/*
    FreeRTOS V8.2.0 - Copyright (C) 2015 Real Time Engineers Ltd.
    All rights reserved

    VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

    This file is part of the FreeRTOS distribution.

    FreeRTOS is free software; you can redistribute it and/or modify it under
    the terms of the GNU General Public License (version 2) as published by the
    Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.

	***************************************************************************
    >>!   NOTE: The modification to the GPL is included to allow you to     !<<
    >>!   distribute a combined work that includes FreeRTOS without being   !<<
    >>!   obliged to provide the source code for proprietary components     !<<
    >>!   outside of the FreeRTOS kernel.                                   !<<
	***************************************************************************

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    FOR A PARTICULAR PURPOSE.  Full license text is available on the following
    link: http://www.freertos.org/a00114.html

    ***************************************************************************
     *                                                                       *
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    ***************************************************************************

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*/

/*******************************************************************************
// Copyright (c) 2003-2015 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.
--------------------------------------------------------------------------------
*/

#include <stdlib.h>
#include <xtensa/config/core.h>

#include "xtensa_rtos.h"

#include "rom/ets_sys.h"
#include "soc/cpu.h"

#include "FreeRTOS.h"
#include "task.h"

#include "esp_panic.h"
#include "esp_heap_caps.h"
#include "esp_crosscore_int.h"

#include "esp_intr_alloc.h"

/* Defined in portasm.h */
extern void _frxt_tick_timer_init(void);

/* Defined in xtensa_context.S */
extern void _xt_coproc_init(void);


#if CONFIG_FREERTOS_CORETIMER_0
    #define SYSTICK_INTR_ID (ETS_INTERNAL_TIMER0_INTR_SOURCE+ETS_INTERNAL_INTR_SOURCE_OFF)
#endif
#if CONFIG_FREERTOS_CORETIMER_1
    #define SYSTICK_INTR_ID (ETS_INTERNAL_TIMER1_INTR_SOURCE+ETS_INTERNAL_INTR_SOURCE_OFF)
#endif

/*-----------------------------------------------------------*/

unsigned port_xSchedulerRunning[portNUM_PROCESSORS] = {0}; // Duplicate of inaccessible xSchedulerRunning; needed at startup to avoid counting nesting
unsigned port_interruptNesting[portNUM_PROCESSORS] = {0};  // Interrupt nesting level. Increased/decreased in portasm.c, _frxt_int_enter/_frxt_int_exit

/*-----------------------------------------------------------*/

// User exception dispatcher when exiting
void _xt_user_exit(void);

/*
 * Stack initialization
 */
#if portUSING_MPU_WRAPPERS
StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters, BaseType_t xRunPrivileged )
#else
StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
#endif
{
	StackType_t *sp, *tp;
	XtExcFrame  *frame;
	#if XCHAL_CP_NUM > 0
	uint32_t *p;
	#endif

	/* Create interrupt stack frame aligned to 16 byte boundary */
	sp = (StackType_t *) (((UBaseType_t)(pxTopOfStack + 1) - XT_CP_SIZE - XT_STK_FRMSZ) & ~0xf);

	/* Clear the entire frame (do not use memset() because we don't depend on C library) */
	for (tp = sp; tp <= pxTopOfStack; ++tp)
		*tp = 0;

	frame = (XtExcFrame *) sp;

	/* Explicitly initialize certain saved registers */
	frame->pc   = (UBaseType_t) pxCode;             /* task entrypoint                */
	frame->a0   = 0;                                /* to terminate GDB backtrace     */
	frame->a1   = (UBaseType_t) sp + XT_STK_FRMSZ;  /* physical top of stack frame    */
	frame->exit = (UBaseType_t) _xt_user_exit;      /* user exception exit dispatcher */

	/* Set initial PS to int level 0, EXCM disabled ('rfe' will enable), user mode. */
	/* Also set entry point argument parameter. */
	#ifdef __XTENSA_CALL0_ABI__
	frame->a2 = (UBaseType_t) pvParameters;
	frame->ps = PS_UM | PS_EXCM;
	#else
	/* + for windowed ABI also set WOE and CALLINC (pretend task was 'call4'd). */
	frame->a6 = (UBaseType_t) pvParameters;
	frame->ps = PS_UM | PS_EXCM | PS_WOE | PS_CALLINC(1);
	#endif

	#ifdef XT_USE_SWPRI
	/* Set the initial virtual priority mask value to all 1's. */
	frame->vpri = 0xFFFFFFFF;
	#endif

