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