xref: /openbmc/linux/arch/sparc/lib/checksum_32.S (revision 9123e3a7) 
1/* SPDX-License-Identifier: GPL-2.0 */
2/* checksum.S: Sparc optimized checksum code.
3 *
4 *  Copyright(C) 1995 Linus Torvalds
5 *  Copyright(C) 1995 Miguel de Icaza
6 *  Copyright(C) 1996 David S. Miller
7 *  Copyright(C) 1997 Jakub Jelinek
8 *
9 * derived from:
10 *	Linux/Alpha checksum c-code
11 *      Linux/ix86 inline checksum assembly
12 *      RFC1071 Computing the Internet Checksum (esp. Jacobsons m68k code)
13 *	David Mosberger-Tang for optimized reference c-code
14 *	BSD4.4 portable checksum routine
15 */
16
17#include <asm/errno.h>
18#include <asm/export.h>
19
20#define CSUM_BIGCHUNK(buf, offset, sum, t0, t1, t2, t3, t4, t5)	\
21	ldd	[buf + offset + 0x00], t0;			\
22	ldd	[buf + offset + 0x08], t2;			\
23	addxcc	t0, sum, sum;					\
24	addxcc	t1, sum, sum;					\
25	ldd	[buf + offset + 0x10], t4;			\
26	addxcc	t2, sum, sum;					\
27	addxcc	t3, sum, sum;					\
28	ldd	[buf + offset + 0x18], t0;			\
29	addxcc	t4, sum, sum;					\
30	addxcc	t5, sum, sum;					\
31	addxcc	t0, sum, sum;					\
32	addxcc	t1, sum, sum;
33
34#define CSUM_LASTCHUNK(buf, offset, sum, t0, t1, t2, t3)	\
35	ldd	[buf - offset - 0x08], t0;			\
36	ldd	[buf - offset - 0x00], t2;			\
37	addxcc	t0, sum, sum;					\
38	addxcc	t1, sum, sum;					\
39	addxcc	t2, sum, sum;					\
40	addxcc	t3, sum, sum;
41
42	/* Do end cruft out of band to get better cache patterns. */
43csum_partial_end_cruft:
44	be	1f				! caller asks %o1 & 0x8
45	 andcc	%o1, 4, %g0			! nope, check for word remaining
46	ldd	[%o0], %g2			! load two
47	addcc	%g2, %o2, %o2			! add first word to sum
48	addxcc	%g3, %o2, %o2			! add second word as well
49	add	%o0, 8, %o0			! advance buf ptr
50	addx	%g0, %o2, %o2			! add in final carry
51	andcc	%o1, 4, %g0			! check again for word remaining
521:	be	1f				! nope, skip this code
53	 andcc	%o1, 3, %o1			! check for trailing bytes
54	ld	[%o0], %g2			! load it
55	addcc	%g2, %o2, %o2			! add to sum
56	add	%o0, 4, %o0			! advance buf ptr
57	addx	%g0, %o2, %o2			! add in final carry
58	andcc	%o1, 3, %g0			! check again for trailing bytes
591:	be	1f				! no trailing bytes, return
60	 addcc	%o1, -1, %g0			! only one byte remains?
61	bne	2f				! at least two bytes more
62	 subcc	%o1, 2, %o1			! only two bytes more?
