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Diffstat (limited to 'arch/mips/include/asm/stackframe.h')
| -rw-r--r-- | arch/mips/include/asm/stackframe.h | 574 |
1 files changed, 574 insertions, 0 deletions
diff --git a/arch/mips/include/asm/stackframe.h b/arch/mips/include/asm/stackframe.h new file mode 100644 index 0000000..4c37c4e5 --- /dev/null +++ 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 */ |