2 * linux/arch/unicore32/mm/alignment.c
4 * Code specific to PKUnity SoC and UniCore ISA
6 * Copyright (C) 2001-2010 GUAN Xue-tao
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
14 * FPU ldm/stm not handling
16 #include <linux/compiler.h>
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/string.h>
20 #include <linux/init.h>
21 #include <linux/sched.h>
22 #include <linux/uaccess.h>
24 #include <asm/tlbflush.h>
25 #include <asm/unaligned.h>
29 #define CODING_BITS(i) (i & 0xe0000120)
31 #define LDST_P_BIT(i) (i & (1 << 28)) /* Preindex */
32 #define LDST_U_BIT(i) (i & (1 << 27)) /* Add offset */
33 #define LDST_W_BIT(i) (i & (1 << 25)) /* Writeback */
34 #define LDST_L_BIT(i) (i & (1 << 24)) /* Load */
36 #define LDST_P_EQ_U(i) ((((i) ^ ((i) >> 1)) & (1 << 27)) == 0)
38 #define LDSTH_I_BIT(i) (i & (1 << 26)) /* half-word immed */
39 #define LDM_S_BIT(i) (i & (1 << 26)) /* write ASR from BSR */
40 #define LDM_H_BIT(i) (i & (1 << 6)) /* select r0-r15 or r16-r31 */
42 #define RN_BITS(i) ((i >> 19) & 31) /* Rn */
43 #define RD_BITS(i) ((i >> 14) & 31) /* Rd */
44 #define RM_BITS(i) (i & 31) /* Rm */
46 #define REGMASK_BITS(i) (((i & 0x7fe00) >> 3) | (i & 0x3f))
47 #define OFFSET_BITS(i) (i & 0x03fff)
49 #define SHIFT_BITS(i) ((i >> 9) & 0x1f)
50 #define SHIFT_TYPE(i) (i & 0xc0)
51 #define SHIFT_LSL 0x00
52 #define SHIFT_LSR 0x40
53 #define SHIFT_ASR 0x80
54 #define SHIFT_RORRRX 0xc0
66 #define TYPE_COLS 5 /* Coprocessor load/store */
68 #define get8_unaligned_check(val, addr, err) \
70 "1: ldb.u %1, [%2], #1\n" \
72 " .pushsection .fixup,\"ax\"\n" \
77 " .pushsection __ex_table,\"a\"\n" \
81 : "=r" (err), "=&r" (val), "=r" (addr) \
82 : "0" (err), "2" (addr))
84 #define get8t_unaligned_check(val, addr, err) \
86 "1: ldb.u %1, [%2], #1\n" \
88 " .pushsection .fixup,\"ax\"\n" \
93 " .pushsection __ex_table,\"a\"\n" \
97 : "=r" (err), "=&r" (val), "=r" (addr) \
98 : "0" (err), "2" (addr))
100 #define get16_unaligned_check(val, addr) \
102 unsigned int err = 0, v, a = addr; \
103 get8_unaligned_check(val, a, err); \
104 get8_unaligned_check(v, a, err); \
110 #define put16_unaligned_check(val, addr) \
112 unsigned int err = 0, v = val, a = addr; \
114 "1: stb.u %1, [%2], #1\n" \
115 " mov %1, %1 >> #8\n" \
116 "2: stb.u %1, [%2]\n" \
118 " .pushsection .fixup,\"ax\"\n" \
123 " .pushsection __ex_table,\"a\"\n" \
128 : "=r" (err), "=&r" (v), "=&r" (a) \
129 : "0" (err), "1" (v), "2" (a)); \
134 #define __put32_unaligned_check(ins, val, addr) \
136 unsigned int err = 0, v = val, a = addr; \
138 "1: "ins" %1, [%2], #1\n" \
139 " mov %1, %1 >> #8\n" \
140 "2: "ins" %1, [%2], #1\n" \
141 " mov %1, %1 >> #8\n" \
142 "3: "ins" %1, [%2], #1\n" \
143 " mov %1, %1 >> #8\n" \
144 "4: "ins" %1, [%2]\n" \
146 " .pushsection .fixup,\"ax\"\n" \
151 " .pushsection __ex_table,\"a\"\n" \
158 : "=r" (err), "=&r" (v), "=&r" (a) \
159 : "0" (err), "1" (v), "2" (a)); \
164 #define get32_unaligned_check(val, addr) \
166 unsigned int err = 0, v, a = addr; \
167 get8_unaligned_check(val, a, err); \
168 get8_unaligned_check(v, a, err); \
170 get8_unaligned_check(v, a, err); \
172 get8_unaligned_check(v, a, err); \
178 #define put32_unaligned_check(val, addr) \
179 __put32_unaligned_check("stb.u", val, addr)
181 #define get32t_unaligned_check(val, addr) \
183 unsigned int err = 0, v, a = addr; \
184 get8t_unaligned_check(val, a, err); \
185 get8t_unaligned_check(v, a, err); \
187 get8t_unaligned_check(v, a, err); \
189 get8t_unaligned_check(v, a, err); \
