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[NET]: ARM checksum annotations and cleanups.
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* sanitize prototypes, annotate
* kill csum_partial_copy
* usual ntohs->shift, this time in assembler part

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Al Viro authored and David S. Miller committed Dec 3, 2006
1 parent a4f89fb commit eb5a965
Showing 1 changed file with 41 additions and 42 deletions.
83 changes: 41 additions & 42 deletions include/asm-arm/checksum.h
Original file line number Diff line number Diff line change
Expand Up @@ -23,7 +23,7 @@
*
* it's best to have buff aligned on a 32-bit boundary
*/
unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
__wsum csum_partial(const void *buff, int len, __wsum sum);

/*
* the same as csum_partial, but copies from src while it
Expand All @@ -33,26 +33,18 @@ unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum)
* better 64-bit) boundary
*/

unsigned int
csum_partial_copy_nocheck(const char *src, char *dst, int len, int sum);
__wsum
csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);

unsigned int
csum_partial_copy_from_user(const char __user *src, char *dst, int len, int sum, int *err_ptr);

/*
* This is the old (and unsafe) way of doing checksums, a warning message will
* be printed if it is used and an exception occurs.
*
* this functions should go away after some time.
*/
#define csum_partial_copy(src,dst,len,sum) csum_partial_copy_nocheck(src,dst,len,sum)
__wsum
csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *err_ptr);

/*
* This is a version of ip_compute_csum() optimized for IP headers,
* which always checksum on 4 octet boundaries.
*/
static inline unsigned short
ip_fast_csum(unsigned char * iph, unsigned int ihl)
static inline __sum16
ip_fast_csum(const void *iph, unsigned int ihl)
{
unsigned int sum, tmp1;

Expand All @@ -78,81 +70,88 @@ ip_fast_csum(unsigned char * iph, unsigned int ihl)
: "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (tmp1)
: "1" (iph), "2" (ihl)
: "cc", "memory");
return sum;
return (__force __sum16)sum;
}

/*
* Fold a partial checksum without adding pseudo headers
*/
static inline unsigned int
csum_fold(unsigned int sum)
static inline __sum16 csum_fold(__wsum sum)
{
__asm__(
"adds %0, %1, %1, lsl #16 @ csum_fold \n\
addcs %0, %0, #0x10000"
: "=r" (sum)
: "r" (sum)
: "cc");
return (~sum) >> 16;
return (__force __sum16)(~(__force u32)sum >> 16);
}

static inline unsigned int
csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len,
unsigned int proto, unsigned int sum)
static inline __wsum
csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
unsigned short proto, __wsum sum)
{
__asm__(
"adds %0, %1, %2 @ csum_tcpudp_nofold \n\
adcs %0, %0, %3 \n\
adcs %0, %0, %4 \n\
adcs %0, %0, %5 \n\
adcs %0, %0, %3 \n"
#ifdef __ARMEB__
"adcs %0, %0, %4 \n"
#else
"adcs %0, %0, %4, lsl #8 \n"
#endif
"adcs %0, %0, %5 \n\
adc %0, %0, #0"
: "=&r"(sum)
: "r" (sum), "r" (daddr), "r" (saddr), "r" (ntohs(len)), "Ir" (ntohs(proto))
: "r" (sum), "r" (daddr), "r" (saddr), "r" (len), "Ir" (htons(proto))
: "cc");
return sum;
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
static inline unsigned short int
csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,
unsigned int proto, unsigned int sum)
static inline __sum16
csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
unsigned short proto, __wsum sum)
{
__asm__(
"adds %0, %1, %2 @ csum_tcpudp_magic \n\
adcs %0, %0, %3 \n\
adcs %0, %0, %4 \n\
adcs %0, %0, %5 \n\
adcs %0, %0, %3 \n"
#ifdef __ARMEB__
"adcs %0, %0, %4 \n"
#else
"adcs %0, %0, %4, lsl #8 \n"
#endif
"adcs %0, %0, %5 \n\
adc %0, %0, #0 \n\
adds %0, %0, %0, lsl #16 \n\
addcs %0, %0, #0x10000 \n\
mvn %0, %0"
: "=&r"(sum)
: "r" (sum), "r" (daddr), "r" (saddr), "r" (ntohs(len)), "Ir" (ntohs(proto))
: "r" (sum), "r" (daddr), "r" (saddr), "r" (len), "Ir" (htons(proto))
: "cc");
return sum >> 16;
return (__force __sum16)((__force u32)sum >> 16);
}


/*
* this routine is used for miscellaneous IP-like checksums, mainly
* in icmp.c
*/
static inline unsigned short
ip_compute_csum(unsigned char * buff, int len)
static inline __sum16
ip_compute_csum(const void *buff, int len)
{
return csum_fold(csum_partial(buff, len, 0));
}

#define _HAVE_ARCH_IPV6_CSUM
extern unsigned long
__csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, __u32 len,
__u32 proto, unsigned int sum);
extern __wsum
__csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, __be32 len,
__be32 proto, __wsum sum);

static inline unsigned short int
csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, __u32 len,
unsigned short proto, unsigned int sum)
static inline __sum16
csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, __u32 len,
unsigned short proto, __wsum sum)
{
return csum_fold(__csum_ipv6_magic(saddr, daddr, htonl(len),
htonl(proto), sum));
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