161 lines
3.7 KiB
ArmAsm
161 lines
3.7 KiB
ArmAsm
|
/* SPDX-License-Identifier: GPL-2.0-only */
|
||
|
|
/*
|
||
|
|
* linux/arch/arm/kernel/entry-v7m.S
|
||
|
|
*
|
||
|
|
* Copyright (C) 2008 ARM Ltd.
|
||
|
|
*
|
||
|
|
* Low-level vector interface routines for the ARMv7-M architecture
|
||
|
|
*/
|
||
|
|
#include <asm/memory.h>
|
||
|
|
#include <asm/glue.h>
|
||
|
|
#include <asm/thread_notify.h>
|
||
|
|
#include <asm/v7m.h>
|
||
|
|
|
||
|
|
#include "entry-header.S"
|
||
|
|
|
||
|
|
#ifdef CONFIG_TRACE_IRQFLAGS
|
||
|
|
#error "CONFIG_TRACE_IRQFLAGS not supported on the current ARMv7M implementation"
|
||
|
|
#endif
|
||
|
|
|
||
|
|
__invalid_entry:
|
||
|
|
v7m_exception_entry
|
||
|
|
#ifdef CONFIG_PRINTK
|
||
|
|
adr r0, strerr
|
||
|
|
mrs r1, ipsr
|
||
|
|
mov r2, lr
|
||
|
|
bl _printk
|
||
|
|
#endif
|
||
|
|
mov r0, sp
|
||
|
|
bl show_regs
|
||
|
|
1: b 1b
|
||
|
|
ENDPROC(__invalid_entry)
|
||
|
|
|
||
|
|
strerr: .asciz "\nUnhandled exception: IPSR = %08lx LR = %08lx\n"
|
||
|
|
|
||
|
|
.align 2
|
||
|
|
__irq_entry:
|
||
|
|
v7m_exception_entry
|
||
|
|
|
||
|
|
@
|
||
|
|
@ Invoke the IRQ handler
|
||
|
|
@
|
||
|
|
mov r0, sp
|
||
|
|
ldr_this_cpu sp, irq_stack_ptr, r1, r2
|
||
|
|
|
||
|
|
@
|
||
|
|
@ If we took the interrupt while running in the kernel, we may already
|
||
|
|
@ be using the IRQ stack, so revert to the original value in that case.
|
||
|
|
@
|
||
|
|
subs r2, sp, r0 @ SP above bottom of IRQ stack?
|
||
|
|
rsbscs r2, r2, #THREAD_SIZE @ ... and below the top?
|
||
|
|
movcs sp, r0
|
||
|
|
|
||
|
|
push {r0, lr} @ preserve LR and original SP
|
||
|
|
|
||
|
|
@ routine called with r0 = struct pt_regs *
|
||
|
|
bl generic_handle_arch_irq
|
||
|
|
|
||
|
|
pop {r0, lr}
|
||
|
|
mov sp, r0
|
||
|
|
|
||
|
|
@
|
||
|
|
@ Check for any pending work if returning to user
|
||
|
|
@
|
||
|
|
ldr r1, =BASEADDR_V7M_SCB
|
||
|
|
ldr r0, [r1, V7M_SCB_ICSR]
|
||
|
|
tst r0, V7M_SCB_ICSR_RETTOBASE
|
||
|
|
beq 2f
|
||
|
|
|
||
|
|
get_thread_info tsk
|
||
|
|
ldr r2, [tsk, #TI_FLAGS]
|
||
|
|
movs r2, r2, lsl #16
|
||
|
|
beq 2f @ no work pending
|
||
|
|
mov r0, #V7M_SCB_ICSR_PENDSVSET
|
||
|
|
str r0, [r1, V7M_SCB_ICSR] @ raise PendSV
|
||
|
|
|
||
|
|
2:
|
||
|
|
@ registers r0-r3 and r12 are automatically restored on exception
|
||
|
|
@ return. r4-r7 were not clobbered in v7m_exception_entry so for
|
||
|
|
@ correctness they don't need to be restored. So only r8-r11 must be
|
||
|
|
@ restored here. The easiest way to do so is to restore r0-r7, too.
