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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Unified implementation of memcpy, memmove and the __copy_user backend.
7 *
8 * Copyright (C) 1998, 99, 2000, 01, 2002 Ralf Baechle (ralf@gnu.org)
9 * Copyright (C) 1999, 2000, 01, 2002 Silicon Graphics, Inc.
10 * Copyright (C) 2002 Broadcom, Inc.
11 * memcpy/copy_user author: Mark Vandevoorde
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +010012 * Copyright (C) 2007 Maciej W. Rozycki
Markos Chandras5bc05972014-01-07 12:57:04 +000013 * Copyright (C) 2014 Imagination Technologies Ltd.
Linus Torvalds1da177e2005-04-16 15:20:36 -070014 *
15 * Mnemonic names for arguments to memcpy/__copy_user
16 */
Ralf Baechlee5adb872005-10-20 22:55:26 +010017
18/*
19 * Hack to resolve longstanding prefetch issue
20 *
21 * Prefetching may be fatal on some systems if we're prefetching beyond the
22 * end of memory on some systems. It's also a seriously bad idea on non
23 * dma-coherent systems.
24 */
Ralf Baechle634286f2009-01-28 17:48:40 +000025#ifdef CONFIG_DMA_NONCOHERENT
Ralf Baechlee5adb872005-10-20 22:55:26 +010026#undef CONFIG_CPU_HAS_PREFETCH
27#endif
28#ifdef CONFIG_MIPS_MALTA
29#undef CONFIG_CPU_HAS_PREFETCH
30#endif
31
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <asm/asm.h>
Sam Ravnborg048eb582005-09-09 22:32:31 +020033#include <asm/asm-offsets.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <asm/regdef.h>
35
36#define dst a0
37#define src a1
38#define len a2
39
40/*
41 * Spec
42 *
43 * memcpy copies len bytes from src to dst and sets v0 to dst.
44 * It assumes that
45 * - src and dst don't overlap
46 * - src is readable
47 * - dst is writable
48 * memcpy uses the standard calling convention
49 *
50 * __copy_user copies up to len bytes from src to dst and sets a2 (len) to
51 * the number of uncopied bytes due to an exception caused by a read or write.
52 * __copy_user assumes that src and dst don't overlap, and that the call is
53 * implementing one of the following:
54 * copy_to_user
55 * - src is readable (no exceptions when reading src)
56 * copy_from_user
57 * - dst is writable (no exceptions when writing dst)
58 * __copy_user uses a non-standard calling convention; see
59 * include/asm-mips/uaccess.h
60 *
61 * When an exception happens on a load, the handler must
62 # ensure that all of the destination buffer is overwritten to prevent
63 * leaking information to user mode programs.
64 */
65
66/*
67 * Implementation
68 */
69
70/*
71 * The exception handler for loads requires that:
72 * 1- AT contain the address of the byte just past the end of the source
73 * of the copy,
74 * 2- src_entry <= src < AT, and
75 * 3- (dst - src) == (dst_entry - src_entry),
76 * The _entry suffix denotes values when __copy_user was called.
77 *
78 * (1) is set up up by uaccess.h and maintained by not writing AT in copy_user
79 * (2) is met by incrementing src by the number of bytes copied
80 * (3) is met by not doing loads between a pair of increments of dst and src
81 *
82 * The exception handlers for stores adjust len (if necessary) and return.
83 * These handlers do not need to overwrite any data.
84 *
85 * For __rmemcpy and memmove an exception is always a kernel bug, therefore
86 * they're not protected.
87 */
88
Markos Chandras5bc05972014-01-07 12:57:04 +000089/* Instruction type */
90#define LD_INSN 1
91#define ST_INSN 2
Markos Chandrasbda4d982014-01-07 15:59:03 +000092/* Pretech type */
93#define SRC_PREFETCH 1
94#define DST_PREFETCH 2
Markos Chandrascf62a8b2014-01-07 14:34:05 +000095#define LEGACY_MODE 1
96#define EVA_MODE 2
97#define USEROP 1
98#define KERNELOP 2
Markos Chandras5bc05972014-01-07 12:57:04 +000099
100/*
101 * Wrapper to add an entry in the exception table
102 * in case the insn causes a memory exception.
