/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2021-05-18     Jesven       the first version
 */

#include "rtconfig.h"
#include "asm-generic.h"

#include "asm-fpu.h"

.text
.weak rt_hw_cpu_id_set
.type rt_hw_cpu_id_set, @function
rt_hw_cpu_id_set:
    mrs x0, mpidr_el1           /* MPIDR_EL1: Multi-Processor Affinity Register */
#ifdef ARCH_ARM_CORTEX_A55
    lsr x0, x0, #8
#endif
    and x0, x0, #15
    msr tpidr_el1, x0
    ret

/*
int rt_hw_cpu_id(void)
*/
.weak rt_hw_cpu_id
.type rt_hw_cpu_id, @function
rt_hw_cpu_id:
   mrs x0, tpidr_el1           /* MPIDR_EL1: Multi-Processor Affinity Register */
   ret

/*
void rt_hw_set_process_id(size_t id)
*/
.global rt_hw_set_process_id
rt_hw_set_process_id:
    msr CONTEXTIDR_EL1, x0
    ret

  /*
 *enable gtimer
 */
.globl rt_hw_gtimer_enable
rt_hw_gtimer_enable:
    MOV X0,#1
    MSR CNTP_CTL_EL0,X0
    RET

/*
 *set gtimer CNTP_TVAL_EL0 value
 */
.globl rt_hw_set_gtimer_val
rt_hw_set_gtimer_val:
    MSR CNTP_TVAL_EL0,X0
    RET

/*
 *get gtimer CNTP_TVAL_EL0 value
 */
.globl rt_hw_get_gtimer_val
rt_hw_get_gtimer_val:
    MRS X0,CNTP_TVAL_EL0
    RET


.globl rt_hw_get_cntpct_val
rt_hw_get_cntpct_val:
    MRS X0, CNTPCT_EL0
    RET

/*
 *get gtimer frq value
 */
.globl rt_hw_get_gtimer_frq
rt_hw_get_gtimer_frq:
    MRS X0,CNTFRQ_EL0
    RET

START_POINT(_thread_start)
    blr x19
    mov x29, #0
    blr x20
    b   .   /* never here */
START_POINT_END(_thread_start)

.macro SAVE_CONTEXT
    /* Save the entire context. */
    SAVE_FPU SP
    STP     X0, X1, [SP, #-0x10]!
    STP     X2, X3, [SP, #-0x10]!
    STP     X4, X5, [SP, #-0x10]!
    STP     X6, X7, [SP, #-0x10]!
    STP     X8, X9, [SP, #-0x10]!
    STP     X10, X11, [SP, #-0x10]!
    STP     X12, X13, [SP, #-0x10]!
    STP     X14, X15, [SP, #-0x10]!
    STP     X16, X17, [SP, #-0x10]!
    STP     X18, X19, [SP, #-0x10]!
    STP     X20, X21, [SP, #-0x10]!
    STP     X22, X23, [SP, #-0x10]!
    STP     X24, X25, [SP, #-0x10]!
    STP     X26, X27, [SP, #-0x10]!
    STP     X28, X29, [SP, #-0x10]!
    MRS     X28, FPCR
    MRS     X29, FPSR
    STP     X28, X29, [SP, #-0x10]!
    MRS     X29, SP_EL0
    STP     X29, X30, [SP, #-0x10]!

    MRS     X3, SPSR_EL1
    MRS     X2, ELR_EL1

    STP     X2, X3, [SP, #-0x10]!

    MOV     X0, SP   /* Move SP into X0 for saving. */
.endm

.macro SAVE_CONTEXT_FROM_EL1
    /* Save the entire context. */
    SAVE_FPU SP
    STP     X0, X1, [SP, #-0x10]!
    STP     X2, X3, [SP, #-0x10]!
    STP     X4, X5, [SP, #-0x10]!
    STP     X6, X7, [SP, #-0x10]!
    STP     X8, X9, [SP, #-0x10]!
    STP     X10, X11, [SP, #-0x10]!
    STP     X12, X13, [SP, #-0x10]!
    STP     X14, X15, [SP, #-0x10]!
    STP     X16, X17, [SP, #-0x10]!
    STP     X18, X19, [SP, #-0x10]!
    STP     X20, X21, [SP, #-0x10]!
    STP     X22, X23, [SP, #-0x10]!
    STP     X24, X25, [SP, #-0x10]!
    STP     X26, X27, [SP, #-0x10]!
    STP     X28, X29, [SP, #-0x10]!
    MRS     X28, FPCR
    MRS     X29, FPSR
    STP     X28, X29, [SP, #-0x10]!
    MRS     X29, SP_EL0
    STP     X29, X30, [SP, #-0x10]!

