xref: /openbmc/linux/arch/parisc/kernel/real2.S (revision 6e3220ba)
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	.export real_stack
19	.export real64_stack
20	__PAGE_ALIGNED_BSS
21real_stack:
22real64_stack:
23	.block	8192
24
25#define N_SAVED_REGS 9
26	.section	.bss
27save_cr_space:
28	.block	REG_SZ * N_SAVED_REGS
29save_cr_end:
30
31
32/************************ 32-bit real-mode calls ***********************/
33/* This can be called in both narrow and wide kernels */
34
35	.text
36
37	/* unsigned long real32_call_asm(unsigned int *sp,
38	 *		unsigned int *arg0p,
39	 *		unsigned int iodc_fn)
40	 *	sp is value of stack pointer to adopt before calling PDC (virt)
41	 *	arg0p points to where saved arg values may be found
42	 *	iodc_fn is the IODC function to call
43	 */
44
45ENTRY_CFI(real32_call_asm)
46	STREG	%rp, -RP_OFFSET(%sp)	/* save RP */
47#ifdef CONFIG_64BIT
48	callee_save
49	ldo	2*REG_SZ(%sp), %sp	/* room for a couple more saves */
50	STREG	%r27, -1*REG_SZ(%sp)
51	STREG	%r29, -2*REG_SZ(%sp)
52#endif
53	STREG	%sp, -REG_SZ(%arg0)	/* save SP on real-mode stack */
54	copy	%arg0, %sp		/* adopt the real-mode SP */
55
56	/* save iodc_fn */
57	copy	%arg2, %r31
58
59	/* load up the arg registers from the saved arg area */
60	/* 32-bit calling convention passes first 4 args in registers */
61	ldw	0(%arg1), %arg0		/* note overwriting arg0 */
62	ldw	-8(%arg1), %arg2
63	ldw	-12(%arg1), %arg3
64	ldw	-4(%arg1), %arg1	/* obviously must do this one last! */
65
66	tophys_r1  %sp
67
68	b,l	rfi_virt2real,%r2
69	nop
70
71	b,l	save_control_regs,%r2		/* modifies r1, r2, r28 */
72	nop
73
74#ifdef CONFIG_64BIT
75	rsm	PSW_SM_W, %r0		/* go narrow */
76#endif
77
78	load32	PA(ric_ret), %r2
79	bv	0(%r31)
80	nop
81ric_ret:
82#ifdef CONFIG_64BIT
83	ssm	PSW_SM_W, %r0		/* go wide */
84#endif
85	/* restore CRs before going virtual in case we page fault */
86	b,l	restore_control_regs, %r2	/* modifies r1, r2, r26 */
87	nop
88
89	b,l	rfi_real2virt,%r2
90	nop
91
92	tovirt_r1 %sp
93	LDREG	-REG_SZ(%sp), %sp	/* restore SP */
94#ifdef CONFIG_64BIT
95	LDREG	-1*REG_SZ(%sp), %r27
96	LDREG	-2*REG_SZ(%sp), %r29
97	ldo	-2*REG_SZ(%sp), %sp
98	callee_rest
99#endif
100	LDREG	-RP_OFFSET(%sp), %rp	/* restore RP */
101	bv	0(%rp)
102	nop
103ENDPROC_CFI(real32_call_asm)
104
105
106#  define PUSH_CR(r, where) mfctl r, %r1 ! STREG,ma %r1, REG_SZ(where)
107#  define POP_CR(r, where) LDREG,mb -REG_SZ(where), %r1 ! mtctl %r1, r
108
109	.text
110ENTRY_CFI(save_control_regs)
111	load32	PA(save_cr_space), %r28
112	PUSH_CR(%cr24, %r28)
113	PUSH_CR(%cr25, %r28)
114	PUSH_CR(%cr26, %r28)
115	PUSH_CR(%cr27, %r28)
116	PUSH_CR(%cr28, %r28)
117	PUSH_CR(%cr29, %r28)
118	PUSH_CR(%cr30, %r28)
119	PUSH_CR(%cr31, %r28)
120	PUSH_CR(%cr15, %r28)
121	bv 0(%r2)
122	nop
123ENDPROC_CFI(save_control_regs)
124
125ENTRY_CFI(restore_control_regs)
126	load32	PA(save_cr_end), %r26
