xref: /openbmc/linux/arch/sparc/lib/csum_copy.S (revision d0e22329)
1/* SPDX-License-Identifier: GPL-2.0 */
2/* csum_copy.S: Checksum+copy code for sparc64
3 *
4 * Copyright (C) 2005 David S. Miller <davem@davemloft.net>
5 */
6
7#include <asm/export.h>
8
9#ifdef __KERNEL__
10#define GLOBAL_SPARE	%g7
11#else
12#define GLOBAL_SPARE	%g5
13#endif
14
15#ifndef EX_LD
16#define EX_LD(x)	x
17#endif
18
19#ifndef EX_ST
20#define EX_ST(x)	x
21#endif
22
23#ifndef EX_RETVAL
24#define EX_RETVAL(x)	x
25#endif
26
27#ifndef LOAD
28#define LOAD(type,addr,dest)	type [addr], dest
29#endif
30
31#ifndef STORE
32#define STORE(type,src,addr)	type src, [addr]
33#endif
34
35#ifndef FUNC_NAME
36#define FUNC_NAME	csum_partial_copy_nocheck
37#endif
38
39	.register	%g2, #scratch
40	.register	%g3, #scratch
41
42	.text
43
4490:
45	/* We checked for zero length already, so there must be
46	 * at least one byte.
47	 */
48	be,pt		%icc, 1f
49	 nop
50	EX_LD(LOAD(ldub, %o0 + 0x00, %o4))
51	add		%o0, 1, %o0
52	sub		%o2, 1, %o2
53	EX_ST(STORE(stb, %o4, %o1 + 0x00))
54	add		%o1, 1, %o1
551:	andcc		%o0, 0x2, %g0
56	be,pn		%icc, 80f
57	 cmp		%o2, 2
58	blu,pn		%icc, 60f
59	 nop
60	EX_LD(LOAD(lduh, %o0 + 0x00, %o5))
61	add		%o0, 2, %o0
62	sub		%o2, 2, %o2
63	EX_ST(STORE(sth, %o5, %o1 + 0x00))
64	add		%o1, 2, %o1
65	ba,pt		%xcc, 80f
66	 add		%o5, %o4, %o4
67
68	.globl		FUNC_NAME
69	.type		FUNC_NAME,#function
70	EXPORT_SYMBOL(FUNC_NAME)
71FUNC_NAME:		/* %o0=src, %o1=dst, %o2=len, %o3=sum */
72	LOAD(prefetch, %o0 + 0x000, #n_reads)
73	xor		%o0, %o1, %g1
74	clr		%o4
75	andcc		%g1, 0x3, %g0
76	bne,pn		%icc, 95f
77	 LOAD(prefetch, %o0 + 0x040, #n_reads)
78
79	brz,pn		%o2, 70f
80	 andcc		%o0, 0x3, %g0
81
82	/* We "remember" whether the lowest bit in the address
83	 * was set in GLOBAL_SPARE.  Because if it is, we have to swap
84	 * upper and lower 8 bit fields of the sum we calculate.
85	*/
86	bne,pn		%icc, 90b
87	 andcc		%o0, 0x1, GLOBAL_SPARE
88
8980:
90	LOAD(prefetch, %o0 + 0x080, #n_reads)
91	andncc		%o2, 0x3f, %g3
92
93	LOAD(prefetch, %o0 + 0x0c0, #n_reads)
94	sub		%o2, %g3, %o2
95	brz,pn		%g3, 2f
96	 LOAD(prefetch, %o0 + 0x100, #n_reads)
97
98	/* So that we don't need to use the non-pairing
99	 * add-with-carry instructions we accumulate 32-bit
100	 * values into a 64-bit register.  At the end of the
101	 * loop we fold it down to 32-bits and so on.
