/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __SPARC64_CHECKSUM_H
#define __SPARC64_CHECKSUM_H

/*  checksum.h:  IP/UDP/TCP checksum routines on the V9.
 *
 *  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 <linux/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
 */
__wsum csum_partial(const void * buff, int len, __wsum sum);

/* the same as csum_partial, but copies from user space while it
 * checksums
 *
 * here even more important to align src and dst on a 32-bit (or even
 * better 64-bit) boundary
 */
__wsum csum_partial_copy_nocheck(const void *src, void *dst,
                                 int len, __wsum sum);

long __csum_partial_copy_from_user(const void __user *src,
                                   void *dst, int len,
                                   __wsum sum);

static inline __wsum
csum_partial_copy_from_user(const void __user *src,
                            void *dst, int len,
                            __wsum sum, int *err)
{
        long ret = __csum_partial_copy_from_user(src, dst, len, sum);
        if (ret < 0)
                *err = -EFAULT;
        return (__force __wsum) ret;
}

/*
 *      Copy and checksum to user
 */
#define HAVE_CSUM_COPY_USER
long __csum_partial_copy_to_user(const void *src,
                                 void __user *dst, int len,
                                 __wsum sum);

static inline __wsum
csum_and_copy_to_user(const void *src,
                      void __user *dst, int len,
                      __wsum sum, int *err)
{
        long ret = __csum_partial_copy_to_user(src, dst, len, sum);
        if (ret < 0)
                *err = -EFAULT;
        return (__force __wsum) ret;
}

/* ihl is always 5 or greater, almost always is 5, and iph is word aligned
 * the majority of the time.
 */
__sum16 ip_fast_csum(const void *iph, unsigned int ihl);

/* Fold a partial checksum without adding pseudo headers. */
static inline __sum16 csum_fold(__wsum sum)
{
        unsigned int tmp;

        __asm__ __volatile__(
"       addcc           %0, %1, %1\n"
"       srl             %1, 16, %1\n"
"       addc            %1, %%g0, %1\n"
"       xnor            %%g0, %1, %0\n"
        : "=&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,
                                        __u32 len, __u8 proto,
                                        __wsum sum)
{
        __asm__ __volatile__(
"       addcc           %1, %0, %0\n"
"       addccc          %2, %0, %0\n"
"       addccc          %3, %0, %0\n"
"       addc            %0, %%g0, %0\n"
        : "=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,
                                        __u32 len, __u8 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, __u8 proto, __wsum sum)
{
        __asm__ __volatile__ (
"       addcc           %3, %4, %%g7\n"
"       addccc          %5, %%g7, %%g7\n"
"       lduw            [%2 + 0x0c], %%g2\n"
"       lduw            [%2 + 0x08], %%g3\n"
"       addccc          %%g2, %%g7, %%g7\n"
"       lduw            [%2 + 0x04], %%g2\n"
"       addccc          %%g3, %%g7, %%g7\n"
"       lduw            [%2 + 0x00], %%g3\n"
"       addccc          %%g2, %%g7, %%g7\n"
"       lduw            [%1 + 0x0c], %%g2\n"
"       addccc          %%g3, %%g7, %%g7\n"
"       lduw            [%1 + 0x08], %%g3\n"
"       addccc          %%g2, %%g7, %%g7\n"
"       lduw            [%1 + 0x04], %%g2\n"
"       addccc          %%g3, %%g7, %%g7\n"
"       lduw            [%1 + 0x00], %%g3\n"
"       addccc          %%g2, %%g7, %%g7\n"
"       addccc          %%g3, %%g7, %0\n"
"       addc            0, %0, %0\n"
        : "=&r" (sum)
        : "r" (saddr), "r" (daddr), "r"(htonl(len)),
          "r"(htonl(proto)), "r"(sum)
        : "g2", "g3", "g7", "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));
}

#define HAVE_ARCH_CSUM_ADD
static inline __wsum csum_add(__wsum csum, __wsum addend)
{
        __asm__ __volatile__(
                "addcc   %0, %1, %0\n"
                "addx    %0, %%g0, %0"
                : "=r" (csum)
                : "r" (addend), "0" (csum));

        return csum;
}

#endif /* !(__SPARC64_CHECKSUM_H) */