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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1994, 95, 96, 99, 2001 Ralf Baechle
* Copyright (C) 1994, 1995, 1996 Paul M. Antoine.
* Copyright (C) 1999 Silicon Graphics, Inc.
* Copyright (C) 2007 Maciej W. Rozycki
*/
#ifndef _ASM_STACKFRAME_H
#define _ASM_STACKFRAME_H
#include <linux/threads.h>
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/mipsregs.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
/* Make the addition of cfi info a little easier. */
.macro cfi_rel_offset reg offset=0 docfi=0
.if \docfi
.cfi_rel_offset \reg, \offset
.endif
.endm
.macro cfi_st reg offset=0 docfi=0
LONG_S \reg, \offset(sp)
cfi_rel_offset \reg, \offset, \docfi
.endm
.macro cfi_restore reg offset=0 docfi=0
.if \docfi
.cfi_restore \reg
.endif
.endm
.macro cfi_ld reg offset=0 docfi=0
LONG_L \reg, \offset(sp)
cfi_restore \reg \offset \docfi
.endm
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
#define STATMASK 0x3f
#else
#define STATMASK 0x1f
#endif
.macro SAVE_AT docfi=0
.set push
.set noat
cfi_st $1, PT_R1, \docfi
.set pop
.endm
.macro SAVE_TEMP docfi=0
#ifdef CONFIG_CPU_HAS_SMARTMIPS
mflhxu v1
LONG_S v1, PT_LO(sp)
mflhxu v1
LONG_S v1, PT_HI(sp)
mflhxu v1
LONG_S v1, PT_ACX(sp)
#elif !defined(CONFIG_CPU_MIPSR6)
mfhi v1
#endif
#ifdef CONFIG_32BIT
cfi_st $8, PT_R8, \docfi
cfi_st $9, PT_R9, \docfi
#endif
cfi_st $10, PT_R10, \docfi
cfi_st $11, PT_R11, \docfi
cfi_st $12, PT_R12, \docfi
#if !defined(CONFIG_CPU_HAS_SMARTMIPS) && !defined(CONFIG_CPU_MIPSR6)
LONG_S v1, PT_HI(sp)
mflo v1
#endif
cfi_st $13, PT_R13, \docfi
cfi_st $14, PT_R14, \docfi
cfi_st $15, PT_R15, \docfi
cfi_st $24, PT_R24, \docfi
#if !defined(CONFIG_CPU_HAS_SMARTMIPS) && !defined(CONFIG_CPU_MIPSR6)
LONG_S v1, PT_LO(sp)
#endif
#ifdef CONFIG_CPU_CAVIUM_OCTEON
/*
* The Octeon multiplier state is affected by general
* multiply instructions. It must be saved before and
* kernel code might corrupt it
*/
jal octeon_mult_save
#endif
.endm
.macro SAVE_STATIC docfi=0
cfi_st $16, PT_R16, \docfi
cfi_st $17, PT_R17, \docfi
cfi_st $18, PT_R18, \docfi
cfi_st $19, PT_R19, \docfi
cfi_st $20, PT_R20, \docfi
cfi_st $21, PT_R21, \docfi
cfi_st $22, PT_R22, \docfi
cfi_st $23, PT_R23, \docfi
cfi_st $30, PT_R30, \docfi
.endm
/*
* get_saved_sp returns the SP for the current CPU by looking in the
* kernelsp array for it. If tosp is set, it stores the current sp in
* k0 and loads the new value in sp. If not, it clobbers k0 and
* stores the new value in k1, leaving sp unaffected.
