/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/asm_linkage.h>
#include <sys/privregs.h>
#include <sys/scb.h>
#include <sys/machparam.h>
#include <sys/machthread.h>

#include "assym.h"

/*
 * void
 * reestablish_curthread(void)
 *    - reestablishes the invariant that THREAD_REG contains
 *      the same value as the cpu struct for this cpu (implicit from
 *      where we're running). This is needed for OBP callback routines.
 *      The CPU_ADDR macro figures out the cpuid by reading hardware registers.
 */

        ENTRY_NP(reestablish_curthread)

        CPU_ADDR(%o0, %o1)
        retl
        ldn     [%o0 + CPU_THREAD], THREAD_REG
        SET_SIZE(reestablish_curthread)


/*
 * Return the current THREAD pointer.
 * This is also available as an inline function.
 */

        ENTRY_NP(threadp)
        retl
        mov     THREAD_REG, %o0
        SET_SIZE(threadp)


/*
 * The IEEE 1275-1994 callback handler for a 64-bit SPARC V9 PROM calling
 * a 32 bit client program. The PROM calls us with a 64 bit stack and a
 * pointer to a client interface argument array in %o0.  The called code
 * returns 0 if the call succeeded (i.e. the service name exists) or -1
 * if the call failed. NOTE: All addresses are in the range 0..2^^32-1
 *
 * This code is called as trusted subroutine of the firmware, and is
 * called with %tba pointing to the boot firmware's trap table.  All of
 * the prom's window handlers are mixed mode handlers.
 */

        ENTRY_NP(callback_handler)
        !
        ! We assume we are called with a 64 bit stack with PSTATE_AM clear
        !
        save    %sp, -SA64(MINFRAME64), %sp     ! 64 bit save
        rdpr    %wstate, %l5                    ! save %wstate
        andn    %l5, WSTATE_MASK, %l6
        wrpr    %l6, WSTATE_KMIX, %wstate
        rdpr    %pstate, %l0                    ! save %pstate

        !
        ! If anybody tries to trace the call stack of this callback
        ! then the traceback should stop here.  This matters
        ! particularly for sync callbacks on Serengeti, but it's a
        ! good idea generally.
        !
        flushw
        mov     %fp, %l1
        clr     %fp                             ! terminate stack traces

        call    vx_handler                      ! vx_handler(void **arg_array)
          mov   %i0, %o0                        ! delay; argument array
        sra     %o0, 0, %i0                     ! sign extend result

        mov     %l1, %fp                        ! restore %fp for return

1:      wrpr    %g0, %l0, %pstate               ! restore %pstate
        wrpr    %g0, %l5, %wstate               ! restore %wstate

        ret                                     ! return result in %o0
        restore                                 ! back to a 64 bit stack
        SET_SIZE(callback_handler)