103 * Arguments:
104 * insn : Load/store instruction
105 * type : Instruction type
106 * reg : Register
107 * addr : Address
108 * handler : Exception handler
109 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000111#define EXC(insn, type, reg, addr, handler) \
112 .if \mode == LEGACY_MODE; \
1139: insn reg, addr; \
114 .section __ex_table,"a"; \
115 PTR 9b, handler; \
116 .previous; \
Markos Chandrascd26cb42014-01-07 16:20:22 +0000117 /* This is assembled in EVA mode */ \
118 .else; \
119 /* If loading from user or storing to user */ \
120 .if ((\from == USEROP) && (type == LD_INSN)) || \
121 ((\to == USEROP) && (type == ST_INSN)); \
1229: __BUILD_EVA_INSN(insn##e, reg, addr); \
123 .section __ex_table,"a"; \
124 PTR 9b, handler; \
125 .previous; \
126 .else; \
127 /* \
128 * Still in EVA, but no need for \
129 * exception handler or EVA insn \
130 */ \
131 insn reg, addr; \
132 .endif; \
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000133 .endif
Markos Chandrascd26cb42014-01-07 16:20:22 +0000134
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135/*
136 * Only on the 64-bit kernel we can made use of 64-bit registers.
137 */
Ralf Baechle875d43e2005-09-03 15:56:16 -0700138#ifdef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139#define USE_DOUBLE
140#endif
141
142#ifdef USE_DOUBLE
143
Markos Chandras5bc05972014-01-07 12:57:04 +0000144#define LOADK ld /* No exception */
145#define LOAD(reg, addr, handler) EXC(ld, LD_INSN, reg, addr, handler)
146#define LOADL(reg, addr, handler) EXC(ldl, LD_INSN, reg, addr, handler)
147#define LOADR(reg, addr, handler) EXC(ldr, LD_INSN, reg, addr, handler)
148#define STOREL(reg, addr, handler) EXC(sdl, ST_INSN, reg, addr, handler)
149#define STORER(reg, addr, handler) EXC(sdr, ST_INSN, reg, addr, handler)
150#define STORE(reg, addr, handler) EXC(sd, ST_INSN, reg, addr, handler)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151#define ADD daddu
152#define SUB dsubu
153#define SRL dsrl
154#define SRA dsra
155#define SLL dsll
156#define SLLV dsllv
157#define SRLV dsrlv
158#define NBYTES 8
159#define LOG_NBYTES 3
160
Ralf Baechle42a3b4f2005-09-03 15:56:17 -0700161/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 * As we are sharing code base with the mips32 tree (which use the o32 ABI
163 * register definitions). We need to redefine the register definitions from
164 * the n64 ABI register naming to the o32 ABI register naming.
165 */
166#undef t0
167#undef t1
168#undef t2
169#undef t3
170#define t0 $8
171#define t1 $9
172#define t2 $10
173#define t3 $11
174#define t4 $12
175#define t5 $13
176#define t6 $14
177#define t7 $15
Ralf Baechle42a3b4f2005-09-03 15:56:17 -0700178
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179#else
180
Markos Chandras5bc05972014-01-07 12:57:04 +0000181#define LOADK lw /* No exception */
182#define LOAD(reg, addr, handler) EXC(lw, LD_INSN, reg, addr, handler)
183#define LOADL(reg, addr, handler) EXC(lwl, LD_INSN, reg, addr, handler)
184#define LOADR(reg, addr, handler) EXC(lwr, LD_INSN, reg, addr, handler)
185#define STOREL(reg, addr, handler) EXC(swl, ST_INSN, reg, addr, handler)
186#define STORER(reg, addr, handler) EXC(swr, ST_INSN, reg, addr, handler)
187#define STORE(reg, addr, handler) EXC(sw, ST_INSN, reg, addr, handler)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188#define ADD addu
189#define SUB subu
190#define SRL srl
191#define SLL sll
192#define SRA sra
193#define SLLV sllv
