2 * csum_partial_copy - do IP checksumming and copy
4 * (C) Copyright 1996 Linus Torvalds
5 * accelerated versions (and 21264 assembly versions ) contributed by
6 * Rick Gorton <rick.gorton@alpha-processor.com>
8 * Don't look at this too closely - you'll go mad. The things
9 * we do for performance..
12 #include <linux/types.h>
13 #include <linux/string.h>
14 #include <linux/uaccess.h>
18 __asm__ __volatile__("ldq_u %0,%1":"=r" (x):"m" (*(const unsigned long *)(y)))
21 __asm__ __volatile__("stq_u %1,%0":"=m" (*(unsigned long *)(y)):"r" (x))
23 #define extql(x,y,z) \
24 __asm__ __volatile__("extql %1,%2,%0":"=r" (z):"r" (x),"r" (y))
26 #define extqh(x,y,z) \
27 __asm__ __volatile__("extqh %1,%2,%0":"=r" (z):"r" (x),"r" (y))
29 #define mskql(x,y,z) \
30 __asm__ __volatile__("mskql %1,%2,%0":"=r" (z):"r" (x),"r" (y))
32 #define mskqh(x,y,z) \
33 __asm__ __volatile__("mskqh %1,%2,%0":"=r" (z):"r" (x),"r" (y))
35 #define insql(x,y,z) \
36 __asm__ __volatile__("insql %1,%2,%0":"=r" (z):"r" (x),"r" (y))
38 #define insqh(x,y,z) \
39 __asm__ __volatile__("insqh %1,%2,%0":"=r" (z):"r" (x),"r" (y))
42 #define __get_user_u(x,ptr) \
45 __asm__ __volatile__( \
49 : "=r"(x), "=r"(__guu_err) \
50 : "m"(__m(ptr)), "1"(0)); \
54 #define __put_user_u(x,ptr) \
57 __asm__ __volatile__( \
62 : "m"(__m(addr)), "rJ"(x), "0"(0)); \
67 static inline unsigned short from64to16(unsigned long x
)
69 /* Using extract instructions is a bit more efficient
70 than the original shift/bitmask version. */
79 tmp_v
.ul
= (unsigned long) in_v
.ui
[0] + (unsigned long) in_v
.ui
[1];
81 /* Since the bits of tmp_v.sh[3] are going to always be zero,
82 we don't have to bother to add that in. */
83 out_v
.ul
= (unsigned long) tmp_v
.us
[0] + (unsigned long) tmp_v
.us
[1]
84 + (unsigned long) tmp_v
.us
[2];
86 /* Similarly, out_v.us[2] is always zero for the final add. */
87 return out_v
.us
[0] + out_v
.us
[1];
93 * Ok. This isn't fun, but this is the EASY case.
95 static inline unsigned long
96 csum_partial_cfu_aligned(const unsigned long __user
*src
, unsigned long *dst
,
97 long len
, unsigned long checksum
,
100 unsigned long carry
= 0;
105 err
|= __get_user(word
, src
);
110 carry
= checksum
< word
;
117 unsigned long word
, tmp
;
118 err
|= __get_user(word
, src
);
120 mskql(word
, len
, word
);
122 mskqh(tmp
, len
, tmp
);
123 carry
= checksum
< word
;
127 if (err
&& errp
) *errp
= err
;
132 * This is even less fun, but this is still reasonably
135 static inline unsigned long
136 csum_partial_cfu_dest_aligned(const unsigned long __user
*src
,
139 long len
, unsigned long checksum
,
143 unsigned long word
, carry
;
144 unsigned long lastsrc
= 7+len
+(unsigned long)src
;
147 err
|= __get_user_u(first
,src
);
150 unsigned long second
;
152 err
|= __get_user_u(second
, src
+1);
153 extql(first
, soff
, word
);
156 extqh(second
, soff
, first
);
163 carry
= checksum
< word
;
169 unsigned long second
;
170 err
|= __get_user_u(second
, lastsrc
);
172 extql(first
, soff
, word
);
173 extqh(second
, soff
, first
);
175 mskql(word
, len
, word
);
177 mskqh(tmp
, len
, tmp
);
178 carry
= checksum
< word
;
182 if (err
&& errp
) *errp
= err
;
187 * This is slightly less fun than the above..