63	b	4f				! only one byte remains
64	 or	%g0, %g0, %o4			! clear fake hword value
652:	lduh	[%o0], %o4			! get hword
66	be	6f				! jmp if only hword remains
67	 add	%o0, 2, %o0			! advance buf ptr either way
68	sll	%o4, 16, %o4			! create upper hword
694:	ldub	[%o0], %o5			! get final byte
70	sll	%o5, 8, %o5			! put into place
71	or	%o5, %o4, %o4			! coalese with hword (if any)
726:	addcc	%o4, %o2, %o2			! add to sum
731:	retl					! get outta here
74	 addx	%g0, %o2, %o0			! add final carry into retval
75
76	/* Also do alignment out of band to get better cache patterns. */
77csum_partial_fix_alignment:
78	cmp	%o1, 6
79	bl	cpte - 0x4
80	 andcc	%o0, 0x2, %g0
81	be	1f
82	 andcc	%o0, 0x4, %g0
83	lduh	[%o0 + 0x00], %g2
84	sub	%o1, 2, %o1
85	add	%o0, 2, %o0
86	sll	%g2, 16, %g2
87	addcc	%g2, %o2, %o2
88	srl	%o2, 16, %g3
89	addx	%g0, %g3, %g2
90	sll	%o2, 16, %o2
91	sll	%g2, 16, %g3
92	srl	%o2, 16, %o2
93	andcc	%o0, 0x4, %g0
94	or	%g3, %o2, %o2
951:	be	cpa
96	 andcc	%o1, 0xffffff80, %o3
97	ld	[%o0 + 0x00], %g2
98	sub	%o1, 4, %o1
99	addcc	%g2, %o2, %o2
100	add	%o0, 4, %o0
101	addx	%g0, %o2, %o2
102	b	cpa
103	 andcc	%o1, 0xffffff80, %o3
104
105	/* The common case is to get called with a nicely aligned
106	 * buffer of size 0x20.  Follow the code path for that case.
107	 */
108	.globl	csum_partial
109	EXPORT_SYMBOL(csum_partial)
110csum_partial:			/* %o0=buf, %o1=len, %o2=sum */
111	andcc	%o0, 0x7, %g0				! alignment problems?
112	bne	csum_partial_fix_alignment		! yep, handle it
113	 sethi	%hi(cpte - 8), %g7			! prepare table jmp ptr
114	andcc	%o1, 0xffffff80, %o3			! num loop iterations
115cpa:	be	3f					! none to do
116	 andcc	%o1, 0x70, %g1				! clears carry flag too
1175:	CSUM_BIGCHUNK(%o0, 0x00, %o2, %o4, %o5, %g2, %g3, %g4, %g5)
118	CSUM_BIGCHUNK(%o0, 0x20, %o2, %o4, %o5, %g2, %g3, %g4, %g5)
119	CSUM_BIGCHUNK(%o0, 0x40, %o2, %o4, %o5, %g2, %g3, %g4, %g5)
120	CSUM_BIGCHUNK(%o0, 0x60, %o2, %o4, %o5, %g2, %g3, %g4, %g5)
121	addx	%g0, %o2, %o2				! sink in final carry
122	subcc	%o3, 128, %o3				! detract from loop iters
123	bne	5b					! more to do
124	 add	%o0, 128, %o0				! advance buf ptr
125	andcc	%o1, 0x70, %g1				! clears carry flag too
1263:	be	cpte					! nope
127	 andcc	%o1, 0xf, %g0				! anything left at all?
128	srl	%g1, 1, %o4				! compute offset
129	sub	%g7, %g1, %g7				! adjust jmp ptr
130	sub	%g7, %o4, %g7				! final jmp ptr adjust
131	jmp	%g7 + %lo(cpte - 8)			! enter the table
132	 add	%o0, %g1, %o0				! advance buf ptr
133cptbl:	CSUM_LASTCHUNK(%o0, 0x68, %o2, %g2, %g3, %g4, %g5)
134	CSUM_LASTCHUNK(%o0, 0x58, %o2, %g2, %g3, %g4, %g5)
135	CSUM_LASTCHUNK(%o0, 0x48, %o2, %g2, %g3, %g4, %g5)
136	CSUM_LASTCHUNK(%o0, 0x38, %o2, %g2, %g3, %g4, %g5)
137	CSUM_LASTCHUNK(%o0, 0x28, %o2, %g2, %g3, %g4, %g5)
138	CSUM_LASTCHUNK(%o0, 0x18, %o2, %g2, %g3, %g4, %g5)
139	CSUM_LASTCHUNK(%o0, 0x08, %o2, %g2, %g3, %g4, %g5)
140	addx	%g0, %o2, %o2				! fetch final carry
141	andcc	%o1, 0xf, %g0				! anything left at all?
