378ed6f0e3
We currently have 2 commonly used methods for switching ISA within
assembly code, then restoring the original ISA.
1) Using a pair of .set push & .set pop directives. For example:
.set push
.set mips32r2
<some_insn>
.set pop
2) Using .set mips0 to restore the ISA originally specified on the
command line. For example:
.set mips32r2
<some_insn>
.set mips0
Unfortunately method 2 does not work with nanoMIPS toolchains, where the
assembler rejects the .set mips0 directive like so:
Error: cannot change ISA from nanoMIPS to mips0
In preparation for supporting nanoMIPS builds, switch all instances of
method 2 in generic non-platform-specific code to use push & pop as in
method 1 instead. The .set push & .set pop is arguably cleaner anyway,
and if nothing else it's good to consistently use one method.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21037/
Cc: linux-mips@linux-mips.org
493 lines
11 KiB
C
493 lines
11 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1994, 95, 96, 99, 2001 Ralf Baechle
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* Copyright (C) 1994, 1995, 1996 Paul M. Antoine.
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* Copyright (C) 1999 Silicon Graphics, Inc.
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* Copyright (C) 2007 Maciej W. Rozycki
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*/
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#ifndef _ASM_STACKFRAME_H
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#define _ASM_STACKFRAME_H
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#include <linux/threads.h>
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#include <asm/asm.h>
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#include <asm/asmmacro.h>
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#include <asm/mipsregs.h>
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#include <asm/asm-offsets.h>
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#include <asm/thread_info.h>
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/* Make the addition of cfi info a little easier. */
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.macro cfi_rel_offset reg offset=0 docfi=0
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.if \docfi
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.cfi_rel_offset \reg, \offset
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.endif
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.endm
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.macro cfi_st reg offset=0 docfi=0
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LONG_S \reg, \offset(sp)
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cfi_rel_offset \reg, \offset, \docfi
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.endm
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.macro cfi_restore reg offset=0 docfi=0
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.if \docfi
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.cfi_restore \reg
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.endif
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.endm
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.macro cfi_ld reg offset=0 docfi=0
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LONG_L \reg, \offset(sp)
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cfi_restore \reg \offset \docfi
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.endm
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#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
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#define STATMASK 0x3f
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#else
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#define STATMASK 0x1f
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#endif
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.macro SAVE_AT docfi=0
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.set push
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.set noat
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cfi_st $1, PT_R1, \docfi
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.set pop
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.endm
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.macro SAVE_TEMP docfi=0
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#ifdef CONFIG_CPU_HAS_SMARTMIPS
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mflhxu v1
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LONG_S v1, PT_LO(sp)
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mflhxu v1
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LONG_S v1, PT_HI(sp)
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mflhxu v1
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LONG_S v1, PT_ACX(sp)
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#elif !defined(CONFIG_CPU_MIPSR6)
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mfhi v1
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#endif
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#ifdef CONFIG_32BIT
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cfi_st $8, PT_R8, \docfi
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cfi_st $9, PT_R9, \docfi
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#endif
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cfi_st $10, PT_R10, \docfi
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cfi_st $11, PT_R11, \docfi
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cfi_st $12, PT_R12, \docfi
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#if !defined(CONFIG_CPU_HAS_SMARTMIPS) && !defined(CONFIG_CPU_MIPSR6)
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LONG_S v1, PT_HI(sp)
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mflo v1
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#endif
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cfi_st $13, PT_R13, \docfi
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cfi_st $14, PT_R14, \docfi
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cfi_st $15, PT_R15, \docfi
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cfi_st $24, PT_R24, \docfi
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#if !defined(CONFIG_CPU_HAS_SMARTMIPS) && !defined(CONFIG_CPU_MIPSR6)
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LONG_S v1, PT_LO(sp)
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#endif
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#ifdef CONFIG_CPU_CAVIUM_OCTEON
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/*
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* The Octeon multiplier state is affected by general
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* multiply instructions. It must be saved before and
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* kernel code might corrupt it
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*/
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jal octeon_mult_save
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#endif
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.endm
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.macro SAVE_STATIC docfi=0
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cfi_st $16, PT_R16, \docfi
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cfi_st $17, PT_R17, \docfi
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cfi_st $18, PT_R18, \docfi
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cfi_st $19, PT_R19, \docfi
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cfi_st $20, PT_R20, \docfi
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cfi_st $21, PT_R21, \docfi
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cfi_st $22, PT_R22, \docfi
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cfi_st $23, PT_R23, \docfi
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cfi_st $30, PT_R30, \docfi
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.endm
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/*
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* get_saved_sp returns the SP for the current CPU by looking in the
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* kernelsp array for it. If tosp is set, it stores the current sp in
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* k0 and loads the new value in sp. If not, it clobbers k0 and
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* stores the new value in k1, leaving sp unaffected.
