1 /* align.c - handle alignment exceptions for the Power PC.
3 * Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au>
4 * Copyright (c) 1998-1999 TiVo, Inc.
5 * PowerPC 403GCX modifications.
6 * Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu>
7 * PowerPC 403GCX/405GP modifications.
8 * Copyright (c) 2001-2002 PPC64 team, IBM Corp
9 * 64-bit and Power4 support
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
17 #include <linux/kernel.h>
19 #include <asm/processor.h>
20 #include <asm/uaccess.h>
21 #include <asm/system.h>
22 #include <asm/cache.h>
23 #include <asm/cputable.h>
30 #define IS_XFORM(inst) (((inst) >> 26) == 31)
31 #define IS_DSFORM(inst) (((inst) >> 26) >= 56)
33 #define INVALID { 0, 0 }
35 #define LD 1 /* load */
36 #define ST 2 /* store */
37 #define SE 4 /* sign-extend value */
38 #define F 8 /* to/from fp regs */
39 #define U 0x10 /* update index register */
40 #define M 0x20 /* multiple load/store */
41 #define SW 0x40 /* byte swap */
43 #define DCBZ 0x5f /* 8xx/82xx dcbz faults when cache not enabled */
46 * The PowerPC stores certain bits of the instruction that caused the
47 * alignment exception in the DSISR register. This array maps those
48 * bits to information about the operand length and what the
49 * instruction would do.
51 static struct aligninfo aligninfo
[128] = {
52 { 4, LD
}, /* 00 0 0000: lwz / lwarx */
53 INVALID
, /* 00 0 0001 */
54 { 4, ST
}, /* 00 0 0010: stw */
55 INVALID
, /* 00 0 0011 */
56 { 2, LD
}, /* 00 0 0100: lhz */
57 { 2, LD
+SE
}, /* 00 0 0101: lha */
58 { 2, ST
}, /* 00 0 0110: sth */
59 { 4, LD
+M
}, /* 00 0 0111: lmw */
60 { 4, LD
+F
}, /* 00 0 1000: lfs */
61 { 8, LD
+F
}, /* 00 0 1001: lfd */
62 { 4, ST
+F
}, /* 00 0 1010: stfs */
63 { 8, ST
+F
}, /* 00 0 1011: stfd */
64 INVALID
, /* 00 0 1100 */
65 { 8, LD
}, /* 00 0 1101: ld */
66 INVALID
, /* 00 0 1110 */
67 { 8, ST
}, /* 00 0 1111: std */
68 { 4, LD
+U
}, /* 00 1 0000: lwzu */
69 INVALID
, /* 00 1 0001 */
70 { 4, ST
+U
}, /* 00 1 0010: stwu */
71 INVALID
, /* 00 1 0011 */
72 { 2, LD
+U
}, /* 00 1 0100: lhzu */
73 { 2, LD
+SE
+U
}, /* 00 1 0101: lhau */
74 { 2, ST
+U
}, /* 00 1 0110: sthu */
75 { 4, ST
+M
}, /* 00 1 0111: stmw */
76 { 4, LD
+F
+U
}, /* 00 1 1000: lfsu */
77 { 8, LD
+F
+U
}, /* 00 1 1001: lfdu */
78 { 4, ST
+F
+U
}, /* 00 1 1010: stfsu */
79 { 8, ST
+F
+U
}, /* 00 1 1011: stfdu */
80 INVALID
, /* 00 1 1100 */
81 INVALID
, /* 00 1 1101 */
82 INVALID
, /* 00 1 1110 */
83 INVALID
, /* 00 1 1111 */
84 { 8, LD
}, /* 01 0 0000: ldx */
85 INVALID
, /* 01 0 0001 */
86 { 8, ST
}, /* 01 0 0010: stdx */
87 INVALID
, /* 01 0 0011 */
88 INVALID
, /* 01 0 0100 */
89 { 4, LD
+SE
}, /* 01 0 0101: lwax */
90 INVALID
, /* 01 0 0110 */
91 INVALID
, /* 01 0 0111 */
92 { 0, LD
}, /* 01 0 1000: lswx */
93 { 0, LD
}, /* 01 0 1001: lswi */
94 { 0, ST
}, /* 01 0 1010: stswx */
95 { 0, ST
}, /* 01 0 1011: stswi */
96 INVALID
, /* 01 0 1100 */
97 { 8, LD
+U
}, /* 01 0 1101: ldu */
98 INVALID
, /* 01 0 1110 */
99 { 8, ST
+U
}, /* 01 0 1111: stdu */
100 { 8, LD
+U
}, /* 01 1 0000: ldux */
101 INVALID
, /* 01 1 0001 */
102 { 8, ST
+U
}, /* 01 1 0010: stdux */
103 INVALID
, /* 01 1 0011 */
104 INVALID
, /* 01 1 0100 */
105 { 4, LD
+SE
+U
}, /* 01 1 0101: lwaux */
106 INVALID
, /* 01 1 0110 */
107 INVALID
, /* 01 1 0111 */
108 INVALID
, /* 01 1 1000 */
109 INVALID
