/**
 * @file shutdown_m.c
 *
 * @brief Describes behavior of shutdown API in M-Mode.
 *
 * Copyright (c) 2022, NVIDIA CORPORATION. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * 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.
 * * Neither the name of NVIDIA CORPORATION nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``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 COPYRIGHT OWNER 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.
 */

/* Compiler headers */

/* Early FSP headers */
#include <misc/gcc_attrs.h>
#include <misc/gcc_builtins.h>
#include <misc/ct-assert.h>

/* Hardware headers */
#include <cpu/csr.h>

/* Late FSP headers */
#include <misc/macros.h>                   // for START_RFD_BLOCK, END_RFD_BLOCK, INLINE_RFD
#include <cpu/shutdown.h>

/*
 * Compile-time check for FSP header files
 *   Each FSP header file contains a signature unique to that file, and the
 *   FSP project.  The CT_ASSERT macro (contained in misc/ct-assert.h) can
 *   check for this signature.  If it does not exist, then the build will
 *   abort.
 *
 *   This is a trap for projects which have their own include files of the
 *   same names, but different contents.  This trap ensures that only the
 *   files from the FSP project, are built into the FSP source code.
 */
START_RFD_BLOCK(MISRA, DEVIATE, Rule_1_2, "Approval: Bug 200531996, DR: SWE-FSP-009-SWSADR.docx",
                MISRA, DEVIATE, Directive_4_9, "Approval: Bug 200531995, DR: SWE-FSP-012-SWSADR.docx")
CT_ASSERT(FSP__MISC__MACROS_H, "Header file missing or invalid.")
CT_ASSERT(FSP__CPU__SHUTDOWN_H, "Header file missing or invalid.")
CT_ASSERT(FSP__CPU__CSR_H, "Header file missing or invalid.")
CT_ASSERT(FSP__MISC__GCC_ATTRS_H, "Header file missing or invalid.")
CT_ASSERT(FSP__MISC__GCC_BUILTINS_H, "Header file missing or invalid.")

GCC_ATTR_NAKED
GCC_ATTR_NORETURN
GCC_ATTR_NO_SSP
static void riscv_shutdown_int(void)
{
    __asm__("csrw   mie,  zero \n" // Disable interrupts
            "csrrw  zero, 0x800, zero\n" // lwfenceIO
#if defined(NV_RISCV_CSR_MOPT)
            "csrrwi zero, 0x7d8, 0\n" // write MOPT.HALT
#endif
            "1: \n"
            "j      1b\n" // infinite loop if halt fails (or not available)
    );
    _Static_assert(NV_RISCV_CSR_LWFENCEIO == 0x800,
                   "LWFENCEIO address has changed. Update assembly in riscv_shutdown_int.");
    _Static_assert(NV_RISCV_CSR_MOPT == 0x7d8,
                   "MOPT address has changed. Update assembly in riscv_shutdown_int.");
    _Static_assert(NV_RISCV_CSR_MOPT_CMD_HALT == 0,
                   "MOPT_CMD_HALT value has changed. Update assembly in riscv_shutdown_int.");
    NVRV_BUILTIN_UNREACHABLE();
}

GCC_ATTR_NAKED
GCC_ATTR_NORETURN
GCC_ATTR_NO_SSP
void riscv_panic(void)
{
    riscv_shutdown_int();
}

GCC_ATTR_NORETURN
GCC_ATTR_NO_SSP
void riscv_shutdown(void)
{
    riscv_shutdown_int();
}

END_RFD_BLOCK(MISRA, DEVIATE, Rule_1_2, "Approval: Bug 200531996, DR: SWE-FSP-009-SWSADR.docx",
              MISRA, DEVIATE, Directive_4_9, "Approval: Bug 200531995, DR: SWE-FSP-012-SWSADR.docx")

/** end of file **/
