/*      $NetBSD: fusu.S,v 1.10 2003/12/01 13:34:44 rearnsha Exp $       */

/*-
 * Copyright (c) 1996-1998 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
 * 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 <machine/asm.h>
#include <machine/armreg.h>
#include "assym.inc"
        .syntax unified

#define GET_PCB(tmp) \
        mrc p15, 0, tmp, c13, c0, 4; \
        add     tmp, tmp, #(TD_PCB)

/*
 * casueword32(volatile uint32_t *base, uint32_t oldval, uint32_t *oldvalp,
 *    uint32_t newval);
 */

ENTRY(casueword)
EENTRY_NP(casueword32)
        stmfd   sp!, {r4, r5, r6}

        ldr     r4, =(VM_MAXUSER_ADDRESS-3)
        cmp     r0, r4
        mvncs   r0, #0
        bcs     1f

        GET_PCB(r6)
        ldr     r6, [r6]

#ifdef DIAGNOSTIC
        teq     r6, #0x00000000
        ldmfdeq sp!, {r4, r5, r6}
        beq     .Lfusupcbfault
#endif

        adr     r4, .Lcasuwordfault
        str     r4, [r6, #PCB_ONFAULT]

        mov     r5, #1
        ldrex   r4, [r0]
        cmp     r4, r1
        strexeq r5, r3, [r0]
        str     r4, [r2]
        mov     r0, #0
        str     r0, [r6, #PCB_ONFAULT]
        mov     r0, r5
1:
        ldmfd   sp!, {r4, r5, r6}
        RET
EEND(casueword32)
END(casueword)

/*
 * Handle faults from casuword.  Clean up and return -1.
 */

.Lcasuwordfault:
        mov     r0, #0x00000000
        str     r0, [r6, #PCB_ONFAULT]
        mvn     r0, #0
        ldmfd   sp!, {r4, r5, r6}
        RET

/*
 * fueword(caddr_t uaddr, long *val);
 * Fetch an int from the user's address space.
 */

ENTRY(fueword)
EENTRY_NP(fueword32)
        ldr     r3, =(VM_MAXUSER_ADDRESS-3)
        cmp     r0, r3
        mvncs   r0, #0
        RETc(cs)

        GET_PCB(r2)
        ldr     r2, [r2]

#ifdef DIAGNOSTIC
        teq     r2, #0x00000000
        beq     .Lfusupcbfault
#endif

        adr     r3, .Lfusufault
        str     r3, [r2, #PCB_ONFAULT]

        ldrt    r3, [r0]
        str     r3, [r1]

        mov     r0, #0x00000000
        str     r0, [r2, #PCB_ONFAULT]
        RET
EEND(fueword32)
END(fueword)

/*
 * fusword(caddr_t uaddr);
 * Fetch a short from the user's address space.
 */

ENTRY(fusword)
        ldr     r3, =(VM_MAXUSER_ADDRESS-1)
        cmp     r0, r3
        mvncs   r0, #0
        RETc(cs)

        GET_PCB(r2)
        ldr     r2, [r2]

#ifdef DIAGNOSTIC
        teq     r2, #0x00000000
        beq     .Lfusupcbfault
#endif

        adr     r1, .Lfusufault
        str     r1, [r2, #PCB_ONFAULT]

        ldrbt   r3, [r0], #1
        ldrbt   ip, [r0]
        orr     r0, r3, ip, asl #8
        mov     r1, #0x00000000
        str     r1, [r2, #PCB_ONFAULT]
        RET
END(fusword)

/*
 * fubyte(caddr_t uaddr);
 * Fetch a byte from the user's address space.
 */

ENTRY(fubyte)
        ldr     r3, =VM_MAXUSER_ADDRESS
        cmp     r0, r3
        mvncs   r0, #0
        RETc(cs)

        GET_PCB(r2)
        ldr     r2, [r2]