195 #define put32t_unaligned_check(val, addr) \
196 __put32_unaligned_check("stb.u", val, addr)
199 do_alignment_finish_ldst(unsigned long addr
, unsigned long instr
,
200 struct pt_regs
*regs
, union offset_union offset
)
202 if (!LDST_U_BIT(instr
))
203 offset
.un
= -offset
.un
;
205 if (!LDST_P_BIT(instr
))
208 if (!LDST_P_BIT(instr
) || LDST_W_BIT(instr
))
209 regs
->uregs
[RN_BITS(instr
)] = addr
;
213 do_alignment_ldrhstrh(unsigned long addr
, unsigned long instr
,
214 struct pt_regs
*regs
)
216 unsigned int rd
= RD_BITS(instr
);
218 /* old value 0x40002120, can't judge swap instr correctly */
219 if ((instr
& 0x4b003fe0) == 0x40000120)
222 if (LDST_L_BIT(instr
)) {
224 get16_unaligned_check(val
, addr
);
226 /* signed half-word? */
228 val
= (signed long)((signed short)val
);
230 regs
->uregs
[rd
] = val
;
232 put16_unaligned_check(regs
->uregs
[rd
], addr
);
237 /* only handle swap word
238 * for swap byte should not active this alignment exception */
239 get32_unaligned_check(regs
->uregs
[RD_BITS(instr
)], addr
);
240 put32_unaligned_check(regs
->uregs
[RM_BITS(instr
)], addr
);
248 do_alignment_ldrstr(unsigned long addr
, unsigned long instr
,
249 struct pt_regs
*regs
)
251 unsigned int rd
= RD_BITS(instr
);
253 if (!LDST_P_BIT(instr
) && LDST_W_BIT(instr
))
256 if (LDST_L_BIT(instr
))
257 get32_unaligned_check(regs
->uregs
[rd
], addr
);
259 put32_unaligned_check(regs
->uregs
[rd
], addr
);
263 if (LDST_L_BIT(instr
))
264 get32t_unaligned_check(regs
->uregs
[rd
], addr
);
266 put32t_unaligned_check(regs
->uregs
[rd
], addr
);
274 * LDM/STM alignment handler.
276 * There are 4 variants of this instruction:
278 * B = rn pointer before instruction, A = rn pointer after instruction
279 * ------ increasing address ----->
280 * | | r0 | r1 | ... | rx | |
287 do_alignment_ldmstm(unsigned long addr
, unsigned long instr
,
288 struct pt_regs
*regs
)
290 unsigned int rd
, rn
, pc_correction
, reg_correction
, nr_regs
, regbits
;
291 unsigned long eaddr
, newaddr
;
293 if (LDM_S_BIT(instr
))
296 pc_correction
= 4; /* processor implementation defined */
298 /* count the number of registers in the mask to be transferred */
299 nr_regs
= hweight16(REGMASK_BITS(instr
)) * 4;
302 newaddr
= eaddr
= regs
->uregs
[rn
];
304 if (!LDST_U_BIT(instr
))
307 if (!LDST_U_BIT(instr
))
310 if (LDST_P_EQ_U(instr
)) /* U = P */
314 * This is a "hint" - we already have eaddr worked out by the
318 printk(KERN_ERR
"LDMSTM: PC = %08lx, instr = %08lx, "
319 "addr = %08lx, eaddr = %08lx\n",
320 instruction_pointer(regs
), instr
, addr
, eaddr
);
324 if (LDM_H_BIT(instr
))
325 reg_correction
= 0x10;
327 reg_correction
= 0x00;
329 for (regbits
= REGMASK_BITS(instr
), rd
= 0; regbits
;
330 regbits
>>= 1, rd
+= 1)
332 if (LDST_L_BIT(instr
))
333 get32_unaligned_check(regs
->
334 uregs
[rd
+ reg_correction
], eaddr
);
336 put32_unaligned_check(regs
->
337 uregs
[rd
+ reg_correction
], eaddr
);
341 if (LDST_W_BIT(instr
))
342 regs
->uregs
[rn
] = newaddr
;
346 regs
->UCreg_pc
-= pc_correction
;
350 printk(KERN_ERR
"Alignment trap: not handling ldm with s-bit set\n");
355 do_alignment(unsigned long addr
, unsigned int error_code
, struct pt_regs
*regs
)
357 union offset_union offset
;
358 unsigned long instr
, instrptr
;
359 int (*handler
) (unsigned long addr
, unsigned long instr
,
360 struct pt_regs
*regs
);
363 instrptr
= instruction_pointer(regs
);
364 if (instrptr
>= PAGE_OFFSET
)
365 instr
= *(unsigned long *)instrptr
;
