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/* $OpenBSD: locore.S,v 1.18 1998/09/15 10:58:53 pefo Exp $ */ /*- * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Digital Equipment Corporation and Ralph Campbell. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * Copyright (C) 1989 Digital Equipment Corporation. * Permission to use, copy, modify, and distribute this software and * its documentation for any purpose and without fee is hereby granted, * provided that the above copyright notice appears in all copies. * Digital Equipment Corporation makes no representations about the * suitability of this software for any purpose. It is provided "as is" * without express or implied warranty. * * from: Header: /sprite/src/kernel/mach/ds3100.md/RCS/loMem.s, * v 1.1 89/07/11 17:55:04 nelson Exp SPRITE (DECWRL) * from: Header: /sprite/src/kernel/mach/ds3100.md/RCS/machAsm.s, * v 9.2 90/01/29 18:00:39 shirriff Exp SPRITE (DECWRL) * from: Header: /sprite/src/kernel/vm/ds3100.md/vmPmaxAsm.s, * v 1.1 89/07/10 14:27:41 nelson Exp SPRITE (DECWRL) * from: @(#)locore.s 8.5 (Berkeley) 1/4/94 * JNPR: exception.S,v 1.5 2007/01/08 04:58:37 katta * $FreeBSD: release/9.1.0/sys/mips/mips/exception.S 224612 2011-08-02 17:49:27Z attilio $ */ /* * Contains code that is the first executed at boot time plus * assembly language support routines. */ #include "opt_cputype.h" #include "opt_ddb.h" #include <machine/asm.h> #include <machine/cpu.h> #include <machine/regnum.h> #include <machine/cpuregs.h> #include <machine/pte.h> #include "opt_cputype.h" #include "assym.s" .set noreorder # Noreorder is default style! /* * Reasonable limit */ #define INTRCNT_COUNT 128 /* *---------------------------------------------------------------------------- * * MipsTLBMiss -- * * Vector code for the TLB-miss exception vector 0x80000000. * * This code is copied to the TLB exception vector address to * which the CPU jumps in response to an exception or a TLB miss. * NOTE: This code must be position independent!!! * * */ VECTOR(MipsTLBMiss, unknown) .set push .set noat j MipsDoTLBMiss MFC0 k0, MIPS_COP_0_BAD_VADDR # get the fault address .set pop VECTOR_END(MipsTLBMiss) /* *---------------------------------------------------------------------------- * * MipsDoTLBMiss -- * * This is the real TLB Miss Handler code. * 'segbase' points to the base of the segment table for user processes. * * Don't check for invalid pte's here. We load them as well and * let the processor trap to load the correct value after service. *---------------------------------------------------------------------------- */ .set push .set noat MipsDoTLBMiss: bltz k0, 1f #02: k0<0 -> 1f (kernel fault) PTR_SRL k0, k0, SEGSHIFT - PTRSHIFT #03: k0=seg offset (almost) GET_CPU_PCPU(k1) PTR_L k1, PC_SEGBASE(k1) beqz k1, 2f #05: make sure segbase is not null andi k0, k0, PDEPTRMASK #06: k0=seg offset PTR_ADDU k1, k0, k1 #07: k1=seg entry address PTR_L k1, 0(k1) #08: k1=seg entry MFC0 k0, MIPS_COP_0_BAD_VADDR #09: k0=bad address (again) beq k1, zero, 2f #0a: ==0 -- no page table #ifdef __mips_n64 PTR_SRL k0, PDRSHIFT - PTRSHIFT # k0=VPN andi k0, k0, PDEPTRMASK # k0=pde offset PTR_ADDU k1, k0, k1 # k1=pde entry address PTR_L k1, 0(k1) # k1=pde entry MFC0 k0, MIPS_COP_0_BAD_VADDR # k0=bad address (again) beq k1, zero, 2f # ==0 -- no page table #endif PTR_SRL k0, PAGE_SHIFT - PTESHIFT #0b: k0=VPN (aka va>>10) andi k0, k0, PTE2MASK #0c: k0=page tab offset PTR_ADDU k1, k1, k0 #0d: k1=pte address PTE_L k0, 0(k1) #0e: k0=lo0 