/* * 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 #include #include #include #include #include /* * 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 #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 #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) #ifndef CONFIG_CPU_HAS_SMARTMIPS 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) #ifndef CONFIG_CPU_HAS_SMARTMIPS 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 .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 k0, CP0_TCSTATUS .set mips0 LONG_S k0, 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 #ifdef CONFIG_CPU_CAVIUM_OCTEON .set mips64 pref 0, 0($28) /* Prefetch the current pointer */ #endif .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 #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 accommodate * 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 */