102	 */
103	ba,pt		%xcc, 1f
104	LOAD(prefetch, %o0 + 0x140, #n_reads)
105
106	.align		32
1071:	EX_LD(LOAD(lduw, %o0 + 0x00, %o5))
108	EX_LD(LOAD(lduw, %o0 + 0x04, %g1))
109	EX_LD(LOAD(lduw, %o0 + 0x08, %g2))
110	add		%o4, %o5, %o4
111	EX_ST(STORE(stw, %o5, %o1 + 0x00))
112	EX_LD(LOAD(lduw, %o0 + 0x0c, %o5))
113	add		%o4, %g1, %o4
114	EX_ST(STORE(stw, %g1, %o1 + 0x04))
115	EX_LD(LOAD(lduw, %o0 + 0x10, %g1))
116	add		%o4, %g2, %o4
117	EX_ST(STORE(stw, %g2, %o1 + 0x08))
118	EX_LD(LOAD(lduw, %o0 + 0x14, %g2))
119	add		%o4, %o5, %o4
120	EX_ST(STORE(stw, %o5, %o1 + 0x0c))
121	EX_LD(LOAD(lduw, %o0 + 0x18, %o5))
122	add		%o4, %g1, %o4
123	EX_ST(STORE(stw, %g1, %o1 + 0x10))
124	EX_LD(LOAD(lduw, %o0 + 0x1c, %g1))
125	add		%o4, %g2, %o4
126	EX_ST(STORE(stw, %g2, %o1 + 0x14))
127	EX_LD(LOAD(lduw, %o0 + 0x20, %g2))
128	add		%o4, %o5, %o4
129	EX_ST(STORE(stw, %o5, %o1 + 0x18))
130	EX_LD(LOAD(lduw, %o0 + 0x24, %o5))
131	add		%o4, %g1, %o4
132	EX_ST(STORE(stw, %g1, %o1 + 0x1c))
133	EX_LD(LOAD(lduw, %o0 + 0x28, %g1))
134	add		%o4, %g2, %o4
135	EX_ST(STORE(stw, %g2, %o1 + 0x20))
136	EX_LD(LOAD(lduw, %o0 + 0x2c, %g2))
137	add		%o4, %o5, %o4
138	EX_ST(STORE(stw, %o5, %o1 + 0x24))
139	EX_LD(LOAD(lduw, %o0 + 0x30, %o5))
140	add		%o4, %g1, %o4
141	EX_ST(STORE(stw, %g1, %o1 + 0x28))
142	EX_LD(LOAD(lduw, %o0 + 0x34, %g1))
143	add		%o4, %g2, %o4
144	EX_ST(STORE(stw, %g2, %o1 + 0x2c))
145	EX_LD(LOAD(lduw, %o0 + 0x38, %g2))
146	add		%o4, %o5, %o4
147	EX_ST(STORE(stw, %o5, %o1 + 0x30))
148	EX_LD(LOAD(lduw, %o0 + 0x3c, %o5))
149	add		%o4, %g1, %o4
150	EX_ST(STORE(stw, %g1, %o1 + 0x34))
151	LOAD(prefetch, %o0 + 0x180, #n_reads)
152	add		%o4, %g2, %o4
153	EX_ST(STORE(stw, %g2, %o1 + 0x38))
154	subcc		%g3, 0x40, %g3
155	add		%o0, 0x40, %o0
156	add		%o4, %o5, %o4
157	EX_ST(STORE(stw, %o5, %o1 + 0x3c))
158	bne,pt		%icc, 1b
159	 add		%o1, 0x40, %o1
160
1612:	and		%o2, 0x3c, %g3
162	brz,pn		%g3, 2f
163	 sub		%o2, %g3, %o2
1641:	EX_LD(LOAD(lduw, %o0 + 0x00, %o5))
165	subcc		%g3, 0x4, %g3
166	add		%o0, 0x4, %o0
167	add		%o4, %o5, %o4
168	EX_ST(STORE(stw, %o5, %o1 + 0x00))
169	bne,pt		%icc, 1b
170	 add		%o1, 0x4, %o1
171
1722:
173	/* fold 64-->32 */
174	srlx		%o4, 32, %o5
175	srl		%o4, 0, %o4
176	add		%o4, %o5, %o4
177	srlx		%o4, 32, %o5
178	srl		%o4, 0, %o4
179	add		%o4, %o5, %o4
180
181	/* fold 32-->16 */
182	sethi		%hi(0xffff0000), %g1
183	srl		%o4, 16, %o5
184	andn		%o4, %g1, %g2
185	add		%o5, %g2, %o4
186	srl		%o4, 16, %o5
187	andn		%o4, %g1, %g2
188	add		%o5, %g2, %o4
189
19060:
191	/* %o4 has the 16-bit sum we have calculated so-far.  */
192	cmp		%o2, 2
193	blu,pt		%icc, 1f
194	 nop
195	EX_LD(LOAD(lduh, %o0 + 0x00, %o5))
196	sub		%o2, 2, %o2
197	add		%o0, 2, %o0
198	add		%o4, %o5, %o4
199	EX_ST(STORE(sth, %o5, %o1 + 0x00))
200	add		%o1, 0x2, %o1
2011:	brz,pt		%o2, 1f
202	 nop
203	EX_LD(LOAD(ldub, %o0 + 0x00, %o5))