    MOV     X19, #((3 << 6) | 0x4 | 0x1)  /* el1h, disable interrupt */
    MOV     X18, X30

    STP     X18, X19, [SP, #-0x10]!
.endm

#ifdef RT_USING_SMP
.macro RESTORE_CONTEXT
    /* Set the SP to point to the stack of the task being restored. */
    MOV     SP, X0

    LDP     X2, X3, [SP], #0x10  /* SPSR and ELR. */

    TST     X3, #0x1f
    MSR     SPSR_EL1, X3
    MSR     ELR_EL1, X2

    LDP     X29, X30, [SP], #0x10
    MSR     SP_EL0, X29
    LDP     X28, X29, [SP], #0x10
    MSR     FPCR, X28
    MSR     FPSR, X29
    LDP     X28, X29, [SP], #0x10
    LDP     X26, X27, [SP], #0x10
    LDP     X24, X25, [SP], #0x10
    LDP     X22, X23, [SP], #0x10
    LDP     X20, X21, [SP], #0x10
    LDP     X18, X19, [SP], #0x10
    LDP     X16, X17, [SP], #0x10
    LDP     X14, X15, [SP], #0x10
    LDP     X12, X13, [SP], #0x10
    LDP     X10, X11, [SP], #0x10
    LDP     X8, X9, [SP], #0x10
    LDP     X6, X7, [SP], #0x10
    LDP     X4, X5, [SP], #0x10
    LDP     X2, X3, [SP], #0x10
    LDP     X0, X1, [SP], #0x10
    RESTORE_FPU SP
#ifdef RT_USING_LWP
    BEQ     arch_ret_to_user
#endif
    ERET
.endm
#else
.macro RESTORE_CONTEXT
    /* Set the SP to point to the stack of the task being restored. */
    MOV     SP, X0
#ifdef RT_USING_LWP
    BL      rt_thread_self
    MOV     X19, X0
    BL      lwp_aspace_switch
    MOV     X0, X19
    BL      lwp_user_setting_restore
#endif
    LDP     X2, X3, [SP], #0x10  /* SPSR and ELR. */

    TST     X3, #0x1f
    MSR     SPSR_EL1, X3
    MSR     ELR_EL1, X2

    LDP     X29, X30, [SP], #0x10
    MSR     SP_EL0, X29
    LDP     X28, X29, [SP], #0x10
    MSR     FPCR, X28
    MSR     FPSR, X29
    LDP     X28, X29, [SP], #0x10
    LDP     X26, X27, [SP], #0x10
    LDP     X24, X25, [SP], #0x10
    LDP     X22, X23, [SP], #0x10
    LDP     X20, X21, [SP], #0x10
    LDP     X18, X19, [SP], #0x10
    LDP     X16, X17, [SP], #0x10
    LDP     X14, X15, [SP], #0x10
    LDP     X12, X13, [SP], #0x10
    LDP     X10, X11, [SP], #0x10
    LDP     X8, X9, [SP], #0x10
    LDP     X6, X7, [SP], #0x10
    LDP     X4, X5, [SP], #0x10
    LDP     X2, X3, [SP], #0x10
    LDP     X0, X1, [SP], #0x10
    RESTORE_FPU SP
#ifdef RT_USING_LWP
    BEQ     arch_ret_to_user
#endif
    ERET
.endm
#endif

.macro RESTORE_CONTEXT_WITHOUT_MMU_SWITCH
    /* the SP is already ok */
    LDP     X2, X3, [SP], #0x10  /* SPSR and ELR. */

    TST     X3, #0x1f
    MSR     SPSR_EL1, X3
    MSR     ELR_EL1, X2

    LDP     X29, X30, [SP], #0x10
    MSR     SP_EL0, X29
    LDP     X28, X29, [SP], #0x10
    MSR     FPCR, X28
    MSR     FPSR, X29
    LDP     X28, X29, [SP], #0x10
    LDP     X26, X27, [SP], #0x10
    LDP     X24, X25, [SP], #0x10
    LDP     X22, X23, [SP], #0x10
    LDP     X20, X21, [SP], #0x10
    LDP     X18, X19, [SP], #0x10
    LDP     X16, X17, [SP], #0x10
    LDP     X14, X15, [SP], #0x10
    LDP     X12, X13, [SP], #0x10
    LDP     X10, X11, [SP], #0x10
    LDP     X8, X9, [SP], #0x10
    LDP     X6, X7, [SP], #0x10
    LDP     X4, X5, [SP], #0x10
    LDP     X2, X3, [SP], #0x10
    LDP     X0, X1, [SP], #0x10
    RESTORE_FPU SP
#ifdef RT_USING_LWP
    BEQ     arch_ret_to_user
#endif
    ERET
.endm

