1/*
2 * Signal trampolines for 32 bits processes in a ppc64 kernel for
3 * use in the vDSO
4 *
5 * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org), IBM Corp.
6 * Copyright (C) 2004 Alan Modra (amodra@au.ibm.com)), IBM Corp.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 */
13#include <asm/processor.h>
14#include <asm/ppc_asm.h>
15#include <asm/unistd.h>
16#include <asm/vdso.h>
17
18	.text
19
20/* The nop here is a hack.  The dwarf2 unwind routines subtract 1 from
21   the return address to get an address in the middle of the presumed
22   call instruction.  Since we don't have a call here, we artificially
23   extend the range covered by the unwind info by adding a nop before
24   the real start.  */
25	nop
26V_FUNCTION_BEGIN(__kernel_sigtramp32)
27.Lsig_start = . - 4
28	li	r0,__NR_sigreturn
29	sc
30.Lsig_end:
31V_FUNCTION_END(__kernel_sigtramp32)
32
33.Lsigrt_start:
34	nop
35V_FUNCTION_BEGIN(__kernel_sigtramp_rt32)
36	li	r0,__NR_rt_sigreturn
37	sc
38.Lsigrt_end:
39V_FUNCTION_END(__kernel_sigtramp_rt32)
40
41	.section .eh_frame,"a",@progbits
42
43/* Register r1 can be found at offset 4 of a pt_regs structure.
44   A pointer to the pt_regs is stored in memory at the old sp plus PTREGS.  */
45#define cfa_save \
46  .byte 0x0f;			/* DW_CFA_def_cfa_expression */		\
47  .uleb128 9f - 1f;		/*   length */				\
481:									\
49  .byte 0x71; .sleb128 PTREGS;	/*     DW_OP_breg1 */			\
50  .byte 0x06;			/*     DW_OP_deref */			\
51  .byte 0x23; .uleb128 RSIZE;	/*     DW_OP_plus_uconst */		\
52  .byte 0x06;			/*     DW_OP_deref */			\
539:
54
55/* Register REGNO can be found at offset OFS of a pt_regs structure.
56   A pointer to the pt_regs is stored in memory at the old sp plus PTREGS.  */
57#define rsave(regno, ofs) \
58  .byte 0x10;			/* DW_CFA_expression */			\
59  .uleb128 regno;		/*   regno */				\
60  .uleb128 9f - 1f;		/*   length */				\
611:									\
62  .byte 0x71; .sleb128 PTREGS;	/*     DW_OP_breg1 */			\
63  .byte 0x06;			/*     DW_OP_deref */			\
64  .ifne ofs;								\
65    .byte 0x23; .uleb128 ofs;	/*     DW_OP_plus_uconst */		\
66  .endif;								\
679:
68
69/* If msr bit 1<<25 is set, then VMX register REGNO is at offset REGNO*16
70   of the VMX reg struct.  The VMX reg struct is at offset VREGS of
71   the pt_regs struct.  This macro is for REGNO == 0, and contains
72   'subroutines' that the other macros jump to.  */
73#define vsave_msr0(regno) \
74  .byte 0x10;			/* DW_CFA_expression */			\
75  .uleb128 regno + 77;		/*   regno */				\
76  .uleb128 9f - 1f;		/*   length */				\
771:									\
78  .byte 0x30 + regno;		/*     DW_OP_lit0 */			\
792:									\
80  .byte 0x40;			/*     DW_OP_lit16 */			\
81  .byte 0x1e;			/*     DW_OP_mul */			\
823:									\
83  .byte 0x71; .sleb128 PTREGS;	/*     DW_OP_breg1 */			\
84  .byte 0x06;			/*     DW_OP_deref */			\
85  .byte 0x12;			/*     DW_OP_dup */			\
86  .byte 0x23;			/*     DW_OP_plus_uconst */		\
87    .uleb128 33*RSIZE;		/*       msr offset */			\
88  .byte 0x06;			/*     DW_OP_deref */			\
89  .byte 0x0c; .long 1 << 25;	/*     DW_OP_const4u */			\
90  .byte 0x1a;			/*     DW_OP_and */			\
91  .byte 0x12;			/*     DW_OP_dup, ret 0 if bra taken */	\
92  .byte 0x30;			/*     DW_OP_lit0 */			\
93  .byte 0x29;			/*     DW_OP_eq */			\
94  .byte 0x28; .short 0x7fff;	/*     DW_OP_bra to end */		\
95  .byte 0x13;			/*     DW_OP_drop, pop the 0 */		\
96  .byte 0x23; .uleb128 VREGS;	/*     DW_OP_plus_uconst */		\