#ifdef DIAGNOSTIC
        teq     r2, #0x00000000
        beq     .Lfusupcbfault
#endif

        adr     r1, .Lfusufault
        str     r1, [r2, #PCB_ONFAULT]

        ldrbt   r3, [r0]

        mov     r1, #0x00000000
        str     r1, [r2, #PCB_ONFAULT]
        mov     r0, r3
        RET
END(fubyte)

/*
 * Handle faults from [fs]u*().  Clean up and return -1.
 */

.Lfusufault:
        mov     r0, #0x00000000
        str     r0, [r2, #PCB_ONFAULT]
        mvn     r0, #0x00000000
        RET

#ifdef DIAGNOSTIC
/*
 * Handle earlier faults from [fs]u*(), due to no pcb
 */

.Lfusupcbfault:
        mov     r1, r0
        adr     r0, fusupcbfaulttext
        b       _C_LABEL(panic)

fusupcbfaulttext:
        .asciz  "Yikes - no valid PCB during fusuxxx() addr=%08x\n"
        .align  2
#endif

/*
 * suword16(caddr_t uaddr, int x);
 * Store an uint16_t in the user's address space.
 */

ENTRY(suword16)
        ldr     r3, =(VM_MAXUSER_ADDRESS-3)
        cmp     r0, r3
        mvncs   r0, #0
        RETc(cs)

        GET_PCB(r2)
        ldr     r2, [r2]

#ifdef DIAGNOSTIC
        teq     r2, #0x00000000
        beq     .Lfusupcbfault
#endif

        adr     r3, .Lfusufault
        str     r3, [r2, #PCB_ONFAULT]

        strht   r1, [r0], #0

        mov     r0, #0x00000000
        str     r0, [r2, #PCB_ONFAULT]
        RET
END(suword16)

/*
 * suword(caddr_t uaddr, int x);
 * Store an int in the user's address space.
 */

ENTRY(suword)
EENTRY_NP(suword32)
        ldr     r3, =(VM_MAXUSER_ADDRESS-3)
        cmp     r0, r3
        mvncs   r0, #0
        RETc(cs)

        GET_PCB(r2)
        ldr     r2, [r2]

#ifdef DIAGNOSTIC
        teq     r2, #0x00000000
        beq     .Lfusupcbfault
#endif

        adr     r3, .Lfusufault
        str     r3, [r2, #PCB_ONFAULT]

        strt    r1, [r0]

        mov     r0, #0x00000000
        str     r0, [r2, #PCB_ONFAULT]
        RET
EEND(suword32)
END(suword)

/*
 * susword(caddr_t uaddr, short x);
 * Store a short in the user's address space.
 */

ENTRY(susword)
        ldr     r3, =(VM_MAXUSER_ADDRESS-1)
        cmp     r0, r3
        mvncs   r0, #0
        RETc(cs)

        GET_PCB(r2)
        ldr     r2, [r2]

#ifdef DIAGNOSTIC
        teq     r2, #0x00000000
        beq     .Lfusupcbfault
#endif

        adr     r3, .Lfusufault
        str     r3, [r2, #PCB_ONFAULT]

        strbt   r1, [r0], #1
        mov     r1, r1, lsr #8
        strbt   r1, [r0]

        mov     r0, #0x00000000
        str     r0, [r2, #PCB_ONFAULT]
        RET
END(susword)

/*
 * subyte(caddr_t uaddr, char x);
 * Store a byte in the user's address space.
 */

ENTRY(subyte)
        ldr     r3, =VM_MAXUSER_ADDRESS
        cmp     r0, r3
        mvncs   r0, #0
        RETc(cs)

        GET_PCB(r2)
        ldr     r2, [r2]


#ifdef DIAGNOSTIC
        teq     r2, #0x00000000
        beq     .Lfusupcbfault
#endif

        adr     r3, .Lfusufault
        str     r3, [r2, #PCB_ONFAULT]

        strbt   r1, [r0]
        mov     r0, #0x00000000
        str     r0, [r2, #PCB_ONFAULT]
        RET
END(subyte)