pte PTE_L k1, PTESIZE(k1) #0f: k1=lo0 pte CLEAR_PTE_SWBITS(k0) PTE_MTC0 k0, MIPS_COP_0_TLB_LO0 #12: lo0 is loaded COP0_SYNC CLEAR_PTE_SWBITS(k1) PTE_MTC0 k1, MIPS_COP_0_TLB_LO1 #15: lo1 is loaded COP0_SYNC tlbwr #1a: write to tlb HAZARD_DELAY eret #1f: retUrn from exception 1: j MipsTLBMissException #20: kernel exception nop #21: branch delay slot 2: j SlowFault #22: no page table present nop #23: branch delay slot .set pop /* * This code is copied to the general exception vector address to * handle all execptions except RESET and TLBMiss. * NOTE: This code must be position independent!!! */ VECTOR(MipsException, unknown) /* * Find out what mode we came from and jump to the proper handler. */ .set noat mfc0 k0, MIPS_COP_0_STATUS # Get the status register mfc0 k1, MIPS_COP_0_CAUSE # Get the cause register value. and k0, k0, SR_KSU_USER # test for user mode # sneaky but the bits are # with us........ sll k0, k0, 3 # shift user bit for cause index and k1, k1, MIPS3_CR_EXC_CODE # Mask out the cause bits. or k1, k1, k0 # change index to user table #if defined(__mips_n64) PTR_SLL k1, k1, 1 # shift to get 8-byte offset #endif 1: PTR_LA k0, _C_LABEL(machExceptionTable) # get base of the jump table PTR_ADDU k0, k0, k1 # Get the address of the # function entry. Note that # the cause is already # shifted left by 2 bits so # we dont have to shift. PTR_L k0, 0(k0) # Get the function address nop j k0 # Jump to the function. nop .set at VECTOR_END(MipsException) /* * We couldn't find a TLB entry. * Find out what mode we came from and call the appropriate handler. */ SlowFault: .set noat mfc0 k0, MIPS_COP_0_STATUS nop and k0, k0, SR_KSU_USER bne k0, zero, _C_LABEL(MipsUserGenException) nop .set at /* * Fall though ... */ /*---------------------------------------------------------------------------- * * MipsKernGenException -- * * Handle an exception from kernel mode. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------------- */ #define SAVE_REG(reg, offs, base) \ REG_S reg, CALLFRAME_SIZ + (SZREG * offs) (base) #if defined(CPU_CNMIPS) #define CLEAR_STATUS \ mfc0 a0, MIPS_COP_0_STATUS ;\ li a2, (MIPS_SR_KX | MIPS_SR_SX | MIPS_SR_UX) ; \ or a0, a0, a2 ; \ li a2, ~(MIPS_SR_INT_IE | MIPS_SR_EXL | SR_KSU_USER) ; \ and a0, a0, a2 ; \ mtc0 a0, MIPS_COP_0_STATUS ; \ ITLBNOPFIX #elif defined(CPU_RMI) || defined(CPU_NLM) #define CLEAR_STATUS \ mfc0 a0, MIPS_COP_0_STATUS ;\ li a2, (MIPS_SR_KX | MIPS_SR_UX | MIPS_SR_COP_2_BIT) ; \ or a0, a0, a2 ; \ li a2, ~(MIPS_SR_INT_IE | MIPS_SR_EXL | SR_KSU_USER) ; \ and a0, a0, a2 ; \ mtc0 a0, MIPS_COP_0_STATUS ; \ ITLBNOPFIX #else #define CLEAR_STATUS \ mfc0 a0, MIPS_COP_0_STATUS ;\ li a2, ~(MIPS_SR_INT_IE | MIPS_SR_EXL | SR_KSU_USER) ; \ and a0, a0, a2 ; \ mtc0 a0, MIPS_COP_0_STATUS ; \ ITLBNOPFIX #endif /* * Save CPU and CP0 register state. * * This is straightforward except for saving the exception program * counter. The ddb backtrace code looks for the first instruction * matching the form "sw ra, (off)sp" to figure out the address of the * calling function. So we must make sure that we save the exception * PC by staging it through 'ra' as opposed to any other register. */ #define SAVE_CPU \ SAVE_REG(AT, AST, sp) ;\ .set at ; \ SAVE_REG(v0, V0, sp) ;\ SAVE_REG(v1, V1, sp) ;\ SAVE_REG(a0, A0, sp) ;\ SAVE_REG(a1, A1, sp) ;\ SAVE_REG(a2, A2, sp) ;\ SAVE_REG(a3, A3, sp) ;\ SAVE_REG(t0, T0, sp) ;\ SAVE_REG(t1, T1, sp) ;\ SAVE_REG(t2, T2, sp) ;\ SAVE_REG(t3, T3, sp) ;\ SAVE_REG(ta0, TA0, sp) ;\ SAVE_REG(ta1, TA1, sp) ;\ SAVE_REG(ta2, TA2, sp) ;\ SAVE_REG(ta3, TA3, sp) ;\ SAVE_REG(t8, T8, sp) ;\ SAVE_REG(t9, T9, sp) ;\ SAVE_REG(gp, GP, sp) ;\ SAVE_REG(s0, S0, sp) ;\ SAVE_REG(s1, S1, sp) ;\ SAVE_REG(s2, S2, sp) ;\ SAVE_REG(s3, S3, sp) ;\ SAVE_REG(s4, S4, sp) ;\ SAVE_REG(s5, S5, sp) ;\ SAVE_REG(s6, S6, sp) ;\ SAVE_REG(s7, S7, sp) ;\ SAVE_REG(s8, S8, sp) ;\ mflo v0 ;\ mfhi v1 ;\ mfc0 a0, MIPS_COP_0_STATUS ;\ mfc0 a1, MIPS_COP_0_CAUSE ;\ MFC0 a2, MIPS_COP_0_BAD_VADDR;\ MFC0 a3, MIPS_COP_0_EXC_PC ;\ SAVE_REG(v0, MULLO, sp) ;\ SAVE_REG(v1, MULHI, sp) ;\ SAVE_REG(a0, SR, sp) ;\ SAVE_REG(a1, CAUSE, sp) ;\ SAVE_REG(a2, BADVADDR, sp) ;\ move t0, ra ;\ move ra, a3 ;\ SAVE_REG(ra, PC, sp) ;\ move ra, t0 ;\ SAVE_REG(ra, RA, sp) ;\ PTR_ADDU v0, sp, KERN_EXC_FRAME_SIZE ;\ SAVE_REG(v0, SP, sp) ;\ CLEAR_STATUS ;\ PTR_ADDU a0, sp, CALLFRAME_SIZ ;\ ITLBNOPFIX #define RESTORE_REG(reg, offs, base) \ REG_L reg, CALLFRAME_SIZ + (SZREG * offs) (base) #define RESTORE_CPU \ CLEAR_STATUS ;\ RESTORE_REG(k0, SR, sp) ;\ RESTORE_REG(t0, MULLO, sp) ;\ RESTORE_REG(t1, MULHI, sp) ;\ mtlo t0 ;\ mthi t1 ;\ MTC0 v0, MIPS_COP_0_EXC_PC ;\ .set noat ;\ RESTORE_REG(AT, AST, sp) ;\ RESTORE_REG(v0, V0, sp) ;\ RESTORE_REG(v1, V1, sp) ;\ RESTORE_REG(a0, A0, sp) ;\ RESTORE_REG(a1, A1, sp) ;\ RESTORE_REG(a2, A2, sp) ;\ RESTORE_REG(a3, A3, sp) ;\ RESTORE_REG(t0, T0, sp) ;\ RESTORE_REG(t1, T1, sp) ;\ RESTORE_REG(t2, T2, sp) ;\ RESTORE_REG(t3, T3, sp) ;\ RESTORE_REG(ta0, TA0, sp) ;\ RESTORE_REG(ta1, TA1, sp) ;\ RESTORE_REG(ta2, TA2, sp) ;\ RESTORE_REG(ta3, TA3, sp) ;\ RESTORE_REG(t8, T8, sp) ;\ RESTORE_REG(t9, T9, sp) ;\ RESTORE_REG(s0, S0, sp) ;\ RESTORE_REG(s1, S1, sp) ;\ RESTORE_REG(s2, S2, sp) ;\ RESTORE_REG(s3, S3, sp) ;\ RESTORE_REG(s4, S4, sp) ;\ RESTORE_REG(s5, S5, sp) ;\ RESTORE_REG(s6, S6, sp) ;\ RESTORE_REG(s7, S7, sp) ;\ RESTORE_REG(s8, S8, sp) ;\ RESTORE_REG(gp, GP, sp) ;\ RESTORE_REG(ra, RA, sp) ;\ PTR_ADDU sp, sp, KERN_EXC_FRAME_SIZE;\ mtc0 k0, MIPS_COP_0_STATUS /* * The kernel exception stack contains 18 saved general registers, * the status register and the multiply lo and high registers. * In addition, we set this up for linkage conventions. */ #define KERN_REG_SIZE (NUMSAVEREGS * SZREG) #define KERN_EXC_FRAME_SIZE (CALLFRAME_SIZ + KERN_REG_SIZE + 16) NNON_LEAF(MipsKernGenException, KERN_EXC_FRAME_SIZE, ra) .set noat PTR_SUBU sp, sp, KERN_EXC_FRAME_SIZE .mask 0x80000000, (CALLFRAME_RA - KERN_EXC_FRAME_SIZE) /* * Save CPU state, building 'frame'. */ SAVE_CPU /* * Call the exception handler. a0 points at the saved frame. */ PTR_LA gp, _C_LABEL(_gp) PTR_LA k0, _C_LABEL(trap) jalr k0 REG_S a3, CALLFRAME_RA + KERN_REG_SIZE(sp) # for debugging /* * Update interrupt mask in saved status register * Some of interrupts could be disabled by * intr filters if interrupts are enabled later * in trap handler */ mfc0 a0, MIPS_COP_0_STATUS and a0, a0, MIPS_SR_INT_MASK RESTORE_REG(a1, SR, sp) and a1, a1, ~MIPS_SR_INT_MASK or a1, a1, a0 SAVE_REG(a1, SR, sp) RESTORE_CPU # v0 contains the return address. sync eret .set at END(MipsKernGenException) #define SAVE_U_PCB_REG(reg, offs, base) \ REG_S reg, U_PCB_REGS + (SZREG * offs) (base) #define RESTORE_U_PCB_REG(reg, offs, base) \ REG_L reg, U_PCB_REGS + (SZREG * offs) (base) /*---------------------------------------------------------------------------- * * MipsUserGenException -- * * Handle an exception from user mode. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------------- */ NNON_LEAF(MipsUserGenException, CALLFRAME_SIZ, ra) .set noat .mask 0x80000000, (CALLFRAME_RA - CALLFRAME_SIZ) /* * Save all of the registers except for the kernel temporaries in u.u_pcb. */ GET_CPU_PCPU(k1) PTR_L k1, PC_CURPCB(k1) SAVE_U_PCB_REG(AT, AST, k1) .set at SAVE_U_PCB_REG(v0, V0, k1) SAVE_U_PCB_REG(v1, V1, k1) SAVE_U_PCB_REG(a0, A0, k1) mflo v0 SAVE_U_PCB_REG(a1, A1, k1) SAVE_U_PCB_REG(a2, A2, k1) SAVE_U_PCB_REG(a3, A3, k1) SAVE_U_PCB_REG(t0, T0, k1) mfhi v1 SAVE_U_PCB_REG(t1, T1, k1) SAVE_U_PCB_REG(t2, T2, k1) SAVE_U_PCB_REG(t3, T3, k1) SAVE_U_PCB_REG(ta0, TA0, k1) mfc0 a0, MIPS_COP_0_STATUS # First arg is the status reg. SAVE_U_PCB_REG(ta1, TA1, k1) SAVE_U_PCB_REG(ta2, TA2, k1) SAVE_U_PCB_REG(ta3, TA3, k1) SAVE_U_PCB_REG(s0, S0, k1) mfc0 a1, MIPS_COP_0_CAUSE # Second arg is the cause reg. SAVE_U_PCB_REG(s1, S1, k1) SAVE_U_PCB_REG(s2, S2, k1) SAVE_U_PCB_REG(s3, S3, k1) SAVE_U_PCB_REG(s4, S4, k1) MFC0 a2, MIPS_COP_0_BAD_VADDR # Third arg is the fault addr SAVE_U_PCB_REG(s5, S5, k1) SAVE_U_PCB_REG(s6, S6, k1) SAVE_U_PCB_REG(s7, S7, k1) SAVE_U_PCB_REG(t8, T8, k1) MFC0 a3, MIPS_COP_0_EXC_PC # Fourth arg is the pc. SAVE_U_PCB_REG(t9, T9, k1) SAVE_U_PCB_REG(gp, GP, k1) SAVE_U_PCB_REG(sp, SP, k1) SAVE_U_PCB_REG(s8, S8, k1) PTR_SUBU sp, k1, CALLFRAME_SIZ # switch to kernel SP SAVE_U_PCB_REG(ra, RA, k1) SAVE_U_PCB_REG(v0, MULLO, k1) SAVE_U_PCB_REG(v1, MULHI, k1) SAVE_U_PCB_REG(a0, SR, k1) SAVE_U_PCB_REG(a1, CAUSE, k1) SAVE_U_PCB_REG(a2, BADVADDR, k1) SAVE_U_PCB_REG(a3, PC, k1) REG_S a3, CALLFRAME_RA(sp) # for debugging PTR_LA gp, _C_LABEL(_gp) # switch to kernel GP # Turn off fpu and enter kernel mode and t0, a0, ~(MIPS_SR_COP_1_BIT | MIPS_SR_EXL | MIPS3_SR_KSU_MASK | MIPS_SR_INT_IE) #if defined(CPU_CNMIPS) or t0, t0, (MIPS_SR_KX | MIPS_SR_SX | MIPS_SR_UX | MIPS_SR_PX) #elif defined(CPU_RMI) || defined(CPU_NLM) or t0, t0, (MIPS_SR_KX | MIPS_SR_UX | MIPS_SR_COP_2_BIT) #endif mtc0 t0, MIPS_COP_0_STATUS PTR_ADDU a0, k1, U_PCB_REGS ITLBNOPFIX /* * Call the exception handler. */ PTR_LA k0, _C_LABEL(trap) jalr k0 nop /* * Restore user registers and return. * First disable interrupts and set exeption level. */ DO_AST CLEAR_STATUS /* * The use of k1 for storing the PCB pointer must be done only * after interrupts are disabled. Otherwise it will get overwritten * by the interrupt code. */ GET_CPU_PCPU(k1) PTR_L k1, PC_CURPCB(k1) /* * Update interrupt mask in saved status register * Some of interrupts could be enabled by ithread * scheduled by ast() */ mfc0 a0, MIPS_COP_0_STATUS and a0, a0, MIPS_SR_INT_MASK RESTORE_U_PCB_REG(a1, SR, k1) and a1, a1, ~MIPS_SR_INT_MASK or a1, a1, a0 SAVE_U_PCB_REG(a1, SR, k1) RESTORE_U_PCB_REG(t0, MULLO, k1) RESTORE_U_PCB_REG(t1, MULHI, k1) mtlo t0 mthi t1 RESTORE_U_PCB_REG(a0, PC, k1) RESTORE_U_PCB_REG(v0, V0, k1) MTC0 a0, MIPS_COP_0_EXC_PC # set return address RESTORE_U_PCB_REG(v1, V1, k1) RESTORE_U_PCB_REG(a0, A0, k1) RESTORE_U_PCB_REG(a1, A1, k1) RESTORE_U_PCB_REG(a2, A2, k1) RESTORE_U_PCB_REG(a3, A3, k1) RESTORE_U_PCB_REG(t0, T0, k1) RESTORE_U_PCB_REG(t1, T1, k1) RESTORE_U_PCB_REG(t2, T2, k1) RESTORE_U_PCB_REG(t3, T3, k1) RESTORE_U_PCB_REG(ta0, TA0, k1) RESTORE_U_PCB_REG(ta1, TA1, k1) RESTORE_U_PCB_REG(ta2, TA2, k1) RESTORE_U_PCB_REG(ta3, TA3, k1) RESTORE_U_PCB_REG(s0, S0, k1) RESTORE_U_PCB_REG(s1, S1, k1) RESTORE_U_PCB_REG(s2, S2, k1) RESTORE_U_PCB_REG(s3, S3, k1) RESTORE_U_PCB_REG(s4, S4, k1) RESTORE_U_PCB_REG(s5, S5, k1) RESTORE_U_PCB_REG(s6, S6, k1) RESTORE_U_PCB_REG(s7, S7, k1) RESTORE_U_PCB_REG(t8, T8, k1) RESTORE_U_PCB_REG(t9, T9, k1) RESTORE_U_PCB_REG(gp, GP, k1) RESTORE_U_PCB_REG(sp, SP, k1) RESTORE_U_PCB_REG(k0, SR, k1) RESTORE_U_PCB_REG(s8, S8, k1) RESTORE_U_PCB_REG(ra, RA, k1) .set noat RESTORE_U_PCB_REG(AT, AST, k1) mtc0 k0, MIPS_COP_0_STATUS # still exception level ITLBNOPFIX sync eret .set at END(MipsUserGenException) /*---------------------------------------------------------------------------- * * MipsKernIntr -- * * Handle an interrupt from kernel mode. * Interrupts use the standard kernel stack. * switch_exit sets up a kernel stack after exit so interrupts won't fail. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------------- */ NNON_LEAF(MipsKernIntr, KERN_EXC_FRAME_SIZE, ra) .set noat PTR_SUBU sp, sp, KERN_EXC_FRAME_SIZE .mask 0x80000000, (CALLFRAME_RA - KERN_EXC_FRAME_SIZE) /* * Save CPU state, building 'frame'. */ SAVE_CPU /* * Call the interrupt handler. a0 points at the saved frame. */ PTR_LA gp, _C_LABEL(_gp) PTR_LA k0, _C_LABEL(cpu_intr) jalr k0 REG_S a3, CALLFRAME_RA + KERN_REG_SIZE(sp) # for debugging /* * Update interrupt mask in saved status register * Some of interrupts could be disabled by * intr filters if interrupts are enabled later * in trap handler */ mfc0 a0, MIPS_COP_0_STATUS and a0, a0, MIPS_SR_INT_MASK RESTORE_REG(a1, SR, sp) and a1, a1, ~MIPS_SR_INT_MASK or a1, a1, a0 SAVE_REG(a1, SR, sp) REG_L v0, CALLFRAME_RA + KERN_REG_SIZE(sp) RESTORE_CPU # v0 contains the return address. sync eret .set at END(MipsKernIntr) /*---------------------------------------------------------------------------- * * MipsUserIntr -- * * Handle an interrupt from user mode. * Note: we save minimal state in the u.u_pcb struct and use the standard * kernel stack since there has to be a u page if we came from user mode. * If there is a pending software interrupt, then save the remaining state * and call softintr(). This is all because if we call switch() inside * interrupt(), not all the user registers have been saved in u.u_pcb. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------------- */ NNON_LEAF(MipsUserIntr, CALLFRAME_SIZ, ra) .set noat .mask 0x80000000, (CALLFRAME_RA - CALLFRAME_SIZ) /* * Save the relevant user registers into the u.u_pcb struct. * We don't need to save s0 - s8 because the compiler does it for us. */ GET_CPU_PCPU(k1) PTR_L k1, PC_CURPCB(k1) SAVE_U_PCB_REG(AT, AST, k1) .set at SAVE_U_PCB_REG(v0, V0, k1) SAVE_U_PCB_REG(v1, V1, k1) SAVE_U_PCB_REG(a0, A0, k1) SAVE_U_PCB_REG(a1, A1, k1) SAVE_U_PCB_REG(a2, A2, k1) SAVE_U_PCB_REG(a3, A3, k1) SAVE_U_PCB_REG(t0, T0, k1) SAVE_U_PCB_REG(t1, T1, k1) SAVE_U_PCB_REG(t2, T2, k1) SAVE_U_PCB_REG(t3, T3, k1) SAVE_U_PCB_REG(ta0, TA0, k1) SAVE_U_PCB_REG(ta1, TA1, k1) SAVE_U_PCB_REG(ta2, TA2, k1) SAVE_U_PCB_REG(ta3, TA3, k1) SAVE_U_PCB_REG(t8, T8, k1) SAVE_U_PCB_REG(t9, T9, k1) SAVE_U_PCB_REG(gp, GP, k1) SAVE_U_PCB_REG(sp, SP, k1) SAVE_U_PCB_REG(ra, RA, k1) /* * save remaining user state in u.u_pcb. */ SAVE_U_PCB_REG(s0, S0, k1) SAVE_U_PCB_REG(s1, S1, k1) SAVE_U_PCB_REG(s2, S2, k1) SAVE_U_PCB_REG(s3, S3, k1) SAVE_U_PCB_REG(s4, S4, k1) SAVE_U_PCB_REG(s5, S5, k1) SAVE_U_PCB_REG(s6, S6, k1) SAVE_U_PCB_REG(s7, S7, k1) SAVE_U_PCB_REG(s8, S8, k1) mflo v0 # get lo/hi late to avoid stall mfhi v1 mfc0 a0, MIPS_COP_0_STATUS mfc0 a1, MIPS_COP_0_CAUSE MFC0 a3, MIPS_COP_0_EXC_PC SAVE_U_PCB_REG(v0, MULLO, k1) SAVE_U_PCB_REG(v1, MULHI, k1) SAVE_U_PCB_REG(a0, SR, k1) SAVE_U_PCB_REG(a1, CAUSE, k1) SAVE_U_PCB_REG(a3, PC, k1) # PC in a3, note used later! PTR_SUBU sp, k1, CALLFRAME_SIZ # switch to kernel SP PTR_LA gp, _C_LABEL(_gp) # switch to kernel GP # Turn