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*/
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#ifdef CONFIG_SMP
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/* SMP variation */
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.macro get_saved_sp docfi=0 tosp=0
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ASM_CPUID_MFC0 k0, ASM_SMP_CPUID_REG
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#if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
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lui k1, %hi(kernelsp)
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#else
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lui k1, %highest(kernelsp)
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daddiu k1, %higher(kernelsp)
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dsll k1, 16
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daddiu k1, %hi(kernelsp)
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dsll k1, 16
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#endif
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LONG_SRL k0, SMP_CPUID_PTRSHIFT
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LONG_ADDU k1, k0
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.if \tosp
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move k0, sp
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.if \docfi
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.cfi_register sp, k0
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.endif
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LONG_L sp, %lo(kernelsp)(k1)
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.else
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LONG_L k1, %lo(kernelsp)(k1)
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.endif
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.endm
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.macro set_saved_sp stackp temp temp2
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ASM_CPUID_MFC0 \temp, ASM_SMP_CPUID_REG
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LONG_SRL \temp, SMP_CPUID_PTRSHIFT
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LONG_S \stackp, kernelsp(\temp)
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.endm
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#else /* !CONFIG_SMP */
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/* Uniprocessor variation */
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.macro get_saved_sp docfi=0 tosp=0
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#ifdef CONFIG_CPU_JUMP_WORKAROUNDS
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/*
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* Clear BTB (branch target buffer), forbid RAS (return address
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* stack) to workaround the Out-of-order Issue in Loongson2F
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* via its diagnostic register.
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*/
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move k0, ra
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jal 1f
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nop
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1: jal 1f
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nop
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1: jal 1f
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nop
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1: jal 1f
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nop
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1: move ra, k0
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li k0, 3
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mtc0 k0, $22
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#endif /* CONFIG_CPU_JUMP_WORKAROUNDS */
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#if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
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lui k1, %hi(kernelsp)
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#else
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lui k1, %highest(kernelsp)
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daddiu k1, %higher(kernelsp)
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dsll k1, k1, 16
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daddiu k1, %hi(kernelsp)
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dsll k1, k1, 16
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#endif
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.if \tosp
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move k0, sp
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.if \docfi
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.cfi_register sp, k0
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.endif
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LONG_L sp, %lo(kernelsp)(k1)
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.else
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LONG_L k1, %lo(kernelsp)(k1)
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.endif
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.endm
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.macro set_saved_sp stackp temp temp2
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LONG_S \stackp, kernelsp
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.endm
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#endif
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.macro SAVE_SOME docfi=0
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.set push
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.set noat
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.set reorder
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mfc0 k0, CP0_STATUS
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sll k0, 3 /* extract cu0 bit */
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.set noreorder
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bltz k0, 8f
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move k0, sp
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.if \docfi
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.cfi_register sp, k0
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.endif
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#ifdef CONFIG_EVA
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/*
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* Flush interAptiv's Return Prediction Stack (RPS) by writing
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* EntryHi. Toggling Config7.RPS is slower and less portable.
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*
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* The RPS isn't automatically flushed when exceptions are
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* taken, which can result in kernel mode speculative accesses
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* to user addresses if the RPS mispredicts. That's harmless
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* when user and kernel share the same address space, but with
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* EVA the same user segments may be unmapped to kernel mode,
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* even containing sensitive MMIO regions or invalid memory.
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*
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* This can happen when the kernel sets the return address to
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* ret_from_* and jr's to the exception handler, which looks
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* more like a tail call than a function call. If nested calls
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* don't evict the last user address in the RPS, it will
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* mispredict the return and fetch from a user controlled
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* address into the icache.
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*
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* More recent EVA-capable cores with MAAR to restrict
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* speculative accesses aren't affected.
