xref: /openbmc/linux/arch/parisc/kernel/real2.S (revision 1c2dd16a)
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/pdc.h>
12#include <asm/psw.h>
13#include <asm/assembly.h>
14#include <asm/asm-offsets.h>
15
16#include <linux/linkage.h>
17
18
19	.section	.bss
20
21	.export pdc_result
22	.export pdc_result2
23	.align 8
24pdc_result:
25	.block	ASM_PDC_RESULT_SIZE
26pdc_result2:
27	.block	ASM_PDC_RESULT_SIZE
28
29	.export real_stack
30	.export real32_stack
31	.export real64_stack
32	.align	64
33real_stack:
34real32_stack:
35real64_stack:
36	.block	8192
37
38#ifdef CONFIG_64BIT
39#  define REG_SZ 8
40#else
41#  define REG_SZ 4
42#endif
43
44#define N_SAVED_REGS 9
45
46save_cr_space:
47	.block	REG_SZ * N_SAVED_REGS
48save_cr_end:
49
50
51/************************ 32-bit real-mode calls ***********************/
52/* This can be called in both narrow and wide kernels */
53
54	.text
55
56	/* unsigned long real32_call_asm(unsigned int *sp,
57	 *		unsigned int *arg0p,
58	 *		unsigned int iodc_fn)
59	 *	sp is value of stack pointer to adopt before calling PDC (virt)
60	 *	arg0p points to where saved arg values may be found
61	 *	iodc_fn is the IODC function to call
62	 */
63
64ENTRY_CFI(real32_call_asm)
65	STREG	%rp, -RP_OFFSET(%sp)	/* save RP */
66#ifdef CONFIG_64BIT
67	callee_save
68	ldo	2*REG_SZ(%sp), %sp	/* room for a couple more saves */
69	STREG	%r27, -1*REG_SZ(%sp)
70	STREG	%r29, -2*REG_SZ(%sp)
71#endif
72	STREG	%sp, -REG_SZ(%arg0)	/* save SP on real-mode stack */
73	copy	%arg0, %sp		/* adopt the real-mode SP */
74
75	/* save iodc_fn */
76	copy	%arg2, %r31
77
78	/* load up the arg registers from the saved arg area */
79	/* 32-bit calling convention passes first 4 args in registers */
80	ldw	0(%arg1), %arg0		/* note overwriting arg0 */
81	ldw	-8(%arg1), %arg2
82	ldw	-12(%arg1), %arg3
83	ldw	-4(%arg1), %arg1	/* obviously must do this one last! */
84
85	tophys_r1  %sp
86
87	b,l	rfi_virt2real,%r2
88	nop
89
90	b,l	save_control_regs,%r2		/* modifies r1, r2, r28 */
91	nop
92
93#ifdef CONFIG_64BIT
94	rsm	PSW_SM_W, %r0		/* go narrow */
95#endif
96
97	load32	PA(ric_ret), %r2
98	bv	0(%r31)
99	nop
100ric_ret:
101#ifdef CONFIG_64BIT
102	ssm	PSW_SM_W, %r0		/* go wide */
103#endif
104	/* restore CRs before going virtual in case we page fault */
105	b,l	restore_control_regs, %r2	/* modifies r1, r2, r26 */
106	nop
107
108	b,l	rfi_real2virt,%r2
109	nop
110
111	tovirt_r1 %sp
112	LDREG	-REG_SZ(%sp), %sp	/* restore SP */
113#ifdef CONFIG_64BIT
114	LDREG	-1*REG_SZ(%sp), %r27
115	LDREG	-2*REG_SZ(%sp), %r29
116	ldo	-2*REG_SZ(%sp), %sp
117	callee_rest
118#endif
119	LDREG	-RP_OFFSET(%sp), %rp	/* restore RP */
120	bv	0(%rp)
121	nop
122ENDPROC_CFI(real32_call_asm)
123
124
125#  define PUSH_CR(r, where) mfctl r, %r1 ! STREG,ma %r1, REG_SZ(where)
126#  define POP_CR(r, where) LDREG,mb -REG_SZ(where), %r1 ! mtctl %r1, r
127
128	.text
129ENTRY_CFI(save_control_regs)
130	load32	PA(save_cr_space), %r28
131	PUSH_CR(%cr24, %r28)
132	PUSH_CR(%cr25, %r28)
133	PUSH_CR(%cr26, %r28)
134	PUSH_CR(%cr27, %r28)
135	PUSH_CR(%cr28, %r28)
136	PUSH_CR(%cr29, %r28)
137	PUSH_CR(%cr30, %r28)
138	PUSH_CR(%cr31, %r28)
139	PUSH_CR(%cr15, %r28)
140	bv 0(%r2)
141	nop
142ENDPROC_CFI(save_control_regs)
143
144ENTRY_CFI(restore_control_regs)
145	load32	PA(save_cr_end), %r26
146	POP_CR(%cr15, %r26)
147	POP_CR(%cr31, %r26)
148	POP_CR(%cr30, %r26)
149	POP_CR(%cr29, %r26)
150	POP_CR(%cr28, %r26)
151	POP_CR(%cr27, %r26)
152	POP_CR(%cr26, %r26)
153	POP_CR(%cr25, %r26)
154	POP_CR(%cr24, %r26)
155	bv 0(%r2)
156	nop
157ENDPROC_CFI(restore_control_regs)
158
