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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>
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
#define STATMASK 0x3f
#else
#define STATMASK 0x1f
#endif
.macro SAVE_AT
.set push
.set noat
LONG_S $1, PT_R1(sp)
.set pop
.endm
.macro SAVE_TEMP
#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
LONG_S $8, PT_R8(sp)
LONG_S $9, PT_R9(sp)
#endif
LONG_S $10, PT_R10(sp)
LONG_S $11, PT_R11(sp)
LONG_S $12, PT_R12(sp)
#if !defined(CONFIG_CPU_HAS_SMARTMIPS) && !defined(CONFIG_CPU_MIPSR6)
LONG_S v1, PT_HI(sp)
mflo v1
#endif
LONG_S $13, PT_R13(sp)
LONG_S $14, PT_R14(sp)
LONG_S $15, PT_R15(sp)
LONG_S $24, PT_R24(sp)
#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
LONG_S $16, PT_R16(sp)
LONG_S $17, PT_R17(sp)
LONG_S $18, PT_R18(sp)
LONG_S $19, PT_R19(sp)
LONG_S $20, PT_R20(sp)
LONG_S $21, PT_R21(sp)
LONG_S $22, PT_R22(sp)
LONG_S $23, PT_R23(sp)
LONG_S $30, PT_R30(sp)
.endm
#ifdef CONFIG_SMP
.macro get_saved_sp /* SMP variation */
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
LONG_L k1, %lo(kernelsp)(k1)
.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 */
.macro get_saved_sp /* Uniprocessor variation */
#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
LONG_L k1, %lo(kernelsp)(k1)
.endm
.macro set_saved_sp stackp temp temp2
LONG_S \stackp, kernelsp
.endm
#endif
.macro SAVE_SOME
.set push
.set noat
.set reorder
mfc0 k0, CP0_STATUS
sll k0, 3 /* extract cu0 bit */
.set noreorder
bltz k0, 8f
move k1, sp
#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
#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
8: move k0, sp
PTR_SUBU sp, k1, PT_SIZE
#else
.set at=k0
8: PTR_SUBU k1, PT_SIZE
.set noat
move k0, sp
move sp, k1
#endif
LONG_S k0, PT_R29(sp)
LONG_S $3, PT_R3(sp)
/*
* 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
LONG_S $2, PT_R2(sp)
LONG_S v1, PT_STATUS(sp)
LONG_S $4, PT_R4(sp)
mfc0 v1, CP0_CAUSE
LONG_S $5, PT_R5(sp)
LONG_S v1, PT_CAUSE(sp)
LONG_S $6, PT_R6(sp)
MFC0 v1, CP0_EPC
LONG_S $7, PT_R7(sp)
#ifdef CONFIG_64BIT
LONG_S $8, PT_R8(sp)
LONG_S $9, PT_R9(sp)
#endif
LONG_S v1, PT_EPC(sp)
LONG_S $25, PT_R25(sp)
LONG_S $28, PT_R28(sp)
LONG_S $31, PT_R31(sp)
/* 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
SAVE_SOME
SAVE_AT
SAVE_TEMP
SAVE_STATIC
.endm
.macro RESTORE_AT
.set push
.set noat
LONG_L $1, PT_R1(sp)
.set pop
.endm
.macro RESTORE_TEMP
#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
LONG_L $8, PT_R8(sp)
LONG_L $9, PT_R9(sp)
#endif
LONG_L $10, PT_R10(sp)
LONG_L $11, PT_R11(sp)
LONG_L $12, PT_R12(sp)
LONG_L $13, PT_R13(sp)
LONG_L $14, PT_R14(sp)
LONG_L $15, PT_R15(sp)
LONG_L $24, PT_R24(sp)
.endm
.macro RESTORE_STATIC
LONG_L $16, PT_R16(sp)
LONG_L $17, PT_R17(sp)
LONG_L $18, PT_R18(sp)
LONG_L $19, PT_R19(sp)
LONG_L $20, PT_R20(sp)
LONG_L $21, PT_R21(sp)
LONG_L $22, PT_R22(sp)
LONG_L $23, PT_R23(sp)
LONG_L $30, PT_R30(sp)
.endm
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
.macro RESTORE_SOME
.set push
.set reorder
.set noat
mfc0 a0, CP0_STATUS
li v1, 0xff00
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
LONG_L $31, PT_R31(sp)
LONG_L $28, PT_R28(sp)
LONG_L $25, PT_R25(sp)
LONG_L $7, PT_R7(sp)
LONG_L $6, PT_R6(sp)
LONG_L $5, PT_R5(sp)
LONG_L $4, PT_R4(sp)
LONG_L $3, PT_R3(sp)
LONG_L $2, PT_R2(sp)
.set pop
.endm
.macro RESTORE_SP_AND_RET
.set push
.set noreorder
LONG_L k0, PT_EPC(sp)
LONG_L sp, PT_R29(sp)
jr k0
rfe
.set pop
.endm
#else
.macro RESTORE_SOME
.set push
.set reorder
.set noat
mfc0 a0, CP0_STATUS
ori a0, STATMASK
xori a0, STATMASK
mtc0 a0, CP0_STATUS
li v1, 0xff00
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
LONG_L $31, PT_R31(sp)
LONG_L $28, PT_R28(sp)
LONG_L $25, PT_R25(sp)
#ifdef CONFIG_64BIT
LONG_L $8, PT_R8(sp)
LONG_L $9, PT_R9(sp)
#endif
LONG_L $7, PT_R7(sp)
LONG_L $6, PT_R6(sp)
LONG_L $5, PT_R5(sp)
LONG_L $4, PT_R4(sp)
LONG_L $3, PT_R3(sp)
LONG_L $2, PT_R2(sp)
.set pop
.endm
.macro RESTORE_SP_AND_RET
LONG_L sp, PT_R29(sp)
.set arch=r4000
eret
.set mips0
.endm
#endif
.macro RESTORE_SP
LONG_L sp, PT_R29(sp)
.endm
.macro RESTORE_ALL
RESTORE_TEMP
RESTORE_STATIC
RESTORE_AT
RESTORE_SOME
RESTORE_SP
.endm
.macro RESTORE_ALL_AND_RET
RESTORE_TEMP
RESTORE_STATIC
RESTORE_AT
RESTORE_SOME
RESTORE_SP_AND_RET
.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_CU0 | 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_CU0 | 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_CU0 | (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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