/* $Id: checksum.h,v 1.33 2002/02/01 22:01:05 davem Exp $ */
  #ifndef __SPARC_CHECKSUM_H
  #define __SPARC_CHECKSUM_H
  
  /*  checksum.h:  IP/UDP/TCP checksum routines on the Sparc.
   *
   *  Copyright(C) 1995 Linus Torvalds
   *  Copyright(C) 1995 Miguel de Icaza
   *  Copyright(C) 1996 David S. Miller
   *  Copyright(C) 1996 Eddie C. Dost
   *  Copyright(C) 1997 Jakub Jelinek
   *
   * derived from:
   *	Alpha checksum c-code
   *      ix86 inline assembly
   *      RFC1071 Computing the Internet Checksum
   */
   
  #include <linux/in6.h>
  #include <asm/uaccess.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
   */

  extern __wsum csum_partial(const void *buff, int len, __wsum sum);

  
  /* the same as csum_partial, but copies from fs:src while it
   * checksums
   *
   * here even more important to align src and dst on a 32-bit (or even
   * better 64-bit) boundary
   */
  
  extern unsigned int __csum_partial_copy_sparc_generic (const unsigned char *, unsigned char *);

  static inline __wsum
  csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)

  {
  	register unsigned int ret asm("o0") = (unsigned int)src;
  	register char *d asm("o1") = dst;
  	register int l asm("g1") = len;
  
  	__asm__ __volatile__ (
  		"call __csum_partial_copy_sparc_generic
  \t"
  		" mov %6, %%g7
  "
  	: "=&r" (ret), "=&r" (d), "=&r" (l)
  	: "0" (ret), "1" (d), "2" (l), "r" (sum)
  	: "o2", "o3", "o4", "o5", "o7",
  	  "g2", "g3", "g4", "g5", "g7",
  	  "memory", "cc");

  	return (__force __wsum)ret;

  }

  static inline __wsum
  csum_partial_copy_from_user(const void __user *src, void *dst, int len,
  			    __wsum sum, int *err)

    {

  	register unsigned long ret asm("o0") = (unsigned long)src;
  	register char *d asm("o1") = dst;
  	register int l asm("g1") = len;
  	register __wsum s asm("g7") = sum;

  	__asm__ __volatile__ (
  	".section __ex_table,#alloc
  \t"
  	".align 4
  \t"
  	".word 1f,2
  \t"
  	".previous
  "
  	"1:
  \t"
  	"call __csum_partial_copy_sparc_generic
  \t"
  	" st %8, [%%sp + 64]
  "
  	: "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
  	: "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
  	: "o2", "o3", "o4", "o5", "o7", "g2", "g3", "g4", "g5",
  	  "cc", "memory");
  	return (__force __wsum)ret;
  }

  static inline __wsum
  csum_partial_copy_to_user(const void *src, void __user *dst, int len,
  			  __wsum sum, int *err)

  {
  	if (!access_ok (VERIFY_WRITE, dst, len)) {
  		*err = -EFAULT;
  		return sum;
  	} else {
  		register unsigned long ret asm("o0") = (unsigned long)src;
  		register char __user *d asm("o1") = dst;
  		register int l asm("g1") = len;

  		register __wsum s asm("g7") = sum;

  
  		__asm__ __volatile__ (
  		".section __ex_table,#alloc
  \t"
  		".align 4
  \t"
  		".word 1f,1
  \t"
  		".previous
  "
  		"1:
  \t"
  		"call __csum_partial_copy_sparc_generic
  \t"
  		" st %8, [%%sp + 64]
  "
  		: "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
  		: "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
  		: "o2", "o3", "o4", "o5", "o7",
  		  "g2", "g3", "g4", "g5",
  		  "cc", "memory");

  		return (__force __wsum)ret;

  	}
  }
  
  #define HAVE_CSUM_COPY_USER
  #define csum_and_copy_to_user csum_partial_copy_to_user
  
  /* ihl is always 5 or greater, almost always is 5, and iph is word aligned
   * the majority of the time.
   */

  static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)

