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-rw-r--r--arch/mips/include/asm/stackframe.h574
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diff --git a/arch/mips/include/asm/stackframe.h b/arch/mips/include/asm/stackframe.h
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index 000000000000..4c37c4e5f72e
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+++ b/arch/mips/include/asm/stackframe.h
@@ -0,0 +1,574 @@
+/*
+ * 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>
+
+/*
+ * For SMTC kernel, global IE should be left set, and interrupts
+ * controlled exclusively via IXMT.
+ */
+#ifdef CONFIG_MIPS_MT_SMTC
+#define STATMASK 0x1e
+#elif defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
+#define STATMASK 0x3f
+#else
+#define STATMASK 0x1f
+#endif
+
+#ifdef CONFIG_MIPS_MT_SMTC
+#include <asm/mipsmtregs.h>
+#endif /* CONFIG_MIPS_MT_SMTC */
+
+ .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)
+#else
+ mfhi v1
+ LONG_S v1, PT_HI(sp)
+ mflo v1
+ LONG_S v1, PT_LO(sp)
+#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)
+ LONG_S $13, PT_R13(sp)
+ LONG_S $14, PT_R14(sp)
+ LONG_S $15, PT_R15(sp)
+ LONG_S $24, PT_R24(sp)
+ .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
+#ifdef CONFIG_MIPS_MT_SMTC
+#define PTEBASE_SHIFT 19 /* TCBIND */
+#else
+#define PTEBASE_SHIFT 23 /* CONTEXT */
+#endif
+ .macro get_saved_sp /* SMP variation */
+#ifdef CONFIG_MIPS_MT_SMTC
+ mfc0 k0, CP0_TCBIND
+#else
+ MFC0 k0, CP0_CONTEXT
+#endif
+#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, PTEBASE_SHIFT
+ LONG_ADDU k1, k0
+ LONG_L k1, %lo(kernelsp)(k1)
+ .endm
+
+ .macro set_saved_sp stackp temp temp2
+#ifdef CONFIG_MIPS_MT_SMTC
+ mfc0 \temp, CP0_TCBIND
+#else
+ MFC0 \temp, CP0_CONTEXT
+#endif
+ LONG_SRL \temp, PTEBASE_SHIFT
+ LONG_S \stackp, kernelsp(\temp)
+ .endm
+#else
+ .macro get_saved_sp /* Uniprocessor variation */
+#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
+ .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)
+#ifdef CONFIG_MIPS_MT_SMTC
+ /*
+ * Ideally, these instructions would be shuffled in
+ * to cover the pipeline delay.
+ */
+ .set mips32
+ mfc0 v1, CP0_TCSTATUS
+ .set mips0
+ LONG_S v1, PT_TCSTATUS(sp)
+#endif /* CONFIG_MIPS_MT_SMTC */
+ 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)
+ ori $28, sp, _THREAD_MASK
+ xori $28, _THREAD_MASK
+ .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_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
+#else
+ 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
+#ifdef CONFIG_MIPS_MT_SMTC
+ .set mips32r2
+ /*
+ * We need to make sure the read-modify-write
+ * of Status below isn't perturbed by an interrupt
+ * or cross-TC access, so we need to do at least a DMT,
+ * protected by an interrupt-inhibit. But setting IXMT
+ * also creates a few-cycle window where an IPI could
+ * be queued and not be detected before potentially
+ * returning to a WAIT or user-mode loop. It must be
+ * replayed.
+ *
+ * We're in the middle of a context switch, and
+ * we can't dispatch it directly without trashing
+ * some registers, so we'll try to detect this unlikely
+ * case and program a software interrupt in the VPE,
+ * as would be done for a cross-VPE IPI. To accomodate
+ * the handling of that case, we're doing a DVPE instead
+ * of just a DMT here to protect against other threads.
+ * This is a lot of cruft to cover a tiny window.
+ * If you can find a better design, implement it!
+ *
+ */
+ mfc0 v0, CP0_TCSTATUS
+ ori v0, TCSTATUS_IXMT
+ mtc0 v0, CP0_TCSTATUS
+ _ehb
+ DVPE 5 # dvpe a1
+ jal mips_ihb
+#endif /* CONFIG_MIPS_MT_SMTC */
+ 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
+#ifdef CONFIG_MIPS_MT_SMTC
+/*
+ * Only after EXL/ERL have been restored to status can we
+ * restore TCStatus.IXMT.
+ */
+ LONG_L v1, PT_TCSTATUS(sp)
+ _ehb
+ mfc0 a0, CP0_TCSTATUS
+ andi v1, TCSTATUS_IXMT
+ bnez v1, 0f
+
+/*
+ * We'd like to detect any IPIs queued in the tiny window
+ * above and request an software interrupt to service them
+ * when we ERET.
+ *
+ * Computing the offset into the IPIQ array of the executing
+ * TC's IPI queue in-line would be tedious. We use part of
+ * the TCContext register to hold 16 bits of offset that we
+ * can add in-line to find the queue head.
