zephyr/arch/arm64/core/vector_table.S

358 lines
9.5 KiB
ArmAsm

/*
* Copyright (c) 2019 Carlo Caione <ccaione@baylibre.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
/*
* Populated vector table
*/
#include <zephyr/toolchain.h>
#include <zephyr/linker/sections.h>
#include <offsets.h>
#include <zephyr/arch/cpu.h>
#include <zephyr/arch/arm64/tpidrro_el0.h>
#include <offsets_short.h>
#include "macro_priv.inc"
_ASM_FILE_PROLOGUE
/*
* Save volatile registers, LR, SPSR_EL1 and ELR_EL1
*
* Save the volatile registers and LR on the process stack. This is
* needed if the thread is switched out because they can be clobbered by the
* ISR and/or context switch.
*/
.macro z_arm64_enter_exc xreg0, xreg1, el
/*
* Two things can happen to the remaining registers:
*
* - No context-switch: in this case x19-x28 are callee-saved register
* so we can be sure they are not going to be clobbered by ISR.
* - Context-switch: the callee-saved registers are saved by
* z_arm64_context_switch() in the kernel structure.
*/
sub sp, sp, ___esf_t_SIZEOF
#ifdef CONFIG_ARM64_SAFE_EXCEPTION_STACK
.if \el == el1
/*
* EL1t mode cannot access sp_el1, so set x0 to sp_el1 without corrupt
* other registers
*/
add sp, sp, x0 // sp' = sp + x0
sub x0, sp, x0 // x0' = sp' - x0 = sp
msr SPSel, #0
stp x16, x17, [sp, -(___esf_t_SIZEOF - ___esf_t_x16_x17_OFFSET)]
stp x18, lr, [sp, -(___esf_t_SIZEOF - ___esf_t_x18_lr_OFFSET)]
bl z_arm64_quick_stack_check
.endif
#endif
stp x0, x1, [sp, ___esf_t_x0_x1_OFFSET]
stp x2, x3, [sp, ___esf_t_x2_x3_OFFSET]
stp x4, x5, [sp, ___esf_t_x4_x5_OFFSET]
stp x6, x7, [sp, ___esf_t_x6_x7_OFFSET]
stp x8, x9, [sp, ___esf_t_x8_x9_OFFSET]
stp x10, x11, [sp, ___esf_t_x10_x11_OFFSET]
stp x12, x13, [sp, ___esf_t_x12_x13_OFFSET]
stp x14, x15, [sp, ___esf_t_x14_x15_OFFSET]
#ifdef CONFIG_ARM64_SAFE_EXCEPTION_STACK
/* The expection from el1 does not need to save x16, x17, x18 and lr */
.if \el == el0
#endif
stp x16, x17, [sp, ___esf_t_x16_x17_OFFSET]
stp x18, lr, [sp, ___esf_t_x18_lr_OFFSET]
#ifdef CONFIG_ARM64_SAFE_EXCEPTION_STACK
.endif
#endif
#ifdef CONFIG_ARM64_ENABLE_FRAME_POINTER
str x29, [sp, ___esf_t_fp_OFFSET]
#endif
mrs \xreg0, spsr_el1
mrs \xreg1, elr_el1
stp \xreg0, \xreg1, [sp, ___esf_t_spsr_elr_OFFSET]
#ifdef CONFIG_ARM64_SAFE_EXCEPTION_STACK
.if \el == el0
mrs x0, sp_el0
str x0, [sp, ___esf_t_sp_el0_OFFSET]
/* Retrieving safe exception stack */
get_cpu x0
ldr x1, [x0, #_cpu_offset_to_safe_exception_stack]
msr sp_el0, x1
.endif
#endif
/* Clear usermode flag and increment exception depth */
mrs \xreg0, tpidrro_el0
mov \xreg1, #TPIDRROEL0_EXC_UNIT
bic \xreg0, \xreg0, #TPIDRROEL0_IN_EL0
add \xreg0, \xreg0, \xreg1
msr tpidrro_el0, \xreg0
#ifdef CONFIG_FPU_SHARING
bl z_arm64_fpu_enter_exc
#endif
.endm
/*
* Four types of exceptions:
* - synchronous: aborts from MMU, SP/CP alignment checking, unallocated
* instructions, SVCs/SMCs/HVCs, ...)