194#define SRLV srlv
195#define NBYTES 4
196#define LOG_NBYTES 2
197
198#endif /* USE_DOUBLE */
199
Markos Chandras5bc05972014-01-07 12:57:04 +0000200#define LOADB(reg, addr, handler) EXC(lb, LD_INSN, reg, addr, handler)
201#define STOREB(reg, addr, handler) EXC(sb, ST_INSN, reg, addr, handler)
202
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000203#define _PREF(hint, addr, type) \
204 .if \mode == LEGACY_MODE; \
205 PREF(hint, addr); \
Markos Chandrascd26cb42014-01-07 16:20:22 +0000206 .else; \
207 .if ((\from == USEROP) && (type == SRC_PREFETCH)) || \
208 ((\to == USEROP) && (type == DST_PREFETCH)); \
209 /* \
210 * PREFE has only 9 bits for the offset \
211 * compared to PREF which has 16, so it may \
212 * need to use the $at register but this \
213 * register should remain intact because it's \
214 * used later on. Therefore use $v1. \
215 */ \
216 .set at=v1; \
217 PREFE(hint, addr); \
218 .set noat; \
219 .else; \
220 PREF(hint, addr); \
221 .endif; \
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000222 .endif
Markos Chandrasbda4d982014-01-07 15:59:03 +0000223
224#define PREFS(hint, addr) _PREF(hint, addr, SRC_PREFETCH)
225#define PREFD(hint, addr) _PREF(hint, addr, DST_PREFETCH)
226
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227#ifdef CONFIG_CPU_LITTLE_ENDIAN
228#define LDFIRST LOADR
Ralf Baechle70342282013-01-22 12:59:30 +0100229#define LDREST LOADL
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230#define STFIRST STORER
Ralf Baechle70342282013-01-22 12:59:30 +0100231#define STREST STOREL
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232#define SHIFT_DISCARD SLLV
233#else
234#define LDFIRST LOADL
Ralf Baechle70342282013-01-22 12:59:30 +0100235#define LDREST LOADR
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236#define STFIRST STOREL
Ralf Baechle70342282013-01-22 12:59:30 +0100237#define STREST STORER
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238#define SHIFT_DISCARD SRLV
239#endif
240
241#define FIRST(unit) ((unit)*NBYTES)
242#define REST(unit) (FIRST(unit)+NBYTES-1)
243#define UNIT(unit) FIRST(unit)
244
245#define ADDRMASK (NBYTES-1)
246
247 .text
248 .set noreorder
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100249#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 .set noat
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100251#else
252 .set at=v1
253#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 .align 5
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000256
257 /*
258 * Macro to build the __copy_user common code
259 * Arguements:
260 * mode : LEGACY_MODE or EVA_MODE
261 * from : Source operand. USEROP or KERNELOP
262 * to : Destination operand. USEROP or KERNELOP
263 */
264 .macro __BUILD_COPY_USER mode, from, to
265
266 /* initialize __memcpy if this the first time we execute this macro */
267 .ifnotdef __memcpy
268 .set __memcpy, 1
269 .hidden __memcpy /* make sure it does not leak */
270 .endif
271
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 /*
273 * Note: dst & src may be unaligned, len may be 0
274 * Temps
275 */
276#define rem t8
277
Thomas Bogendoerfer930bff82007-11-25 11:47:56 +0100278 R10KCBARRIER(0(ra))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 /*
280 * The "issue break"s below are very approximate.
281 * Issue delays for dcache fills will perturb the schedule, as will
282 * load queue full replay traps, etc.
283 *
284 * If len < NBYTES use byte operations.