367 __asm__
__volatile__(
375 switch (CODING_BITS(instr
)) {
376 case 0x40000120: /* ldrh or strh */
377 if (LDSTH_I_BIT(instr
))
378 offset
.un
= (instr
& 0x3e00) >> 4 | (instr
& 31);
380 offset
.un
= regs
->uregs
[RM_BITS(instr
)];
381 handler
= do_alignment_ldrhstrh
;
384 case 0x60000000: /* ldr or str immediate */
385 case 0x60000100: /* ldr or str immediate */
386 case 0x60000020: /* ldr or str immediate */
387 case 0x60000120: /* ldr or str immediate */
388 offset
.un
= OFFSET_BITS(instr
);
389 handler
= do_alignment_ldrstr
;
392 case 0x40000000: /* ldr or str register */
393 offset
.un
= regs
->uregs
[RM_BITS(instr
)];
395 unsigned int shiftval
= SHIFT_BITS(instr
);
397 switch (SHIFT_TYPE(instr
)) {
399 offset
.un
<<= shiftval
;
403 offset
.un
>>= shiftval
;
407 offset
.sn
>>= shiftval
;
413 if (regs
->UCreg_asr
& PSR_C_BIT
)
414 offset
.un
|= 1 << 31;
416 offset
.un
= offset
.un
>> shiftval
|
417 offset
.un
<< (32 - shiftval
);
421 handler
= do_alignment_ldrstr
;
424 case 0x80000000: /* ldm or stm */
425 case 0x80000020: /* ldm or stm */
426 handler
= do_alignment_ldmstm
;
433 type
= handler(addr
, instr
, regs
);
435 if (type
== TYPE_ERROR
|| type
== TYPE_FAULT
)
438 if (type
== TYPE_LDST
)
439 do_alignment_finish_ldst(addr
, instr
, regs
, offset
);
444 if (type
== TYPE_ERROR
)
448 * We got a fault - fix it up, or die.
450 do_bad_area(addr
, error_code
, regs
);
455 * Oops, we didn't handle the instruction.
456 * However, we must handle fpu instr firstly.
458 #ifdef CONFIG_UNICORE_FPU_F64
459 /* handle co.load/store */
460 #define CODING_COLS 0xc0000000
461 #define COLS_OFFSET_BITS(i) (i & 0x1FF)
462 #define COLS_L_BITS(i) (i & (1<<24))
463 #define COLS_FN_BITS(i) ((i>>14) & 31)
464 if ((instr
& 0xe0000000) == CODING_COLS
) {
465 unsigned int fn
= COLS_FN_BITS(instr
);
466 unsigned long val
= 0;
467 if (COLS_L_BITS(instr
)) {
468 get32t_unaligned_check(val
, addr
);
470 #define ASM_MTF(n) case n: \
471 __asm__ __volatile__("MTF %0, F" __stringify(n) \
474 ASM_MTF(0); ASM_MTF(1); ASM_MTF(2); ASM_MTF(3);
475 ASM_MTF(4); ASM_MTF(5); ASM_MTF(6); ASM_MTF(7);
476 ASM_MTF(8); ASM_MTF(9); ASM_MTF(10); ASM_MTF(11);
477 ASM_MTF(12); ASM_MTF(13); ASM_MTF(14); ASM_MTF(15);
478 ASM_MTF(16); ASM_MTF(17); ASM_MTF(18); ASM_MTF(19);
479 ASM_MTF(20); ASM_MTF(21); ASM_MTF(22); ASM_MTF(23);
480 ASM_MTF(24); ASM_MTF(25); ASM_MTF(26); ASM_MTF(27);
481 ASM_MTF(28); ASM_MTF(29); ASM_MTF(30); ASM_MTF(31);
486 #define ASM_MFF(n) case n: \
487 __asm__ __volatile__("MFF %0, F" __stringify(n) \
490 ASM_MFF(0); ASM_MFF(1); ASM_MFF(2); ASM_MFF(3);
491 ASM_MFF(4); ASM_MFF(5); ASM_MFF(6); ASM_MFF(7);
492 ASM_MFF(8); ASM_MFF(9); ASM_MFF(10); ASM_MFF(11);
493 ASM_MFF(12); ASM_MFF(13); ASM_MFF(14); ASM_MFF(15);
494 ASM_MFF(16); ASM_MFF(17); ASM_MFF(18); ASM_MFF(19);
495 ASM_MFF(20); ASM_MFF(21); ASM_MFF(22); ASM_MFF(23);
496 ASM_MFF(24); ASM_MFF(25); ASM_MFF(26); ASM_MFF(27);
497 ASM_MFF(28); ASM_MFF(29); ASM_MFF(30); ASM_MFF(31);
500 put32t_unaligned_check(val
, addr
);
507 printk(KERN_ERR
"Alignment trap: not handling instruction "
508 "%08lx at [<%08lx>]\n", instr
, instrptr
);
513 * This needs to be done after sysctl_init, otherwise sys/ will be
514 * overwritten. Actually, this shouldn't be in sys/ at all since
515 * it isn't a sysctl, and it doesn't contain sysctl information.
517 static int __init
alignment_init(void)
519 hook_fault_code(1, do_alignment
, SIGBUS
, BUS_ADRALN
,
520 "alignment exception");
525 fs_initcall(alignment_init
);