xref: /openbmc/linux/arch/sparc/lib/copy_user.S (revision 18afb028) 
1/* SPDX-License-Identifier: GPL-2.0 */
2/* copy_user.S: Sparc optimized copy_from_user and copy_to_user code.
3 *
4 *  Copyright(C) 1995 Linus Torvalds
5 *  Copyright(C) 1996 David S. Miller
6 *  Copyright(C) 1996 Eddie C. Dost
7 *  Copyright(C) 1996,1998 Jakub Jelinek
8 *
9 * derived from:
10 *	e-mail between David and Eddie.
11 *
12 * Returns 0 if successful, otherwise count of bytes not copied yet
13 */
14
15#include <linux/export.h>
16#include <asm/ptrace.h>
17#include <asm/asmmacro.h>
18#include <asm/page.h>
19#include <asm/thread_info.h>
20
21/* Work around cpp -rob */
22#define ALLOC #alloc
23#define EXECINSTR #execinstr
24
25#define EX_ENTRY(l1, l2)			\
26	.section __ex_table,ALLOC;		\
27	.align	4;				\
28	.word	l1, l2;				\
29	.text;
30
31#define EX(x,y,a,b) 				\
3298: 	x,y;					\
33	.section .fixup,ALLOC,EXECINSTR;	\
34	.align	4;				\
3599:	retl;					\
36	 a, b, %o0;				\
37	EX_ENTRY(98b, 99b)
38
39#define EX2(x,y,c,d,e,a,b) 			\
4098: 	x,y;					\
41	.section .fixup,ALLOC,EXECINSTR;	\
42	.align	4;				\
4399:	c, d, e;				\
44	retl;					\
45	 a, b, %o0;				\
46	EX_ENTRY(98b, 99b)
47
48#define EXO2(x,y) 				\
4998: 	x, y;					\
50	EX_ENTRY(98b, 97f)
51
52#define LD(insn, src, offset, reg, label)	\
5398:	insn [%src + (offset)], %reg;		\
54	.section .fixup,ALLOC,EXECINSTR;	\
5599:	ba	label;				\
56	 mov	offset, %g5;			\
57	EX_ENTRY(98b, 99b)
58
59#define ST(insn, dst, offset, reg, label)	\
6098:	insn %reg, [%dst + (offset)];		\
61	.section .fixup,ALLOC,EXECINSTR;	\
6299:	ba	label;				\
63	 mov	offset, %g5;			\
64	EX_ENTRY(98b, 99b)
65
66/* Both these macros have to start with exactly the same insn */
67/* left: g7 + (g1 % 128) - offset */
68#define MOVE_BIGCHUNK(src, dst, offset, t0, t1, t2, t3, t4, t5, t6, t7) \
69	LD(ldd, src, offset + 0x00, t0, bigchunk_fault)	\
70	LD(ldd, src, offset + 0x08, t2, bigchunk_fault)	\
71	LD(ldd, src, offset + 0x10, t4, bigchunk_fault)	\
72	LD(ldd, src, offset + 0x18, t6, bigchunk_fault)	\
73	ST(st, dst, offset + 0x00, t0, bigchunk_fault)	\
74	ST(st, dst, offset + 0x04, t1, bigchunk_fault)	\
75	ST(st, dst, offset + 0x08, t2, bigchunk_fault)	\
76	ST(st, dst, offset + 0x0c, t3, bigchunk_fault)	\
77	ST(st, dst, offset + 0x10, t4, bigchunk_fault)	\
78	ST(st, dst, offset + 0x14, t5, bigchunk_fault)	\
79	ST(st, dst, offset + 0x18, t6, bigchunk_fault)	\
80	ST(st, dst, offset + 0x1c, t7, bigchunk_fault)
81
82/* left: g7 + (g1 % 128) - offset */
83#define MOVE_BIGALIGNCHUNK(src, dst, offset, t0, t1, t2, t3, t4, t5, t6, t7) \
84	LD(ldd, src, offset + 0x00, t0, bigchunk_fault)	\
85	LD(ldd, src, offset + 0x08, t2, bigchunk_fault)	\