285 */
Markos Chandrasbda4d982014-01-07 15:59:03 +0000286 PREFS( 0, 0(src) )
287 PREFD( 1, 0(dst) )
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 sltu t2, len, NBYTES
289 and t1, dst, ADDRMASK
Markos Chandrasbda4d982014-01-07 15:59:03 +0000290 PREFS( 0, 1*32(src) )
291 PREFD( 1, 1*32(dst) )
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000292 bnez t2, .Lcopy_bytes_checklen\@
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 and t0, src, ADDRMASK
Markos Chandrasbda4d982014-01-07 15:59:03 +0000294 PREFS( 0, 2*32(src) )
295 PREFD( 1, 2*32(dst) )
Leonid Yegoshinb0ce4bd2014-11-14 11:55:50 +0000296#ifndef CONFIG_CPU_MIPSR6
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000297 bnez t1, .Ldst_unaligned\@
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 nop
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000299 bnez t0, .Lsrc_unaligned_dst_aligned\@
Leonid Yegoshinb0ce4bd2014-11-14 11:55:50 +0000300#else
301 or t0, t0, t1
302 bnez t0, .Lcopy_unaligned_bytes\@
303#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 /*
305 * use delay slot for fall-through
306 * src and dst are aligned; need to compute rem
307 */
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000308.Lboth_aligned\@:
Ralf Baechle70342282013-01-22 12:59:30 +0100309 SRL t0, len, LOG_NBYTES+3 # +3 for 8 units/iter
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000310 beqz t0, .Lcleanup_both_aligned\@ # len < 8*NBYTES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 and rem, len, (8*NBYTES-1) # rem = len % (8*NBYTES)
Markos Chandrasbda4d982014-01-07 15:59:03 +0000312 PREFS( 0, 3*32(src) )
313 PREFD( 1, 3*32(dst) )
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 .align 4
3151:
Thomas Bogendoerfer930bff82007-11-25 11:47:56 +0100316 R10KCBARRIER(0(ra))
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000317 LOAD(t0, UNIT(0)(src), .Ll_exc\@)
318 LOAD(t1, UNIT(1)(src), .Ll_exc_copy\@)
319 LOAD(t2, UNIT(2)(src), .Ll_exc_copy\@)
320 LOAD(t3, UNIT(3)(src), .Ll_exc_copy\@)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 SUB len, len, 8*NBYTES
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000322 LOAD(t4, UNIT(4)(src), .Ll_exc_copy\@)
323 LOAD(t7, UNIT(5)(src), .Ll_exc_copy\@)
324 STORE(t0, UNIT(0)(dst), .Ls_exc_p8u\@)
325 STORE(t1, UNIT(1)(dst), .Ls_exc_p7u\@)
326 LOAD(t0, UNIT(6)(src), .Ll_exc_copy\@)
327 LOAD(t1, UNIT(7)(src), .Ll_exc_copy\@)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 ADD src, src, 8*NBYTES
329 ADD dst, dst, 8*NBYTES
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000330 STORE(t2, UNIT(-6)(dst), .Ls_exc_p6u\@)
331 STORE(t3, UNIT(-5)(dst), .Ls_exc_p5u\@)
332 STORE(t4, UNIT(-4)(dst), .Ls_exc_p4u\@)
333 STORE(t7, UNIT(-3)(dst), .Ls_exc_p3u\@)
334 STORE(t0, UNIT(-2)(dst), .Ls_exc_p2u\@)
335 STORE(t1, UNIT(-1)(dst), .Ls_exc_p1u\@)
Markos Chandrasbda4d982014-01-07 15:59:03 +0000336 PREFS( 0, 8*32(src) )
337 PREFD( 1, 8*32(dst) )
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 bne len, rem, 1b
339 nop
340
341 /*
342 * len == rem == the number of bytes left to copy < 8*NBYTES
343 */
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000344.Lcleanup_both_aligned\@:
345 beqz len, .Ldone\@
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 sltu t0, len, 4*NBYTES
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000347 bnez t0, .Lless_than_4units\@
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 and rem, len, (NBYTES-1) # rem = len % NBYTES
349 /*
350 * len >= 4*NBYTES
351 */
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000352 LOAD( t0, UNIT(0)(src), .Ll_exc\@)
353 LOAD( t1, UNIT(1)(src), .Ll_exc_copy\@)
354 LOAD( t2, UNIT(2)(src), .Ll_exc_copy\@)
355 LOAD( t3, UNIT(3)(src), .Ll_exc_copy\@)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 SUB len, len, 4*NBYTES
357 ADD src, src, 4*NBYTES
Thomas Bogendoerfer930bff82007-11-25 11:47:56 +0100358 R10KCBARRIER(0(ra))
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000359 STORE(t0, UNIT(0)(dst), .Ls_exc_p4u\@)
360 STORE(t1, UNIT(1)(dst), .Ls_exc_p3u\@)
361 STORE(t2, UNIT(2)(dst), .Ls_exc_p2u\@)
362 STORE(t3, UNIT(3)(dst), .Ls_exc_p1u\@)
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100363 .set reorder /* DADDI_WAR */
364 ADD dst, dst, 4*NBYTES
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000365 beqz len, .Ldone\@
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100366 .set noreorder
