// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Copyright (C) 2001 Russell King
 */
#include "xor_impl.h"
#include "xor_arch.h"

#define __XOR(a1, a2) a1 ^= a2

#define GET_BLOCK_2(dst) \
        __asm__("ldmia  %0, {%1, %2}" \
                : "=r" (dst), "=r" (a1), "=r" (a2) \
                : "0" (dst))

#define GET_BLOCK_4(dst) \
        __asm__("ldmia  %0, {%1, %2, %3, %4}" \
                : "=r" (dst), "=r" (a1), "=r" (a2), "=r" (a3), "=r" (a4) \
                : "0" (dst))

#define XOR_BLOCK_2(src) \
        __asm__("ldmia  %0!, {%1, %2}" \
                : "=r" (src), "=r" (b1), "=r" (b2) \
                : "0" (src)); \
        __XOR(a1, b1); __XOR(a2, b2);

#define XOR_BLOCK_4(src) \
        __asm__("ldmia  %0!, {%1, %2, %3, %4}" \
                : "=r" (src), "=r" (b1), "=r" (b2), "=r" (b3), "=r" (b4) \
                : "0" (src)); \
        __XOR(a1, b1); __XOR(a2, b2); __XOR(a3, b3); __XOR(a4, b4)

#define PUT_BLOCK_2(dst) \
        __asm__ __volatile__("stmia     %0!, {%2, %3}" \
                : "=r" (dst) \
                : "0" (dst), "r" (a1), "r" (a2))

#define PUT_BLOCK_4(dst) \
        __asm__ __volatile__("stmia     %0!, {%2, %3, %4, %5}" \
                : "=r" (dst) \
                : "0" (dst), "r" (a1), "r" (a2), "r" (a3), "r" (a4))

static void
xor_arm4regs_2(unsigned long bytes, unsigned long * __restrict p1,
               const unsigned long * __restrict p2)
{
        unsigned int lines = bytes / sizeof(unsigned long) / 4;
        register unsigned int a1 __asm__("r4");
        register unsigned int a2 __asm__("r5");
        register unsigned int a3 __asm__("r6");
        register unsigned int a4 __asm__("r10");
        register unsigned int b1 __asm__("r8");
        register unsigned int b2 __asm__("r9");
        register unsigned int b3 __asm__("ip");
        register unsigned int b4 __asm__("lr");

        do {
                GET_BLOCK_4(p1);
                XOR_BLOCK_4(p2);
                PUT_BLOCK_4(p1);
        } while (--lines);
}

static void
xor_arm4regs_3(unsigned long bytes, unsigned long * __restrict p1,
               const unsigned long * __restrict p2,
               const unsigned long * __restrict p3)
{
        unsigned int lines = bytes / sizeof(unsigned long) / 4;
        register unsigned int a1 __asm__("r4");
        register unsigned int a2 __asm__("r5");
        register unsigned int a3 __asm__("r6");
        register unsigned int a4 __asm__("r10");
        register unsigned int b1 __asm__("r8");
        register unsigned int b2 __asm__("r9");
        register unsigned int b3 __asm__("ip");
        register unsigned int b4 __asm__("lr");

        do {
                GET_BLOCK_4(p1);
                XOR_BLOCK_4(p2);
                XOR_BLOCK_4(p3);
                PUT_BLOCK_4(p1);
        } while (--lines);
}

static void
xor_arm4regs_4(unsigned long bytes, unsigned long * __restrict p1,
               const unsigned long * __restrict p2,
               const unsigned long * __restrict p3,
               const unsigned long * __restrict p4)
{
        unsigned int lines = bytes / sizeof(unsigned long) / 2;
        register unsigned int a1 __asm__("r8");
        register unsigned int a2 __asm__("r9");
        register unsigned int b1 __asm__("ip");
        register unsigned int b2 __asm__("lr");

        do {
                GET_BLOCK_2(p1);
                XOR_BLOCK_2(p2);
                XOR_BLOCK_2(p3);
                XOR_BLOCK_2(p4);
                PUT_BLOCK_2(p1);
        } while (--lines);
}

static void
xor_arm4regs_5(unsigned long bytes, unsigned long * __restrict p1,
               const unsigned long * __restrict p2,
               const unsigned long * __restrict p3,
               const unsigned long * __restrict p4,
               const unsigned long * __restrict p5)
{
        unsigned int lines = bytes / sizeof(unsigned long) / 2;
        register unsigned int a1 __asm__("r8");
        register unsigned int a2 __asm__("r9");
        register unsigned int b1 __asm__("ip");
        register unsigned int b2 __asm__("lr");

        do {
                GET_BLOCK_2(p1);
                XOR_BLOCK_2(p2);
                XOR_BLOCK_2(p3);
                XOR_BLOCK_2(p4);
                XOR_BLOCK_2(p5);
                PUT_BLOCK_2(p1);
        } while (--lines);
}

DO_XOR_BLOCKS(arm4regs, xor_arm4regs_2, xor_arm4regs_3, xor_arm4regs_4,
                xor_arm4regs_5);

struct xor_block_template xor_block_arm4regs = {
        .name           = "arm4regs",
        .xor_gen        = xor_gen_arm4regs,
};