diff options
Diffstat (limited to 'include/asm-avr32/checksum.h')
| -rw-r--r-- | include/asm-avr32/checksum.h | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/include/asm-avr32/checksum.h b/include/asm-avr32/checksum.h new file mode 100644 index 000000000000..41b7af09edc4 --- /dev/null +++ b/include/asm-avr32/checksum.h @@ -0,0 +1,156 @@ +/* + * Copyright (C) 2004-2006 Atmel Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#ifndef __ASM_AVR32_CHECKSUM_H +#define __ASM_AVR32_CHECKSUM_H + +/* + * computes the checksum of a memory block at buff, length len, + * and adds in "sum" (32-bit) + * + * returns a 32-bit number suitable for feeding into itself + * or csum_tcpudp_magic + * + * this function must be called with even lengths, except + * for the last fragment, which may be odd + * + * 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); + +/* + * the same as csum_partial, but copies from src while it + * checksums, and handles user-space pointer exceptions correctly, when needed. + * + * here even more important to align src and dst on a 32-bit (or even + * better 64-bit) boundary + */ +unsigned int csum_partial_copy_generic(const char *src, char *dst, int len, + int sum, int *src_err_ptr, + int *dst_err_ptr); + +/* + * Note: when you get a NULL pointer exception here this means someone + * passed in an incorrect kernel address to one of these functions. + * + * If you use these functions directly please don't forget the + * verify_area(). + */ +static inline +unsigned int csum_partial_copy_nocheck(const char *src, char *dst, + int len, int sum) +{ + return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL); +} + +static inline +unsigned int csum_partial_copy_from_user (const char __user *src, char *dst, + int len, int sum, int *err_ptr) +{ + return csum_partial_copy_generic((const char __force *)src, dst, len, + sum, err_ptr, NULL); +} + +/* + * 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) +{ + unsigned int sum, tmp; + + __asm__ __volatile__( + " ld.w %0, %1++\n" + " ld.w %3, %1++\n" + " sub %2, 4\n" + " add %0, %3\n" + " ld.w %3, %1++\n" + " adc %0, %0, %3\n" + " ld.w %3, %1++\n" + " adc %0, %0, %3\n" + " acr %0\n" + "1: ld.w %3, %1++\n" + " add %0, %3\n" + " acr %0\n" + " sub %2, 1\n" + " brne 1b\n" + " lsl %3, %0, 16\n" + " andl %0, 0\n" + " mov %2, 0xffff\n" + " add %0, %3\n" + " adc %0, %0, %2\n" + " com %0\n" + " lsr %0, 16\n" + : "=r"(sum), "=r"(iph), "=r"(ihl), "=r"(tmp) + : "1"(iph), "2"(ihl) + : "memory", "cc"); + return sum; +} + +/* + * Fold a partial checksum + */ + +static inline unsigned int csum_fold(unsigned int sum) +{ + unsigned int tmp; + + asm(" bfextu %1, %0, 0, 16\n" + " lsr %0, 16\n" + " add %0, %1\n" + " bfextu %1, %0, 16, 16\n" + " add %0, %1" + : "=&r"(sum), "=&r"(tmp) + : "0"(sum)); + + return ~sum; +} + +static inline unsigned long csum_tcpudp_nofold(unsigned long saddr, + unsigned long daddr, + unsigned short len, + unsigned short proto, + unsigned int sum) +{ + asm(" add %0, %1\n" + " adc %0, %0, %2\n" + " adc %0, %0, %3\n" + " acr %0" + : "=r"(sum) + : "r"(daddr), "r"(saddr), "r"(ntohs(len) | (proto << 16)), + "0"(sum) + : "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 short proto, + unsigned int sum) +{ + return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); +} + +/* + * 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) +{ + return csum_fold(csum_partial(buff, len, 0)); +} + +#endif /* __ASM_AVR32_CHECKSUM_H */ |