1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 4 * 5 * Joern Rennecke <joern.rennecke@embecosm.com>: Jan 2012 6 * -Insn Scheduling improvements to csum core routines. 7 * = csum_fold( ) largely derived from ARM version. 8 * = ip_fast_cum( ) to have module scheduling 9 * -gcc 4.4.x broke networking. Alias analysis needed to be primed. 10 * worked around by adding memory clobber to ip_fast_csum( ) 11 * 12 * vineetg: May 2010 13 * -Rewrote ip_fast_cscum( ) and csum_fold( ) with fast inline asm 14 */ 15 16 #ifndef _ASM_ARC_CHECKSUM_H 17 #define _ASM_ARC_CHECKSUM_H 18 19 /* 20 * Fold a partial checksum 21 * 22 * The 2 swords comprising the 32bit sum are added, any carry to 16th bit 23 * added back and final sword result inverted. 24 */ 25 static inline __sum16 csum_fold(__wsum s) 26 { 27 unsigned r = s << 16 | s >> 16; /* ror */ 28 s = ~s; 29 s -= r; 30 return s >> 16; 31 } 32 33 /* 34 * This is a version of ip_compute_csum() optimized for IP headers, 35 * which always checksum on 4 octet boundaries. 36 */ 37 static inline __sum16 38 ip_fast_csum(const void *iph, unsigned int ihl) 39 { 40 const void *ptr = iph; 41 unsigned int tmp, tmp2, sum; 42 43 __asm__( 44 " ld.ab %0, [%3, 4] \n" 45 " ld.ab %2, [%3, 4] \n" 46 " sub %1, %4, 2 \n" 47 " lsr.f lp_count, %1, 1 \n" 48 " bcc 0f \n" 49 " add.f %0, %0, %2 \n" 50 " ld.ab %2, [%3, 4] \n" 51 "0: lp 1f \n" 52 " ld.ab %1, [%3, 4] \n" 53 " adc.f %0, %0, %2 \n" 54 " ld.ab %2, [%3, 4] \n" 55 " adc.f %0, %0, %1 \n" 56 "1: adc.f %0, %0, %2 \n" 57 " add.cs %0,%0,1 \n" 58 : "=&r"(sum), "=r"(tmp), "=&r"(tmp2), "+&r" (ptr) 59 : "r"(ihl) 60 : "cc", "lp_count", "memory"); 61 62 return csum_fold(sum); 63 } 64 65 /* 66 * TCP pseudo Header is 12 bytes: 67 * SA [4], DA [4], zeroes [1], Proto[1], TCP Seg(hdr+data) Len [2] 68 */ 69 static inline __wsum 70 csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len, 71 __u8 proto, __wsum sum) 72 { 73 __asm__ __volatile__( 74 " add.f %0, %0, %1 \n" 75 " adc.f %0, %0, %2 \n" 76 " adc.f %0, %0, %3 \n" 77 " adc.f %0, %0, %4 \n" 78 " adc %0, %0, 0 \n" 79 : "+&r"(sum) 80 : "r"(saddr), "r"(daddr), 81 #ifdef CONFIG_CPU_BIG_ENDIAN 82 "r"(len), 83 #else 84 "r"(len << 8), 85 #endif 86 "r"(htons(proto)) 87 : "cc"); 88 89 return sum; 90 } 91 92 #define csum_fold csum_fold 93 #define ip_fast_csum ip_fast_csum 94 #define csum_tcpudp_nofold csum_tcpudp_nofold 95 96 #include <asm-generic/checksum.h> 97 98 #endif /* _ASM_ARC_CHECKSUM_H */ 99