142cpte:	bne	csum_partial_end_cruft			! yep, handle it
143	 andcc	%o1, 8, %g0				! check how much
144cpout:	retl						! get outta here
145	 mov	%o2, %o0				! return computed csum
146
147	.globl __csum_partial_copy_start, __csum_partial_copy_end
148__csum_partial_copy_start:
149
150/* Work around cpp -rob */
151#define ALLOC #alloc
152#define EXECINSTR #execinstr
153#define EX(x,y,a,b)				\
15498:     x,y;                                    \
155        .section .fixup,ALLOC,EXECINSTR;	\
156        .align  4;                              \
15799:     ba 30f;                                 \
158         a, b, %o3;                             \
159        .section __ex_table,ALLOC;		\
160        .align  4;                              \
161        .word   98b, 99b;                       \
162        .text;                                  \
163        .align  4
164
165#define EX2(x,y)				\
16698:     x,y;                                    \
167        .section __ex_table,ALLOC;		\
168        .align  4;                              \
169        .word   98b, 30f;                       \
170        .text;                                  \
171        .align  4
172
173#define EX3(x,y)				\
17498:     x,y;                                    \
175        .section __ex_table,ALLOC;		\
176        .align  4;                              \
177        .word   98b, 96f;                       \
178        .text;                                  \
179        .align  4
180
181#define EXT(start,end,handler)			\
182        .section __ex_table,ALLOC;		\
183        .align  4;                              \
184        .word   start, 0, end, handler;         \
185        .text;                                  \
186        .align  4
187
188	/* This aligned version executes typically in 8.5 superscalar cycles, this
189	 * is the best I can do.  I say 8.5 because the final add will pair with
190	 * the next ldd in the main unrolled loop.  Thus the pipe is always full.
191	 * If you change these macros (including order of instructions),
192	 * please check the fixup code below as well.
193	 */
194#define CSUMCOPY_BIGCHUNK_ALIGNED(src, dst, sum, off, t0, t1, t2, t3, t4, t5, t6, t7)	\
195	ldd	[src + off + 0x00], t0;							\
196	ldd	[src + off + 0x08], t2;							\
197	addxcc	t0, sum, sum;								\
198	ldd	[src + off + 0x10], t4;							\
199	addxcc	t1, sum, sum;								\
200	ldd	[src + off + 0x18], t6;							\
201	addxcc	t2, sum, sum;								\
202	std	t0, [dst + off + 0x00];							\
203	addxcc	t3, sum, sum;								\
204	std	t2, [dst + off + 0x08];							\
205	addxcc	t4, sum, sum;								\
206	std	t4, [dst + off + 0x10];							\
207	addxcc	t5, sum, sum;								\
208	std	t6, [dst + off + 0x18];							\
209	addxcc	t6, sum, sum;								\
210	addxcc	t7, sum, sum;
211
212	/* 12 superscalar cycles seems to be the limit for this case,
213	 * because of this we thus do all the ldd's together to get
214	 * Viking MXCC into streaming mode.  Ho hum...