97  .byte 0x22;			/*     DW_OP_plus */			\
98  .byte 0x2f; .short 0x7fff;	/*     DW_OP_skip to end */		\
999:
100
101/* If msr bit 1<<25 is set, then VMX register REGNO is at offset REGNO*16
102   of the VMX reg struct.  REGNO is 1 thru 31.  */
103#define vsave_msr1(regno) \
104  .byte 0x10;			/* DW_CFA_expression */			\
105  .uleb128 regno + 77;		/*   regno */				\
106  .uleb128 9f - 1f;		/*   length */				\
1071:									\
108  .byte 0x30 + regno;		/*     DW_OP_lit n */			\
109  .byte 0x2f; .short 2b - 9f;	/*     DW_OP_skip */			\
1109:
111
112/* If msr bit 1<<25 is set, then VMX register REGNO is at offset OFS of
113   the VMX save block.  */
114#define vsave_msr2(regno, ofs) \
115  .byte 0x10;			/* DW_CFA_expression */			\
116  .uleb128 regno + 77;		/*   regno */				\
117  .uleb128 9f - 1f;		/*   length */				\
1181:									\
119  .byte 0x0a; .short ofs;	/*     DW_OP_const2u */			\
120  .byte 0x2f; .short 3b - 9f;	/*     DW_OP_skip */			\
1219:
122
123/* VMX register REGNO is at offset OFS of the VMX save area.  */
124#define vsave(regno, ofs) \
125  .byte 0x10;			/* DW_CFA_expression */			\
126  .uleb128 regno + 77;		/*   regno */				\
127  .uleb128 9f - 1f;		/*   length */				\
1281:									\
129  .byte 0x71; .sleb128 PTREGS;	/*     DW_OP_breg1 */			\
130  .byte 0x06;			/*     DW_OP_deref */			\
131  .byte 0x23; .uleb128 VREGS;	/*     DW_OP_plus_uconst */		\
132  .byte 0x23; .uleb128 ofs;	/*     DW_OP_plus_uconst */		\
1339:
134
135/* This is where the pt_regs pointer can be found on the stack.  */
136#define PTREGS 64+28
137
138/* Size of regs.  */
139#define RSIZE 4
140
141/* This is the offset of the VMX regs.  */
142#define VREGS 48*RSIZE+34*8
143
144/* Describe where general purpose regs are saved.  */
145#define EH_FRAME_GEN \
146  cfa_save;								\
147  rsave ( 0,  0*RSIZE);							\
148  rsave ( 2,  2*RSIZE);							\
149  rsave ( 3,  3*RSIZE);							\
150  rsave ( 4,  4*RSIZE);							\
151  rsave ( 5,  5*RSIZE);							\
152  rsave ( 6,  6*RSIZE);							\
153  rsave ( 7,  7*RSIZE);							\
154  rsave ( 8,  8*RSIZE);							\
155  rsave ( 9,  9*RSIZE);							\
156  rsave (10, 10*RSIZE);							\
157  rsave (11, 11*RSIZE);							\
158  rsave (12, 12*RSIZE);							\
159  rsave (13, 13*RSIZE);							\
160  rsave (14, 14*RSIZE);							\
161  rsave (15, 15*RSIZE);							\
162  rsave (16, 16*RSIZE);							\
163  rsave (17, 17*RSIZE);							\
164  rsave (18, 18*RSIZE);							\
165  rsave (19, 19*RSIZE);							\
166  rsave (20, 20*RSIZE);							\
167  rsave (21, 21*RSIZE);							\
168  rsave (22, 22*RSIZE);							\
169  rsave (23, 23*RSIZE);							\
170  rsave (24, 24*RSIZE);							\
171  rsave (25, 25*RSIZE);							\
172  rsave (26, 26*RSIZE);							\
173  rsave (27, 27*RSIZE);							\
174  rsave (28, 28*RSIZE);							\
175  rsave (29, 29*RSIZE);							\
176  rsave (30, 30*RSIZE);							\
177  rsave (31, 31*RSIZE);							\
178  rsave (67, 32*RSIZE);		/* ap, used as temp for nip */		\
179  rsave (65, 36*RSIZE);		/* lr */				\
180  rsave (70, 38*RSIZE)		/* cr */
181
182/* Describe where the FP regs are saved.  */
183#define EH_FRAME_FP \
184  rsave (32, 48*RSIZE +  0*8);						\
185  rsave (33, 48*RSIZE +  1*8);						\
186  rsave (34, 48*RSIZE +  2*8);						\
187  rsave (35, 48*RSIZE +  3*8);						\
188  rsave (36, 48*RSIZE +  4*8);						\
189  rsave (37, 48*RSIZE +  5*8);						\
190  rsave (38, 48*RSIZE +  6*8);						\