189 static inline unsigned long
190 csum_partial_cfu_src_aligned(const unsigned long __user
*src
,
193 long len
, unsigned long checksum
,
194 unsigned long partial_dest
,
197 unsigned long carry
= 0;
199 unsigned long second_dest
;
202 mskql(partial_dest
, doff
, partial_dest
);
204 err
|= __get_user(word
, src
);
206 insql(word
, doff
, second_dest
);
208 stq_u(partial_dest
| second_dest
, dst
);
211 insqh(word
, doff
, partial_dest
);
212 carry
= checksum
< word
;
218 err
|= __get_user(word
, src
);
219 mskql(word
, len
, word
);
222 insql(word
, doff
, second_dest
);
224 carry
= checksum
< word
;
225 partial_dest
|= second_dest
;
227 stq_u(partial_dest
, dst
);
230 insqh(word
, doff
, partial_dest
);
234 ldq_u(second_dest
, dst
);
235 mskqh(second_dest
, doff
, second_dest
);
236 stq_u(partial_dest
| second_dest
, dst
);
239 if (err
&& errp
) *errp
= err
;
244 * This is so totally un-fun that it's frightening. Don't
245 * look at this too closely, you'll go blind.
247 static inline unsigned long
248 csum_partial_cfu_unaligned(const unsigned long __user
* src
,
250 unsigned long soff
, unsigned long doff
,
251 long len
, unsigned long checksum
,
252 unsigned long partial_dest
,
255 unsigned long carry
= 0;
257 unsigned long lastsrc
;
260 err
|= __get_user_u(first
, src
);
261 lastsrc
= 7+len
+(unsigned long)src
;
262 mskql(partial_dest
, doff
, partial_dest
);
264 unsigned long second
, word
;
265 unsigned long second_dest
;
267 err
|= __get_user_u(second
, src
+1);
268 extql(first
, soff
, word
);
271 extqh(second
, soff
, first
);
275 insql(word
, doff
, second_dest
);
277 stq_u(partial_dest
| second_dest
, dst
);
278 carry
= checksum
< word
;
279 insqh(word
, doff
, partial_dest
);
285 unsigned long second
, word
;
286 unsigned long second_dest
;
288 err
|= __get_user_u(second
, lastsrc
);
289 extql(first
, soff
, word
);
290 extqh(second
, soff
, first
);
293 mskql(word
, len
-doff
, word
);
295 insql(word
, doff
, second_dest
);
296 carry
= checksum
< word
;
297 stq_u(partial_dest
| second_dest
, dst
);
299 ldq_u(second_dest
, dst
+1);
300 insqh(word
, doff
, partial_dest
);
301 mskqh(second_dest
, len
, second_dest
);
302 stq_u(partial_dest
| second_dest
, dst
+1);
306 unsigned long second
, word
;
307 unsigned long second_dest
;
309 err
|= __get_user_u(second
, lastsrc
);
310 extql(first
, soff
, word
);
311 extqh(second
, soff
, first
);
313 ldq_u(second_dest
, dst
);
314 mskql(word
, len
-doff
, word
);
316 mskqh(second_dest
, len
, second_dest
);
317 carry
= checksum
< word
;
318 insql(word
, doff
, word
);
319 stq_u(partial_dest
| word
| second_dest
, dst
);
322 if (err
&& errp
) *errp
= err
;
327 csum_partial_copy_from_user(const void __user
*src
, void *dst
, int len
,
328 __wsum sum
, int *errp
)
330 unsigned long checksum
= (__force u32
) sum
;
331 unsigned long soff
= 7 & (unsigned long) src
;
332 unsigned long doff
= 7 & (unsigned long) dst
;
335 if (!access_ok(VERIFY_READ
, src
, len
)) {
336 if (errp
) *errp
= -EFAULT
;
342 checksum
= csum_partial_cfu_aligned(
343 (const unsigned long __user
*) src
,
344 (unsigned long *) dst
,
345 len
-8, checksum
, errp
);
347 checksum
= csum_partial_cfu_dest_aligned(
348 (const unsigned long __user
*) src
,
349 (unsigned long *) dst
,
350 soff
, len
-8, checksum
, errp
);
352 unsigned long partial_dest
;
353 ldq_u(partial_dest
, dst
);
355 checksum
= csum_partial_cfu_src_aligned(
356 (const unsigned long __user
*) src
,
357 (unsigned long *) dst
,
358 doff
, len
-8, checksum
,
361 checksum
= csum_partial_cfu_unaligned(
362 (const unsigned long __user
*) src
,
363 (unsigned long *) dst
,
364 soff
, doff
, len
-8, checksum
,
367 checksum
= from64to16 (checksum
);
369 return (__force __wsum
)checksum
;
371 EXPORT_SYMBOL(csum_partial_copy_from_user
);
374 csum_partial_copy_nocheck(const void *src
, void *dst
, int len
, __wsum sum
)
377 mm_segment_t oldfs
= get_fs();
379 checksum
= csum_partial_copy_from_user((__force
const void __user
*)src
,
380 dst
, len
, sum
, NULL
);
384 EXPORT_SYMBOL(csum_partial_copy_nocheck
);