xref: /openbmc/linux/arch/mips/lib/memset.S (revision 6c359eb1)
1/*
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 * Copyright (C) 1998, 1999, 2000 by Ralf Baechle
7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8 * Copyright (C) 2007 by Maciej W. Rozycki
9 * Copyright (C) 2011, 2012 MIPS Technologies, Inc.
10 */
11#include <asm/asm.h>
12#include <asm/asm-offsets.h>
13#include <asm/export.h>
14#include <asm/regdef.h>
15
16#if LONGSIZE == 4
17#define LONG_S_L swl
18#define LONG_S_R swr
19#else
20#define LONG_S_L sdl
21#define LONG_S_R sdr
22#endif
23
24#ifdef CONFIG_CPU_MICROMIPS
25#define STORSIZE (LONGSIZE * 2)
26#define STORMASK (STORSIZE - 1)
27#define FILL64RG t8
28#define FILLPTRG t7
29#undef  LONG_S
30#define LONG_S LONG_SP
31#else
32#define STORSIZE LONGSIZE
33#define STORMASK LONGMASK
34#define FILL64RG a1
35#define FILLPTRG t0
36#endif
37
38#define LEGACY_MODE 1
39#define EVA_MODE    2
40
41/*
42 * No need to protect it with EVA #ifdefery. The generated block of code
43 * will never be assembled if EVA is not enabled.
44 */
45#define __EVAFY(insn, reg, addr) __BUILD_EVA_INSN(insn##e, reg, addr)
46#define ___BUILD_EVA_INSN(insn, reg, addr) __EVAFY(insn, reg, addr)
47
48#define EX(insn,reg,addr,handler)			\
49	.if \mode == LEGACY_MODE;			\
509:		insn	reg, addr;			\
51	.else;						\
529:		___BUILD_EVA_INSN(insn, reg, addr);	\
53	.endif;						\
54	.section __ex_table,"a";			\
55	PTR	9b, handler;				\
56	.previous
57
58	.macro	f_fill64 dst, offset, val, fixup, mode
59	EX(LONG_S, \val, (\offset +  0 * STORSIZE)(\dst), \fixup)
60	EX(LONG_S, \val, (\offset +  1 * STORSIZE)(\dst), \fixup)
61	EX(LONG_S, \val, (\offset +  2 * STORSIZE)(\dst), \fixup)
62	EX(LONG_S, \val, (\offset +  3 * STORSIZE)(\dst), \fixup)
63#if ((defined(CONFIG_CPU_MICROMIPS) && (LONGSIZE == 4)) || !defined(CONFIG_CPU_MICROMIPS))
64	EX(LONG_S, \val, (\offset +  4 * STORSIZE)(\dst), \fixup)
65	EX(LONG_S, \val, (\offset +  5 * STORSIZE)(\dst), \fixup)
66	EX(LONG_S, \val, (\offset +  6 * STORSIZE)(\dst), \fixup)
67	EX(LONG_S, \val, (\offset +  7 * STORSIZE)(\dst), \fixup)
68#endif
69#if (!defined(CONFIG_CPU_MICROMIPS) && (LONGSIZE == 4))
70	EX(LONG_S, \val, (\offset +  8 * STORSIZE)(\dst), \fixup)
71	EX(LONG_S, \val, (\offset +  9 * STORSIZE)(\dst), \fixup)
72	EX(LONG_S, \val, (\offset + 10 * STORSIZE)(\dst), \fixup)
73	EX(LONG_S, \val, (\offset + 11 * STORSIZE)(\dst), \fixup)
74	EX(LONG_S, \val, (\offset + 12 * STORSIZE)(\dst), \fixup)
75	EX(LONG_S, \val, (\offset + 13 * STORSIZE)(\dst), \fixup)
76	EX(LONG_S, \val, (\offset + 14 * STORSIZE)(\dst), \fixup)
77	EX(LONG_S, \val, (\offset + 15 * STORSIZE)(\dst), \fixup)
78#endif
79	.endm
80
81	.set	noreorder
82	.align	5
83
84	/*
85	 * Macro to generate the __bzero{,_user} symbol
86	 * Arguments:
87	 * mode: LEGACY_MODE or EVA_MODE