	#if XCHAL_CP_NUM > 0
	/* Init the coprocessor save area (see xtensa_context.h) */
	/* No access to TCB here, so derive indirectly. Stack growth is top to bottom.
         * //p = (uint32_t *) xMPUSettings->coproc_area;
	 */
	p = (uint32_t *)(((uint32_t) pxTopOfStack - XT_CP_SIZE) & ~0xf);
	p[0] = 0;
	p[1] = 0;
	p[2] = (((uint32_t) p) + 12 + XCHAL_TOTAL_SA_ALIGN - 1) & -XCHAL_TOTAL_SA_ALIGN;
	#endif

	return sp;
}

/*-----------------------------------------------------------*/

void vPortEndScheduler( void )
{
	/* It is unlikely that the Xtensa port will get stopped.  If required simply
	disable the tick interrupt here. */
}

/*-----------------------------------------------------------*/

BaseType_t xPortStartScheduler( void )
{
	// Interrupts are disabled at this point and stack contains PS with enabled interrupts when task context is restored

	#if XCHAL_CP_NUM > 0
	/* Initialize co-processor management for tasks. Leave CPENABLE alone. */
	_xt_coproc_init();
	#endif

	/* Init the tick divisor value */
	_xt_tick_divisor_init();

	/* Setup the hardware to generate the tick. */
	_frxt_tick_timer_init();

	port_xSchedulerRunning[xPortGetCoreID()] = 1;

	// Cannot be directly called from C; never returns
	__asm__ volatile ("call0    _frxt_dispatch\n");

	/* Should not get here. */
	return pdTRUE;
}
/*-----------------------------------------------------------*/

BaseType_t xPortSysTickHandler( void )
{
	BaseType_t ret;
	unsigned interruptMask;

	portbenchmarkIntLatency();
	traceISR_ENTER(SYSTICK_INTR_ID);

	/* Interrupts upto configMAX_SYSCALL_INTERRUPT_PRIORITY must be
	 * disabled before calling xTaskIncrementTick as it access the
	 * kernel lists. */
	interruptMask = portSET_INTERRUPT_MASK_FROM_ISR();
	{
		ret = xTaskIncrementTick();
	}
	portCLEAR_INTERRUPT_MASK_FROM_ISR( interruptMask );

	if( ret != pdFALSE )
	{
		portYIELD_FROM_ISR();
	} else {
		traceISR_EXIT();
	}
	return ret;
}


void vPortYieldOtherCore( BaseType_t coreid ) {
	esp_crosscore_int_send_yield( coreid );
}

/*-----------------------------------------------------------*/

/*
 * Used to set coprocessor area in stack. Current hack is to reuse MPU pointer for coprocessor area.
 */
#if portUSING_MPU_WRAPPERS
void vPortStoreTaskMPUSettings( xMPU_SETTINGS *xMPUSettings, const struct xMEMORY_REGION * const xRegions, StackType_t *pxBottomOfStack, uint32_t usStackDepth )
{
	#if XCHAL_CP_NUM > 0
	xMPUSettings->coproc_area = (StackType_t*)((((uint32_t)(pxBottomOfStack + usStackDepth - 1)) - XT_CP_SIZE ) & ~0xf);


	/* NOTE: we cannot initialize the coprocessor save area here because FreeRTOS is going to
         * clear the stack area after we return. This is done in pxPortInitialiseStack().
	 */
	#endif
}

void vPortReleaseTaskMPUSettings( xMPU_SETTINGS *xMPUSettings )
{
	/* If task has live floating point registers somewhere, release them */
	_xt_coproc_release( xMPUSettings->coproc_area );
}

#endif

/*
 * Returns true if the current core is in ISR context; low prio ISR, med prio ISR or timer tick ISR. High prio ISRs
 * aren't detected here, but they normally cannot call C code, so that should not be an issue anyway.
 */
BaseType_t xPortInIsrContext()
{
	unsigned int irqStatus;
	BaseType_t ret;
	irqStatus=portENTER_CRITICAL_NESTED();
	ret=(port_interruptNesting[xPortGetCoreID()] != 0);
	portEXIT_CRITICAL_NESTED(irqStatus);
	return ret;
}

/*
 * This function will be called in High prio ISRs. Returns true if the current core was in ISR context
 * before calling into high prio ISR context.
 */
BaseType_t IRAM_ATTR xPortInterruptedFromISRContext()
{
	return (port_interruptNesting[xPortGetCoreID()] != 0);
}

void vPortAssertIfInISR()
{
	if (xPortInIsrContext()) {
		ets_printf("core=%d port_interruptNesting=%d\n\n", xPortGetCoreID(), port_interruptNesting[xPortGetCoreID()]);
	}
	configASSERT(!xPortInIsrContext());
}

/*
 * For kernel use: Initialize a per-CPU mux. Mux will be initialized unlocked.
 */
void vPortCPUInitializeMutex(portMUX_TYPE *mux) {

#ifdef CONFIG_FREERTOS_PORTMUX_DEBUG
	ets_printf("Initializing mux %p\n", mux);
	mux->lastLockedFn="(never locked)";
	mux->lastLockedLine=-1;
#endif
	mux->owner=portMUX_FREE_VAL;
	mux->count=0;
}