215	 */
216#define CSUMCOPY_BIGCHUNK(src, dst, sum, off, t0, t1, t2, t3, t4, t5, t6, t7)	\
217	ldd	[src + off + 0x00], t0;						\
218	ldd	[src + off + 0x08], t2;						\
219	ldd	[src + off + 0x10], t4;						\
220	ldd	[src + off + 0x18], t6;						\
221	st	t0, [dst + off + 0x00];						\
222	addxcc	t0, sum, sum;							\
223	st	t1, [dst + off + 0x04];						\
224	addxcc	t1, sum, sum;							\
225	st	t2, [dst + off + 0x08];						\
226	addxcc	t2, sum, sum;							\
227	st	t3, [dst + off + 0x0c];						\
228	addxcc	t3, sum, sum;							\
229	st	t4, [dst + off + 0x10];						\
230	addxcc	t4, sum, sum;							\
231	st	t5, [dst + off + 0x14];						\
232	addxcc	t5, sum, sum;							\
233	st	t6, [dst + off + 0x18];						\
234	addxcc	t6, sum, sum;							\
235	st	t7, [dst + off + 0x1c];						\
236	addxcc	t7, sum, sum;
237
238	/* Yuck, 6 superscalar cycles... */
239#define CSUMCOPY_LASTCHUNK(src, dst, sum, off, t0, t1, t2, t3)	\
240	ldd	[src - off - 0x08], t0;				\
241	ldd	[src - off - 0x00], t2;				\
242	addxcc	t0, sum, sum;					\
243	st	t0, [dst - off - 0x08];				\
244	addxcc	t1, sum, sum;					\
245	st	t1, [dst - off - 0x04];				\
246	addxcc	t2, sum, sum;					\
247	st	t2, [dst - off - 0x00];				\
248	addxcc	t3, sum, sum;					\
249	st	t3, [dst - off + 0x04];
250
251	/* Handle the end cruft code out of band for better cache patterns. */
252cc_end_cruft:
253	be	1f
254	 andcc	%o3, 4, %g0
255	EX(ldd	[%o0 + 0x00], %g2, and %o3, 0xf)
256	add	%o1, 8, %o1
257	addcc	%g2, %g7, %g7
258	add	%o0, 8, %o0
259	addxcc	%g3, %g7, %g7
260	EX2(st	%g2, [%o1 - 0x08])
261	addx	%g0, %g7, %g7
262	andcc	%o3, 4, %g0
263	EX2(st	%g3, [%o1 - 0x04])
2641:	be	1f
265	 andcc	%o3, 3, %o3
266	EX(ld	[%o0 + 0x00], %g2, add %o3, 4)
267	add	%o1, 4, %o1
268	addcc	%g2, %g7, %g7
269	EX2(st	%g2, [%o1 - 0x04])
270	addx	%g0, %g7, %g7
271	andcc	%o3, 3, %g0
272	add	%o0, 4, %o0
2731:	be	1f
274	 addcc	%o3, -1, %g0
275	bne	2f
276	 subcc	%o3, 2, %o3
277	b	4f
278	 or	%g0, %g0, %o4
2792:	EX(lduh	[%o0 + 0x00], %o4, add %o3, 2)
280	add	%o0, 2, %o0
281	EX2(sth	%o4, [%o1 + 0x00])
282	be	6f
283	 add	%o1, 2, %o1
284	sll	%o4, 16, %o4
2854:	EX(ldub	[%o0 + 0x00], %o5, add %g0, 1)
286	EX2(stb	%o5, [%o1 + 0x00])
287	sll	%o5, 8, %o5
288	or	%o5, %o4, %o4
2896:	addcc	%o4, %g7, %g7
2901:	retl
291	 addx	%g0, %g7, %o0
292
293	/* Also, handle the alignment code out of band. */
294cc_dword_align:
295	cmp	%g1, 16
296	bge	1f
297	 srl	%g1, 1, %o3
2982:	cmp	%o3, 0
299	be,a	ccte
300	 andcc	%g1, 0xf, %o3
301	andcc	%o3, %o0, %g0	! Check %o0 only (%o1 has the same last 2 bits)
302	be,a	2b
303	 srl	%o3, 1, %o3
3041:	andcc	%o0, 0x1, %g0
305	bne	ccslow
306	 andcc	%o0, 0x2, %g0
307	be	1f
308	 andcc	%o0, 0x4, %g0
309	EX(lduh	[%o0 + 0x00], %g4, add %g1, 0)
310	sub	%g1, 2, %g1
311	EX2(sth	%g4, [%o1 + 0x00])
312	add	%o0, 2, %o0
313	sll	%g4, 16, %g4
314	addcc	%g4, %g7, %g7
315	add	%o1, 2, %o1
316	srl	%g7, 16, %g3
317	addx	%g0, %g3, %g4
318	sll	%g7, 16, %g7
319	sll	%g4, 16, %g3
320	srl	%g7, 16, %g7
321	andcc	%o0, 0x4, %g0
322	or	%g3, %g7, %g7
3231:	be	3f
324	 andcc	%g1, 0xffffff80, %g0
325	EX(ld	[%o0 + 0x00], %g4, add %g1, 0)
326	sub	%g1, 4, %g1
327	EX2(st	%g4, [%o1 + 0x00])
328	add	%o0, 4, %o0
329	addcc	%g4, %g7, %g7
330	add	%o1, 4, %o1
331	addx	%g0, %g7, %g7
332	b	3f
333	 andcc	%g1, 0xffffff80, %g0
334
335	/* Sun, you just can't beat me, you just can't.  Stop trying,
336	 * give up.  I'm serious, I am going to kick the living shit
337	 * out of you, game over, lights out.