86	LD(ldd, src, offset + 0x10, t4, bigchunk_fault)	\
87	LD(ldd, src, offset + 0x18, t6, bigchunk_fault)	\
88	ST(std, dst, offset + 0x00, t0, bigchunk_fault)	\
89	ST(std, dst, offset + 0x08, t2, bigchunk_fault)	\
90	ST(std, dst, offset + 0x10, t4, bigchunk_fault)	\
91	ST(std, dst, offset + 0x18, t6, bigchunk_fault)
92
93	.section .fixup,#alloc,#execinstr
94bigchunk_fault:
95	sub	%g7, %g5, %o0
96	and	%g1, 127, %g1
97	retl
98	 add	%o0, %g1, %o0
99
100/* left: offset + 16 + (g1 % 16) */
101#define MOVE_LASTCHUNK(src, dst, offset, t0, t1, t2, t3) \
102	LD(ldd, src, -(offset + 0x10), t0, lastchunk_fault)	\
103	LD(ldd, src, -(offset + 0x08), t2, lastchunk_fault)	\
104	ST(st, dst, -(offset + 0x10), t0, lastchunk_fault)	\
105	ST(st, dst, -(offset + 0x0c), t1, lastchunk_fault)	\
106	ST(st, dst, -(offset + 0x08), t2, lastchunk_fault)	\
107	ST(st, dst, -(offset + 0x04), t3, lastchunk_fault)
108
109	.section .fixup,#alloc,#execinstr
110lastchunk_fault:
111	and	%g1, 15, %g1
112	retl
113	 sub	%g1, %g5, %o0
114
115/* left: o3 + (o2 % 16) - offset */
116#define MOVE_HALFCHUNK(src, dst, offset, t0, t1, t2, t3) \
117	LD(lduh, src, offset + 0x00, t0, halfchunk_fault)	\
118	LD(lduh, src, offset + 0x02, t1, halfchunk_fault)	\
119	LD(lduh, src, offset + 0x04, t2, halfchunk_fault)	\
120	LD(lduh, src, offset + 0x06, t3, halfchunk_fault)	\
121	ST(sth, dst, offset + 0x00, t0, halfchunk_fault)	\
122	ST(sth, dst, offset + 0x02, t1, halfchunk_fault)	\
123	ST(sth, dst, offset + 0x04, t2, halfchunk_fault)	\
124	ST(sth, dst, offset + 0x06, t3, halfchunk_fault)
125
126/* left: o3 + (o2 % 16) + offset + 2 */
127#define MOVE_SHORTCHUNK(src, dst, offset, t0, t1) \
128	LD(ldub, src, -(offset + 0x02), t0, halfchunk_fault)	\
129	LD(ldub, src, -(offset + 0x01), t1, halfchunk_fault)	\
130	ST(stb, dst, -(offset + 0x02), t0, halfchunk_fault)	\
131	ST(stb, dst, -(offset + 0x01), t1, halfchunk_fault)
132
133	.section .fixup,#alloc,#execinstr
134halfchunk_fault:
135	and	%o2, 15, %o2
136	sub	%o3, %g5, %o3
137	retl
138	 add	%o2, %o3, %o0
139
140/* left: offset + 2 + (o2 % 2) */
141#define MOVE_LAST_SHORTCHUNK(src, dst, offset, t0, t1) \
142	LD(ldub, src, -(offset + 0x02), t0, last_shortchunk_fault)	\
143	LD(ldub, src, -(offset + 0x01), t1, last_shortchunk_fault)	\
144	ST(stb, dst, -(offset + 0x02), t0, last_shortchunk_fault)	\
145	ST(stb, dst, -(offset + 0x01), t1, last_shortchunk_fault)
146
147	.section .fixup,#alloc,#execinstr
148last_shortchunk_fault:
149	and	%o2, 1, %o2
150	retl
151	 sub	%o2, %g5, %o0
152
153	.text
154	.align	4
155
156	.globl  __copy_user_begin
157__copy_user_begin:
158
159	.globl	__copy_user
160	EXPORT_SYMBOL(__copy_user)
161dword_align:
162	andcc	%o1, 1, %g0
163	be	4f