191  rsave (39, 48*RSIZE +  7*8);						\
192  rsave (40, 48*RSIZE +  8*8);						\
193  rsave (41, 48*RSIZE +  9*8);						\
194  rsave (42, 48*RSIZE + 10*8);						\
195  rsave (43, 48*RSIZE + 11*8);						\
196  rsave (44, 48*RSIZE + 12*8);						\
197  rsave (45, 48*RSIZE + 13*8);						\
198  rsave (46, 48*RSIZE + 14*8);						\
199  rsave (47, 48*RSIZE + 15*8);						\
200  rsave (48, 48*RSIZE + 16*8);						\
201  rsave (49, 48*RSIZE + 17*8);						\
202  rsave (50, 48*RSIZE + 18*8);						\
203  rsave (51, 48*RSIZE + 19*8);						\
204  rsave (52, 48*RSIZE + 20*8);						\
205  rsave (53, 48*RSIZE + 21*8);						\
206  rsave (54, 48*RSIZE + 22*8);						\
207  rsave (55, 48*RSIZE + 23*8);						\
208  rsave (56, 48*RSIZE + 24*8);						\
209  rsave (57, 48*RSIZE + 25*8);						\
210  rsave (58, 48*RSIZE + 26*8);						\
211  rsave (59, 48*RSIZE + 27*8);						\
212  rsave (60, 48*RSIZE + 28*8);						\
213  rsave (61, 48*RSIZE + 29*8);						\
214  rsave (62, 48*RSIZE + 30*8);						\
215  rsave (63, 48*RSIZE + 31*8)
216
217/* Describe where the VMX regs are saved.  */
218#ifdef CONFIG_ALTIVEC
219#define EH_FRAME_VMX \
220  vsave_msr0 ( 0);							\
221  vsave_msr1 ( 1);							\
222  vsave_msr1 ( 2);							\
223  vsave_msr1 ( 3);							\
224  vsave_msr1 ( 4);							\
225  vsave_msr1 ( 5);							\
226  vsave_msr1 ( 6);							\
227  vsave_msr1 ( 7);							\
228  vsave_msr1 ( 8);							\
229  vsave_msr1 ( 9);							\
230  vsave_msr1 (10);							\
231  vsave_msr1 (11);							\
232  vsave_msr1 (12);							\
233  vsave_msr1 (13);							\
234  vsave_msr1 (14);							\
235  vsave_msr1 (15);							\
236  vsave_msr1 (16);							\
237  vsave_msr1 (17);							\
238  vsave_msr1 (18);							\
239  vsave_msr1 (19);							\
240  vsave_msr1 (20);							\
241  vsave_msr1 (21);							\
242  vsave_msr1 (22);							\
243  vsave_msr1 (23);							\
244  vsave_msr1 (24);							\
245  vsave_msr1 (25);							\
246  vsave_msr1 (26);							\
247  vsave_msr1 (27);							\
248  vsave_msr1 (28);							\
249  vsave_msr1 (29);							\
250  vsave_msr1 (30);							\
251  vsave_msr1 (31);							\
252  vsave_msr2 (33, 32*16+12);						\
253  vsave      (32, 32*16)
254#else
255#define EH_FRAME_VMX
256#endif
257
258.Lcie:
259	.long .Lcie_end - .Lcie_start
260.Lcie_start:
261	.long 0			/* CIE ID */
262	.byte 1			/* Version number */
263	.string "zRS"		/* NUL-terminated augmentation string */
264	.uleb128 4		/* Code alignment factor */
265	.sleb128 -4		/* Data alignment factor */
266	.byte 67		/* Return address register column, ap */
267	.uleb128 1		/* Augmentation value length */
268	.byte 0x1b		/* DW_EH_PE_pcrel | DW_EH_PE_sdata4. */
269	.byte 0x0c,1,0		/* DW_CFA_def_cfa: r1 ofs 0 */
270	.balign 4
271.Lcie_end:
272
273	.long .Lfde0_end - .Lfde0_start
274.Lfde0_start:
275	.long .Lfde0_start - .Lcie	/* CIE pointer. */
276	.long .Lsig_start - .		/* PC start, length */
277	.long .Lsig_end - .Lsig_start
278	.uleb128 0			/* Augmentation */
279	EH_FRAME_GEN
280	EH_FRAME_FP
281	EH_FRAME_VMX
282	.balign 4
283.Lfde0_end:
284
285/* We have a different stack layout for rt_sigreturn.  */
286#undef PTREGS
287#define PTREGS 64+16+128+20+28
288
289	.long .Lfde1_end - .Lfde1_start
290.Lfde1_start:
291	.long .Lfde1_start - .Lcie	/* CIE pointer. */
292	.long .Lsigrt_start - .		/* PC start, length */
293	.long .Lsigrt_end - .Lsigrt_start
294	.uleb128 0			/* Augmentation */
295	EH_FRAME_GEN
296	EH_FRAME_FP
297	EH_FRAME_VMX
298	.balign 4
299.Lfde1_end:
300