+ */
+ mfc0 v0, CP0_TCCONTEXT
+ la a2, IPIQ
+ srl v0, v0, 16
+ addu a2, a2, v0
+ LONG_L v0, 0(a2)
+ beqz v0, 0f
+/*
+ * If we have a queue, provoke dispatch within the VPE by setting C_SW1
+ */
+ mfc0 v0, CP0_CAUSE
+ ori v0, v0, C_SW1
+ mtc0 v0, CP0_CAUSE
+0:
+ /*
+ * This test should really never branch but
+ * let's be prudent here. Having atomized
+ * the shared register modifications, we can
+ * now EVPE, and must do so before interrupts
+ * are potentially re-enabled.
+ */
+ andi a1, a1, MVPCONTROL_EVP
+ beqz a1, 1f
+ evpe
+1:
+ /* We know that TCStatua.IXMT should be set from above */
+ xori a0, a0, TCSTATUS_IXMT
+ or a0, a0, v1
+ mtc0 a0, CP0_TCSTATUS
+ _ehb
+
+ .set mips0
+#endif /* CONFIG_MIPS_MT_SMTC */
+ 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 mips3
+ 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
+#if !defined(CONFIG_MIPS_MT_SMTC)
+ mfc0 t0, CP0_STATUS
+ li t1, ST0_CU0 | STATMASK
+ or t0, t1
+ xori t0, STATMASK
+ mtc0 t0, CP0_STATUS
+#else /* CONFIG_MIPS_MT_SMTC */
+ /*
+ * For SMTC, we need to set privilege
+ * and disable interrupts only for the
+ * current TC, using the TCStatus register.
+ */
+ mfc0 t0, CP0_TCSTATUS
+ /* Fortunately CU 0 is in the same place in both registers */
+ /* Set TCU0, TMX, TKSU (for later inversion) and IXMT */
+ li t1, ST0_CU0 | 0x08001c00
+ or t0, t1
+ /* Clear TKSU, leave IXMT */
+ xori t0, 0x00001800
+ mtc0 t0, CP0_TCSTATUS
+ _ehb
+ /* We need to leave the global IE bit set, but clear EXL...*/
+ mfc0 t0, CP0_STATUS
+ ori t0, ST0_EXL | ST0_ERL
+ xori t0, ST0_EXL | ST0_ERL
+ mtc0 t0, CP0_STATUS
+#endif /* CONFIG_MIPS_MT_SMTC */
+ 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
+#if !defined(CONFIG_MIPS_MT_SMTC)
+ mfc0 t0, CP0_STATUS
+ li t1, ST0_CU0 | STATMASK
+ or t0, t1
+ xori t0, STATMASK & ~1
+ mtc0 t0, CP0_STATUS
+#else /* CONFIG_MIPS_MT_SMTC */
+ /*
+ * For SMTC, we need to set privilege
+ * and enable interrupts only for the
+ * current TC, using the TCStatus register.
+ */
+ _ehb
+ mfc0 t0, CP0_TCSTATUS
+ /* Fortunately CU 0 is in the same place in both registers */
+ /* Set TCU0, TKSU (for later inversion) and IXMT */
+ li t1, ST0_CU0 | 0x08001c00
+ or t0, t1
+ /* Clear TKSU *and* IXMT */
+ xori t0, 0x00001c00
+ mtc0 t0, CP0_TCSTATUS
+ _ehb
+ /* We need to leave the global IE bit set, but clear EXL...*/
+ mfc0 t0, CP0_STATUS
+ ori t0, ST0_EXL
+ xori t0, ST0_EXL
+ mtc0 t0, CP0_STATUS
+ /* irq_enable_hazard below should expand to EHB for 24K/34K cpus */
+#endif /* CONFIG_MIPS_MT_SMTC */
+ 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
+#ifdef CONFIG_MIPS_MT_SMTC
+ /*
+ * This gets baroque in SMTC. We want to
+ * protect the non-atomic clearing of EXL
+ * with DMT/EMT, but we don't want to take
+ * an interrupt while DMT is still in effect.
+ */
+
+ /* KMODE gets invoked from both reorder and noreorder code */
+ .set push
+ .set mips32r2
+ .set noreorder
+ mfc0 v0, CP0_TCSTATUS
+ andi v1, v0, TCSTATUS_IXMT
+ ori v0, TCSTATUS_IXMT
+ mtc0 v0, CP0_TCSTATUS
+ _ehb
+ DMT 2 # dmt v0
+ /*
+ * We don't know a priori if ra is "live"
+ */
+ move t0, ra
+ jal mips_ihb
+ nop /* delay slot */
+ move ra, t0
+#endif /* CONFIG_MIPS_MT_SMTC */
+ 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
+#ifdef CONFIG_MIPS_MT_SMTC
+ _ehb
+ andi v0, v0, VPECONTROL_TE
+ beqz v0, 2f
+ nop /* delay slot */
+ emt
+2:
+ mfc0 v0, CP0_TCSTATUS
+ /* Clear IXMT, then OR in previous value */
+ ori v0, TCSTATUS_IXMT
+ xori v0, TCSTATUS_IXMT
+ or v0, v1, v0
+ mtc0 v0, CP0_TCSTATUS
+ /*
+ * irq_disable_hazard below should expand to EHB
+ * on 24K/34K CPUS
+ */
+ .set pop
+#endif /* CONFIG_MIPS_MT_SMTC */
+ irq_disable_hazard
+ .endm
+
+#endif /* _ASM_STACKFRAME_H */
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