187 lines
5.9 KiB
ArmAsm
187 lines
5.9 KiB
ArmAsm
/*
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* Copyright (c) 2015-2019 Cadence Design Systems, Inc.
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be included
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* in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
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* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
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* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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#include <xtensa/config/core-isa.h>
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#include <syscalls.h>
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//#define PS_OWB_SHIFT 8
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//#define PS_OWB_BITS 4
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//#define EXCCAUSE_ALLOCA 5 /* Stack Extension Assist (MOVSP instruction) for alloca */
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#if XCHAL_HAVE_L32R
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.section .rodata
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_sim_panic_msg:
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.ascii "PANIC: Unhandled exception!\n"
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_sim_panic_msg_len = . - _sim_panic_msg
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.section .text
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.literal .Lpanic_msg, _sim_panic_msg
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.literal .Lpanic_msg_len, _sim_panic_msg_len
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.align 4
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_xt_unhandled_exc:
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movi a2, SYS_write
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movi a3, 2
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l32r a4, .Lpanic_msg
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l32r a5, .Lpanic_msg_len
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simcall
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#else
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_xt_unhandled_exc:
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#endif
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movi a2, SYS_exit
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movi a3, 1
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simcall
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/*
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--------------------------------------------------------------------------------
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Handle alloca exception generated by interruptee executing 'movsp'.
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This uses space between the window vectors, so is essentially "free".
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All interruptee's regs are intact except a0 which is saved in EXCSAVE_1,
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and PS.EXCM has been set by the exception hardware (can't be interrupted).
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The fact the alloca exception was taken means the registers associated with
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the base-save area have been spilled and will be restored by the underflow
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handler, so those 4 registers are available for scratch.
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The code is optimized to avoid unaligned branches and minimize cache misses.
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--------------------------------------------------------------------------------
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*/
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#if XCHAL_HAVE_WINDOWED
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.section .text
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.global _xt_alloca_exc
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.align 4
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_xt_alloca_exc:
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rsr a0, WINDOWBASE /* grab WINDOWBASE before rotw changes it */
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rotw -1 /* WINDOWBASE goes to a4, new a0-a3 are scratch */
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rsr a2, PS
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extui a3, a2, 8/*PS_OWB_BITS*/, 4/*PS_OWB_BITS*/
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xor a3, a3, a4 /* bits changed from old to current windowbase */
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rsr a4, EXCSAVE1 /* restore original a0 (now in a4) */
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slli a3, a3, 8
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xor a2, a2, a3 /* flip changed bits in old window base */
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wsr a2, PS /* update PS.OWB to new window base */
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rsync
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bbci.l a4, 31, _WindowUnderflow4
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rotw -1 /* original a0 goes to a8 */
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bbci.l a8, 30, _WindowUnderflow8
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rotw -1
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j _WindowUnderflow12
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#endif
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/*
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--------------------------------------------------------------------------------
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User exception handler.
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--------------------------------------------------------------------------------
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*/
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#if XCHAL_HAVE_WINDOWED
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.section .text
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.align 4
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_xt_to_alloca_exc:
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j _xt_alloca_exc /* in window vectors section */
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#endif
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.type _xt_user_exc,@function
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.align 4
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_xt_user_exc:
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rsr a0, EXCCAUSE
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/* Handle alloca and syscall exceptions */
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#if XCHAL_HAVE_WINDOWED
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beqi a0, 5/*EXCCAUSE_ALLOCA*/, _xt_to_alloca_exc
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#endif
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j _xt_unhandled_exc
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/*
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--------------------------------------------------------------------------------
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NMI Exception
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--------------------------------------------------------------------------------
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*/
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.begin literal_prefix .NMIExceptionVector
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.section .NMIExceptionVector.text, "ax"
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.global NMIExceptionVector
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.type NMIExceptionVector,@function
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.align 4
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NMIExceptionVector:
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j _xt_unhandled_exc
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.end literal_prefix
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/*
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--------------------------------------------------------------------------------
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Kernel Exception
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--------------------------------------------------------------------------------
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*/
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.begin literal_prefix .KernelExceptionVector
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.section .KernelExceptionVector.text, "ax"
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.global KernelExceptionVector
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.type KernelExceptionVector,@function
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.align 4
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KernelExceptionVector:
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j _xt_unhandled_exc
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.end literal_prefix
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/*
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--------------------------------------------------------------------------------
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User Exception
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--------------------------------------------------------------------------------
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*/
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.begin literal_prefix .UserExceptionVector
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.section .UserExceptionVector.text, "ax"
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.global _UserExceptionVector
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.type _UserExceptionVector,@function
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.align 4
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_UserExceptionVector:
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wsr a0, EXCSAVE1 /* preserve a0 */
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j _xt_user_exc /* user exception handler */
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/* never returns here - call0 is used as a jump (see note at top) */
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.end literal_prefix
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/*
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--------------------------------------------------------------------------------
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Double Exception
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--------------------------------------------------------------------------------
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*/
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.begin literal_prefix .DoubleExceptionVector
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.section .DoubleExceptionVector.text, "ax"
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.global DoubleExceptionVector
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.type DoubleExceptionVector,@function
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.align 4
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DoubleExceptionVector:
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j _xt_unhandled_exc
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.end literal_prefix
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