  {

  	__sum16 sum;

  
  	/* Note: We must read %2 before we touch %0 for the first time,
  	 *       because GCC can legitimately use the same register for
  	 *       both operands.
  	 */
  	__asm__ __volatile__("sub\t%2, 4, %%g4
  \t"
  			     "ld\t[%1 + 0x00], %0
  \t"
  			     "ld\t[%1 + 0x04], %%g2
  \t"
  			     "ld\t[%1 + 0x08], %%g3
  \t"
  			     "addcc\t%%g2, %0, %0
  \t"
  			     "addxcc\t%%g3, %0, %0
  \t"
  			     "ld\t[%1 + 0x0c], %%g2
  \t"
  			     "ld\t[%1 + 0x10], %%g3
  \t"
  			     "addxcc\t%%g2, %0, %0
  \t"
  			     "addx\t%0, %%g0, %0
  "
  			     "1:\taddcc\t%%g3, %0, %0
  \t"
  			     "add\t%1, 4, %1
  \t"
  			     "addxcc\t%0, %%g0, %0
  \t"
  			     "subcc\t%%g4, 1, %%g4
  \t"
  			     "be,a\t2f
  \t"
  			     "sll\t%0, 16, %%g2
  \t"
  			     "b\t1b
  \t"
  			     "ld\t[%1 + 0x10], %%g3
  "
  			     "2:\taddcc\t%0, %%g2, %%g2
  \t"
  			     "srl\t%%g2, 16, %0
  \t"
  			     "addx\t%0, %%g0, %0
  \t"
  			     "xnor\t%%g0, %0, %0"
  			     : "=r" (sum), "=&r" (iph)
  			     : "r" (ihl), "1" (iph)

  			     : "g2", "g3", "g4", "cc", "memory");

  	return sum;
  }
  
  /* Fold a partial checksum without adding pseudo headers. */

  static inline __sum16 csum_fold(__wsum sum)

  {
  	unsigned int tmp;
  
  	__asm__ __volatile__("addcc\t%0, %1, %1
  \t"
  			     "srl\t%1, 16, %1
  \t"
  			     "addx\t%1, %%g0, %1
  \t"
  			     "xnor\t%%g0, %1, %0"
  			     : "=&r" (sum), "=r" (tmp)

  			     : "0" (sum), "1" ((__force u32)sum<<16)

  			     : "cc");

  	return (__force __sum16)sum;

  }

  static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
  					       unsigned short len,

  					       unsigned short proto,

  					       __wsum sum)

  {
  	__asm__ __volatile__("addcc\t%1, %0, %0
  \t"
  			     "addxcc\t%2, %0, %0
  \t"
  			     "addxcc\t%3, %0, %0
  \t"
  			     "addx\t%0, %%g0, %0
  \t"
  			     : "=r" (sum), "=r" (saddr)

  			     : "r" (daddr), "r" (proto + len), "0" (sum),

  			       "1" (saddr)
  			     : "cc");
  	return sum;
  }
  
  /*
   * computes the checksum of the TCP/UDP pseudo-header
   * returns a 16-bit checksum, already complemented
   */

  static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,

  						   unsigned short len,
  						   unsigned short proto,

  						   __wsum sum)

  {
  	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
  }
  
  #define _HAVE_ARCH_IPV6_CSUM

  static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
  				      const struct in6_addr *daddr,
  				      __u32 len, unsigned short proto,
  				      __wsum sum)

  {
  	__asm__ __volatile__ (
  		"addcc	%3, %4, %%g4
  \t"
  		"addxcc	%5, %%g4, %%g4
  \t"
  		"ld	[%2 + 0x0c], %%g2
  \t"
  		"ld	[%2 + 0x08], %%g3
  \t"
  		"addxcc	%%g2, %%g4, %%g4
  \t"
  		"ld	[%2 + 0x04], %%g2
  \t"
  		"addxcc	%%g3, %%g4, %%g4
  \t"
  		"ld	[%2 + 0x00], %%g3
  \t"
  		"addxcc	%%g2, %%g4, %%g4
  \t"
  		"ld	[%1 + 0x0c], %%g2
  \t"
  		"addxcc	%%g3, %%g4, %%g4
  \t"
  		"ld	[%1 + 0x08], %%g3
  \t"
  		"addxcc	%%g2, %%g4, %%g4
  \t"
  		"ld	[%1 + 0x04], %%g2
  \t"
  		"addxcc	%%g3, %%g4, %%g4
  \t"
  		"ld	[%1 + 0x00], %%g3
  \t"
  		"addxcc	%%g2, %%g4, %%g4
  \t"
  		"addxcc	%%g3, %%g4, %0
  \t"
  		"addx	0, %0, %0
  "
  		: "=&r" (sum)
  		: "r" (saddr), "r" (daddr), 
  		  "r"(htonl(len)), "r"(htonl(proto)), "r"(sum)
  		: "g2", "g3", "g4", "cc");
  
  	return csum_fold(sum);
  }
  
  /* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */

  static inline __sum16 ip_compute_csum(const void *buff, int len)

  {
  	return csum_fold(csum_partial(buff, len, 0));
  }
  
  #endif /* !(__SPARC_CHECKSUM_H) */