338	 */
339	.align	8
340	.globl	__csum_partial_copy_sparc_generic
341	EXPORT_SYMBOL(__csum_partial_copy_sparc_generic)
342__csum_partial_copy_sparc_generic:
343					/* %o0=src, %o1=dest, %g1=len, %g7=sum */
344	xor	%o0, %o1, %o4		! get changing bits
345	andcc	%o4, 3, %g0		! check for mismatched alignment
346	bne	ccslow			! better this than unaligned/fixups
347	 andcc	%o0, 7, %g0		! need to align things?
348	bne	cc_dword_align		! yes, we check for short lengths there
349	 andcc	%g1, 0xffffff80, %g0	! can we use unrolled loop?
3503:	be	3f			! nope, less than one loop remains
351	 andcc	%o1, 4, %g0		! dest aligned on 4 or 8 byte boundary?
352	be	ccdbl + 4		! 8 byte aligned, kick ass
3535:	CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x00,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
354	CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x20,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
355	CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x40,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
356	CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x60,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
35710:	EXT(5b, 10b, 20f)		! note for exception handling
358	sub	%g1, 128, %g1		! detract from length
359	addx	%g0, %g7, %g7		! add in last carry bit
360	andcc	%g1, 0xffffff80, %g0	! more to csum?
361	add	%o0, 128, %o0		! advance src ptr
362	bne	5b			! we did not go negative, continue looping
363	 add	%o1, 128, %o1		! advance dest ptr
3643:	andcc	%g1, 0x70, %o2		! can use table?
365ccmerge:be	ccte			! nope, go and check for end cruft
366	 andcc	%g1, 0xf, %o3		! get low bits of length (clears carry btw)
367	srl	%o2, 1, %o4		! begin negative offset computation
368	sethi	%hi(12f), %o5		! set up table ptr end
369	add	%o0, %o2, %o0		! advance src ptr
370	sub	%o5, %o4, %o5		! continue table calculation
371	sll	%o2, 1, %g2		! constant multiplies are fun...
372	sub	%o5, %g2, %o5		! some more adjustments
373	jmp	%o5 + %lo(12f)		! jump into it, duff style, wheee...
374	 add	%o1, %o2, %o1		! advance dest ptr (carry is clear btw)
375cctbl:	CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x68,%g2,%g3,%g4,%g5)
376	CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x58,%g2,%g3,%g4,%g5)
377	CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x48,%g2,%g3,%g4,%g5)
378	CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x38,%g2,%g3,%g4,%g5)
379	CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x28,%g2,%g3,%g4,%g5)
380	CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x18,%g2,%g3,%g4,%g5)
381	CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x08,%g2,%g3,%g4,%g5)
38212:	EXT(cctbl, 12b, 22f)		! note for exception table handling
383	addx	%g0, %g7, %g7
384	andcc	%o3, 0xf, %g0		! check for low bits set
385ccte:	bne	cc_end_cruft		! something left, handle it out of band
386	 andcc	%o3, 8, %g0		! begin checks for that code
387	retl				! return
388	 mov	%g7, %o0		! give em the computed checksum
389ccdbl:	CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x00,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
390	CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x20,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
391	CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x40,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
392	CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x60,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
39311:	EXT(ccdbl, 11b, 21f)		! note for exception table handling
394	sub	%g1, 128, %g1		! detract from length
395	addx	%g0, %g7, %g7		! add in last carry bit
396	andcc	%g1, 0xffffff80, %g0	! more to csum?