* - IRQ: group 1 (normal) interrupts
* - FIQ: group 0 or secure interrupts
* - SError: fatal system errors
*
* Four different contexts:
* - from same exception level, when using the SP_EL0 stack pointer
* - from same exception level, when using the SP_ELx stack pointer
* - from lower exception level, when this is AArch64
* - from lower exception level, when this is AArch32
*
* +------------------+------------------+-------------------------+
* | Address | Exception type | Description |
* +------------------+------------------+-------------------------+
* | VBAR_ELn + 0x000 | Synchronous | Current EL with SP0 |
* | + 0x080 | IRQ / vIRQ | |
* | + 0x100 | FIQ / vFIQ | |
* | + 0x180 | SError / vSError | |
* +------------------+------------------+-------------------------+
* | + 0x200 | Synchronous | Current EL with SPx |
* | + 0x280 | IRQ / vIRQ | |
* | + 0x300 | FIQ / vFIQ | |
* | + 0x380 | SError / vSError | |
* +------------------+------------------+-------------------------+
* | + 0x400 | Synchronous | Lower EL using AArch64 |
* | + 0x480 | IRQ / vIRQ | |
* | + 0x500 | FIQ / vFIQ | |
* | + 0x580 | SError / vSError | |
* +------------------+------------------+-------------------------+
* | + 0x600 | Synchronous | Lower EL using AArch32 |
* | + 0x680 | IRQ / vIRQ | |
* | + 0x700 | FIQ / vFIQ | |
* | + 0x780 | SError / vSError | |
* +------------------+------------------+-------------------------+
*/
GDATA(_vector_table)
SECTION_SUBSEC_FUNC(exc_vector_table,_vector_table_section,_vector_table)
/* The whole table must be 2K aligned */
.align 11
/* Current EL with SP0 / Synchronous */
.align 7
z_arm64_enter_exc x0, x1, el1
b z_arm64_sync_exc
/* Current EL with SP0 / IRQ */
.align 7
z_arm64_enter_exc x0, x1, el1
#ifdef CONFIG_GEN_SW_ISR_TABLE
b _isr_wrapper
#else
b z_irq_spurious
#endif
/* Current EL with SP0 / FIQ */
.align 7
b .
/* Current EL with SP0 / SError */
.align 7
z_arm64_enter_exc x0, x1, el1
b z_arm64_serror
/* Current EL with SPx / Synchronous */
.align 7
z_arm64_enter_exc x0, x1, el1
b z_arm64_sync_exc
/* Current EL with SPx / IRQ */
.align 7
z_arm64_enter_exc x0, x1, el1
#ifdef CONFIG_GEN_SW_ISR_TABLE
b _isr_wrapper
#else
b z_irq_spurious
#endif
/* Current EL with SPx / FIQ */
.align 7
b .
/* Current EL with SPx / SError */
.align 7
z_arm64_enter_exc x0, x1, el1
b z_arm64_serror
/* Lower EL using AArch64 / Synchronous */
.align 7
z_arm64_enter_exc x0, x1, el0
b z_arm64_sync_exc
/* Lower EL using AArch64 / IRQ */
.align 7
z_arm64_enter_exc x0, x1, el0
#ifdef CONFIG_GEN_SW_ISR_TABLE
b _isr_wrapper
#else
b z_irq_spurious
#endif
/* Lower EL using AArch64 / FIQ */
.align 7
b .
/* Lower EL using AArch64 / SError */
.align 7
z_arm64_enter_exc x0, x1, el0
b z_arm64_serror
/* Lower EL using AArch32 / Synchronous */
.align 7
b .
/* Lower EL using AArch32 / IRQ */
.align 7
b .
/* Lower EL using AArch32 / FIQ */
.align 7
b .
/* Lower EL using AArch32 / SError */
.align 7
b .
GTEXT(z_arm64_serror)
SECTION_FUNC(TEXT, z_arm64_serror)
mov x1, sp
mov x0, #0 /* K_ERR_CPU_EXCEPTION */
bl z_arm64_fatal_error
/* Return here only in case of recoverable error */
b z_arm64_exit_exc
#ifdef CONFIG_ARM64_SAFE_EXCEPTION_STACK
GTEXT(z_arm64_quick_stack_check)
SECTION_FUNC(TEXT, z_arm64_quick_stack_check)
/*
* x0 is SP_EL1
* Retrieve the current stack limit
*/
get_cpu x16
ldr x17, [x16, #_cpu_offset_to_current_stack_limit]
/*
* If priv sp <= the stack limit, then keep the safe exception stack
* go to the stack overflow process.