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000367.Lless_than_4units\@:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 /*
369 * rem = len % NBYTES
370 */
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000371 beq rem, len, .Lcopy_bytes\@
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 nop
3731:
Thomas Bogendoerfer930bff82007-11-25 11:47:56 +0100374 R10KCBARRIER(0(ra))
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000375 LOAD(t0, 0(src), .Ll_exc\@)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 ADD src, src, NBYTES
377 SUB len, len, NBYTES
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000378 STORE(t0, 0(dst), .Ls_exc_p1u\@)
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100379 .set reorder /* DADDI_WAR */
380 ADD dst, dst, NBYTES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 bne rem, len, 1b
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100382 .set noreorder
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383
Leonid Yegoshinb0ce4bd2014-11-14 11:55:50 +0000384#ifndef CONFIG_CPU_MIPSR6
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 /*
386 * src and dst are aligned, need to copy rem bytes (rem < NBYTES)
387 * A loop would do only a byte at a time with possible branch
Ralf Baechle70342282013-01-22 12:59:30 +0100388 * mispredicts. Can't do an explicit LOAD dst,mask,or,STORE
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 * because can't assume read-access to dst. Instead, use
390 * STREST dst, which doesn't require read access to dst.
391 *
392 * This code should perform better than a simple loop on modern,
393 * wide-issue mips processors because the code has fewer branches and
394 * more instruction-level parallelism.
395 */
396#define bits t2
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000397 beqz len, .Ldone\@
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 ADD t1, dst, len # t1 is just past last byte of dst
399 li bits, 8*NBYTES
400 SLL rem, len, 3 # rem = number of bits to keep
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000401 LOAD(t0, 0(src), .Ll_exc\@)
Ralf Baechle70342282013-01-22 12:59:30 +0100402 SUB bits, bits, rem # bits = number of bits to discard
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 SHIFT_DISCARD t0, t0, bits
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000404 STREST(t0, -1(t1), .Ls_exc\@)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 jr ra
406 move len, zero
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000407.Ldst_unaligned\@:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 /*
409 * dst is unaligned
410 * t0 = src & ADDRMASK
411 * t1 = dst & ADDRMASK; T1 > 0
412 * len >= NBYTES
413 *
414 * Copy enough bytes to align dst
415 * Set match = (src and dst have same alignment)
416 */
417#define match rem
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000418 LDFIRST(t3, FIRST(0)(src), .Ll_exc\@)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 ADD t2, zero, NBYTES
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000420 LDREST(t3, REST(0)(src), .Ll_exc_copy\@)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 SUB t2, t2, t1 # t2 = number of bytes copied
422 xor match, t0, t1
Thomas Bogendoerfer930bff82007-11-25 11:47:56 +0100423 R10KCBARRIER(0(ra))
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000424 STFIRST(t3, FIRST(0)(dst), .Ls_exc\@)
425 beq len, t2, .Ldone\@
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 SUB len, len, t2
427 ADD dst, dst, t2
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000428 beqz match, .Lboth_aligned\@
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 ADD src, src, t2
430
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000431.Lsrc_unaligned_dst_aligned\@:
Ralf Baechle70342282013-01-22 12:59:30 +0100432 SRL t0, len, LOG_NBYTES+2 # +2 for 4 units/iter
Markos Chandrasbda4d982014-01-07 15:59:03 +0000433 PREFS( 0, 3*32(src) )
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000434 beqz t0, .Lcleanup_src_unaligned\@
Ralf Baechle70342282013-01-22 12:59:30 +0100435 and rem, len, (4*NBYTES-1) # rem = len % 4*NBYTES
Markos Chandrasbda4d982014-01-07 15:59:03 +0000436 PREFD( 1, 3*32(dst) )
Linus Torvalds1da177e2005-04-16 15:20:36 -07004371:
438/*
439 * Avoid consecutive LD*'s to the same register since some mips
440 * implementations can't issue them in the same cycle.
441 * It's OK to load FIRST(N+1) before REST(N) because the two addresses
442 * are to the same unit (unless src is aligned, but it's not).