397	add	%o0, 128, %o0		! advance src ptr
398	bne	ccdbl			! we did not go negative, continue looping
399	 add	%o1, 128, %o1		! advance dest ptr
400	b	ccmerge			! finish it off, above
401	 andcc	%g1, 0x70, %o2		! can use table? (clears carry btw)
402
403ccslow:	cmp	%g1, 0
404	mov	0, %g5
405	bleu	4f
406	 andcc	%o0, 1, %o5
407	be,a	1f
408	 srl	%g1, 1, %g4
409	sub	%g1, 1, %g1
410	EX(ldub	[%o0], %g5, add %g1, 1)
411	add	%o0, 1, %o0
412	EX2(stb	%g5, [%o1])
413	srl	%g1, 1, %g4
414	add	%o1, 1, %o1
4151:	cmp	%g4, 0
416	be,a	3f
417	 andcc	%g1, 1, %g0
418	andcc	%o0, 2, %g0
419	be,a	1f
420	 srl	%g4, 1, %g4
421	EX(lduh	[%o0], %o4, add %g1, 0)
422	sub	%g1, 2, %g1
423	srl	%o4, 8, %g2
424	sub	%g4, 1, %g4
425	EX2(stb	%g2, [%o1])
426	add	%o4, %g5, %g5
427	EX2(stb	%o4, [%o1 + 1])
428	add	%o0, 2, %o0
429	srl	%g4, 1, %g4
430	add	%o1, 2, %o1
4311:	cmp	%g4, 0
432	be,a	2f
433	 andcc	%g1, 2, %g0
434	EX3(ld	[%o0], %o4)
4355:	srl	%o4, 24, %g2
436	srl	%o4, 16, %g3
437	EX2(stb	%g2, [%o1])
438	srl	%o4, 8, %g2
439	EX2(stb	%g3, [%o1 + 1])
440	add	%o0, 4, %o0
441	EX2(stb	%g2, [%o1 + 2])
442	addcc	%o4, %g5, %g5
443	EX2(stb	%o4, [%o1 + 3])
444	addx	%g5, %g0, %g5	! I am now to lazy to optimize this (question it
445	add	%o1, 4, %o1	! is worthy). Maybe some day - with the sll/srl
446	subcc	%g4, 1, %g4	! tricks
447	bne,a	5b
448	 EX3(ld	[%o0], %o4)
449	sll	%g5, 16, %g2
450	srl	%g5, 16, %g5
451	srl	%g2, 16, %g2
452	andcc	%g1, 2, %g0
453	add	%g2, %g5, %g5
4542:	be,a	3f
455	 andcc	%g1, 1, %g0
456	EX(lduh	[%o0], %o4, and %g1, 3)
457	andcc	%g1, 1, %g0
458	srl	%o4, 8, %g2
459	add	%o0, 2, %o0
460	EX2(stb	%g2, [%o1])
461	add	%g5, %o4, %g5
462	EX2(stb	%o4, [%o1 + 1])
463	add	%o1, 2, %o1
4643:	be,a	1f
465	 sll	%g5, 16, %o4
466	EX(ldub	[%o0], %g2, add %g0, 1)
467	sll	%g2, 8, %o4
468	EX2(stb	%g2, [%o1])
469	add	%g5, %o4, %g5
470	sll	%g5, 16, %o4
4711:	addcc	%o4, %g5, %g5
472	srl	%g5, 16, %o4
473	addx	%g0, %o4, %g5
474	orcc	%o5, %g0, %g0
475	be	4f
476	 srl	%g5, 8, %o4
477	and	%g5, 0xff, %g2
478	and	%o4, 0xff, %o4
479	sll	%g2, 8, %g2
480	or	%g2, %o4, %g5
4814:	addcc	%g7, %g5, %g7
482	retl
483	 addx	%g0, %g7, %o0
484__csum_partial_copy_end:
485
486/* We do these strange calculations for the csum_*_from_user case only, ie.