*/
cmp x0, x17
/* Restore the sp_el1 */
msr SPSel, #1 // switch sp to sp_el1
sub x0, sp, x0 // x0'' = sp' - x0' = x0
sub sp, sp, x0 // sp'' = sp' - x0 = sp
ble 1f
/*
* If the stack does not overflow, keep using sp_el1, copy the original
* x16, x17, x18, lr from sp_el0 (safe_exception_stack) to sp_el1. So
* the four registers can be restroed directly from sp_el1 without a
* stack mode switch.
*/
mrs x18, sp_el0
ldp x16, x17, [x18, -(___esf_t_SIZEOF - ___esf_t_x16_x17_OFFSET)]
stp x16, x17, [sp, ___esf_t_x16_x17_OFFSET]
ldp x16, x17, [x18, -(___esf_t_SIZEOF - ___esf_t_x18_lr_OFFSET)]
stp x16, x17, [sp, ___esf_t_x18_lr_OFFSET]
ret
1: /*
* If stack overflow, save the current sp and then switch sp to safe
* exception stack
* x16 is still the current _cpu
*/
mrs x18, sp_el0
mov x17, sp
str x17, [x16, #_cpu_offset_to_corrupted_sp]
/*
* switch sp to safe exception stack, which means we handle the fatal
* error with safe exception stack.
*/
sub sp, x18, ___esf_t_SIZEOF
ret
#endif
/*
* Restore volatile registers, LR, SPSR_EL1 and ELR_EL1
*
* This is the common exit point for z_arm64_sync_exc() and _isr_wrapper().
*/
GTEXT(z_arm64_exit_exc)
SECTION_FUNC(TEXT, z_arm64_exit_exc)
#ifdef CONFIG_FPU_SHARING
bl z_arm64_fpu_exit_exc
GTEXT(z_arm64_exit_exc_fpu_done)
z_arm64_exit_exc_fpu_done:
#endif
ldp x0, x1, [sp, ___esf_t_spsr_elr_OFFSET]
msr spsr_el1, x0
msr elr_el1, x1
/* Restore the kernel/user mode flag and decrement exception depth */
tst x0, #SPSR_MODE_MASK /* EL0 == 0 */
mrs x0, tpidrro_el0
mov x1, #TPIDRROEL0_EXC_UNIT
orr x2, x0, #TPIDRROEL0_IN_EL0
csel x0, x2, x0, eq
sub x0, x0, x1
msr tpidrro_el0, x0
#ifdef CONFIG_ARM64_SAFE_EXCEPTION_STACK
bne 1f
ldr x0, [sp, ___esf_t_sp_el0_OFFSET]
msr sp_el0, x0
1:
#endif
ldp x0, x1, [sp, ___esf_t_x0_x1_OFFSET]
ldp x2, x3, [sp, ___esf_t_x2_x3_OFFSET]
ldp x4, x5, [sp, ___esf_t_x4_x5_OFFSET]
ldp x6, x7, [sp, ___esf_t_x6_x7_OFFSET]
ldp x8, x9, [sp, ___esf_t_x8_x9_OFFSET]
ldp x10, x11, [sp, ___esf_t_x10_x11_OFFSET]
ldp x12, x13, [sp, ___esf_t_x12_x13_OFFSET]
ldp x14, x15, [sp, ___esf_t_x14_x15_OFFSET]
ldp x16, x17, [sp, ___esf_t_x16_x17_OFFSET]
ldp x18, lr, [sp, ___esf_t_x18_lr_OFFSET]
#ifdef CONFIG_ARM64_ENABLE_FRAME_POINTER
ldr x29, [sp, ___esf_t_fp_OFFSET]
#endif
add sp, sp, ___esf_t_SIZEOF
/*
* In general in the ELR_EL1 register we can find:
*
* - The address of ret in z_arm64_call_svc()
* - The address of the next instruction at the time of the IRQ when the
* thread was switched out.
* - The address of z_thread_entry() for new threads (see thread.c).
*/
eret