164	 andcc	%o1, 2, %g0
165
166	EXO2(ldub [%o1], %g2)
167	add	%o1, 1, %o1
168	EXO2(stb %g2, [%o0])
169	sub	%o2, 1, %o2
170	bne	3f
171	 add	%o0, 1, %o0
172
173	EXO2(lduh [%o1], %g2)
174	add	%o1, 2, %o1
175	EXO2(sth %g2, [%o0])
176	sub	%o2, 2, %o2
177	b	3f
178	 add	%o0, 2, %o0
1794:
180	EXO2(lduh [%o1], %g2)
181	add	%o1, 2, %o1
182	EXO2(sth %g2, [%o0])
183	sub	%o2, 2, %o2
184	b	3f
185	 add	%o0, 2, %o0
186
187__copy_user:	/* %o0=dst %o1=src %o2=len */
188	xor	%o0, %o1, %o4
1891:
190	andcc	%o4, 3, %o5
1912:
192	bne	cannot_optimize
193	 cmp	%o2, 15
194
195	bleu	short_aligned_end
196	 andcc	%o1, 3, %g0
197
198	bne	dword_align
1993:
200	 andcc	%o1, 4, %g0
201
202	be	2f
203	 mov	%o2, %g1
204
205	EXO2(ld [%o1], %o4)
206	sub	%g1, 4, %g1
207	EXO2(st %o4, [%o0])
208	add	%o1, 4, %o1
209	add	%o0, 4, %o0
2102:
211	andcc	%g1, 0xffffff80, %g7
212	be	3f
213	 andcc	%o0, 4, %g0
214
215	be	ldd_std + 4
2165:
217	MOVE_BIGCHUNK(o1, o0, 0x00, o2, o3, o4, o5, g2, g3, g4, g5)
218	MOVE_BIGCHUNK(o1, o0, 0x20, o2, o3, o4, o5, g2, g3, g4, g5)
219	MOVE_BIGCHUNK(o1, o0, 0x40, o2, o3, o4, o5, g2, g3, g4, g5)
220	MOVE_BIGCHUNK(o1, o0, 0x60, o2, o3, o4, o5, g2, g3, g4, g5)
221	subcc	%g7, 128, %g7
222	add	%o1, 128, %o1
223	bne	5b
224	 add	%o0, 128, %o0
2253:
226	andcc	%g1, 0x70, %g7
227	be	copy_user_table_end
228	 andcc	%g1, 8, %g0
229
230	sethi	%hi(copy_user_table_end), %o5
231	srl	%g7, 1, %o4
232	add	%g7, %o4, %o4
233	add	%o1, %g7, %o1
234	sub	%o5, %o4, %o5
235	jmpl	%o5 + %lo(copy_user_table_end), %g0
236	 add	%o0, %g7, %o0
237
238	MOVE_LASTCHUNK(o1, o0, 0x60, g2, g3, g4, g5)
239	MOVE_LASTCHUNK(o1, o0, 0x50, g2, g3, g4, g5)
240	MOVE_LASTCHUNK(o1, o0, 0x40, g2, g3, g4, g5)
241	MOVE_LASTCHUNK(o1, o0, 0x30, g2, g3, g4, g5)
242	MOVE_LASTCHUNK(o1, o0, 0x20, g2, g3, g4, g5)
243	MOVE_LASTCHUNK(o1, o0, 0x10, g2, g3, g4, g5)
244	MOVE_LASTCHUNK(o1, o0, 0x00, g2, g3, g4, g5)
245copy_user_table_end:
246	be	copy_user_last7
247	 andcc	%g1, 4, %g0
248
249	EX(ldd	[%o1], %g2, and %g1, 0xf)
250	add	%o0, 8, %o0
251	add	%o1, 8, %o1
252	EX(st	%g2, [%o0 - 0x08], and %g1, 0xf)
253	EX2(st	%g3, [%o0 - 0x04], and %g1, 0xf, %g1, sub %g1, 4)
254copy_user_last7:
255	be	1f
256	 andcc	%g1, 2, %g0
257
258	EX(ld	[%o1], %g2, and %g1, 7)
259	add	%o1, 4, %o1
260	EX(st	%g2, [%o0], and %g1, 7)
261	add	%o0, 4, %o0
2621:
263	be	1f
264	 andcc	%g1, 1, %g0
265
266	EX(lduh	[%o1], %g2, and %g1, 3)
267	add	%o1, 2, %o1
268	EX(sth	%g2, [%o0], and %g1, 3)
269	add	%o0, 2, %o0
2701:
271	be	1f
272	 nop
273
274	EX(ldub	[%o1], %g2, add %g0, 1)
275	EX(stb	%g2, [%o0], add %g0, 1)
2761:
277	retl
278 	 clr	%o0
279
280ldd_std:
281	MOVE_BIGALIGNCHUNK(o1, o0, 0x00, o2, o3, o4, o5, g2, g3, g4, g5)
282	MOVE_BIGALIGNCHUNK(o1, o0, 0x20, o2, o3, o4, o5, g2, g3, g4, g5)