*/
#ifdef CONFIG_SMP
/* SMP variation */
.macro get_saved_sp docfi=0 tosp=0
ASM_CPUID_MFC0 k0, ASM_SMP_CPUID_REG
#if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
lui k1, %hi(kernelsp)
#else
lui k1, %highest(kernelsp)
daddiu k1, %higher(kernelsp)
dsll k1, 16
daddiu k1, %hi(kernelsp)
dsll k1, 16
#endif
LONG_SRL k0, SMP_CPUID_PTRSHIFT
LONG_ADDU k1, k0
.if \tosp
move k0, sp
.if \docfi
.cfi_register sp, k0
.endif
LONG_L sp, %lo(kernelsp)(k1)
.else
LONG_L k1, %lo(kernelsp)(k1)
.endif
.endm
.macro set_saved_sp stackp temp temp2
ASM_CPUID_MFC0 \temp, ASM_SMP_CPUID_REG
LONG_SRL \temp, SMP_CPUID_PTRSHIFT
LONG_S \stackp, kernelsp(\temp)
.endm
#else /* !CONFIG_SMP */
/* Uniprocessor variation */
.macro get_saved_sp docfi=0 tosp=0
#ifdef CONFIG_CPU_JUMP_WORKAROUNDS
/*
* Clear BTB (branch target buffer), forbid RAS (return address
* stack) to workaround the Out-of-order Issue in Loongson2F
* via its diagnostic register.
*/
move k0, ra
jal 1f
nop
1: jal 1f
nop
1: jal 1f
nop
1: jal 1f
nop
1: move ra, k0
li k0, 3
mtc0 k0, $22
#endif /* CONFIG_CPU_JUMP_WORKAROUNDS */
#if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
lui k1, %hi(kernelsp)
#else
lui k1, %highest(kernelsp)
daddiu k1, %higher(kernelsp)
dsll k1, k1, 16
daddiu k1, %hi(kernelsp)
dsll k1, k1, 16
#endif
.if \tosp
move k0, sp
.if \docfi
.cfi_register sp, k0
.endif
LONG_L sp, %lo(kernelsp)(k1)
.else
LONG_L k1, %lo(kernelsp)(k1)
.endif
.endm
.macro set_saved_sp stackp temp temp2
LONG_S \stackp, kernelsp
.endm
#endif
.macro SAVE_SOME docfi=0
.set push
.set noat
.set reorder
mfc0 k0, CP0_STATUS
sll k0, 3 /* extract cu0 bit */
.set noreorder
bltz k0, 8f
move k0, sp
.if \docfi
.cfi_register sp, k0
.endif
#ifdef CONFIG_EVA
/*
* Flush interAptiv's Return Prediction Stack (RPS) by writing
* EntryHi. Toggling Config7.RPS is slower and less portable.
*
* The RPS isn't automatically flushed when exceptions are
* taken, which can result in kernel mode speculative accesses
* to user addresses if the RPS mispredicts. That's harmless
* when user and kernel share the same address space, but with
* EVA the same user segments may be unmapped to kernel mode,
* even containing sensitive MMIO regions or invalid memory.
*
* This can happen when the kernel sets the return address to
* ret_from_* and jr's to the exception handler, which looks
* more like a tail call than a function call. If nested calls
* don't evict the last user address in the RPS, it will
* mispredict the return and fetch from a user controlled
* address into the icache.
*
* More recent EVA-capable cores with MAAR to restrict
* speculative accesses aren't affected.
