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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_ARC_ENTRY_ARCV2_H
#define __ASM_ARC_ENTRY_ARCV2_H
#include <asm/asm-offsets.h>
#include <asm/dsp-impl.h>
#include <asm/irqflags-arcv2.h>
#include <asm/thread_info.h> /* For THREAD_SIZE */
/*
* Interrupt/Exception stack layout (pt_regs) for ARCv2
* (End of struct aligned to end of page [unless nested])
*
* INTERRUPT EXCEPTION
*
* manual --------------------- manual
* | orig_r0 |
* | event/ECR |
* | bta |
* | gp |
* | fp |
* | sp |
* | r12 |
* | r30 |
* | r58 |
* | r59 |
* hw autosave ---------------------
* optional | r0 |
* | r1 |
* ~ ~
* | r9 |
* | r10 |
* | r11 |
* | blink |
* | lpe |
* | lps |
* | lpc |
* | ei base |
* | ldi base |
* | jli base |
* ---------------------
* hw autosave | pc / eret |
* mandatory | stat32 / erstatus |
* ---------------------
*/
/*------------------------------------------------------------------------*/
.macro INTERRUPT_PROLOGUE
; Before jumping to Interrupt Vector, hardware micro-ops did following:
; 1. SP auto-switched to kernel mode stack
; 2. STATUS32.Z flag set if in U mode at time of interrupt (U:1,K:0)
; 3. Auto save: (mandatory) Push PC and STAT32 on stack
; hardware does even if CONFIG_ARC_IRQ_NO_AUTOSAVE
; 4a. Auto save: (optional) r0-r11, blink, LPE,LPS,LPC, JLI,LDI,EI
;
; Now
; 4b. If Auto-save (optional) not enabled in hw, manually save them
; 5. Manually save: r12,r30, sp,fp,gp, ACCL pair
;
; At the end, SP points to pt_regs
#ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE
; carve pt_regs on stack (case #3), PC/STAT32 already on stack
sub sp, sp, SZ_PT_REGS - 8
__SAVE_REGFILE_HARD
#else
; carve pt_regs on stack (case #4), which grew partially already
sub sp, sp, PT_r0
#endif
__SAVE_REGFILE_SOFT
.endm
/*------------------------------------------------------------------------*/
.macro EXCEPTION_PROLOGUE_KEEP_AE
; Before jumping to Exception Vector, hardware micro-ops did following:
; 1. SP auto-switched to kernel mode stack
; 2. STATUS32.Z flag set if in U mode at time of exception (U:1,K:0)
;
; Now manually save rest of reg file
; At the end, SP points to pt_regs
sub sp, sp, SZ_PT_REGS ; carve space for pt_regs
; _HARD saves r10 clobbered by _SOFT as scratch hence comes first
__SAVE_REGFILE_HARD
__SAVE_REGFILE_SOFT
st r0, [sp] ; orig_r0
lr r10, [eret]
lr r11, [erstatus]
ST2 r10, r11, PT_ret
lr r10, [ecr]
lr r11, [erbta]
ST2 r10, r11, PT_event
; OUTPUT: r10 has ECR expected by EV_Trap
.endm
.macro EXCEPTION_PROLOGUE
EXCEPTION_PROLOGUE_KEEP_AE ; return ECR in r10
lr r0, [efa]
mov r1, sp
FAKE_RET_FROM_EXCPN ; clobbers r9
.endm
/*------------------------------------------------------------------------
* This macro saves the registers manually which would normally be autosaved
* by hardware on taken interrupts. It is used by
* - exception handlers (which don't have autosave)
* - interrupt autosave disabled due to CONFIG_ARC_IRQ_NO_AUTOSAVE
*/
.macro __SAVE_REGFILE_HARD
ST2 r0, r1, PT_r0
ST2 r2, r3, PT_r2
ST2 r4, r5, PT_r4
ST2 r6, r7, PT_r6
ST2 r8, r9, PT_r8
ST2 r10, r11, PT_r10
st blink, [sp, PT_blink]
lr r10, [lp_end]
lr r11, [lp_start]
ST2 r10, r11, PT_lpe
st lp_count, [sp, PT_lpc]
; skip JLI, LDI, EI for now
.endm
/*------------------------------------------------------------------------
* This macros saves a bunch of other registers which can't be autosaved for