, /* 01 1 1001 */
110 INVALID
, /* 01 1 1010 */
111 INVALID
, /* 01 1 1011 */
112 INVALID
, /* 01 1 1100 */
113 INVALID
, /* 01 1 1101 */
114 INVALID
, /* 01 1 1110 */
115 INVALID
, /* 01 1 1111 */
116 INVALID
, /* 10 0 0000 */
117 INVALID
, /* 10 0 0001 */
118 { 0, ST
}, /* 10 0 0010: stwcx. */
119 INVALID
, /* 10 0 0011 */
120 INVALID
, /* 10 0 0100 */
121 INVALID
, /* 10 0 0101 */
122 INVALID
, /* 10 0 0110 */
123 INVALID
, /* 10 0 0111 */
124 { 4, LD
+SW
}, /* 10 0 1000: lwbrx */
125 INVALID
, /* 10 0 1001 */
126 { 4, ST
+SW
}, /* 10 0 1010: stwbrx */
127 INVALID
, /* 10 0 1011 */
128 { 2, LD
+SW
}, /* 10 0 1100: lhbrx */
129 { 4, LD
+SE
}, /* 10 0 1101 lwa */
130 { 2, ST
+SW
}, /* 10 0 1110: sthbrx */
131 INVALID
, /* 10 0 1111 */
132 INVALID
, /* 10 1 0000 */
133 INVALID
, /* 10 1 0001 */
134 INVALID
, /* 10 1 0010 */
135 INVALID
, /* 10 1 0011 */
136 INVALID
, /* 10 1 0100 */
137 INVALID
, /* 10 1 0101 */
138 INVALID
, /* 10 1 0110 */
139 INVALID
, /* 10 1 0111 */
140 INVALID
, /* 10 1 1000 */
141 INVALID
, /* 10 1 1001 */
142 INVALID
, /* 10 1 1010 */
143 INVALID
, /* 10 1 1011 */
144 INVALID
, /* 10 1 1100 */
145 INVALID
, /* 10 1 1101 */
146 INVALID
, /* 10 1 1110 */
147 { L1_CACHE_BYTES
, ST
}, /* 10 1 1111: dcbz */
148 { 4, LD
}, /* 11 0 0000: lwzx */
149 INVALID
, /* 11 0 0001 */
150 { 4, ST
}, /* 11 0 0010: stwx */
151 INVALID
, /* 11 0 0011 */
152 { 2, LD
}, /* 11 0 0100: lhzx */
153 { 2, LD
+SE
}, /* 11 0 0101: lhax */
154 { 2, ST
}, /* 11 0 0110: sthx */
155 INVALID
, /* 11 0 0111 */
156 { 4, LD
+F
}, /* 11 0 1000: lfsx */
157 { 8, LD
+F
}, /* 11 0 1001: lfdx */
158 { 4, ST
+F
}, /* 11 0 1010: stfsx */
159 { 8, ST
+F
}, /* 11 0 1011: stfdx */
160 INVALID
, /* 11 0 1100 */
161 { 8, LD
+M
}, /* 11 0 1101: lmd */
162 INVALID
, /* 11 0 1110 */
163 { 8, ST
+M
}, /* 11 0 1111: stmd */
164 { 4, LD
+U
}, /* 11 1 0000: lwzux */
165 INVALID
, /* 11 1 0001 */
166 { 4, ST
+U
}, /* 11 1 0010: stwux */
167 INVALID
, /* 11 1 0011 */
168 { 2, LD
+U
}, /* 11 1 0100: lhzux */
169 { 2, LD
+SE
+U
}, /* 11 1 0101: lhaux */
170 { 2, ST
+U
}, /* 11 1 0110: sthux */
171 INVALID
, /* 11 1 0111 */
172 { 4, LD
+F
+U
}, /* 11 1 1000: lfsux */
173 { 8, LD
+F
+U
}, /* 11 1 1001: lfdux */
174 { 4, ST
+F
+U
}, /* 11 1 1010: stfsux */
175 { 8, ST
+F
+U
}, /* 11 1 1011: stfdux */
176 INVALID
, /* 11 1 1100 */
177 INVALID
, /* 11 1 1101 */
178 INVALID
, /* 11 1 1110 */
179 INVALID
, /* 11 1 1111 */
182 #define SWAP(a, b) (t = (a), (a) = (b), (b) = t)
184 static inline unsigned make_dsisr(unsigned instr
)
188 /* create a DSISR value from the instruction */
189 dsisr
= (instr
& 0x03ff0000) >> 16; /* bits 6:15 --> 22:31 */
191 if ( IS_XFORM(instr
) ) {
192 dsisr
|= (instr
& 0x00000006) << 14; /* bits 29:30 --> 15:16 */
193 dsisr
|= (instr
& 0x00000040) << 8; /* bit 25 --> 17 */
194 dsisr
|= (instr
& 0x00000780) << 3; /* bits 21:24 --> 18:21 */
197 dsisr
|= (instr
& 0x04000000) >> 12; /* bit 5 --> 17 */
198 dsisr
|= (instr
& 0x78000000) >> 17; /* bits 1: 4 --> 18:21 */
199 if ( IS_DSFORM(instr
) ) {
200 dsisr
|= (instr
& 0x00000003) << 18; /* bits 30:31 --> 12:13 */
208 fix_alignment(struct pt_regs
*regs
)
210 unsigned int instr
, nb
, flags
;
212 unsigned long reg
, areg
;
216 unsigned char __user
*addr
;
217 unsigned char __user
*p
;
218 unsigned long __user
*lp
;
228 unsigned char hi48
[6];
