/*      $NetBSD: bus_space_asm_generic.S,v 1.12 2020/09/24 11:02:02 skrll Exp $ */

/*
 * Copyright (c) 1997 Causality Limited.
 * Copyright (c) 1997 Mark Brinicombe.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Mark Brinicombe
 *      for the NetBSD Project.
 * 4. The name of the company nor the name of the author may be used to
 *    endorse or promote products derived from this software without specific
 *    prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <arm/asm.h>
#include <arm/cpuconf.h>
#include <arm/byte_swap.h>

#ifdef _ARM_ARCH_7
#define DSB     dsb
#elif defined(_ARM_ARCH_6)
#define DSB     mcr p15, 0, r0, c7, c10, 4
#else
#define DSB
#endif

#if defined(__thumb__) && defined(_ARM_ARCH_T2)
#define CHECK_LENGTH(r, l)      cbz r, l
#elif defined(__thumb__)
#define CHECK_LENGTH(r, l)      cmp r, #0; beq l
#else
#define CHECK_LENGTH(r, l)      cmp r, #0; RETc(eq)
#endif
/*
 * Generic bus_space functions.
 */

/*
 * read single
 */

ENTRY_NP(generic_bs_r_1)
        DSB
        ldrb    r0, [r1, r2]
        RET
END(generic_bs_r_1)

#if (ARM_ARCH_4 + ARM_ARCH_5 + ARM_ARCH_6 + ARM_ARCH_7) > 0
ENTRY_NP(generic_armv4_bs_r_2)
        DSB
        ldrh    r0, [r1, r2]
        RET
END(generic_armv4_bs_r_2)

ENTRY_NP(generic_armv4_bs_r_2_swap)
        DSB
        ldrh    r0, [r1, r2]
        BSWAP16(r0, r0, r1)
        RET
END(generic_armv4_bs_r_2_swap)
#endif

ENTRY_NP(generic_bs_r_4)
        DSB
        ldr     r0, [r1, r2]
        RET
END(generic_bs_r_4)

ENTRY_NP(generic_bs_r_4_swap)
        DSB
        ldr     r0, [r1, r2]
        BSWAP32(r0, r0, r1)
        RET
END(generic_bs_r_4_swap)

/*
 * write single
 */

ENTRY_NP(generic_bs_w_1)
        strb    r3, [r1, r2]
        DSB
        RET
END(generic_bs_w_1)

#if (ARM_ARCH_4 + ARM_ARCH_5 + ARM_ARCH_6 + ARM_ARCH_7) > 0
ENTRY_NP(generic_armv4_bs_w_2_swap)
        BSWAP16(r3, r3, r0)             /* swap and fallthrough */
ENTRY_NP(generic_armv4_bs_w_2)
        strh    r3, [r1, r2]
        DSB
        RET
END(generic_armv4_bs_w_2)
END(generic_armv4_bs_w_2_swap)
#endif

ENTRY_NP(generic_bs_w_4_swap)
        BSWAP32(r3, r3, r0)
ENTRY_NP(generic_bs_w_4)
        str     r3, [r1, r2]
        DSB
        RET
END(generic_bs_w_4)
END(generic_bs_w_4_swap)

/*
 * read multiple
 */

ENTRY_NP(generic_bs_rm_1)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)
        DSB

1:      ldrb    r3, [r0]
        strb    r3, [r1], #1
        subs    r2, r2, #1
        bne     1b

99:     RET
END(generic_bs_rm_1)

#if (ARM_ARCH_4 + ARM_ARCH_5 + ARM_ARCH_6 + ARM_ARCH_7) > 0
ENTRY_NP(generic_armv4_bs_rm_2)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)
        DSB

1:      ldrh    r3, [r0]
        strh    r3, [r1], #2
        subs    r2, r2, #1
        bne     1b

99:     RET
END(generic_armv4_bs_rm_2)

ENTRY_NP(generic_armv4_bs_rm_2_swap)
        DSB
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)
        DSB

