| /* |
| * arch/sh/lib/csum_parial.c |
| * |
| * This file contains network checksum routines that are better done |
| * in an architecture-specific manner due to speed.. |
| */ |
| |
| #include <linux/config.h> |
| #include <linux/string.h> |
| #include <linux/errno.h> |
| #include <asm/byteorder.h> |
| #include <asm/uaccess.h> |
| |
| #if 1 |
| #define dprintk(x...) |
| #else |
| #define dprintk(x...) printk(x) |
| #endif |
| |
| 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) |
| /* |
| typedef unsigned short u16; |
| typedef unsigned u32; |
| */ |
| #define U16(x) ntohs(x) |
| |
| static unsigned long do_moronic_csum(const unsigned char *a16p, int cnt) |
| { |
| u32 sum; |
| int oddb; |
| |
| /* This algorithm is correct only for those values of cnt < 65536 */ |
| |
| oddb = odd(cnt); |
| cnt >>= 1; /* convert to a word count */ |
| sum = 0; /* do a straight two's complement sum */ |
| while (cnt--) |
| sum += U16(*a16p++); |
| if (oddb) /* pick up the odd byte */ |
| sum += U16(*a16p++) & (u16) 0xFF00; |
| /* add in the sum of the `carry' bits, making this one's complement */ |
| sum = (sum & (u32) 0xFFFF) + ((sum >> 16) & (u32) 0xFFFF); |
| if (sum & (u32) 0x10000) /* one last possible carry */ |
| sum = (sum + 1) & (u32) 0xFFFF; |
| if (sum == (u32) 0xFFFF) /* remove the -0 ambiguity */ |
| sum = (u32) 0; |
| return sum; |
| |
| } |
| |
| #if 0 |
| static inline unsigned long do_csum(const unsigned char *buff, int len) |
| { |
| int odd, count; |
| unsigned long long result = 0; |
| |
| 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) { |
| if (4 & (unsigned long) buff) { |
| result += *(unsigned int *) buff; |
| count--; |
| len -= 4; |
| buff += 4; |
| } |
| count >>= 1; /* nr of 64-bit words.. */ |
| if (count) { |
| unsigned long carry = 0; |
| do { |
| unsigned long w = |
| *(unsigned long *) buff; |
| count--; |
| buff += 8; |
| result += carry; |
| result += w; |
| carry = (w > result); |
| } while (count); |
| result += carry; |
| result = (result & 0xffffffff) + (result >> 32); |
| } |
| if (len & 4) { |
| result += *(unsigned int *) buff; |
| buff += 4; |
| } |
| } |
| if (len & 2) { |
| result += *(unsigned short *) buff; |
| buff += 2; |
| } |
| } |
| if (len & 1) |
| result += *buff; |
| result = from64to16(result); |
| if (odd) |
| result = ((result >> 8) & 0xff) | ((result & 0xff) << 8); |
| out: |
| return result; |
| } |
| |
| #else |
| |
| static unsigned long do_csum(const unsigned char *buff, int len) |
| { |
| int odd, count; |
| unsigned long result = 0; |
| |
| dprintk("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); |
| |
| dprintk("\nCHECKSUM is 0x%x\n", result); |
| |
| out: |
| return result; |
| } |
| |
| #endif |
| |
| /* computes the checksum of a memory block at buff, length len, |
| and adds in "sum" (32-bit) */ |
| unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum) |
| { |
| unsigned long long result = do_csum(buff, len); |
| |
| /* add in old sum, and carry.. */ |
| result += sum; |
| /* 32+c bits -> 32 bits */ |
| result = (result & 0xffffffff) + (result >> 32); |
| |
| dprintk("csum_partial, buff %p len %d sum 0x%x result=0x%016Lx\n", |
| buff, len, sum, result); |
| |
| return result; |
| } |
| |
| /* Copy while checksumming, otherwise like csum_partial. */ |
| unsigned int |
| csum_partial_copy(const char *src, char *dst, int len, unsigned int 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. */ |
| unsigned int |
| csum_partial_copy_from_user(const char *src, char *dst, int len, |
| unsigned int sum, int *err_ptr) |
| { |
| int missing; |
| |
| dprintk |
| ("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); |
| dprintk(" access_ok %d\n", __access_ok((unsigned long) src, len)); |
| dprintk(" 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. */ |
| unsigned int |
| csum_partial_copy_to_user(const char *src, char *dst, int len, |
| unsigned int 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. |
| */ |
| unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl) |
| { |
| dprintk("ip_fast_csum %p,%d\n", iph, ihl); |
| |
| return ~do_csum(iph, ihl * 4); |
| } |
| |
| unsigned int csum_tcpudp_nofold(unsigned long saddr, |
| unsigned long daddr, |
| unsigned short len, |
| unsigned short proto, unsigned int sum) |
| { |
| unsigned long long result; |
| |
| dprintk("ntohs(0x%x)=0x%x\n", 0xdead, ntohs(0xdead)); |
| dprintk("htons(0x%x)=0x%x\n", 0xdead, htons(0xdead)); |
| |
| result = ((unsigned long long) saddr + |
| (unsigned long long) daddr + |
| (unsigned long long) sum + |
| ((unsigned long long) ntohs(len) << 16) + |
| ((unsigned long long) 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); |
| |
| dprintk("%s saddr %x daddr %x len %x proto %x sum %x result %08Lx\n", |
| __FUNCTION__, saddr, daddr, len, proto, sum, result); |
| |
| return result; |
| } |
| |
| // Post SIM: |
| unsigned int |
| csum_partial_copy_nocheck(const char *src, char *dst, int len, unsigned int sum) |
| { |
| // unsigned dummy; |
| dprintk("csum_partial_copy_nocheck src %p dst %p len %d\n", src, dst, |
| len); |
| |
| return csum_partial_copy(src, dst, len, sum); |
| } |