88	 */
89	.macro __BUILD_BZERO mode
90	/* Initialize __memset if this is the first time we call this macro */
91	.ifnotdef __memset
92	.set __memset, 1
93	.hidden __memset /* Make sure it does not leak */
94	.endif
95
96	sltiu		t0, a2, STORSIZE	/* very small region? */
97	bnez		t0, .Lsmall_memset\@
98	 andi		t0, a0, STORMASK	/* aligned? */
99
100#ifdef CONFIG_CPU_MICROMIPS
101	move		t8, a1			/* used by 'swp' instruction */
102	move		t9, a1
103#endif
104#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
105	beqz		t0, 1f
106	 PTR_SUBU	t0, STORSIZE		/* alignment in bytes */
107#else
108	.set		noat
109	li		AT, STORSIZE
110	beqz		t0, 1f
111	 PTR_SUBU	t0, AT			/* alignment in bytes */
112	.set		at
113#endif
114
115#ifndef CONFIG_CPU_MIPSR6
116	R10KCBARRIER(0(ra))
117#ifdef __MIPSEB__
118	EX(LONG_S_L, a1, (a0), .Lfirst_fixup\@)	/* make word/dword aligned */
119#else
120	EX(LONG_S_R, a1, (a0), .Lfirst_fixup\@)	/* make word/dword aligned */
121#endif
122	PTR_SUBU	a0, t0			/* long align ptr */
123	PTR_ADDU	a2, t0			/* correct size */
124
125#else /* CONFIG_CPU_MIPSR6 */
126#define STORE_BYTE(N)				\
127	EX(sb, a1, N(a0), .Lbyte_fixup\@);	\
128	beqz		t0, 0f;			\
129	PTR_ADDU	t0, 1;
130
131	PTR_ADDU	a2, t0			/* correct size */
132	PTR_ADDU	t0, 1
133	STORE_BYTE(0)
134	STORE_BYTE(1)
135#if LONGSIZE == 4
136	EX(sb, a1, 2(a0), .Lbyte_fixup\@)
137#else
138	STORE_BYTE(2)
139	STORE_BYTE(3)
140	STORE_BYTE(4)
141	STORE_BYTE(5)
142	EX(sb, a1, 6(a0), .Lbyte_fixup\@)
143#endif
1440:
145	ori		a0, STORMASK
146	xori		a0, STORMASK
147	PTR_ADDIU	a0, STORSIZE
148#endif /* CONFIG_CPU_MIPSR6 */
1491:	ori		t1, a2, 0x3f		/* # of full blocks */
150	xori		t1, 0x3f
151	beqz		t1, .Lmemset_partial\@	/* no block to fill */
152	 andi		t0, a2, 0x40-STORSIZE
153
154	PTR_ADDU	t1, a0			/* end address */
155	.set		reorder
1561:	PTR_ADDIU	a0, 64
157	R10KCBARRIER(0(ra))
158	f_fill64 a0, -64, FILL64RG, .Lfwd_fixup\@, \mode
159	bne		t1, a0, 1b
160	.set		noreorder
161
162.Lmemset_partial\@:
163	R10KCBARRIER(0(ra))
164	PTR_LA		t1, 2f			/* where to start */
165#ifdef CONFIG_CPU_MICROMIPS
166	LONG_SRL	t7, t0, 1
167#endif
168#if LONGSIZE == 4
169	PTR_SUBU	t1, FILLPTRG
170#else
171	.set		noat
172	LONG_SRL	AT, FILLPTRG, 1
173	PTR_SUBU	t1, AT
174	.set		at
175#endif
176	jr		t1
177	 PTR_ADDU	a0, t0			/* dest ptr */
178
179	.set		push
180	.set		noreorder
181	.set		nomacro
182	/* ... but first do longs ... */
183	f_fill64 a0, -64, FILL64RG, .Lpartial_fixup\@, \mode
1842:	.set		pop
185	andi		a2, STORMASK		/* At most one long to go */
186
187	beqz		a2, 1f
188#ifndef CONFIG_CPU_MIPSR6
189	 PTR_ADDU	a0, a2			/* What's left */
190	R10KCBARRIER(0(ra))
191#ifdef __MIPSEB__
192	EX(LONG_S_R, a1, -1(a0), .Llast_fixup\@)
193#else
194	EX(LONG_S_L, a1, -1(a0), .Llast_fixup\@)
195#endif
196#else