1:      ldrh    r3, [r0]
        BSWAP16(r3, r3, ip)
        strh    r3, [r1], #2
        subs    r2, r2, #1
        bne     1b

99:     RET
END(generic_armv4_bs_rm_2_swap)
#endif

ENTRY_NP(generic_bs_rm_4)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)
        DSB

1:      ldr     r3, [r0]
        str     r3, [r1], #4
        subs    r2, r2, #1
        bne     1b

99:     RET
END(generic_bs_rm_4)

ENTRY_NP(generic_bs_rm_4_swap)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)
        DSB

1:      ldr     r3, [r0]
        BSWAP32(r3, r3, ip)
        str     r3, [r1], #4
        subs    r2, r2, #1
        bne     1b

99:     RET
END(generic_bs_rm_4_swap)

/*
 * write multiple
 */

ENTRY_NP(generic_bs_wm_1)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)

1:      ldrb    r3, [r1], #1
        strb    r3, [r0]
        subs    r2, r2, #1
        bne     1b

        DSB
99:     RET
END(generic_bs_wm_1)

#if (ARM_ARCH_4 + ARM_ARCH_5 + ARM_ARCH_6 + ARM_ARCH_7) > 0
ENTRY_NP(generic_armv4_bs_wm_2)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)

1:      ldrh    r3, [r1], #2
        strh    r3, [r0]
        subs    r2, r2, #1
        bne     1b

        DSB
99:     RET
END(generic_armv4_bs_wm_2)

ENTRY_NP(generic_armv4_bs_wm_2_swap)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]

1:      ldrh    r3, [r1], #2
        BSWAP16(r3, r3, ip)
        strh    r3, [r0]
        subs    r2, r2, #1
        bne     1b

        DSB
99:     RET
END(generic_armv4_bs_wm_2_swap)
#endif

ENTRY_NP(generic_bs_wm_4)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)

1:      ldr     r3, [r1], #4
        str     r3, [r0]
        subs    r2, r2, #1
        bne     1b

        DSB
99:     RET
END(generic_bs_wm_4)

ENTRY_NP(generic_bs_wm_4_swap)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)

1:      ldr     r3, [r1], #4
        BSWAP32(r3, r3, ip)
        str     r3, [r0]
        subs    r2, r2, #1
        bne     1b

        DSB
99:     RET
END(generic_bs_wm_4_swap)

/*
 * read region
 */

ENTRY_NP(generic_bs_rr_1)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)
        DSB

1:      ldrb    r3, [r0], #1
        strb    r3, [r1], #1
        subs    r2, r2, #1
        bne     1b

99:     RET
END(generic_bs_rr_1)

#if (ARM_ARCH_4 + ARM_ARCH_5 + ARM_ARCH_6 + ARM_ARCH_7) > 0
ENTRY_NP(generic_armv4_bs_rr_2)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)
        DSB

1:      ldrh    r3, [r0], #2
        strh    r3, [r1], #2
        subs    r2, r2, #1
        bne     1b

99:     RET
END(generic_armv4_bs_rr_2)

ENTRY_NP(generic_armv4_bs_rr_2_swap)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)
        DSB

1:      ldrh    r3, [r0], #2
        BSWAP16(r3, r3, ip)
        strh    r3, [r1], #2
        subs    r2, r2, #1
        bne     1b

99:     RET
END(generic_armv4_bs_rr_2_swap)
#endif

ENTRY_NP(generic_bs_rr_4)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)

1:      ldr     r3, [r0], #4
        str     r3, [r1], #4
        subs    r2, r2, #1
        bne     1b

99:     RET
END(generic_bs_rr_4)

ENTRY_NP(generic_bs_rr_4_swap)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)
        DSB

1:      ldr     r3, [r0], #4
        BSWAP32(r3, r3, ip)
        str     r3, [r1], #4
        subs    r2, r2, #1
        bne     1b