*/
MFC0 k0, CP0_ENTRYHI
MTC0 k0, CP0_ENTRYHI
#endif
.set reorder
/* Called from user mode, new stack. */
get_saved_sp docfi=\docfi tosp=1
8:
#ifdef CONFIG_CPU_DADDI_WORKAROUNDS
.set at=k1
#endif
PTR_SUBU sp, PT_SIZE
#ifdef CONFIG_CPU_DADDI_WORKAROUNDS
.set noat
#endif
.if \docfi
.cfi_def_cfa sp,0
.endif
cfi_st k0, PT_R29, \docfi
cfi_rel_offset sp, PT_R29, \docfi
cfi_st v1, PT_R3, \docfi
/*
* You might think that you don't need to save $0,
* but the FPU emulator and gdb remote debug stub
* need it to operate correctly
*/
LONG_S $0, PT_R0(sp)
mfc0 v1, CP0_STATUS
cfi_st v0, PT_R2, \docfi
LONG_S v1, PT_STATUS(sp)
cfi_st $4, PT_R4, \docfi
mfc0 v1, CP0_CAUSE
cfi_st $5, PT_R5, \docfi
LONG_S v1, PT_CAUSE(sp)
cfi_st $6, PT_R6, \docfi
cfi_st ra, PT_R31, \docfi
MFC0 ra, CP0_EPC
cfi_st $7, PT_R7, \docfi
#ifdef CONFIG_64BIT
cfi_st $8, PT_R8, \docfi
cfi_st $9, PT_R9, \docfi
#endif
LONG_S ra, PT_EPC(sp)
.if \docfi
.cfi_rel_offset ra, PT_EPC
.endif
cfi_st $25, PT_R25, \docfi
cfi_st $28, PT_R28, \docfi
/* Set thread_info if we're coming from user mode */
mfc0 k0, CP0_STATUS
sll k0, 3 /* extract cu0 bit */
bltz k0, 9f
ori $28, sp, _THREAD_MASK
xori $28, _THREAD_MASK
#ifdef CONFIG_CPU_CAVIUM_OCTEON
.set mips64
pref 0, 0($28) /* Prefetch the current pointer */
#endif
9:
.set pop
.endm
.macro SAVE_ALL docfi=0
SAVE_SOME \docfi
SAVE_AT \docfi
SAVE_TEMP \docfi
SAVE_STATIC \docfi
.endm
.macro RESTORE_AT docfi=0
.set push
.set noat
cfi_ld $1, PT_R1, \docfi
.set pop
.endm
.macro RESTORE_TEMP docfi=0
#ifdef CONFIG_CPU_CAVIUM_OCTEON
/* Restore the Octeon multiplier state */
jal octeon_mult_restore
#endif
#ifdef CONFIG_CPU_HAS_SMARTMIPS
LONG_L $24, PT_ACX(sp)
mtlhx $24
LONG_L $24, PT_HI(sp)
mtlhx $24
LONG_L $24, PT_LO(sp)
mtlhx $24
#elif !defined(CONFIG_CPU_MIPSR6)
LONG_L $24, PT_LO(sp)
mtlo $24
LONG_L $24, PT_HI(sp)
mthi $24
#endif
#ifdef CONFIG_32BIT
cfi_ld $8, PT_R8, \docfi
cfi_ld $9, PT_R9, \docfi
#endif
cfi_ld $10, PT_R10, \docfi
cfi_ld $11, PT_R11, \docfi
cfi_ld $12, PT_R12, \docfi
cfi_ld $13, PT_R13, \docfi
cfi_ld $14, PT_R14, \docfi
cfi_ld $15, PT_R15, \docfi
cfi_ld $24, PT_R24, \docfi
.endm
.macro RESTORE_STATIC docfi=0
cfi_ld $16, PT_R16, \docfi
cfi_ld $17, PT_R17, \docfi
cfi_ld $18, PT_R18, \docfi
cfi_ld $19, PT_R19, \docfi
cfi_ld $20, PT_R20, \docfi
cfi_ld $21, PT_R21, \docfi
cfi_ld $22, PT_R22, \docfi
cfi_ld $23, PT_R23, \docfi
cfi_ld $30, PT_R30, \docfi
.endm
.macro RESTORE_SP docfi=0
cfi_ld sp, PT_R29, \docfi
.endm
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
.macro RESTORE_SOME docfi=0
.set push
.set reorder
.set noat