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*/
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MFC0 k0, CP0_ENTRYHI
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MTC0 k0, CP0_ENTRYHI
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#endif
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.set reorder
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/* Called from user mode, new stack. */
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get_saved_sp docfi=\docfi tosp=1
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8:
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#ifdef CONFIG_CPU_DADDI_WORKAROUNDS
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.set at=k1
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#endif
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PTR_SUBU sp, PT_SIZE
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#ifdef CONFIG_CPU_DADDI_WORKAROUNDS
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.set noat
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#endif
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.if \docfi
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.cfi_def_cfa sp,0
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.endif
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cfi_st k0, PT_R29, \docfi
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cfi_rel_offset sp, PT_R29, \docfi
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cfi_st v1, PT_R3, \docfi
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/*
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* You might think that you don't need to save $0,
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* but the FPU emulator and gdb remote debug stub
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* need it to operate correctly
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*/
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LONG_S $0, PT_R0(sp)
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mfc0 v1, CP0_STATUS
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cfi_st v0, PT_R2, \docfi
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LONG_S v1, PT_STATUS(sp)
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cfi_st $4, PT_R4, \docfi
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mfc0 v1, CP0_CAUSE
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cfi_st $5, PT_R5, \docfi
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LONG_S v1, PT_CAUSE(sp)
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cfi_st $6, PT_R6, \docfi
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cfi_st ra, PT_R31, \docfi
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MFC0 ra, CP0_EPC
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cfi_st $7, PT_R7, \docfi
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#ifdef CONFIG_64BIT
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cfi_st $8, PT_R8, \docfi
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cfi_st $9, PT_R9, \docfi
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#endif
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LONG_S ra, PT_EPC(sp)
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.if \docfi
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.cfi_rel_offset ra, PT_EPC
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.endif
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cfi_st $25, PT_R25, \docfi
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cfi_st $28, PT_R28, \docfi
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/* Set thread_info if we're coming from user mode */
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mfc0 k0, CP0_STATUS
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sll k0, 3 /* extract cu0 bit */
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bltz k0, 9f
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ori $28, sp, _THREAD_MASK
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xori $28, _THREAD_MASK
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#ifdef CONFIG_CPU_CAVIUM_OCTEON
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.set mips64
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pref 0, 0($28) /* Prefetch the current pointer */
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#endif
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9:
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.set pop
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.endm
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.macro SAVE_ALL docfi=0
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SAVE_SOME \docfi
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SAVE_AT \docfi
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SAVE_TEMP \docfi
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SAVE_STATIC \docfi
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.endm
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.macro RESTORE_AT docfi=0
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.set push
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.set noat
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cfi_ld $1, PT_R1, \docfi
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.set pop
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.endm
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.macro RESTORE_TEMP docfi=0
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#ifdef CONFIG_CPU_CAVIUM_OCTEON
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/* Restore the Octeon multiplier state */
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jal octeon_mult_restore
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#endif
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#ifdef CONFIG_CPU_HAS_SMARTMIPS
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LONG_L $24, PT_ACX(sp)
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mtlhx $24
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LONG_L $24, PT_HI(sp)
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mtlhx $24
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LONG_L $24, PT_LO(sp)
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mtlhx $24
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#elif !defined(CONFIG_CPU_MIPSR6)
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LONG_L $24, PT_LO(sp)
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mtlo $24
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LONG_L $24, PT_HI(sp)
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mthi $24
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#endif
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#ifdef CONFIG_32BIT
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cfi_ld $8, PT_R8, \docfi
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cfi_ld $9, PT_R9, \docfi
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#endif
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cfi_ld $10, PT_R10, \docfi
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cfi_ld $11, PT_R11, \docfi
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cfi_ld $12, PT_R12, \docfi
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cfi_ld $13, PT_R13, \docfi
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cfi_ld $14, PT_R14, \docfi
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cfi_ld $15, PT_R15, \docfi
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cfi_ld $24, PT_R24, \docfi
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.endm
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.macro RESTORE_STATIC docfi=0
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cfi_ld $16, PT_R16, \docfi
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cfi_ld $17, PT_R17, \docfi
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cfi_ld $18, PT_R18, \docfi
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cfi_ld $19, PT_R19, \docfi
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cfi_ld $20, PT_R20, \docfi
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cfi_ld $21, PT_R21, \docfi
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cfi_ld $22, PT_R22, \docfi
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cfi_ld $23, PT_R23, \docfi
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cfi_ld $30, PT_R30, \docfi
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.endm
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.macro RESTORE_SP docfi=0
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cfi_ld sp, PT_R29, \docfi
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.endm
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#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
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.macro RESTORE_SOME docfi=0
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.set push
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.set reorder
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.set noat
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mfc0 a0, CP0_STATUS
