
/*
 * Copyright (c) 2015-2019 Cadence Design Systems, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * Xtensa interrupt handling data and assembly routines.
 * Also see xtensa_intr.c and xtensa_vectors.S.
 */

#include <xtensa/hal.h>
#include <xtensa/config/core.h>

#include "xtensa_context.h"

#if XCHAL_HAVE_INTERRUPTS

/*
-------------------------------------------------------------------------------
  INTENABLE virtualization information.
-------------------------------------------------------------------------------
*/

    .data
    .global _xt_intdata
    .align  8
_xt_intdata:
    .global _xt_intenable
    .type   _xt_intenable,@object
    .size   _xt_intenable,4
    .global _xt_vpri_mask
    .type   _xt_vpri_mask,@object
    .size   _xt_vpri_mask,4

_xt_intenable:     .word   0             /* Virtual INTENABLE     */
_xt_vpri_mask:     .word   0xFFFFFFFF    /* Virtual priority mask */


/*
-------------------------------------------------------------------------------
  Table of C-callable interrupt handlers for each interrupt. Note that not all
  slots can be filled, because interrupts at level > EXCM_LEVEL will not be
  dispatched to a C handler by default.
-------------------------------------------------------------------------------
*/

    .data
    .global _xt_interrupt_table
    .align  8

_xt_interrupt_table:

    .set    i, 0
    .rept   XCHAL_NUM_INTERRUPTS
    .word   xt_unhandled_interrupt      /* handler address               */
    .word   i                           /* handler arg (default: intnum) */
    .set    i, i+1
    .endr

#endif /* XCHAL_HAVE_INTERRUPTS */


#if XCHAL_HAVE_EXCEPTIONS

/*
-------------------------------------------------------------------------------
  Table of C-callable exception handlers for each exception. Note that not all
  slots will be active, because some exceptions (e.g. coprocessor exceptions)
  are always handled by the OS and cannot be hooked by user handlers.
-------------------------------------------------------------------------------
*/

    .data
    .global _xt_exception_table
    .align  4

_xt_exception_table:
    .rept   XCHAL_EXCCAUSE_NUM
    .word   xt_unhandled_exception    /* handler address */
    .endr

#endif


/*
-------------------------------------------------------------------------------
  unsigned int xt_ints_on ( unsigned int mask )

  Enables a set of interrupts. Does not simply set INTENABLE directly, but
  computes it as a function of the current virtual priority.
  Can be called from interrupt handlers.
-------------------------------------------------------------------------------
*/

    .text
    .align  4
    .global xt_ints_on
    .type   xt_ints_on,@function

xt_ints_on:

    ENTRY0
#if XCHAL_HAVE_INTERRUPTS
    movi    a3, 0
    movi    a4, _xt_intdata
    xsr     a3, INTENABLE        /* Disables all interrupts   */
    rsync
    l32i    a3, a4, 0            /* a3 = _xt_intenable        */
    l32i    a6, a4, 4            /* a6 = _xt_vpri_mask        */
    or      a5, a3, a2           /* a5 = _xt_intenable | mask */
    s32i    a5, a4, 0            /* _xt_intenable |= mask     */
    and     a5, a5, a6           /* a5 = _xt_intenable & _xt_vpri_mask */
    wsr     a5, INTENABLE        /* Reenable interrupts       */
    mov     a2, a3               /* Previous mask             */
#else
    movi    a2, 0                /* Return zero */
#endif
    RET0

    .size   xt_ints_on, . - xt_ints_on


/*
-------------------------------------------------------------------------------
  unsigned int xt_ints_off ( unsigned int mask )

  Disables a set of interrupts. Does not simply set INTENABLE directly,
  but computes it as a function of the current virtual priority.
  Can be called from interrupt handlers.
-------------------------------------------------------------------------------
*/

    .text
    .align  4
    .global xt_ints_off
    .type   xt_ints_off,@function

xt_ints_off:

    ENTRY0
#if XCHAL_HAVE_INTERRUPTS
    movi    a3, 0
    movi    a4, _xt_intdata
    xsr     a3, INTENABLE        /* Disables all interrupts    */
    rsync
    l32i    a3, a4, 0            /* a3 = _xt_intenable         */
    l32i    a6, a4, 4            /* a6 = _xt_vpri_mask         */
    or      a5, a3, a2           /* a5 = _xt_intenable | mask  */
    xor     a5, a5, a2           /* a5 = _xt_intenable & ~mask */
    s32i    a5, a4, 0            /* _xt_intenable &= ~mask     */
    and     a5, a5, a6           /* a5 = _xt_intenable & _xt_vpri_mask */
    wsr     a5, INTENABLE        /* Reenable interrupts        */
    mov     a2, a3               /* Previous mask              */
#else
    movi    a2, 0                /* return zero */
#endif
    RET0

    .size   xt_ints_off, . - xt_ints_off