|
||
|
|
ldmia sp!, {r0-r11}
|
||
|
|
add sp, #PT_REGS_SIZE-S_IP
|
||
|
|
cpsie i
|
||
|
|
bx lr
|
||
|
|
ENDPROC(__irq_entry)
|
||
|
|
|
||
|
|
__pendsv_entry:
|
||
|
|
v7m_exception_entry
|
||
|
|
|
||
|
|
ldr r1, =BASEADDR_V7M_SCB
|
||
|
|
mov r0, #V7M_SCB_ICSR_PENDSVCLR
|
||
|
|
str r0, [r1, V7M_SCB_ICSR] @ clear PendSV
|
||
|
|
|
||
|
|
@ execute the pending work, including reschedule
|
||
|
|
get_thread_info tsk
|
||
|
|
mov why, #0
|
||
|
|
b ret_to_user_from_irq
|
||
|
|
ENDPROC(__pendsv_entry)
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Register switch for ARMv7-M processors.
|
||
|
|
* r0 = previous task_struct, r1 = previous thread_info, r2 = next thread_info
|
||
|
|
* previous and next are guaranteed not to be the same.
|
||
|
|
*/
|
||
|
|
ENTRY(__switch_to)
|
||
|
|
.fnstart
|
||
|
|
.cantunwind
|
||
|
|
add ip, r1, #TI_CPU_SAVE
|
||
|
|
stmia ip!, {r4 - r11} @ Store most regs on stack
|
||
|
|
str sp, [ip], #4
|
||
|
|
str lr, [ip], #4
|
||
|
|
mov r5, r0
|
||
|
|
mov r6, r2 @ Preserve 'next'
|
||
|
|
add r4, r2, #TI_CPU_SAVE
|
||
|
|
ldr r0, =thread_notify_head
|
||
|
|
mov r1, #THREAD_NOTIFY_SWITCH
|
||
|
|
bl atomic_notifier_call_chain
|
||
|
|
mov r0, r5
|
||
|
|
mov r1, r6
|
||
|
|
ldmia r4, {r4 - r12, lr} @ Load all regs saved previously
|
||
|
|
set_current r1, r2
|
||
|
|
mov sp, ip
|
||
|
|
bx lr
|
||
|
|
.fnend
|
||
|
|
ENDPROC(__switch_to)
|
||
|
|
|
||
|
|
.data
|
||
|
|
#if CONFIG_CPU_V7M_NUM_IRQ <= 112
|
||
|
|
.align 9
|
||
|
|
#else
|
||
|
|
.align 10
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Vector table (Natural alignment need to be ensured)
|
||
|
|
*/
|
||
|
|
ENTRY(vector_table)
|
||
|
|
.long 0 @ 0 - Reset stack pointer
|
||
|
|
.long __invalid_entry @ 1 - Reset
|
||
|
|
.long __invalid_entry @ 2 - NMI
|
||
|
|
.long __invalid_entry @ 3 - HardFault
|
||
|
|
.long __invalid_entry @ 4 - MemManage
|
||
|
|
.long __invalid_entry @ 5 - BusFault
|
||
|
|
.long __invalid_entry @ 6 - UsageFault
|
||
|
|
.long __invalid_entry @ 7 - Reserved
|
||
|
|
.long __invalid_entry @ 8 - Reserved
|
||
|
|
.long __invalid_entry @ 9 - Reserved
|
||
|
|
.long __invalid_entry @ 10 - Reserved
|
||
|
|
.long vector_swi @ 11 - SVCall
|
||
|
|
.long __invalid_entry @ 12 - Debug Monitor
|
||
|
|
.long __invalid_entry @ 13 - Reserved
|
||
|
|
.long __pendsv_entry @ 14 - PendSV
|
||
|
|
.long __invalid_entry @ 15 - SysTick
|
||
|
|
.rept CONFIG_CPU_V7M_NUM_IRQ
|
||
|
|
.long __irq_entry @ External Interrupts
|
||
|
|
.endr
|
||
|
|
.align 2
|
||
|
|
.globl exc_ret
|
||
|
|
exc_ret:
|
||
|
|
.space 4
|