99:     RET
END(generic_bs_rr_4_swap)

/*
 * write region.
 */

ENTRY_NP(generic_bs_wr_1)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)

1:      ldrb    r3, [r1], #1
        strb    r3, [r0], #1
        subs    r2, r2, #1
        bne     1b

        DSB
99:     RET
END(generic_bs_wr_1)

#if (ARM_ARCH_4 + ARM_ARCH_5 + ARM_ARCH_6 + ARM_ARCH_7) > 0
ENTRY_NP(generic_armv4_bs_wr_2)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)

1:      ldrh    r3, [r1], #2
        strh    r3, [r0], #2
        subs    r2, r2, #1
        bne     1b

        DSB
99:     RET
END(generic_armv4_bs_wr_2)

ENTRY_NP(generic_armv4_bs_wr_2_swap)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)

1:      ldrh    r3, [r1], #2
        BSWAP16(r3, r3, ip)
        strh    r3, [r0], #2
        subs    r2, r2, #1
        bne     1b

        DSB
99:     RET
END(generic_armv4_bs_wr_2_swap)
#endif

ENTRY_NP(generic_bs_wr_4)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)

1:      ldr     r3, [r1], #4
        str     r3, [r0], #4
        subs    r2, r2, #1
        bne     1b

        DSB
99:     RET
END(generic_bs_wr_4)

ENTRY_NP(generic_bs_wr_4_swap)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)

1:      ldr     r3, [r1], #4
        BSWAP32(r3, r3, ip)
        str     r3, [r0], #4
        subs    r2, r2, #1
        bne     1b

        DSB
99:     RET
END(generic_bs_wr_4_swap)

/*
 * set region
 */

ENTRY_NP(generic_bs_sr_1)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)

1:      strb    r1, [r0], #1
        subs    r2, r2, #1
        bne     1b

        DSB
99:     RET
END(generic_bs_sr_1)

#if (ARM_ARCH_4 + ARM_ARCH_5 + ARM_ARCH_6 + ARM_ARCH_7) > 0
ENTRY_NP(generic_armv4_bs_sr_2_swap)
        BSWAP16(r3, r3, r0)     /* swap and fallthrough */
ENTRY_NP(generic_armv4_bs_sr_2)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)

1:      strh    r1, [r0], #2
        subs    r2, r2, #1
        bne     1b

        DSB
99:     RET
END(generic_armv4_bs_sr_2)
END(generic_armv4_bs_sr_2_swap)
#endif

ENTRY_NP(generic_bs_sr_4_swap)
        BSWAP32(r3, r3, r0)     /* swap and fallthrough */
ENTRY_NP(generic_bs_sr_4)
        adds    r0, r1, r2
        mov     r1, r3
        ldr     r2, [sp, #0]
        CHECK_LENGTH(r2, 99f)

1:      str     r1, [r0], #4
        subs    r2, r2, #1
        bne     1b

        DSB
99:     RET
END(generic_bs_sr_4)
END(generic_bs_sr_4_swap)

/*
 * copy region
 */

#if (ARM_ARCH_4 + ARM_ARCH_5 + ARM_ARCH_6 + ARM_ARCH_7) > 0
ENTRY_NP(generic_armv4_bs_c_2)
        adds    r0, r1, r2
        ldr     r2, [sp, #0]
        adds    r1, r2, r3
        ldr     r2, [sp, #4]
        CHECK_LENGTH(r2, 99f)

        lsls    r2, r2, #1

        cmp     r0, r1
        blt     2f

        adds    r0, r0, r2
        adds    r1, r1, r2
        negs    r2, r2

1:      ldrh    r3, [r0, r2]
        strh    r3, [r1, r2]
        adds    r2, r2, #2
        bne     1b

        DSB
        RET

2:      subs    r2, r2, #2
        ldrh    r3, [r0, r2]
        strh    r3, [r1, r2]
        bne     2b

        DSB
99:     RET
END(generic_armv4_bs_c_2)
#endif