487 * we only bother with faults on loads... */
488
489/* o2 = ((g2%20)&3)*8
490 * o3 = g1 - (g2/20)*32 - o2 */
49120:
492	cmp	%g2, 20
493	blu,a	1f
494	 and	%g2, 3, %o2
495	sub	%g1, 32, %g1
496	b	20b
497	 sub	%g2, 20, %g2
4981:
499	sll	%o2, 3, %o2
500	b	31f
501	 sub	%g1, %o2, %o3
502
503/* o2 = (!(g2 & 15) ? 0 : (((g2 & 15) + 1) & ~1)*8)
504 * o3 = g1 - (g2/16)*32 - o2 */
50521:
506	andcc	%g2, 15, %o3
507	srl	%g2, 4, %g2
508	be,a	1f
509	 clr	%o2
510	add	%o3, 1, %o3
511	and	%o3, 14, %o3
512	sll	%o3, 3, %o2
5131:
514	sll	%g2, 5, %g2
515	sub	%g1, %g2, %o3
516	b	31f
517	 sub	%o3, %o2, %o3
518
519/* o0 += (g2/10)*16 - 0x70
520 * 01 += (g2/10)*16 - 0x70
521 * o2 = (g2 % 10) ? 8 : 0
522 * o3 += 0x70 - (g2/10)*16 - o2 */
52322:
524	cmp	%g2, 10
525	blu,a	1f
526	 sub	%o0, 0x70, %o0
527	add	%o0, 16, %o0
528	add	%o1, 16, %o1
529	sub	%o3, 16, %o3
530	b	22b
531	 sub	%g2, 10, %g2
5321:
533	sub	%o1, 0x70, %o1
534	add	%o3, 0x70, %o3
535	clr	%o2
536	tst	%g2
537	bne,a	1f
538	 mov	8, %o2
5391:
540	b	31f
541	 sub	%o3, %o2, %o3
54296:
543	and	%g1, 3, %g1
544	sll	%g4, 2, %g4
545	add	%g1, %g4, %o3
54630:
547/* %o1 is dst
548 * %o3 is # bytes to zero out
549 * %o4 is faulting address
550 * %o5 is %pc where fault occurred */
551	clr	%o2
55231:
553/* %o0 is src
554 * %o1 is dst
555 * %o2 is # of bytes to copy from src to dst
556 * %o3 is # bytes to zero out
557 * %o4 is faulting address
558 * %o5 is %pc where fault occurred */
559	save	%sp, -104, %sp
560        mov     %i5, %o0
561        mov     %i7, %o1
562        mov	%i4, %o2
563        call    lookup_fault
564	 mov	%g7, %i4
565	cmp	%o0, 2
566	bne	1f
567	 add	%g0, -EFAULT, %i5
568	tst	%i2
569	be	2f
570	 mov	%i0, %o1
571	mov	%i1, %o0
5725:
573	call	memcpy
574	 mov	%i2, %o2
575	tst	%o0
576	bne,a	2f
577	 add	%i3, %i2, %i3
578	add	%i1, %i2, %i1
5792:
580	mov	%i1, %o0
5816:
582	call	__bzero
583	 mov	%i3, %o1
5841:
585	ld	[%sp + 168], %o2		! struct_ptr of parent
586	st	%i5, [%o2]
587	ret
588	 restore
589
590        .section __ex_table,#alloc
591        .align 4
592        .word 5b,2
593	.word 6b,2
594