234 * Return 1 on success
235 * Return 0 if unable to handle the interrupt
236 * Return -EFAULT if data address is bad
241 if (cpu_has_feature(CPU_FTR_NODSISRALIGN
)) {
242 unsigned int real_instr
;
243 if (__get_user(real_instr
, (unsigned int __user
*)regs
->nip
))
245 dsisr
= make_dsisr(real_instr
);
248 /* extract the operation and registers from the dsisr */
249 reg
= (dsisr
>> 5) & 0x1f; /* source/dest register */
250 areg
= dsisr
& 0x1f; /* register to update */
251 instr
= (dsisr
>> 10) & 0x7f;
252 instr
|= (dsisr
>> 13) & 0x60;
254 /* Lookup the operation in our table */
255 nb
= aligninfo
[instr
].len
;
256 flags
= aligninfo
[instr
].flags
;
258 /* DAR has the operand effective address */
259 addr
= (unsigned char __user
*)regs
->dar
;
261 /* A size of 0 indicates an instruction we don't support */
262 /* we also don't support the multiples (lmw, stmw, lmd, stmd) */
263 if ((nb
== 0) || (flags
& M
))
264 return 0; /* too hard or invalid instruction */
267 * Special handling for dcbz
268 * dcbz may give an alignment exception for accesses to caching inhibited
272 addr
= (unsigned char __user
*) ((unsigned long)addr
& -L1_CACHE_BYTES
);
274 /* Verify the address of the operand */
275 if (user_mode(regs
)) {
276 if (!access_ok((flags
& ST
? VERIFY_WRITE
: VERIFY_READ
), addr
, nb
))
277 return -EFAULT
; /* bad address */
280 /* Force the fprs into the save area so we can reference them */
282 if (!user_mode(regs
))
284 flush_fp_to_thread(current
);
287 /* If we are loading, get the data from user space */
294 ret
|= __get_user(data
.v
[0], p
++);
295 ret
|= __get_user(data
.v
[1], p
++);
296 ret
|= __get_user(data
.v
[2], p
++);
297 ret
|= __get_user(data
.v
[3], p
++);
299 ret
|= __get_user(data
.v
[4], p
++);
300 ret
|= __get_user(data
.v
[5], p
++);
302 ret
|= __get_user(data
.v
[6], p
++);
303 ret
|= __get_user(data
.v
[7], p
++);
309 /* If we are storing, get the data from the saved gpr or fpr */
313 /* Doing stfs, have to convert to single */
316 cvt_df(¤t
->thread
.fpr
[reg
], (float *)&data
.v
[4], ¤t
->thread
.fpscr
);
321 data
.dd
= current
->thread
.fpr
[reg
];
324 data
.ll
= regs
->gpr
[reg
];
327 /* Swap bytes as needed */
330 SWAP(data
.v
[6], data
.v
[7]);
331 else { /* nb must be 4 */
332 SWAP(data
.v
[4], data
.v
[7]);
333 SWAP(data
.v
[5], data
.v
[6]);
337 /* Sign extend as needed */
340 data
.ll
= data
.x16
.low16
;
341 else /* nb must be 4 */
342 data
.ll
= data
.x32
.low32
;
345 /* If we are loading, move the data to the gpr or fpr */
349 /* Doing lfs, have to convert to double */
352 cvt_fd((float *)&data
.v
[4], ¤t
->thread
.fpr
[reg
], ¤t
->thread
.fpscr
);
357 current
->thread
.fpr
[reg
] = data
.dd
;
360 regs
->gpr
[reg
] = data
.ll
;
363 /* If we are storing, copy the data to the user */
368 case 128: /* Special case - must be dcbz */
369 lp
= (unsigned long __user
*)p
;
370 for (i
= 0; i
< L1_CACHE_BYTES
/ sizeof(long); ++i
)
371 ret
|= __put_user(0, lp
++);
374 ret
|= __put_user(data
.v
[0], p
++);
375 ret
|= __put_user(data
.v
[1], p
++);
376 ret
|= __put_user(data
.v
[2], p
++);
377 ret
|= __put_user(data
.v
[3], p
++);
379 ret
|= __put_user(data
.v
[4], p
++);
380 ret
|= __put_user(data
.v
[5], p
++);
382 ret
|= __put_user(data
.v
[6], p
++);
383 ret
|= __put_user(data
.v
[7], p
++);
389 /* Update RA as needed */
391 regs
->gpr
[areg
] = regs
->dar
;