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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