mfc0 a0, CP0_STATUS
li v1, ST0_CU1 | ST0_IM
ori a0, STATMASK
xori a0, STATMASK
mtc0 a0, CP0_STATUS
and a0, v1
LONG_L v0, PT_STATUS(sp)
nor v1, $0, v1
and v0, v1
or v0, a0
mtc0 v0, CP0_STATUS
cfi_ld $31, PT_R31, \docfi
cfi_ld $28, PT_R28, \docfi
cfi_ld $25, PT_R25, \docfi
cfi_ld $7, PT_R7, \docfi
cfi_ld $6, PT_R6, \docfi
cfi_ld $5, PT_R5, \docfi
cfi_ld $4, PT_R4, \docfi
cfi_ld $3, PT_R3, \docfi
cfi_ld $2, PT_R2, \docfi
.set pop
.endm
.macro RESTORE_SP_AND_RET docfi=0
.set push
.set noreorder
LONG_L k0, PT_EPC(sp)
RESTORE_SP \docfi
jr k0
rfe
.set pop
.endm
#else
.macro RESTORE_SOME docfi=0
.set push
.set reorder
.set noat
mfc0 a0, CP0_STATUS
ori a0, STATMASK
xori a0, STATMASK
mtc0 a0, CP0_STATUS
li v1, ST0_CU1 | ST0_FR | ST0_IM
and a0, v1
LONG_L v0, PT_STATUS(sp)
nor v1, $0, v1
and v0, v1
or v0, a0
mtc0 v0, CP0_STATUS
LONG_L v1, PT_EPC(sp)
MTC0 v1, CP0_EPC
cfi_ld $31, PT_R31, \docfi
cfi_ld $28, PT_R28, \docfi
cfi_ld $25, PT_R25, \docfi
#ifdef CONFIG_64BIT
cfi_ld $8, PT_R8, \docfi
cfi_ld $9, PT_R9, \docfi
#endif
cfi_ld $7, PT_R7, \docfi
cfi_ld $6, PT_R6, \docfi
cfi_ld $5, PT_R5, \docfi
cfi_ld $4, PT_R4, \docfi
cfi_ld $3, PT_R3, \docfi
cfi_ld $2, PT_R2, \docfi
.set pop
.endm
.macro RESTORE_SP_AND_RET docfi=0
RESTORE_SP \docfi
#if defined(CONFIG_CPU_MIPSR5) || defined(CONFIG_CPU_MIPSR6)
eretnc
#else
.set push
.set arch=r4000
eret
.set pop
#endif
.endm
#endif
.macro RESTORE_ALL docfi=0
RESTORE_TEMP \docfi
RESTORE_STATIC \docfi
RESTORE_AT \docfi
RESTORE_SOME \docfi
RESTORE_SP \docfi
.endm
/*
* Move to kernel mode and disable interrupts.
* Set cp0 enable bit as sign that we're running on the kernel stack
*/
.macro CLI
mfc0 t0, CP0_STATUS
li t1, ST0_KERNEL_CUMASK | STATMASK
or t0, t1
xori t0, STATMASK
mtc0 t0, CP0_STATUS
irq_disable_hazard
.endm
/*
* Move to kernel mode and enable interrupts.
* Set cp0 enable bit as sign that we're running on the kernel stack
*/
.macro STI
mfc0 t0, CP0_STATUS
li t1, ST0_KERNEL_CUMASK | STATMASK
or t0, t1
xori t0, STATMASK & ~1
mtc0 t0, CP0_STATUS
irq_enable_hazard
.endm
/*
* Just move to kernel mode and leave interrupts as they are. Note
* for the R3000 this means copying the previous enable from IEp.
* Set cp0 enable bit as sign that we're running on the kernel stack
*/
.macro KMODE
mfc0 t0, CP0_STATUS
li t1, ST0_KERNEL_CUMASK | (STATMASK & ~1)
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
andi t2, t0, ST0_IEP
srl t2, 2
or t0, t2
#endif
or t0, t1
xori t0, STATMASK & ~1
mtc0 t0, CP0_STATUS
irq_disable_hazard
.endm
#endif /* _ASM_STACKFRAME_H */
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