283	MOVE_BIGALIGNCHUNK(o1, o0, 0x40, o2, o3, o4, o5, g2, g3, g4, g5)
284	MOVE_BIGALIGNCHUNK(o1, o0, 0x60, o2, o3, o4, o5, g2, g3, g4, g5)
285	subcc	%g7, 128, %g7
286	add	%o1, 128, %o1
287	bne	ldd_std
288	 add	%o0, 128, %o0
289
290	andcc	%g1, 0x70, %g7
291	be	copy_user_table_end
292	 andcc	%g1, 8, %g0
293
294	sethi	%hi(copy_user_table_end), %o5
295	srl	%g7, 1, %o4
296	add	%g7, %o4, %o4
297	add	%o1, %g7, %o1
298	sub	%o5, %o4, %o5
299	jmpl	%o5 + %lo(copy_user_table_end), %g0
300	 add	%o0, %g7, %o0
301
302cannot_optimize:
303	bleu	short_end
304	 cmp	%o5, 2
305
306	bne	byte_chunk
307	 and	%o2, 0xfffffff0, %o3
308
309	andcc	%o1, 1, %g0
310	be	10f
311	 nop
312
313	EXO2(ldub [%o1], %g2)
314	add	%o1, 1, %o1
315	EXO2(stb %g2, [%o0])
316	sub	%o2, 1, %o2
317	andcc	%o2, 0xfffffff0, %o3
318	be	short_end
319	 add	%o0, 1, %o0
32010:
321	MOVE_HALFCHUNK(o1, o0, 0x00, g2, g3, g4, g5)
322	MOVE_HALFCHUNK(o1, o0, 0x08, g2, g3, g4, g5)
323	subcc	%o3, 0x10, %o3
324	add	%o1, 0x10, %o1
325	bne	10b
326	 add	%o0, 0x10, %o0
327	b	2f
328	 and	%o2, 0xe, %o3
329
330byte_chunk:
331	MOVE_SHORTCHUNK(o1, o0, -0x02, g2, g3)
332	MOVE_SHORTCHUNK(o1, o0, -0x04, g2, g3)
333	MOVE_SHORTCHUNK(o1, o0, -0x06, g2, g3)
334	MOVE_SHORTCHUNK(o1, o0, -0x08, g2, g3)
335	MOVE_SHORTCHUNK(o1, o0, -0x0a, g2, g3)
336	MOVE_SHORTCHUNK(o1, o0, -0x0c, g2, g3)
337	MOVE_SHORTCHUNK(o1, o0, -0x0e, g2, g3)
338	MOVE_SHORTCHUNK(o1, o0, -0x10, g2, g3)
339	subcc	%o3, 0x10, %o3
340	add	%o1, 0x10, %o1
341	bne	byte_chunk
342	 add	%o0, 0x10, %o0
343
344short_end:
345	and	%o2, 0xe, %o3
3462:
347	sethi	%hi(short_table_end), %o5
348	sll	%o3, 3, %o4
349	add	%o0, %o3, %o0
350	sub	%o5, %o4, %o5
351	add	%o1, %o3, %o1
352	jmpl	%o5 + %lo(short_table_end), %g0
353	 andcc	%o2, 1, %g0
354	MOVE_LAST_SHORTCHUNK(o1, o0, 0x0c, g2, g3)
355	MOVE_LAST_SHORTCHUNK(o1, o0, 0x0a, g2, g3)
356	MOVE_LAST_SHORTCHUNK(o1, o0, 0x08, g2, g3)
357	MOVE_LAST_SHORTCHUNK(o1, o0, 0x06, g2, g3)
358	MOVE_LAST_SHORTCHUNK(o1, o0, 0x04, g2, g3)
359	MOVE_LAST_SHORTCHUNK(o1, o0, 0x02, g2, g3)
360	MOVE_LAST_SHORTCHUNK(o1, o0, 0x00, g2, g3)
361short_table_end:
362	be	1f
363	 nop
364	EX(ldub	[%o1], %g2, add %g0, 1)
365	EX(stb	%g2, [%o0], add %g0, 1)
3661:
367	retl
368 	 clr	%o0
369
370short_aligned_end:
371	bne	short_end
372	 andcc	%o2, 8, %g0
373
374	be	1f
375	 andcc	%o2, 4, %g0
376
377	EXO2(ld	[%o1 + 0x00], %g2)
378	EXO2(ld	[%o1 + 0x04], %g3)
379	add	%o1, 8, %o1
380	EXO2(st	%g2, [%o0 + 0x00])
381	EX(st	%g3, [%o0 + 0x04], sub %o2, 4)
382	add	%o0, 8, %o0
3831:
384	b	copy_user_last7
385	 mov	%o2, %g1
386
387	.section .fixup,#alloc,#execinstr
388	.align	4
38997:
390	retl
391	 mov	%o2, %o0
392
393	.globl  __copy_user_end
394__copy_user_end:
395