197	 PTR_SUBU	t0, $0, a2
198	move		a2, zero		/* No remaining longs */
199	PTR_ADDIU	t0, 1
200	STORE_BYTE(0)
201	STORE_BYTE(1)
202#if LONGSIZE == 4
203	EX(sb, a1, 2(a0), .Lbyte_fixup\@)
204#else
205	STORE_BYTE(2)
206	STORE_BYTE(3)
207	STORE_BYTE(4)
208	STORE_BYTE(5)
209	EX(sb, a1, 6(a0), .Lbyte_fixup\@)
210#endif
2110:
212#endif
2131:	jr		ra
214	 move		a2, zero
215
216.Lsmall_memset\@:
217	beqz		a2, 2f
218	 PTR_ADDU	t1, a0, a2
219
2201:	PTR_ADDIU	a0, 1			/* fill bytewise */
221	R10KCBARRIER(0(ra))
222	bne		t1, a0, 1b
223	 EX(sb, a1, -1(a0), .Lsmall_fixup\@)
224
2252:	jr		ra			/* done */
226	 move		a2, zero
227	.if __memset == 1
228	END(memset)
229	.set __memset, 0
230	.hidden __memset
231	.endif
232
233#ifdef CONFIG_CPU_MIPSR6
234.Lbyte_fixup\@:
235	/*
236	 * unset_bytes = (#bytes - (#unaligned bytes)) - (-#unaligned bytes remaining + 1) + 1
237	 *      a2     =             a2                -              t0                   + 1
238	 */
239	PTR_SUBU	a2, t0
240	jr		ra
241	 PTR_ADDIU	a2, 1
242#endif /* CONFIG_CPU_MIPSR6 */
243
244.Lfirst_fixup\@:
245	/* unset_bytes already in a2 */
246	jr	ra
247	 nop
248
249.Lfwd_fixup\@:
250	/*
251	 * unset_bytes = partial_start_addr +  #bytes   -     fault_addr
252	 *      a2     =         t1         + (a2 & 3f) - $28->task->BUADDR
253	 */
254	PTR_L		t0, TI_TASK($28)
255	andi		a2, 0x3f
256	LONG_L		t0, THREAD_BUADDR(t0)
257	LONG_ADDU	a2, t1
258	jr		ra
259	 LONG_SUBU	a2, t0
260
261.Lpartial_fixup\@:
262	/*
263	 * unset_bytes = partial_end_addr +      #bytes     -     fault_addr
264	 *      a2     =       a0         + (a2 & STORMASK) - $28->task->BUADDR
265	 */
266	PTR_L		t0, TI_TASK($28)
267	andi		a2, STORMASK
268	LONG_L		t0, THREAD_BUADDR(t0)
269	LONG_ADDU	a2, a0
270	jr		ra
271	 LONG_SUBU	a2, t0
272
273.Llast_fixup\@:
274	/* unset_bytes already in a2 */
275	jr		ra
276	 nop
277
278.Lsmall_fixup\@:
279	/*
280	 * unset_bytes = end_addr - current_addr + 1
281	 *      a2     =    t1    -      a0      + 1
282	 */
283	PTR_SUBU	a2, t1, a0
284	jr		ra
285	 PTR_ADDIU	a2, 1
286
287	.endm
288
289/*
290 * memset(void *s, int c, size_t n)
291 *
292 * a0: start of area to clear
293 * a1: char to fill with
294 * a2: size of area to clear
295 */
296
297LEAF(memset)
298EXPORT_SYMBOL(memset)
299	beqz		a1, 1f
300	 move		v0, a0			/* result */
301
302	andi		a1, 0xff		/* spread fillword */
303	LONG_SLL		t1, a1, 8
304	or		a1, t1
305	LONG_SLL		t1, a1, 16
306#if LONGSIZE == 8
307	or		a1, t1
308	LONG_SLL		t1, a1, 32
309#endif
310	or		a1, t1
3111:
312#ifndef CONFIG_EVA
313FEXPORT(__bzero)
314EXPORT_SYMBOL(__bzero)
315#else
316FEXPORT(__bzero_kernel)
317EXPORT_SYMBOL(__bzero_kernel)
318#endif
319	__BUILD_BZERO LEGACY_MODE
320
321#ifdef CONFIG_EVA
322LEAF(__bzero)
323EXPORT_SYMBOL(__bzero)
324	__BUILD_BZERO EVA_MODE
325END(__bzero)
326#endif
327