#ifdef RT_USING_SMP
#define rt_hw_interrupt_disable rt_hw_local_irq_disable
#define rt_hw_interrupt_enable rt_hw_local_irq_enable
#endif

.text
/*
 * rt_base_t rt_hw_interrupt_disable();
 */
.globl rt_hw_interrupt_disable
rt_hw_interrupt_disable:
    MRS     X0, DAIF
    MSR     DAIFSet, #3
    DSB     SY
    RET

/*
 * void rt_hw_interrupt_enable(rt_base_t level);
 */
.globl rt_hw_interrupt_enable
rt_hw_interrupt_enable:
    DSB     SY
    AND     X0, X0, #0xc0
    MRS     X1, DAIF
    BIC     X1, X1, #0xc0
    ORR     X0, X0, X1
    MSR     DAIF, X0
    RET

.text

#ifdef RT_USING_SMP

/*
 * void rt_hw_context_switch_to(rt_uint3 to, struct rt_thread *to_thread);
 * X0 --> to (thread stack)
 * X1 --> to_thread
 */

.globl rt_hw_context_switch_to
rt_hw_context_switch_to:
    LDR     X0, [X0]
    MOV     SP, X0
    MOV     X0, X1
    BL      rt_cpus_lock_status_restore
#ifdef RT_USING_LWP
    BL      rt_thread_self
    BL      lwp_user_setting_restore
#endif
    B       rt_hw_context_switch_exit

/*
 * void rt_hw_context_switch(rt_uint32 from, rt_uint32
to, struct rt_thread *to_thread);
 * X0 --> from (from_thread stack)
 * X1 --> to (to_thread stack)
 * X2 --> to_thread
 */
.globl rt_hw_context_switch
rt_hw_context_switch:
    SAVE_CONTEXT_FROM_EL1
    MOV    X3, SP
    STR    X3, [X0]            // store sp in preempted tasks TCB
    LDR    X0, [X1]            // get new task stack pointer
    MOV    SP, X0
    MOV    X0, X2
    BL     rt_cpus_lock_status_restore
#ifdef RT_USING_LWP
    BL     rt_thread_self
    BL     lwp_user_setting_restore
#endif
    B      rt_hw_context_switch_exit

/*
 * void rt_hw_context_switch_interrupt(context, from sp, to sp, tp tcb)
 * X0 :interrupt context
 * X1 :addr of from_thread's sp
 * X2 :addr of to_thread's sp
 * X3 :to_thread's tcb
 */
.globl rt_hw_context_switch_interrupt
rt_hw_context_switch_interrupt:
    STP     X0, X1, [SP, #-0x10]!
    STP     X2, X3, [SP, #-0x10]!
    STP     X29, X30, [SP, #-0x10]!
#ifdef RT_USING_LWP
    BL      rt_thread_self
    BL      lwp_user_setting_save
#endif
    LDP     X29, X30, [SP], #0x10
    LDP     X2, X3, [SP], #0x10
    LDP     X0, X1, [SP], #0x10
    STR     X0, [X1]
    LDR     X0, [X2]
    MOV     SP, X0
    MOV     X0, X3
    MOV     X19, X0
    BL      rt_cpus_lock_status_restore
    MOV     X0, X19
#ifdef RT_USING_LWP
    BL      lwp_user_setting_restore
#endif
    B       rt_hw_context_switch_exit

.globl vector_fiq
vector_fiq:
    B       .