443 */
Thomas Bogendoerfer930bff82007-11-25 11:47:56 +0100444 R10KCBARRIER(0(ra))
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000445 LDFIRST(t0, FIRST(0)(src), .Ll_exc\@)
446 LDFIRST(t1, FIRST(1)(src), .Ll_exc_copy\@)
Ralf Baechle70342282013-01-22 12:59:30 +0100447 SUB len, len, 4*NBYTES
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000448 LDREST(t0, REST(0)(src), .Ll_exc_copy\@)
449 LDREST(t1, REST(1)(src), .Ll_exc_copy\@)
450 LDFIRST(t2, FIRST(2)(src), .Ll_exc_copy\@)
451 LDFIRST(t3, FIRST(3)(src), .Ll_exc_copy\@)
452 LDREST(t2, REST(2)(src), .Ll_exc_copy\@)
453 LDREST(t3, REST(3)(src), .Ll_exc_copy\@)
Markos Chandrasbda4d982014-01-07 15:59:03 +0000454 PREFS( 0, 9*32(src) ) # 0 is PREF_LOAD (not streamed)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 ADD src, src, 4*NBYTES
456#ifdef CONFIG_CPU_SB1
457 nop # improves slotting
458#endif
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000459 STORE(t0, UNIT(0)(dst), .Ls_exc_p4u\@)
460 STORE(t1, UNIT(1)(dst), .Ls_exc_p3u\@)
461 STORE(t2, UNIT(2)(dst), .Ls_exc_p2u\@)
462 STORE(t3, UNIT(3)(dst), .Ls_exc_p1u\@)
Markos Chandrasbda4d982014-01-07 15:59:03 +0000463 PREFD( 1, 9*32(dst) ) # 1 is PREF_STORE (not streamed)
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100464 .set reorder /* DADDI_WAR */
465 ADD dst, dst, 4*NBYTES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 bne len, rem, 1b
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100467 .set noreorder
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000469.Lcleanup_src_unaligned\@:
470 beqz len, .Ldone\@
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 and rem, len, NBYTES-1 # rem = len % NBYTES
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000472 beq rem, len, .Lcopy_bytes\@
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473 nop
4741:
Thomas Bogendoerfer930bff82007-11-25 11:47:56 +0100475 R10KCBARRIER(0(ra))
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000476 LDFIRST(t0, FIRST(0)(src), .Ll_exc\@)
477 LDREST(t0, REST(0)(src), .Ll_exc_copy\@)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 ADD src, src, NBYTES
479 SUB len, len, NBYTES
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000480 STORE(t0, 0(dst), .Ls_exc_p1u\@)
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100481 .set reorder /* DADDI_WAR */
482 ADD dst, dst, NBYTES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 bne len, rem, 1b
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100484 .set noreorder
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485
Leonid Yegoshinb0ce4bd2014-11-14 11:55:50 +0000486#endif /* !CONFIG_CPU_MIPSR6 */
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000487.Lcopy_bytes_checklen\@:
488 beqz len, .Ldone\@
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 nop
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000490.Lcopy_bytes\@:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 /* 0 < len < NBYTES */
Thomas Bogendoerfer930bff82007-11-25 11:47:56 +0100492 R10KCBARRIER(0(ra))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493#define COPY_BYTE(N) \
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000494 LOADB(t0, N(src), .Ll_exc\@); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 SUB len, len, 1; \
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000496 beqz len, .Ldone\@; \
497 STOREB(t0, N(dst), .Ls_exc_p1\@)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498
499 COPY_BYTE(0)
500 COPY_BYTE(1)
501#ifdef USE_DOUBLE
502 COPY_BYTE(2)
503 COPY_BYTE(3)
504 COPY_BYTE(4)
505 COPY_BYTE(5)
506#endif
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000507 LOADB(t0, NBYTES-2(src), .Ll_exc\@)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 SUB len, len, 1
509 jr ra
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000510 STOREB(t0, NBYTES-2(dst), .Ls_exc_p1\@)
511.Ldone\@:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 jr ra
Markos Chandras51b10292014-11-17 09:32:38 +0000513 nop
Leonid Yegoshinb0ce4bd2014-11-14 11:55:50 +0000514
515#ifdef CONFIG_CPU_MIPSR6
516.Lcopy_unaligned_bytes\@:
5171:
518 COPY_BYTE(0)
519 COPY_BYTE(1)
520 COPY_BYTE(2)
521 COPY_BYTE(3)
522 COPY_BYTE(4)
523 COPY_BYTE(5)
524 COPY_BYTE(6)
525 COPY_BYTE(7)
526 ADD src, src, 8
527 b 1b
528 ADD dst, dst, 8
529#endif /* CONFIG_CPU_MIPSR6 */
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000530 .if __memcpy == 1
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 END(memcpy)
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000532 .set __memcpy, 0
533 .hidden __memcpy
534 .endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000536.Ll_exc_copy\@:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 /*
538 * Copy bytes from src until faulting load address (or until a
539 * lb faults)
540 *
541 * When reached by a faulting LDFIRST/LDREST, THREAD_BUADDR($28)
542 * may be more than a byte beyond the last address.
