xref: /openbmc/linux/arch/parisc/kernel/real2.S (revision d9fd5a71)
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#define N_SAVED_REGS 9
39
40save_cr_space:
41	.block	REG_SZ * N_SAVED_REGS
42save_cr_end:
43
44
45/************************ 32-bit real-mode calls ***********************/
46/* This can be called in both narrow and wide kernels */
47
48	.text
49
50	/* unsigned long real32_call_asm(unsigned int *sp,
51	 *		unsigned int *arg0p,
52	 *		unsigned int iodc_fn)
53	 *	sp is value of stack pointer to adopt before calling PDC (virt)
54	 *	arg0p points to where saved arg values may be found
55	 *	iodc_fn is the IODC function to call
56	 */
57
58ENTRY_CFI(real32_call_asm)
59	STREG	%rp, -RP_OFFSET(%sp)	/* save RP */
60#ifdef CONFIG_64BIT
61	callee_save
62	ldo	2*REG_SZ(%sp), %sp	/* room for a couple more saves */
63	STREG	%r27, -1*REG_SZ(%sp)
64	STREG	%r29, -2*REG_SZ(%sp)
65#endif
66	STREG	%sp, -REG_SZ(%arg0)	/* save SP on real-mode stack */
67	copy	%arg0, %sp		/* adopt the real-mode SP */
68
69	/* save iodc_fn */
70	copy	%arg2, %r31
71
72	/* load up the arg registers from the saved arg area */
73	/* 32-bit calling convention passes first 4 args in registers */
74	ldw	0(%arg1), %arg0		/* note overwriting arg0 */
75	ldw	-8(%arg1), %arg2
76	ldw	-12(%arg1), %arg3
77	ldw	-4(%arg1), %arg1	/* obviously must do this one last! */
78
79	tophys_r1  %sp
80
81	b,l	rfi_virt2real,%r2
82	nop
83
84	b,l	save_control_regs,%r2		/* modifies r1, r2, r28 */
85	nop
86
87#ifdef CONFIG_64BIT
88	rsm	PSW_SM_W, %r0		/* go narrow */
89#endif
90
91	load32	PA(ric_ret), %r2
92	bv	0(%r31)
93	nop
94ric_ret:
95#ifdef CONFIG_64BIT
96	ssm	PSW_SM_W, %r0		/* go wide */
97#endif
98	/* restore CRs before going virtual in case we page fault */
99	b,l	restore_control_regs, %r2	/* modifies r1, r2, r26 */
100	nop
101
102	b,l	rfi_real2virt,%r2
103	nop
104
105	tovirt_r1 %sp
106	LDREG	-REG_SZ(%sp), %sp	/* restore SP */
107#ifdef CONFIG_64BIT
108	LDREG	-1*REG_SZ(%sp), %r27
109	LDREG	-2*REG_SZ(%sp), %r29
110	ldo	-2*REG_SZ(%sp), %sp
111	callee_rest
112#endif
113	LDREG	-RP_OFFSET(%sp), %rp	/* restore RP */
114	bv	0(%rp)
115	nop
116ENDPROC_CFI(real32_call_asm)
117
118
119#  define PUSH_CR(r, where) mfctl r, %r1 ! STREG,ma %r1, REG_SZ(where)
120#  define POP_CR(r, where) LDREG,mb -REG_SZ(where), %r1 ! mtctl %r1, r
121
122	.text
123ENTRY_CFI(save_control_regs)
124	load32	PA(save_cr_space), %r28
125	PUSH_CR(%cr24, %r28)
126	PUSH_CR(%cr25, %r28)
127	PUSH_CR(%cr26, %r28)
128	PUSH_CR(%cr27, %r28)
129	PUSH_CR(%cr28, %r28)
130	PUSH_CR(%cr29, %r28)
131	PUSH_CR(%cr30, %r28)
132	PUSH_CR(%cr31, %r28)
133	PUSH_CR(%cr15, %r28)
134	bv 0(%r2)
135	nop
136ENDPROC_CFI(save_control_regs)
137
138ENTRY_CFI(restore_control_regs)
139	load32	PA(save_cr_end), %r26
140	POP_CR(%cr15, %r26)
141	POP_CR(%cr31, %r26)
142	POP_CR(%cr30, %r26)
143	POP_CR(%cr29, %r26)
144	POP_CR(%cr28, %r26)
145	POP_CR(%cr27, %r26)
146	POP_CR(%cr26, %r26)
147	POP_CR(%cr25, %r26)
148	POP_CR(%cr24, %r26)
149	bv 0(%r2)
150	nop
151ENDPROC_CFI(restore_control_regs)
152
153/* rfi_virt2real() and rfi_real2virt() could perhaps be adapted for
154 * more general-purpose use by the several places which need RFIs
155 */
156	.text
157	.align 128
158ENTRY_CFI(rfi_virt2real)
159#if !defined(BOOTLOADER)
160	/* switch to real mode... */
161	rsm		PSW_SM_I,%r0
