must do this one last! */
71
72	tophys_r1  %sp
73
74	b,l	rfi_virt2real,%r2
75	nop
76
77	b,l	save_control_regs,%r2		/* modifies r1, r2, r28 */
78	nop
79
80#ifdef __LP64__
81	rsm	PSW_SM_W, %r0		/* go narrow */
82#endif
83
84	load32	PA(ric_ret), %r2
85	bv	0(%r31)
86	nop
87ric_ret:
88#ifdef __LP64__
89	ssm	PSW_SM_W, %r0		/* go wide */
90#endif
91	/* restore CRs before going virtual in case we page fault */
92	b,l	restore_control_regs, %r2	/* modifies r1, r2, r26 */
93	nop
94
95	b,l	rfi_real2virt,%r2
96	nop
97
98	tovirt_r1 %sp
99	LDREG	-REG_SZ(%sp), %sp	/* restore SP */
100#ifdef __LP64__
101	LDREG	-1*REG_SZ(%sp), %r27
102	LDREG	-2*REG_SZ(%sp), %r29
103	ldo	-2*REG_SZ(%sp), %sp
104	callee_rest
105#endif
106	LDREG	-RP_OFFSET(%sp), %rp	/* restore RP */
107	bv	0(%rp)
108	nop
109
110
111#  define PUSH_CR(r, where) mfctl r, %r1 ! STREG,ma %r1, REG_SZ(where)
112#  define POP_CR(r, where) LDREG,mb -REG_SZ(where), %r1 ! mtctl %r1, r
113
114	.text
115save_control_regs:
116	load32	PA(save_cr_space), %r28
117	PUSH_CR(%cr24, %r28)
118	PUSH_CR(%cr25, %r28)
119	PUSH_CR(%cr26, %r28)
120	PUSH_CR(%cr27, %r28)
121	PUSH_CR(%cr28, %r28)
122	PUSH_CR(%cr29, %r28)
123	PUSH_CR(%cr30, %r28)
124	PUSH_CR(%cr31, %r28)
125	PUSH_CR(%cr15, %r28)
126	bv 0(%r2)
127	nop
128
129restore_control_regs:
130	load32	PA(save_cr_end), %r26
131	POP_CR(%cr15, %r26)
132	POP_CR(%cr31, %r26)
133	POP_CR(%cr30, %r26)
134	POP_CR(%cr29, %r26)
135	POP_CR(%cr28, %r26)
136	POP_CR(%cr27, %r26)
137	POP_CR(%cr26, %r26)
138	POP_CR(%cr25, %r26)
139	POP_CR(%cr24, %r26)
140	bv 0(%r2)
141	nop
142
143/* rfi_virt2real() and rfi_real2virt() could perhaps be adapted for
144 * more general-purpose use by the several places which need RFIs
145 */
146	.align 128
147	.text
148rfi_virt2real:
149	/* switch to real mode... */
150	ssm		0,0		/* See "relied upon translation" */
151	nop				/* PA 2.0 Arch. F-5 */
152	nop
153	nop
154	nop
155	nop
156	nop
157	nop
158	nop
159
160	rsm             (PSW_SM_Q|PSW_SM_I),%r0  /* disable Q & I bits to load iia queue */
161	mtctl		%r0, %cr17	/* Clear IIASQ tail */
162	mtctl		%r0, %cr17	/* Clear IIASQ head */
163	load32		PA(rfi_v2r_1), %r1
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	.text
185	.align 128
186rfi_real2virt:
187	ssm		0,0		/* See "relied upon translation" */
188	nop				/* PA 2.0 Arch. F-5 */
189	nop
190	nop
191	nop
192	nop
193	nop
194	nop
195	nop
196
197	rsm             PSW_SM_Q,%r0    /* disable Q bit to load iia queue */
198	mtctl		%r0, %cr17	/* Clear IIASQ tail */
199	mtctl		%r0, %cr17	/* Clear IIASQ head */
200	load32		(rfi_r2v_1), %r1
201	mtctl		%r1, %cr18	/* IIAOQ head */
202	ldo		4(%r1), %r1
203	mtctl		%r1, %cr18	/* IIAOQ tail */
204	load32		KERNEL_PSW, %r1
205	mtctl		%r1, %cr22
206	rfi
207
208	nop
209	nop
210	nop
211	nop
212	nop
213	nop
214	nop
215	nop
216rfi_r2v_1:
217	tovirt_r1 %r2
218	bv	0(%r2)
219	nop
220
221#ifdef __LP64__
222
223/************************ 64-bit real-mode calls ***********************/
224/* This is only usable in wide kernels right now and will probably stay so */
225	.text
226	.export real64_call_asm
227	/* unsigned long real64_call_asm(unsigned long *sp,
228	 *		unsigned long *arg0p,
229	 *		unsigned long fn)
230	 *	sp is value of stack pointer to adopt before calling PDC (virt)
231	 *	arg0p points to where saved arg values may be found
232	 *	iodc_fn is the IODC function to call
233	 */
234real64_call_asm:
235	std	%rp, -0x10(%sp)		/* save RP */
236	std	%sp, -8(%arg0)		/* save SP on real-mode stack */
237	copy	%arg0, %sp		/* adopt the real-mode SP */
238
239	/* save fn */
240	copy	%arg2, %r31
241
242	/* set up the new ap */
243	ldo	64(%arg1), %r29
244
245	/* load up the arg registers from the saved arg area */
246	/* 32-bit calling convention passes first 4 args in registers */
247	ldd	0*REG_SZ(%arg1), %arg0		/* note overwriting arg0 */
248	ldd	2*REG_SZ(%arg1), %arg2
249	ldd	3*REG_SZ(%arg1), %arg3
250	ldd	4*REG_SZ(%arg1), %r22
251	ldd	5*REG_SZ(%arg1), %r21
252	ldd	6*REG_SZ(%arg1), %r20
253	ldd	7*REG_SZ(%arg1), %r19
254	ldd	1*REG_SZ(%arg1), %arg1		/* do this one last! */
255
256	tophys_r1 %sp
257
258	b,l	rfi_virt2real,%r2
259	nop
260
261	b,l	save_control_regs,%r2		/* modifies r1, r2, r28 */
262	nop
263
264	load32	PA(r64_ret), %r2
265	bv	0(%r31)
266	nop
267r64_ret:
268	/* restore CRs before going virtual in case we page fault */
269	b,l	restore_control_regs, %r2	/* modifies r1, r2, r26 */
270	nop
271
272	b,l	rfi_real2virt,%r2
273	nop
274
275	tovirt_r1 %sp
276	ldd	-8(%sp), %sp		/* restore SP */
277	ldd	-0x10(%sp), %rp		/* restore RP */
278	bv	0(%rp)
279	nop
280
281#endif
282
283	.export pc_in_user_space
284	.text
285	/* Doesn't belong here but I couldn't find a nicer spot. */
286	/* Should never get called, only used by profile stuff in time.c */
287pc_in_user_space:
288	bv,n	0(%rp)
289	nop
290
291
292	.export __canonicalize_funcptr_for_compare
293	.text
294	/* http://lists.parisc-linux.org/hypermail/parisc-linux/10916.html
295	**	GCC 3.3 and later has a new function in libgcc.a for
296	**	comparing function pointers.
297	*/
298__canonicalize_funcptr_for_compare:
299#ifdef __LP64__
300	bve (%r2)
301#else
302	bv %r0(%r2)
303#endif
304	copy %r26,%r28
305