543 * Hence, the lb below may get an exception.
544 *
545 * Assumes src < THREAD_BUADDR($28)
546 */
Markos Chandras5bc05972014-01-07 12:57:04 +0000547 LOADK t0, TI_TASK($28)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 nop
Markos Chandras5bc05972014-01-07 12:57:04 +0000549 LOADK t0, THREAD_BUADDR(t0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07005501:
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000551 LOADB(t1, 0(src), .Ll_exc\@)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 ADD src, src, 1
553 sb t1, 0(dst) # can't fault -- we're copy_from_user
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100554 .set reorder /* DADDI_WAR */
555 ADD dst, dst, 1
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 bne src, t0, 1b
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100557 .set noreorder
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000558.Ll_exc\@:
Markos Chandras5bc05972014-01-07 12:57:04 +0000559 LOADK t0, TI_TASK($28)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 nop
Markos Chandras5bc05972014-01-07 12:57:04 +0000561 LOADK t0, THREAD_BUADDR(t0) # t0 is just past last good address
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 nop
563 SUB len, AT, t0 # len number of uncopied bytes
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000564 bnez t6, .Ldone\@ /* Skip the zeroing part if inatomic */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 /*
566 * Here's where we rely on src and dst being incremented in tandem,
567 * See (3) above.
568 * dst += (fault addr - src) to put dst at first byte to clear
569 */
570 ADD dst, t0 # compute start address in a1
571 SUB dst, src
572 /*
573 * Clear len bytes starting at dst. Can't call __bzero because it
574 * might modify len. An inefficient loop for these rare times...
575 */
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100576 .set reorder /* DADDI_WAR */
577 SUB src, len, 1
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000578 beqz len, .Ldone\@
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100579 .set noreorder
Linus Torvalds1da177e2005-04-16 15:20:36 -07005801: sb zero, 0(dst)
581 ADD dst, dst, 1
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100582#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 bnez src, 1b
584 SUB src, src, 1
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100585#else
586 .set push
587 .set noat
588 li v1, 1
589 bnez src, 1b
590 SUB src, src, v1
591 .set pop
592#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 jr ra
594 nop
595
596
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100597#define SEXC(n) \
Ralf Baechle70342282013-01-22 12:59:30 +0100598 .set reorder; /* DADDI_WAR */ \
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000599.Ls_exc_p ## n ## u\@: \
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100600 ADD len, len, n*NBYTES; \
601 jr ra; \
602 .set noreorder
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603
604SEXC(8)
605SEXC(7)
606SEXC(6)
607SEXC(5)
608SEXC(4)
609SEXC(3)
610SEXC(2)
611SEXC(1)
612
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000613.Ls_exc_p1\@:
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100614 .set reorder /* DADDI_WAR */
615 ADD len, len, 1
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 jr ra
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100617 .set noreorder
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000618.Ls_exc\@:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 jr ra
620 nop
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000621 .endm
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622
623 .align 5
624LEAF(memmove)
625 ADD t0, a0, a2
626 ADD t1, a1, a2