* various reasons:
* - r12: the last caller saved scratch reg since hardware saves in pairs so r0-r11
* - r30: free reg, used by gcc as scratch
* - ACCL/ACCH pair when they exist
*/
.macro __SAVE_REGFILE_SOFT
ST2 gp, fp, PT_r26 ; gp (r26), fp (r27)
st r12, [sp, PT_r12]
st r30, [sp, PT_r30]
; Saving pt_regs->sp correctly requires some extra work due to the way
; Auto stack switch works
; - U mode: retrieve it from AUX_USER_SP
; - K mode: add the offset from current SP where H/w starts auto push
;
; 1. Utilize the fact that Z bit is set if Intr taken in U mode
; 2. Upon entry SP is always saved (for any inspection, unwinding etc),
; but on return, restored only if U mode
lr r10, [AUX_USER_SP] ; U mode SP
; ISA requires ADD.nz to have same dest and src reg operands
mov.nz r10, sp
add.nz r10, r10, SZ_PT_REGS ; K mode SP
st r10, [sp, PT_sp] ; SP (pt_regs->sp)
#ifdef CONFIG_ARC_HAS_ACCL_REGS
ST2 r58, r59, PT_r58
#endif
/* clobbers r10, r11 registers pair */
DSP_SAVE_REGFILE_IRQ
#ifdef CONFIG_ARC_CURR_IN_REG
GET_CURR_TASK_ON_CPU gp
#endif
.endm
/*------------------------------------------------------------------------*/
.macro __RESTORE_REGFILE_SOFT
LD2 gp, fp, PT_r26 ; gp (r26), fp (r27)
ld r12, [sp, PT_r12]
ld r30, [sp, PT_r30]
; Restore SP (into AUX_USER_SP) only if returning to U mode
; - for K mode, it will be implicitly restored as stack is unwound
; - Z flag set on K is inverse of what hardware does on interrupt entry
; but that doesn't really matter
bz 1f
ld r10, [sp, PT_sp] ; SP (pt_regs->sp)
sr r10, [AUX_USER_SP]
1:
/* clobbers r10, r11 registers pair */
DSP_RESTORE_REGFILE_IRQ
#ifdef CONFIG_ARC_HAS_ACCL_REGS
LD2 r58, r59, PT_r58
#endif
.endm
/*------------------------------------------------------------------------*/
.macro __RESTORE_REGFILE_HARD
ld blink, [sp, PT_blink]
LD2 r10, r11, PT_lpe
sr r10, [lp_end]
sr r11, [lp_start]
ld r10, [sp, PT_lpc] ; lp_count can't be target of LD
mov lp_count, r10
LD2 r0, r1, PT_r0
LD2 r2, r3, PT_r2
LD2 r4, r5, PT_r4
LD2 r6, r7, PT_r6
LD2 r8, r9, PT_r8
LD2 r10, r11, PT_r10
.endm
/*------------------------------------------------------------------------*/
.macro INTERRUPT_EPILOGUE
; INPUT: r0 has STAT32 of calling context
; INPUT: Z flag set if returning to K mode
; _SOFT clobbers r10 restored by _HARD hence the order
__RESTORE_REGFILE_SOFT
#ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE
__RESTORE_REGFILE_HARD
; SP points to PC/STAT32: hw restores them despite NO_AUTOSAVE
add sp, sp, SZ_PT_REGS - 8
#else
add sp, sp, PT_r0
#endif
.endm
/*------------------------------------------------------------------------*/
.macro EXCEPTION_EPILOGUE
; INPUT: r0 has STAT32 of calling context
btst r0, STATUS_U_BIT ; Z flag set if K, used in restoring SP
ld r10, [sp, PT_bta]
sr r10, [erbta]
LD2 r10, r11, PT_ret
sr r10, [eret]
sr r11, [erstatus]
__RESTORE_REGFILE_SOFT
__RESTORE_REGFILE_HARD
add sp, sp, SZ_PT_REGS
.endm
.macro FAKE_RET_FROM_EXCPN
lr r9, [status32]
bic r9, r9, STATUS_AE_MASK
or r9, r9, STATUS_IE_MASK
kflag r9
.endm
/* Get thread_info of "current" tsk */
.macro GET_CURR_THR_INFO_FROM_SP reg
bmskn \reg, sp, THREAD_SHIFT - 1
.endm
/* Get CPU-ID of this core */
.macro GET_CPU_ID reg
lr \reg, [identity]
xbfu \reg, \reg, 0xE8 /* 00111 01000 */
/* M = 8-1 N = 8 */
.endm
#endif
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