127	POP_CR(%cr15, %r26)
128	POP_CR(%cr31, %r26)
129	POP_CR(%cr30, %r26)
130	POP_CR(%cr29, %r26)
131	POP_CR(%cr28, %r26)
132	POP_CR(%cr27, %r26)
133	POP_CR(%cr26, %r26)
134	POP_CR(%cr25, %r26)
135	POP_CR(%cr24, %r26)
136	bv 0(%r2)
137	nop
138ENDPROC_CFI(restore_control_regs)
139
140/* rfi_virt2real() and rfi_real2virt() could perhaps be adapted for
141 * more general-purpose use by the several places which need RFIs
142 */
143	.text
144	.align 128
145ENTRY_CFI(rfi_virt2real)
146#if !defined(BOOTLOADER)
147	/* switch to real mode... */
148	rsm		PSW_SM_I,%r0
149	load32		PA(rfi_v2r_1), %r1
150	nop
151	nop
152	nop
153	nop
154	nop
155
156	rsm             PSW_SM_Q,%r0  /* disable Q & I bits to load iia queue */
157	mtctl		%r0, %cr17	/* Clear IIASQ tail */
158	mtctl		%r0, %cr17	/* Clear IIASQ head */
159	mtctl		%r1, %cr18	/* IIAOQ head */
160	ldo		4(%r1), %r1
161	mtctl		%r1, %cr18	/* IIAOQ tail */
162	load32          REAL_MODE_PSW, %r1
163	mtctl		%r1, %cr22
164	rfi
165
166	nop
167	nop
168	nop
169	nop
170	nop
171	nop
172	nop
173	nop
174rfi_v2r_1:
175	tophys_r1 %r2
176#endif /* defined(BOOTLOADER) */
177	bv	0(%r2)
178	nop
179ENDPROC_CFI(rfi_virt2real)
180
181	.text
182	.align 128
183ENTRY_CFI(rfi_real2virt)
184#if !defined(BOOTLOADER)
185	rsm		PSW_SM_I,%r0
186	load32		(rfi_r2v_1), %r1
187	nop
188	nop
189	nop
190	nop
191	nop
192
193	rsm             PSW_SM_Q,%r0    /* disable Q bit to load iia queue */
194	mtctl		%r0, %cr17	/* Clear IIASQ tail */
195	mtctl		%r0, %cr17	/* Clear IIASQ head */
196	mtctl		%r1, %cr18	/* IIAOQ head */
197	ldo		4(%r1), %r1
198	mtctl		%r1, %cr18	/* IIAOQ tail */
199	load32		KERNEL_PSW, %r1
200	mtctl		%r1, %cr22
201	rfi
202
203	nop
204	nop
205	nop
206	nop
207	nop
208	nop
209	nop
210	nop
211rfi_r2v_1:
212	tovirt_r1 %r2
213#endif /* defined(BOOTLOADER) */
214	bv	0(%r2)
215	nop
216ENDPROC_CFI(rfi_real2virt)
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	.text
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_CFI(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	/* load up the arg registers from the saved arg area */
239	/* 32-bit calling convention passes first 4 args in registers */
240	ldd	0*REG_SZ(%arg1), %arg0		/* note overwriting arg0 */
241	ldd	2*REG_SZ(%arg1), %arg2
242	ldd	3*REG_SZ(%arg1), %arg3
243	ldd	4*REG_SZ(%arg1), %r22
244	ldd	5*REG_SZ(%arg1), %r21
245	ldd	6*REG_SZ(%arg1), %r20
246	ldd	7*REG_SZ(%arg1), %r19
247	ldd	1*REG_SZ(%arg1), %arg1		/* do this one last! */
248
249	/* set up real-mode stack and real-mode ap */
250	tophys_r1 %sp
251	ldo	-16(%sp), %r29			/* Reference param save area */
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_CFI(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_CFI(__canonicalize_funcptr_for_compare)
285#ifdef CONFIG_64BIT
286	bve (%r2)
287#else
288	bv %r0(%r2)
289#endif
290	copy %r26,%r28
291ENDPROC_CFI(__canonicalize_funcptr_for_compare)
292
293