627 sltu t0, a1, t0 # dst + len <= src -> memcpy
628 sltu t1, a0, t1 # dst >= src + len -> memcpy
629 and t0, t1
Ralf Baechlec5ec1982008-01-29 10:14:59 +0000630 beqz t0, .L__memcpy
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 move v0, a0 /* return value */
Ralf Baechlec5ec1982008-01-29 10:14:59 +0000632 beqz a2, .Lr_out
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 END(memmove)
634
635 /* fall through to __rmemcpy */
636LEAF(__rmemcpy) /* a0=dst a1=src a2=len */
637 sltu t0, a1, a0
Ralf Baechlec5ec1982008-01-29 10:14:59 +0000638 beqz t0, .Lr_end_bytes_up # src >= dst
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 nop
640 ADD a0, a2 # dst = dst + len
641 ADD a1, a2 # src = src + len
642
Ralf Baechlec5ec1982008-01-29 10:14:59 +0000643.Lr_end_bytes:
Thomas Bogendoerfer930bff82007-11-25 11:47:56 +0100644 R10KCBARRIER(0(ra))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 lb t0, -1(a1)
646 SUB a2, a2, 0x1
647 sb t0, -1(a0)
648 SUB a1, a1, 0x1
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100649 .set reorder /* DADDI_WAR */
650 SUB a0, a0, 0x1
Ralf Baechlec5ec1982008-01-29 10:14:59 +0000651 bnez a2, .Lr_end_bytes
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100652 .set noreorder
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653
Ralf Baechlec5ec1982008-01-29 10:14:59 +0000654.Lr_out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 jr ra
656 move a2, zero
657
Ralf Baechlec5ec1982008-01-29 10:14:59 +0000658.Lr_end_bytes_up:
Thomas Bogendoerfer930bff82007-11-25 11:47:56 +0100659 R10KCBARRIER(0(ra))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 lb t0, (a1)
661 SUB a2, a2, 0x1
662 sb t0, (a0)
663 ADD a1, a1, 0x1
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100664 .set reorder /* DADDI_WAR */
665 ADD a0, a0, 0x1
Ralf Baechlec5ec1982008-01-29 10:14:59 +0000666 bnez a2, .Lr_end_bytes_up
Maciej W. Rozycki619b6e12007-10-23 12:43:25 +0100667 .set noreorder
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668
669 jr ra
670 move a2, zero
671 END(__rmemcpy)
Markos Chandrascf62a8b2014-01-07 14:34:05 +0000672
673/*
674 * t6 is used as a flag to note inatomic mode.
675 */
676LEAF(__copy_user_inatomic)
677 b __copy_user_common
678 li t6, 1
679 END(__copy_user_inatomic)
680
681/*
682 * A combined memcpy/__copy_user
683 * __copy_user sets len to 0 for success; else to an upper bound of
684 * the number of uncopied bytes.
685 * memcpy sets v0 to dst.
686 */
687 .align 5
688LEAF(memcpy) /* a0=dst a1=src a2=len */
689 move v0, dst /* return value */
690.L__memcpy:
691FEXPORT(__copy_user)
692 li t6, 0 /* not inatomic */
693__copy_user_common:
694 /* Legacy Mode, user <-> user */
695 __BUILD_COPY_USER LEGACY_MODE USEROP USEROP
Markos Chandrascd26cb42014-01-07 16:20:22 +0000696
697#ifdef CONFIG_EVA
698
699/*
700 * For EVA we need distinct symbols for reading and writing to user space.
701 * This is because we need to use specific EVA instructions to perform the
702 * virtual <-> physical translation when a virtual address is actually in user
703 * space
704 */
705
706LEAF(__copy_user_inatomic_eva)
707 b __copy_from_user_common
708 li t6, 1
709 END(__copy_user_inatomic_eva)
710
711/*
712 * __copy_from_user (EVA)
713 */
714
715LEAF(__copy_from_user_eva)
716 li t6, 0 /* not inatomic */
717__copy_from_user_common:
718 __BUILD_COPY_USER EVA_MODE USEROP KERNELOP
719END(__copy_from_user_eva)
720
721
722
723/*
724 * __copy_to_user (EVA)
725 */
726
727LEAF(__copy_to_user_eva)
728__BUILD_COPY_USER EVA_MODE KERNELOP USEROP
729END(__copy_to_user_eva)
730
731/*
732 * __copy_in_user (EVA)
733 */
734
735LEAF(__copy_in_user_eva)
736__BUILD_COPY_USER EVA_MODE USEROP USEROP
737END(__copy_in_user_eva)
738
739#endif