159/* rfi_virt2real() and rfi_real2virt() could perhaps be adapted for
160 * more general-purpose use by the several places which need RFIs
161 */
162	.text
163	.align 128
164ENTRY_CFI(rfi_virt2real)
165	/* switch to real mode... */
166	rsm		PSW_SM_I,%r0
167	load32		PA(rfi_v2r_1), %r1
168	nop
169	nop
170	nop
171	nop
172	nop
173
174	rsm             PSW_SM_Q,%r0  /* disable Q & I bits to load iia queue */
175	mtctl		%r0, %cr17	/* Clear IIASQ tail */
176	mtctl		%r0, %cr17	/* Clear IIASQ head */
177	mtctl		%r1, %cr18	/* IIAOQ head */
178	ldo		4(%r1), %r1
179	mtctl		%r1, %cr18	/* IIAOQ tail */
180	load32          REAL_MODE_PSW, %r1
181	mtctl		%r1, %cr22
182	rfi
183
184	nop
185	nop
186	nop
187	nop
188	nop
189	nop
190	nop
191	nop
192rfi_v2r_1:
193	tophys_r1 %r2
194	bv	0(%r2)
195	nop
196ENDPROC_CFI(rfi_virt2real)
197
198	.text
199	.align 128
200ENTRY_CFI(rfi_real2virt)
201	rsm		PSW_SM_I,%r0
202	load32		(rfi_r2v_1), %r1
203	nop
204	nop
205	nop
206	nop
207	nop
208
209	rsm             PSW_SM_Q,%r0    /* disable Q bit to load iia queue */
210	mtctl		%r0, %cr17	/* Clear IIASQ tail */
211	mtctl		%r0, %cr17	/* Clear IIASQ head */
212	mtctl		%r1, %cr18	/* IIAOQ head */
213	ldo		4(%r1), %r1
214	mtctl		%r1, %cr18	/* IIAOQ tail */
215	load32		KERNEL_PSW, %r1
216	mtctl		%r1, %cr22
217	rfi
218
219	nop
220	nop
221	nop
222	nop
223	nop
224	nop
225	nop
226	nop
227rfi_r2v_1:
228	tovirt_r1 %r2
229	bv	0(%r2)
230	nop
231ENDPROC_CFI(rfi_real2virt)
232
233#ifdef CONFIG_64BIT
234
235/************************ 64-bit real-mode calls ***********************/
236/* This is only usable in wide kernels right now and will probably stay so */
237	.text
238	/* unsigned long real64_call_asm(unsigned long *sp,
239	 *		unsigned long *arg0p,
240	 *		unsigned long fn)
241	 *	sp is value of stack pointer to adopt before calling PDC (virt)
242	 *	arg0p points to where saved arg values may be found
243	 *	iodc_fn is the IODC function to call
244	 */
245ENTRY_CFI(real64_call_asm)
246	std	%rp, -0x10(%sp)		/* save RP */
247	std	%sp, -8(%arg0)		/* save SP on real-mode stack */
248	copy	%arg0, %sp		/* adopt the real-mode SP */
249
250	/* save fn */
251	copy	%arg2, %r31
252
253	/* set up the new ap */
254	ldo	64(%arg1), %r29
255
256	/* load up the arg registers from the saved arg area */
257	/* 32-bit calling convention passes first 4 args in registers */
258	ldd	0*REG_SZ(%arg1), %arg0		/* note overwriting arg0 */
259	ldd	2*REG_SZ(%arg1), %arg2
260	ldd	3*REG_SZ(%arg1), %arg3
261	ldd	4*REG_SZ(%arg1), %r22
262	ldd	5*REG_SZ(%arg1), %r21
263	ldd	6*REG_SZ(%arg1), %r20
264	ldd	7*REG_SZ(%arg1), %r19
265	ldd	1*REG_SZ(%arg1), %arg1		/* do this one last! */
266
267	tophys_r1 %sp
268
269	b,l	rfi_virt2real,%r2
270	nop
271
272	b,l	save_control_regs,%r2		/* modifies r1, r2, r28 */
273	nop
274
275	load32	PA(r64_ret), %r2
276	bv	0(%r31)
277	nop
278r64_ret:
279	/* restore CRs before going virtual in case we page fault */
280	b,l	restore_control_regs, %r2	/* modifies r1, r2, r26 */
281	nop
282
283	b,l	rfi_real2virt,%r2
284	nop
285
286	tovirt_r1 %sp
287	ldd	-8(%sp), %sp		/* restore SP */
288	ldd	-0x10(%sp), %rp		/* restore RP */
289	bv	0(%rp)
290	nop
291ENDPROC_CFI(real64_call_asm)
292
293#endif
294
295	.text
296	/* http://lists.parisc-linux.org/hypermail/parisc-linux/10916.html
297	**	GCC 3.3 and later has a new function in libgcc.a for
298	**	comparing function pointers.
299	*/
300ENTRY_CFI(__canonicalize_funcptr_for_compare)
301#ifdef CONFIG_64BIT
302	bve (%r2)
303#else
304	bv %r0(%r2)
305#endif
306	copy %r26,%r28
307ENDPROC_CFI(__canonicalize_funcptr_for_compare)
308
309