.globl vector_irq
vector_irq:
    CLREX
    SAVE_CONTEXT
    STP     X0, X1, [SP, #-0x10]!   /* X0 is thread sp */

    BL      rt_interrupt_enter
    BL      rt_hw_trap_irq
    BL      rt_interrupt_leave

    LDP     X0, X1, [SP], #0x10
    BL      rt_scheduler_do_irq_switch
    B       rt_hw_context_switch_exit

.global rt_hw_context_switch_exit
rt_hw_context_switch_exit:
    MOV     X0, SP
    RESTORE_CONTEXT

#else

/*
 * void rt_hw_context_switch_to(rt_ubase_t to);
 * X0 --> to sp
 */
.globl rt_hw_context_switch_to
rt_hw_context_switch_to:
    LDR     X0, [X0]
    RESTORE_CONTEXT

/*
 * void rt_hw_context_switch(rt_ubase_t from, rt_ubase_t to);
 * X0 --> from sp
 * X1 --> to sp
 * X2 --> to thread
 */
.globl rt_hw_context_switch
rt_hw_context_switch:

    SAVE_CONTEXT_FROM_EL1

    MOV    X2, SP
    STR    X2, [X0]            // store sp in preempted tasks TCB
    LDR    X0, [X1]            // get new task stack pointer

    RESTORE_CONTEXT

/*
 * void rt_hw_context_switch_interrupt(rt_ubase_t from, rt_ubase_t to, rt_thread_t from_thread, rt_thread_t to_thread);
 */
.globl rt_thread_switch_interrupt_flag
.globl rt_interrupt_from_thread
.globl rt_interrupt_to_thread
.globl rt_hw_context_switch_interrupt
rt_hw_context_switch_interrupt:
    LDR     X6, =rt_thread_switch_interrupt_flag
    LDR     X7, [X6]
    CMP     X7, #1
    B.EQ     _reswitch
    LDR     X4, =rt_interrupt_from_thread   // set rt_interrupt_from_thread
    STR     X0, [X4]
    MOV     X7, #1              // set rt_thread_switch_interrupt_flag to 1
    STR     X7, [X6]
    STP     X1, X30, [SP, #-0x10]!
#ifdef RT_USING_LWP
    MOV     X0, X2
    BL      lwp_user_setting_save
#endif
    LDP     X1, X30, [SP], #0x10
_reswitch:
    LDR     X6, =rt_interrupt_to_thread     // set rt_interrupt_to_thread
    STR     X1, [X6]
    RET

.text

// -- Exception handlers ----------------------------------

    .align  8
.globl vector_fiq
vector_fiq:
    SAVE_CONTEXT
    STP     X0, X1, [SP, #-0x10]!
    BL      rt_hw_trap_fiq
    LDP     X0, X1, [SP], #0x10
    RESTORE_CONTEXT

.globl      rt_interrupt_enter
.globl      rt_interrupt_leave
.globl      rt_thread_switch_interrupt_flag
.globl      rt_interrupt_from_thread
.globl      rt_interrupt_to_thread


// -------------------------------------------------------------------

    .align  8
.globl vector_irq
vector_irq:
    SAVE_CONTEXT
    STP     X0, X1, [SP, #-0x10]!   /* X0 is thread sp */

    BL      rt_interrupt_enter
    BL      rt_hw_trap_irq
    BL      rt_interrupt_leave

    LDP     X0, X1, [SP], #0x10

    // if rt_thread_switch_interrupt_flag set, jump to
    // rt_hw_context_switch_interrupt_do and don't return
    LDR     X1, =rt_thread_switch_interrupt_flag
    LDR     X2, [X1]
    CMP     X2, #1
    B.NE    vector_irq_exit

    MOV     X2,  #0         // clear flag
    STR     X2,  [X1]

    LDR     X3,  =rt_interrupt_from_thread
    LDR     X4,  [X3]
    STR     x0,  [X4]       // store sp in preempted tasks's TCB

    LDR     x3,  =rt_interrupt_to_thread
    LDR     X4,  [X3]
    LDR     x0,  [X4]       // get new task's stack pointer

    RESTORE_CONTEXT

vector_irq_exit:
    MOV     SP, X0
    RESTORE_CONTEXT_WITHOUT_MMU_SWITCH
#endif

// -------------------------------------------------

START_POINT(vector_exception)
    SAVE_CONTEXT
    STP     X0, X1, [SP, #-0x10]!
    BL      rt_hw_trap_exception
    LDP     X0, X1, [SP], #0x10
    MOV     SP, X0
    RESTORE_CONTEXT_WITHOUT_MMU_SWITCH
START_POINT_END(vector_exception)

START_POINT(vector_serror)
    SAVE_CONTEXT
    STP     X0, X1, [SP, #-0x10]!
    BL      rt_hw_trap_serror
    b .
START_POINT_END(vector_exception)
