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/*
* Copyright (c) 2006-2018, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2013-07-05 Bernard the first version
*/
#include <rtconfig.h>
#ifdef RT_USING_VMM
#include <vmm.h>
#endif
.section .text, "ax"
/*
* rt_base_t rt_hw_interrupt_disable();
*/
.globl rt_hw_interrupt_disable
rt_hw_interrupt_disable:
mrs r0, cpsr
cpsid i
bx lr
/*
* void rt_hw_interrupt_enable(rt_base_t level);
*/
.globl rt_hw_interrupt_enable
rt_hw_interrupt_enable:
msr cpsr, r0
bx lr
/*
* void rt_hw_context_switch_to(rt_uint32 to);
* r0 --> to
*/
.globl rt_hw_context_switch_to
rt_hw_context_switch_to:
ldr sp, [r0] @ get new task stack pointer
ldmfd sp!, {r4} @ pop new task spsr
msr spsr_cxsf, r4
ldmfd sp!, {r0-r12, lr, pc}^ @ pop new task r0-r12, lr & pc
.section .bss.share.isr
_guest_switch_lvl:
.word 0
.globl vmm_virq_update
.section .text.isr, "ax"
/*
* void rt_hw_context_switch(rt_uint32 from, rt_uint32 to);
* r0 --> from
* r1 --> to
*/
.globl rt_hw_context_switch
rt_hw_context_switch:
stmfd sp!, {lr} @ push pc (lr should be pushed in place of PC)
stmfd sp!, {r0-r12, lr} @ push lr & register file
mrs r4, cpsr
tst lr, #0x01
orrne r4, r4, #0x20 @ it's thumb code
stmfd sp!, {r4} @ push cpsr
str sp, [r0] @ store sp in preempted tasks TCB
ldr sp, [r1] @ get new task stack pointer
#ifdef RT_USING_VMM
#ifdef RT_VMM_USING_DOMAIN
@ need to make sure we are in vmm domain as we would use rt_current_thread
ldr r2, =vmm_domain_val
ldr r7, [r2]
mcr p15, 0, r7, c3, c0
#endif
/* check whether vmm thread, otherwise, update vIRQ */
ldr r3, =rt_current_thread
ldr r4, [r3]
ldr r5, =vmm_thread
cmp r4, r5
beq switch_to_guest
@ not falling into guest. Simple task ;-)
ldmfd sp!, {r6} @ pop new task cpsr to spsr
msr spsr_cxsf, r6
ldmfd sp!, {r0-r12, lr, pc}^
switch_to_guest:
#ifdef RT_VMM_USING_DOMAIN
@ the stack is saved in the guest domain so we need to
@ come back to the guest domain to get the registers.
ldr r1, =super_domain_val
ldr r0, [r1]
mcr p15, 0, r0, c3, c0
#endif
/* The user can do nearly anything in rt_thread_idle_excute because it will
call the thread->cleanup. One common thing is sending events and wake up
threads. So the guest thread will be preempted. This is the only point that
the guest thread would call rt_hw_context_switch and "yield".
More over, rt_schedule will call this function and this function *will*
reentrant. If that happens, we need to make sure that call the
rt_thread_idle_excute and vmm_virq_update again and we are in super domain.
I use a "reference count" to achieve such behaviour. If you have better
idea, tell me. */
ldr r4, =_guest_switch_lvl
ldr r5, [r4]
add r5, r5, #1
str r5, [r4]
cmp r5, #1
bne _switch_through
bl rt_thread_idle_excute
bl vmm_virq_update
/* we need _guest_switch_lvl to protect until _switch_through, but it's OK
* to cleanup the reference count here because the code below will not be
* reentrant. */
sub r5, r5, #1
str r5, [r4]
#ifdef RT_VMM_USING_DOMAIN
ldr r1, =guest_domain_val
ldr r0, [r1]
mcr p15, 0, r0, c3, c0
#endif
_switch_through:
#endif /* RT_USING_VMM */
ldmfd sp!, {r4} @ pop new task cpsr to spsr
msr spsr_cxsf, r4
ldmfd sp!, {r0-r12, lr, pc}^ @ pop new task r0-r12, lr & pc, copy spsr to cpsr
/*
* void rt_hw_context_switch_interrupt(rt_uint32 from, rt_uint32 to);
*/
.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 r2, =rt_thread_switch_interrupt_flag
ldr r3, [r2]
cmp r3, #1
beq _reswitch
ldr ip, =rt_interrupt_from_thread @ set rt_interrupt_from_thread
mov r3, #1 @ set rt_thread_switch_interrupt_flag to 1
str r0, [ip]
str r3, [r2]
_reswitch:
ldr r2, =rt_interrupt_to_thread @ set rt_interrupt_to_thread
str r1, [r2]
bx lr
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