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-rw-r--r--arch/mips/include/asm/stackframe.h492
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diff --git a/arch/mips/include/asm/stackframe.h b/arch/mips/include/asm/stackframe.h
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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)
+#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)
+
+ .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)
+ 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 */