diff options
Diffstat (limited to 'arch/sh/lib64/c-checksum.c')
| -rw-r--r-- | arch/sh/lib64/c-checksum.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/arch/sh/lib64/c-checksum.c b/arch/sh/lib64/c-checksum.c new file mode 100644 index 000000000000..053137abd8a0 --- /dev/null +++ b/arch/sh/lib64/c-checksum.c @@ -0,0 +1,217 @@ +/* + * arch/sh64/lib/c-checksum.c + * + * This file contains network checksum routines that are better done + * in an architecture-specific manner due to speed.. + */ + +#undef DEBUG + +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <asm/byteorder.h> +#include <asm/uaccess.h> + +static inline unsigned short from64to16(unsigned long long x) +{ + /* add up 32-bit words for 33 bits */ + x = (x & 0xffffffff) + (x >> 32); + /* add up 16-bit and 17-bit words for 17+c bits */ + x = (x & 0xffff) + (x >> 16); + /* add up 16-bit and 2-bit for 16+c bit */ + x = (x & 0xffff) + (x >> 16); + /* add up carry.. */ + x = (x & 0xffff) + (x >> 16); + return x; +} + +static inline unsigned short foldto16(unsigned long x) +{ + /* add up 16-bit for 17 bits */ + x = (x & 0xffff) + (x >> 16); + /* add up carry.. */ + x = (x & 0xffff) + (x >> 16); + return x; +} + +static inline unsigned short myfoldto16(unsigned long long x) +{ + /* Fold down to 32-bits so we don't loose in the typedef-less + network stack. */ + /* 64 to 33 */ + x = (x & 0xffffffff) + (x >> 32); + /* 33 to 32 */ + x = (x & 0xffffffff) + (x >> 32); + + /* add up 16-bit for 17 bits */ + x = (x & 0xffff) + (x >> 16); + /* add up carry.. */ + x = (x & 0xffff) + (x >> 16); + return x; +} + +#define odd(x) ((x)&1) +#define U16(x) ntohs(x) + +static unsigned long do_csum(const unsigned char *buff, int len) +{ + int odd, count; + unsigned long result = 0; + + pr_debug("do_csum buff %p, len %d (0x%x)\n", buff, len, len); +#ifdef DEBUG + for (i = 0; i < len; i++) { + if ((i % 26) == 0) + printk("\n"); + printk("%02X ", buff[i]); + } +#endif + + if (len <= 0) + goto out; + + odd = 1 & (unsigned long) buff; + if (odd) { + result = *buff << 8; + len--; + buff++; + } + count = len >> 1; /* nr of 16-bit words.. */ + if (count) { + if (2 & (unsigned long) buff) { + result += *(unsigned short *) buff; + count--; + len -= 2; + buff += 2; + } + count >>= 1; /* nr of 32-bit words.. */ + if (count) { + unsigned long carry = 0; + do { + unsigned long w = *(unsigned long *) buff; + buff += 4; + count--; + result += carry; + result += w; + carry = (w > result); + } while (count); + result += carry; + result = (result & 0xffff) + (result >> 16); + } + if (len & 2) { + result += *(unsigned short *) buff; + buff += 2; + } + } + if (len & 1) + result += *buff; + result = foldto16(result); + if (odd) + result = ((result >> 8) & 0xff) | ((result & 0xff) << 8); + + pr_debug("\nCHECKSUM is 0x%lx\n", result); + + out: + return result; +} + +/* computes the checksum of a memory block at buff, length len, + and adds in "sum" (32-bit) */ +__wsum csum_partial(const void *buff, int len, __wsum sum) +{ + unsigned long long result = do_csum(buff, len); + + /* add in old sum, and carry.. */ + result += (__force u32)sum; + /* 32+c bits -> 32 bits */ + result = (result & 0xffffffff) + (result >> 32); + + pr_debug("csum_partial, buff %p len %d sum 0x%x result=0x%016Lx\n", + buff, len, sum, result); + + return (__force __wsum)result; +} + +/* Copy while checksumming, otherwise like csum_partial. */ +__wsum +csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum) +{ + sum = csum_partial(src, len, sum); + memcpy(dst, src, len); + + return sum; +} + +/* Copy from userspace and compute checksum. If we catch an exception + then zero the rest of the buffer. */ +__wsum +csum_partial_copy_from_user(const void __user *src, void *dst, int len, + __wsum sum, int *err_ptr) +{ + int missing; + + pr_debug + ("csum_partial_copy_from_user src %p, dest %p, len %d, sum %08x, err_ptr %p\n", + src, dst, len, sum, err_ptr); + missing = copy_from_user(dst, src, len); + pr_debug(" access_ok %d\n", __access_ok((unsigned long) src, len)); + pr_debug(" missing %d\n", missing); + if (missing) { + memset(dst + len - missing, 0, missing); + *err_ptr = -EFAULT; + } + + return csum_partial(dst, len, sum); +} + +/* Copy to userspace and compute checksum. */ +__wsum +csum_partial_copy_to_user(const unsigned char *src, unsigned char *dst, int len, + __wsum sum, int *err_ptr) +{ + sum = csum_partial(src, len, sum); + + if (copy_to_user(dst, src, len)) + *err_ptr = -EFAULT; + + return sum; +} + +/* + * This is a version of ip_compute_csum() optimized for IP headers, + * which always checksum on 4 octet boundaries. + */ +__sum16 ip_fast_csum(const void *iph, unsigned int ihl) +{ + pr_debug("ip_fast_csum %p,%d\n", iph, ihl); + + return (__force __sum16)~do_csum(iph, ihl * 4); +} + +__wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, + unsigned short len, + unsigned short proto, __wsum sum) +{ + unsigned long long result; + + pr_debug("ntohs(0x%x)=0x%x\n", 0xdead, ntohs(0xdead)); + pr_debug("htons(0x%x)=0x%x\n", 0xdead, htons(0xdead)); + + result = (__force u64) saddr + (__force u64) daddr + + (__force u64) sum + ((len + proto) << 8); + + /* Fold down to 32-bits so we don't loose in the typedef-less + network stack. */ + /* 64 to 33 */ + result = (result & 0xffffffff) + (result >> 32); + /* 33 to 32 */ + result = (result & 0xffffffff) + (result >> 32); + + pr_debug("%s saddr %x daddr %x len %x proto %x sum %x result %08Lx\n", + __FUNCTION__, saddr, daddr, len, proto, sum, result); + + return (__wsum)result; +} +EXPORT_SYMBOL(csum_tcpudp_nofold); |