162	load32		PA(rfi_v2r_1), %r1
163	nop
164	nop
165	nop
166	nop
167	nop
168
169	rsm             PSW_SM_Q,%r0  /* disable Q & I bits to load iia queue */
170	mtctl		%r0, %cr17	/* Clear IIASQ tail */
171	mtctl		%r0, %cr17	/* Clear IIASQ head */
172	mtctl		%r1, %cr18	/* IIAOQ head */
173	ldo		4(%r1), %r1
174	mtctl		%r1, %cr18	/* IIAOQ tail */
175	load32          REAL_MODE_PSW, %r1
176	mtctl		%r1, %cr22
177	rfi
178
179	nop
180	nop
181	nop
182	nop
183	nop
184	nop
185	nop
186	nop
187rfi_v2r_1:
188	tophys_r1 %r2
189#endif /* defined(BOOTLOADER) */
190	bv	0(%r2)
191	nop
192ENDPROC_CFI(rfi_virt2real)
193
194	.text
195	.align 128
196ENTRY_CFI(rfi_real2virt)
197#if !defined(BOOTLOADER)
198	rsm		PSW_SM_I,%r0
199	load32		(rfi_r2v_1), %r1
200	nop
201	nop
202	nop
203	nop
204	nop
205
206	rsm             PSW_SM_Q,%r0    /* disable Q bit to load iia queue */
207	mtctl		%r0, %cr17	/* Clear IIASQ tail */
208	mtctl		%r0, %cr17	/* Clear IIASQ head */
209	mtctl		%r1, %cr18	/* IIAOQ head */
210	ldo		4(%r1), %r1
211	mtctl		%r1, %cr18	/* IIAOQ tail */
212	load32		KERNEL_PSW, %r1
213	mtctl		%r1, %cr22
214	rfi
215
216	nop
217	nop
218	nop
219	nop
220	nop
221	nop
222	nop
223	nop
224rfi_r2v_1:
225	tovirt_r1 %r2
226#endif /* defined(BOOTLOADER) */
227	bv	0(%r2)
228	nop
229ENDPROC_CFI(rfi_real2virt)
230
231#ifdef CONFIG_64BIT
232
233/************************ 64-bit real-mode calls ***********************/
234/* This is only usable in wide kernels right now and will probably stay so */
235	.text
236	/* unsigned long real64_call_asm(unsigned long *sp,
237	 *		unsigned long *arg0p,
238	 *		unsigned long fn)
239	 *	sp is value of stack pointer to adopt before calling PDC (virt)
240	 *	arg0p points to where saved arg values may be found
241	 *	iodc_fn is the IODC function to call
242	 */
243ENTRY_CFI(real64_call_asm)
244	std	%rp, -0x10(%sp)		/* save RP */
245	std	%sp, -8(%arg0)		/* save SP on real-mode stack */
246	copy	%arg0, %sp		/* adopt the real-mode SP */
247
248	/* save fn */
249	copy	%arg2, %r31
250
251	/* set up the new ap */
252	ldo	64(%arg1), %r29
253
254	/* load up the arg registers from the saved arg area */
255	/* 32-bit calling convention passes first 4 args in registers */
256	ldd	0*REG_SZ(%arg1), %arg0		/* note overwriting arg0 */
257	ldd	2*REG_SZ(%arg1), %arg2
258	ldd	3*REG_SZ(%arg1), %arg3
259	ldd	4*REG_SZ(%arg1), %r22
260	ldd	5*REG_SZ(%arg1), %r21
261	ldd	6*REG_SZ(%arg1), %r20
262	ldd	7*REG_SZ(%arg1), %r19
263	ldd	1*REG_SZ(%arg1), %arg1		/* do this one last! */
264
265	tophys_r1 %sp
266
267	b,l	rfi_virt2real,%r2
268	nop
269
270	b,l	save_control_regs,%r2		/* modifies r1, r2, r28 */
271	nop
272
273	load32	PA(r64_ret), %r2
274	bv	0(%r31)
275	nop
276r64_ret:
277	/* restore CRs before going virtual in case we page fault */
278	b,l	restore_control_regs, %r2	/* modifies r1, r2, r26 */
279	nop
280
281	b,l	rfi_real2virt,%r2
282	nop
283
284	tovirt_r1 %sp
285	ldd	-8(%sp), %sp		/* restore SP */
286	ldd	-0x10(%sp), %rp		/* restore RP */
287	bv	0(%rp)
288	nop
289ENDPROC_CFI(real64_call_asm)
290
291#endif
292
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	*/
298ENTRY_CFI(__canonicalize_funcptr_for_compare)
299#ifdef CONFIG_64BIT
300	bve (%r2)
301#else
302	bv %r0(%r2)
303#endif
304	copy %r26,%r28
305ENDPROC_CFI(__canonicalize_funcptr_for_compare)
306
307