204	sub		%o2, 1, %o2
205	add		%o0, 1, %o0
206	EX_ST(STORE(stb, %o5, %o1 + 0x00))
207	sllx		%o5, 8, %o5
208	add		%o1, 1, %o1
209	add		%o4, %o5, %o4
2101:
211	/* fold 32-->16 */
212	sethi		%hi(0xffff0000), %g1
213	srl		%o4, 16, %o5
214	andn		%o4, %g1, %g2
215	add		%o5, %g2, %o4
216	srl		%o4, 16, %o5
217	andn		%o4, %g1, %g2
218	add		%o5, %g2, %o4
219
2201:	brz,pt		GLOBAL_SPARE, 1f
221	 nop
222
223	/* We started with an odd byte, byte-swap the result.  */
224	srl		%o4, 8, %o5
225	and		%o4, 0xff, %g1
226	sll		%g1, 8, %g1
227	or		%o5, %g1, %o4
228
2291:	addcc		%o3, %o4, %o3
230	addc		%g0, %o3, %o3
231
23270:
233	retl
234	 srl		%o3, 0, %o0
235
23695:	mov		0, GLOBAL_SPARE
237	brlez,pn	%o2, 4f
238	 andcc		%o0, 1, %o5
239	be,a,pt		%icc, 1f
240	 srl		%o2, 1, %g1
241	sub		%o2, 1, %o2
242	EX_LD(LOAD(ldub, %o0, GLOBAL_SPARE))
243	add		%o0, 1, %o0
244	EX_ST(STORE(stb, GLOBAL_SPARE, %o1))
245	srl		%o2, 1, %g1
246	add		%o1, 1, %o1
2471:	brz,a,pn	%g1, 3f
248	 andcc		%o2, 1, %g0
249	andcc		%o0, 2, %g0
250	be,a,pt		%icc, 1f
251	 srl		%g1, 1, %g1
252	EX_LD(LOAD(lduh, %o0, %o4))
253	sub		%o2, 2, %o2
254	srl		%o4, 8, %g2
255	sub		%g1, 1, %g1
256	EX_ST(STORE(stb, %g2, %o1))
257	add		%o4, GLOBAL_SPARE, GLOBAL_SPARE
258	EX_ST(STORE(stb, %o4, %o1 + 1))
259	add		%o0, 2, %o0
260	srl		%g1, 1, %g1
261	add		%o1, 2, %o1
2621:	brz,a,pn	%g1, 2f
263	 andcc		%o2, 2, %g0
264	EX_LD(LOAD(lduw, %o0, %o4))
2655:	srl		%o4, 24, %g2
266	srl		%o4, 16, %g3
267	EX_ST(STORE(stb, %g2, %o1))
268	srl		%o4, 8, %g2
269	EX_ST(STORE(stb, %g3, %o1 + 1))
270	add		%o0, 4, %o0
271	EX_ST(STORE(stb, %g2, %o1 + 2))
272	addcc		%o4, GLOBAL_SPARE, GLOBAL_SPARE
273	EX_ST(STORE(stb, %o4, %o1 + 3))
274	addc		GLOBAL_SPARE, %g0, GLOBAL_SPARE
275	add		%o1, 4, %o1
276	subcc		%g1, 1, %g1
277	bne,a,pt	%icc, 5b
278	 EX_LD(LOAD(lduw, %o0, %o4))
279	sll		GLOBAL_SPARE, 16, %g2
280	srl		GLOBAL_SPARE, 16, GLOBAL_SPARE
281	srl		%g2, 16, %g2
282	andcc		%o2, 2, %g0
283	add		%g2, GLOBAL_SPARE, GLOBAL_SPARE
2842:	be,a,pt		%icc, 3f
285	 andcc		%o2, 1, %g0
286	EX_LD(LOAD(lduh, %o0, %o4))
287	andcc		%o2, 1, %g0
288	srl		%o4, 8, %g2
289	add		%o0, 2, %o0
290	EX_ST(STORE(stb, %g2, %o1))
291	add		GLOBAL_SPARE, %o4, GLOBAL_SPARE
292	EX_ST(STORE(stb, %o4, %o1 + 1))
293	add		%o1, 2, %o1
2943:	be,a,pt		%icc, 1f
295	 sll		GLOBAL_SPARE, 16, %o4
296	EX_LD(LOAD(ldub, %o0, %g2))
297	sll		%g2, 8, %o4
298	EX_ST(STORE(stb, %g2, %o1))
299	add		GLOBAL_SPARE, %o4, GLOBAL_SPARE
300	sll		GLOBAL_SPARE, 16, %o4
3011:	addcc		%o4, GLOBAL_SPARE, GLOBAL_SPARE
302	srl		GLOBAL_SPARE, 16, %o4
303	addc		%g0, %o4, GLOBAL_SPARE
304	brz,pt		%o5, 4f
305	 srl		GLOBAL_SPARE, 8, %o4
306	and		GLOBAL_SPARE, 0xff, %g2
307	and		%o4, 0xff, %o4
308	sll		%g2, 8, %g2
309	or		%g2, %o4, GLOBAL_SPARE
3104:	addcc		%o3, GLOBAL_SPARE, %o3
311	addc		%g0, %o3, %o0
312	retl
313	 srl		%o0, 0, %o0
314	.size		FUNC_NAME, .-FUNC_NAME
315