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li v1, ST0_CU1 | ST0_IM
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ori a0, STATMASK
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xori a0, STATMASK
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mtc0 a0, CP0_STATUS
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and a0, v1
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LONG_L v0, PT_STATUS(sp)
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nor v1, $0, v1
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and v0, v1
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or v0, a0
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mtc0 v0, CP0_STATUS
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cfi_ld $31, PT_R31, \docfi
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cfi_ld $28, PT_R28, \docfi
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cfi_ld $25, PT_R25, \docfi
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cfi_ld $7, PT_R7, \docfi
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cfi_ld $6, PT_R6, \docfi
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cfi_ld $5, PT_R5, \docfi
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cfi_ld $4, PT_R4, \docfi
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cfi_ld $3, PT_R3, \docfi
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cfi_ld $2, PT_R2, \docfi
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.set pop
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.endm
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.macro RESTORE_SP_AND_RET docfi=0
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.set push
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.set noreorder
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LONG_L k0, PT_EPC(sp)
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RESTORE_SP \docfi
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jr k0
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rfe
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.set pop
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.endm
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#else
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.macro RESTORE_SOME docfi=0
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.set push
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.set reorder
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.set noat
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mfc0 a0, CP0_STATUS
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ori a0, STATMASK
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xori a0, STATMASK
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mtc0 a0, CP0_STATUS
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li v1, ST0_CU1 | ST0_FR | ST0_IM
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and a0, v1
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LONG_L v0, PT_STATUS(sp)
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nor v1, $0, v1
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and v0, v1
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or v0, a0
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mtc0 v0, CP0_STATUS
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LONG_L v1, PT_EPC(sp)
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MTC0 v1, CP0_EPC
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cfi_ld $31, PT_R31, \docfi
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cfi_ld $28, PT_R28, \docfi
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cfi_ld $25, PT_R25, \docfi
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#ifdef CONFIG_64BIT
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cfi_ld $8, PT_R8, \docfi
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cfi_ld $9, PT_R9, \docfi
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#endif
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cfi_ld $7, PT_R7, \docfi
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cfi_ld $6, PT_R6, \docfi
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cfi_ld $5, PT_R5, \docfi
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cfi_ld $4, PT_R4, \docfi
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cfi_ld $3, PT_R3, \docfi
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cfi_ld $2, PT_R2, \docfi
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.set pop
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.endm
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.macro RESTORE_SP_AND_RET docfi=0
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RESTORE_SP \docfi
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#ifdef CONFIG_CPU_MIPSR6
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eretnc
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#else
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.set push
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.set arch=r4000
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eret
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.set pop
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#endif
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.endm
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#endif
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.macro RESTORE_ALL docfi=0
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RESTORE_TEMP \docfi
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RESTORE_STATIC \docfi
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RESTORE_AT \docfi
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RESTORE_SOME \docfi
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RESTORE_SP \docfi
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.endm
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/*
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* Move to kernel mode and disable interrupts.
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* Set cp0 enable bit as sign that we're running on the kernel stack
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*/
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.macro CLI
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mfc0 t0, CP0_STATUS
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li t1, ST0_CU0 | STATMASK
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or t0, t1
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xori t0, STATMASK
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mtc0 t0, CP0_STATUS
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irq_disable_hazard
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.endm
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/*
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* Move to kernel mode and enable interrupts.
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* Set cp0 enable bit as sign that we're running on the kernel stack
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*/
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.macro STI
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mfc0 t0, CP0_STATUS
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li t1, ST0_CU0 | STATMASK
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or t0, t1
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xori t0, STATMASK & ~1
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mtc0 t0, CP0_STATUS
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irq_enable_hazard
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.endm
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/*
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* Just move to kernel mode and leave interrupts as they are. Note
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* for the R3000 this means copying the previous enable from IEp.
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* Set cp0 enable bit as sign that we're running on the kernel stack
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*/
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.macro KMODE
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mfc0 t0, CP0_STATUS
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li t1, ST0_CU0 | (STATMASK & ~1)
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#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
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andi t2, t0, ST0_IEP
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srl t2, 2
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or t0, t2
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#endif
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or t0, t1
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xori t0, STATMASK & ~1
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mtc0 t0, CP0_STATUS
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irq_disable_hazard
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.endm
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#endif /* _ASM_STACKFRAME_H */
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