#include "portmux_impl.h"

/*
 * For kernel use: Acquire a per-CPU mux. Spinlocks, so don't hold on to these muxes for too long.
 */
#ifdef CONFIG_FREERTOS_PORTMUX_DEBUG
void vPortCPUAcquireMutex(portMUX_TYPE *mux, const char *fnName, int line) {
	unsigned int irqStatus = portENTER_CRITICAL_NESTED();
	vPortCPUAcquireMutexIntsDisabled(mux, portMUX_NO_TIMEOUT, fnName, line);
	portEXIT_CRITICAL_NESTED(irqStatus);
}

bool vPortCPUAcquireMutexTimeout(portMUX_TYPE *mux, int timeout_cycles, const char *fnName, int line) {
	unsigned int irqStatus = portENTER_CRITICAL_NESTED();
	bool result = vPortCPUAcquireMutexIntsDisabled(mux, timeout_cycles, fnName, line);
	portEXIT_CRITICAL_NESTED(irqStatus);
	return result;
}

#else
void vPortCPUAcquireMutex(portMUX_TYPE *mux) {
	unsigned int irqStatus = portENTER_CRITICAL_NESTED();
	vPortCPUAcquireMutexIntsDisabled(mux, portMUX_NO_TIMEOUT);
	portEXIT_CRITICAL_NESTED(irqStatus);
}

bool vPortCPUAcquireMutexTimeout(portMUX_TYPE *mux, int timeout_cycles) {
	unsigned int irqStatus = portENTER_CRITICAL_NESTED();
	bool result = vPortCPUAcquireMutexIntsDisabled(mux, timeout_cycles);
	portEXIT_CRITICAL_NESTED(irqStatus);
	return result;
}
#endif


/*
 * For kernel use: Release a per-CPU mux
 *
 * Mux must be already locked by this core
 */
#ifdef CONFIG_FREERTOS_PORTMUX_DEBUG
void vPortCPUReleaseMutex(portMUX_TYPE *mux, const char *fnName, int line) {
	unsigned int irqStatus = portENTER_CRITICAL_NESTED();
	vPortCPUReleaseMutexIntsDisabled(mux, fnName, line);
	portEXIT_CRITICAL_NESTED(irqStatus);
}
#else
void vPortCPUReleaseMutex(portMUX_TYPE *mux) {
	unsigned int irqStatus = portENTER_CRITICAL_NESTED();
	vPortCPUReleaseMutexIntsDisabled(mux);
	portEXIT_CRITICAL_NESTED(irqStatus);
}
#endif

void vPortSetStackWatchpoint( void* pxStackStart ) {
	//Set watchpoint 1 to watch the last 32 bytes of the stack.
	//Unfortunately, the Xtensa watchpoints can't set a watchpoint on a random [base - base+n] region because
	//the size works by masking off the lowest address bits. For that reason, we futz a bit and watch the lowest 32
	//bytes of the stack we can actually watch. In general, this can cause the watchpoint to be triggered at most
	//28 bytes early. The value 32 is chosen because it's larger than the stack canary, which in FreeRTOS is 20 bytes.
	//This way, we make sure we trigger before/when the stack canary is corrupted, not after.
	int addr=(int)pxStackStart;
	addr=(addr+31)&(~31);
	esp_set_watchpoint(1, (char*)addr, 32, ESP_WATCHPOINT_STORE);
}

#if defined(CONFIG_SPIRAM_SUPPORT)
/*
 * Compare & set (S32C1) does not work in external RAM. Instead, this routine uses a mux (in internal memory) to fake it.
 */
static portMUX_TYPE extram_mux = portMUX_INITIALIZER_UNLOCKED;

void uxPortCompareSetExtram(volatile uint32_t *addr, uint32_t compare, uint32_t *set) {
	uint32_t prev;
#ifdef CONFIG_FREERTOS_PORTMUX_DEBUG
	vPortCPUAcquireMutexIntsDisabled(&extram_mux, portMUX_NO_TIMEOUT, __FUNCTION__, __LINE__);
#else
	vPortCPUAcquireMutexIntsDisabled(&extram_mux, portMUX_NO_TIMEOUT); 
#endif
	prev=*addr;
	if (prev==compare) {
		*addr=*set;
	}
	*set=prev;
#ifdef CONFIG_FREERTOS_PORTMUX_DEBUG
	vPortCPUReleaseMutexIntsDisabled(&extram_mux, __FUNCTION__, __LINE__);
#else
	vPortCPUReleaseMutexIntsDisabled(&extram_mux);
#endif
}
#endif //defined(CONFIG_SPIRAM_SUPPORT)



uint32_t xPortGetTickRateHz(void) {
	return (uint32_t)configTICK_RATE_HZ;
}