off fpu, disable interrupts, set kernel mode kernel mode, clear exception level. and t0, a0, ~(MIPS_SR_COP_1_BIT | MIPS_SR_EXL | MIPS_SR_INT_IE | MIPS3_SR_KSU_MASK) #ifdef CPU_CNMIPS or t0, t0, (MIPS_SR_KX | MIPS_SR_SX | MIPS_SR_UX | MIPS_SR_PX) #elif defined(CPU_RMI) || defined(CPU_NLM) or t0, t0, (MIPS_SR_KX | MIPS_SR_UX | MIPS_SR_COP_2_BIT) #endif mtc0 t0, MIPS_COP_0_STATUS ITLBNOPFIX PTR_ADDU a0, k1, U_PCB_REGS /* * Call the interrupt handler. */ PTR_LA k0, _C_LABEL(cpu_intr) jalr k0 REG_S a3, CALLFRAME_RA(sp) # for debugging /* * Enable interrupts before doing ast(). * * On SMP kernels the AST processing might trigger IPI to other processors. * If that processor is also doing AST processing with interrupts disabled * then we may deadlock. */ mfc0 a0, MIPS_COP_0_STATUS or a0, a0, MIPS_SR_INT_IE mtc0 a0, MIPS_COP_0_STATUS ITLBNOPFIX /* * DO_AST enabled interrupts */ DO_AST /* * Restore user registers and return. */ CLEAR_STATUS GET_CPU_PCPU(k1) PTR_L k1, PC_CURPCB(k1) /* * Update interrupt mask in saved status register * Some of interrupts could be disabled by * intr filters */ mfc0 a0, MIPS_COP_0_STATUS and a0, a0, MIPS_SR_INT_MASK RESTORE_U_PCB_REG(a1, SR, k1) and a1, a1, ~MIPS_SR_INT_MASK or a1, a1, a0 SAVE_U_PCB_REG(a1, SR, k1) RESTORE_U_PCB_REG(s0, S0, k1) RESTORE_U_PCB_REG(s1, S1, k1) RESTORE_U_PCB_REG(s2, S2, k1) RESTORE_U_PCB_REG(s3, S3, k1) RESTORE_U_PCB_REG(s4, S4, k1) RESTORE_U_PCB_REG(s5, S5, k1) RESTORE_U_PCB_REG(s6, S6, k1) RESTORE_U_PCB_REG(s7, S7, k1) RESTORE_U_PCB_REG(s8, S8, k1) RESTORE_U_PCB_REG(t0, MULLO, k1) RESTORE_U_PCB_REG(t1, MULHI, k1) RESTORE_U_PCB_REG(t2, PC, k1) mtlo t0 mthi t1 MTC0 t2, MIPS_COP_0_EXC_PC # set return address RESTORE_U_PCB_REG(v0, V0, k1) RESTORE_U_PCB_REG(v1, V1, k1) RESTORE_U_PCB_REG(a0, A0, k1) RESTORE_U_PCB_REG(a1, A1, k1) RESTORE_U_PCB_REG(a2, A2, k1) RESTORE_U_PCB_REG(a3, A3, k1) RESTORE_U_PCB_REG(t0, T0, k1) RESTORE_U_PCB_REG(t1, T1, k1) RESTORE_U_PCB_REG(t2, T2, k1) RESTORE_U_PCB_REG(t3, T3, k1) RESTORE_U_PCB_REG(ta0, TA0, k1) RESTORE_U_PCB_REG(ta1, TA1, k1) RESTORE_U_PCB_REG(ta2, TA2, k1) RESTORE_U_PCB_REG(ta3, TA3, k1) RESTORE_U_PCB_REG(t8, T8, k1) RESTORE_U_PCB_REG(t9, T9, k1) RESTORE_U_PCB_REG(gp, GP, k1) RESTORE_U_PCB_REG(k0, SR, k1) RESTORE_U_PCB_REG(sp, SP, k1) RESTORE_U_PCB_REG(ra, RA, k1) .set noat RESTORE_U_PCB_REG(AT, AST, k1) mtc0 k0, MIPS_COP_0_STATUS # SR with EXL set. ITLBNOPFIX sync eret .set at END(MipsUserIntr) NLEAF(MipsTLBInvalidException) .set push .set noat .set noreorder MFC0 k0, MIPS_COP_0_BAD_VADDR PTR_LI k1, VM_MAXUSER_ADDRESS sltu k1, k0, k1 bnez k1, 1f nop /* Kernel address. */ lui k1, %hi(kernel_segmap) # k1=hi of segbase b 2f PTR_L k1, %lo(kernel_segmap)(k1) # k1=segment tab base 1: /* User address. */ GET_CPU_PCPU(k1) PTR_L k1, PC_SEGBASE(k1) 2: /* Validate page directory pointer. */ beqz k1, 3f nop PTR_SRL k0, SEGSHIFT - PTRSHIFT # k0=seg offset (almost) beq k1, zero, MipsKernGenException # ==0 -- no seg tab andi k0, k0, PDEPTRMASK #06: k0=seg offset PTR_ADDU k1, k0, k1 # k1=seg entry address PTR_L k1, 0(k1) # k1=seg entry /* Validate page table pointer. */ beqz k1, 3f nop #ifdef __mips_n64 MFC0 k0, MIPS_COP_0_BAD_VADDR PTR_SRL k0, PDRSHIFT - PTRSHIFT # k0=pde offset (almost) beq k1, zero, MipsKernGenException # ==0 -- no pde tab andi k0, k0, PDEPTRMASK # k0=pde offset PTR_ADDU k1, k0, k1 # k1=pde entry address PTR_L k1, 0(k1) # k1=pde entry /* Validate pde table pointer. */ beqz k1, 3f nop #endif MFC0 k0, MIPS_COP_0_BAD_VADDR # k0=bad address (again) PTR_SRL k0, PAGE_SHIFT - PTESHIFT # k0=VPN andi k0, k0, PTEMASK # k0=page tab offset PTR_ADDU k1, k1, k0 # k1=pte address PTE_L k0, 0(k1) # k0=this PTE /* Validate page table entry. */ andi k0, PTE_V beqz k0, 3f nop /* Check whether this is an even or odd entry. */ andi k0, k1, PTESIZE bnez k0, odd_page nop PTE_L k0, 0(k1) PTE_L k1, PTESIZE(k1) CLEAR_PTE_SWBITS(k0) PTE_MTC0 k0, MIPS_COP_0_TLB_LO0 COP0_SYNC CLEAR_PTE_SWBITS(k1) PTE_MTC0 k1, MIPS_COP_0_TLB_LO1 COP0_SYNC b tlb_insert_entry nop odd_page: PTE_L k0, -PTESIZE(k1) PTE_L k1, 0(k1) CLEAR_PTE_SWBITS(k0) PTE_MTC0 k0, MIPS_COP_0_TLB_LO0 COP0_SYNC CLEAR_PTE_SWBITS(k1) PTE_MTC0 k1, MIPS_COP_0_TLB_LO1 COP0_SYNC tlb_insert_entry: tlbp HAZARD_DELAY mfc0 k0, MIPS_COP_0_TLB_INDEX bltz k0, tlb_insert_random nop tlbwi eret ssnop tlb_insert_random: tlbwr eret ssnop 3: /* * Branch to the comprehensive exception processing. */ mfc0 k1, MIPS_COP_0_STATUS andi k1, k1, SR_KSU_USER bnez k1, _C_LABEL(MipsUserGenException) nop /* * Check for kernel stack overflow. */ GET_CPU_PCPU(k1) PTR_L k0, PC_CURTHREAD(k1) PTR_L k0, TD_KSTACK(k0) sltu k0, k0, sp bnez k0, _C_LABEL(MipsKernGenException) nop /* * Kernel stack overflow. * * Move to a valid stack before we call panic. We use the boot stack * for this purpose. */ GET_CPU_PCPU(k1) lw k1, PC_CPUID(k1) sll k1, k1, PAGE_SHIFT + 1 PTR_LA k0, _C_LABEL(pcpu_space) PTR_ADDU k0, PAGE_SIZE * 2 PTR_ADDU k0, k0, k1 /* * Stash the original value of 'sp' so we can update trapframe later. * We assume that SAVE_CPU does not trash 'k1'. */ move k1, sp move sp, k0 PTR_SUBU sp, sp, KERN_EXC_FRAME_SIZE move k0, ra move ra, zero REG_S ra, CALLFRAME_RA(sp) /* stop the ddb backtrace right here */ REG_S zero, CALLFRAME_SP(sp) move ra, k0 SAVE_CPU /* * Now restore the value of 'sp' at the time of the tlb exception in * the trapframe. */ SAVE_REG(k1, SP, sp) /* * Squelch any more overflow checks by setting the stack base to 0. */ GET_CPU_PCPU(k1) PTR_L k0, PC_CURTHREAD(k1) PTR_S zero, TD_KSTACK(k0) move a1, a0 PANIC("kernel stack overflow - trapframe at %p") /* * This nop is necessary so that the 'ra' remains within the bounds * of this handler. Otherwise the ddb backtrace code will think that * the panic() was called from MipsTLBMissException. */ nop .set pop END(MipsTLBInvalidException) /*---------------------------------------------------------------------------- * * MipsTLBMissException -- * * Handle a TLB miss exception from kernel mode in kernel space. * The BaddVAddr, Context, and EntryHi registers contain the failed * virtual address. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------------- */ NLEAF(MipsTLBMissException) .set noat MFC0 k0, MIPS_COP_0_BAD_VADDR # k0=bad address PTR_LI k1, VM_MAX_KERNEL_ADDRESS # check fault address against sltu k1, k1, k0 # upper bound of kernel_segmap bnez k1, MipsKernGenException # out of bound lui k1, %hi(kernel_segmap) # k1=hi of segbase PTR_SRL k0, SEGSHIFT - PTRSHIFT # k0=seg offset (almost) PTR_L k1, %lo(kernel_segmap)(k1) # k1=segment tab base beq k1, zero, MipsKernGenException # ==0 -- no seg tab andi k0, k0, PDEPTRMASK #06: k0=seg offset PTR_ADDU k1, k0, k1 # k1=seg entry address PTR_L k1, 0(k1) # k1=seg entry MFC0 k0, MIPS_COP_0_BAD_VADDR # k0=bad address (again) beq k1, zero, MipsKernGenException # ==0 -- no page table #ifdef __mips_n64 PTR_SRL k0, PDRSHIFT - PTRSHIFT # k0=VPN andi k0, k0, PDEPTRMASK # k0=pde offset PTR_ADDU k1, k0, k1 # k1=pde entry address PTR_L k1, 0(k1) # k1=pde entry MFC0 k0, MIPS_COP_0_BAD_VADDR # k0=bad address (again) beq k1, zero, MipsKernGenException # ==0 -- no page table #endif PTR_SRL k0, PAGE_SHIFT - PTESHIFT # k0=VPN andi k0, k0, PTE2MASK # k0=page tab offset PTR_ADDU k1, k1, k0 # k1=pte address PTE_L k0, 0(k1) # k0=lo0 pte PTE_L k1, PTESIZE(k1) # k1=lo1 pte CLEAR_PTE_SWBITS(k0) PTE_MTC0 k0, MIPS_COP_0_TLB_LO0 # lo0 is loaded COP0_SYNC CLEAR_PTE_SWBITS(k1) PTE_MTC0 k1, MIPS_COP_0_TLB_LO1 # lo1 is loaded COP0_SYNC tlbwr # write to tlb HAZARD_DELAY eret # return from exception .set at END(MipsTLBMissException) /*---------------------------------------------------------------------------- * * MipsFPTrap -- * * Handle a floating point Trap. * * MipsFPTrap(statusReg, causeReg, pc) * unsigned statusReg; * unsigned causeReg; * unsigned pc; * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------------- */ NON_LEAF(MipsFPTrap, CALLFRAME_SIZ, ra) PTR_SUBU sp, sp, CALLFRAME_SIZ mfc0 t0, MIPS_COP_0_STATUS REG_S ra, CALLFRAME_RA(sp) .mask 0x80000000, (CALLFRAME_RA - CALLFRAME_SIZ) or t1, t0, MIPS_SR_COP_1_BIT mtc0 t1, MIPS_COP_0_STATUS ITLBNOPFIX cfc1 t1, MIPS_FPU_CSR # stall til FP done cfc1 t1, MIPS_FPU_CSR # now get status nop sll t2, t1, (31 - 17) # unimplemented operation? bgez t2, 3f # no, normal trap nop /* * We got an unimplemented operation trap so * fetch the instruction, compute the next PC and emulate the instruction. */ bgez a1, 1f # Check the branch delay bit. nop /* * The instruction is in the branch delay slot so the branch will have to * be emulated to get the resulting PC. */ PTR_S a2, CALLFRAME_SIZ + 8(sp) GET_CPU_PCPU(a0) #mips64 unsafe? PTR_L a0, PC_CURPCB(a0) PTR_ADDU a0, a0, U_PCB_REGS # first arg is ptr to CPU registers move a1, a2 # second arg is instruction PC move a2, t1 # third arg is floating point CSR PTR_LA t3, _C_LABEL(MipsEmulateBranch) # compute PC after branch jalr t3 # compute PC after branch move a3, zero # fourth arg is FALSE /* * Now load the floating-point instruction in the branch delay slot * to be emulated. */ PTR_L a2, CALLFRAME_SIZ + 8(sp) # restore EXC pc b 2f lw a0, 4(a2) # a0 = coproc instruction /* * This is not in the branch delay slot so calculate the resulting * PC (epc + 4) into v0 and continue to MipsEmulateFP(). */ 1: lw a0, 0(a2) # a0 = coproc instruction #xxx mips64 unsafe? PTR_ADDU v0, a2, 4 # v0 = next pc 2: GET_CPU_PCPU(t2) PTR_L t2, PC_CURPCB(t2) SAVE_U_PCB_REG(v0, PC, t2) # save new pc /* * Check to see if the instruction to be emulated is a floating-point * instruction. */ srl a3, a0, MIPS_OPCODE_SHIFT beq a3, MIPS_OPCODE_C1, 4f # this should never fail nop /* * Send a floating point exception signal to the current process. */ 3: GET_CPU_PCPU(a0) PTR_L a0, PC_CURTHREAD(a0) # get current thread cfc1 a2, MIPS_FPU_CSR # code = FP execptions ctc1 zero, MIPS_FPU_CSR # Clear exceptions PTR_LA t3, _C_LABEL(trapsignal) jalr t3 li a1, SIGFPE b FPReturn nop /* * Finally, we can call MipsEmulateFP() where a0 is the instruction to emulate. */ 4: PTR_LA t3, _C_LABEL(MipsEmulateFP) jalr t3 nop /* * Turn off the floating point coprocessor and return. */ FPReturn: mfc0 t0, MIPS_COP_0_STATUS PTR_L ra, CALLFRAME_RA(sp) and t0, t0, ~MIPS_SR_COP_1_BIT mtc0 t0, MIPS_COP_0_STATUS ITLBNOPFIX j ra PTR_ADDU sp, sp, CALLFRAME_SIZ END(MipsFPTrap) /* * Interrupt counters for vmstat. */ .data .globl intrcnt .globl sintrcnt .globl intrnames .globl sintrnames intrnames: .space INTRCNT_COUNT * (MAXCOMLEN + 1) * 2 sintrnames: #ifdef __mips_n64 .quad INTRCNT_COUNT * (MAXCOMLEN + 1) * 2 #else .int INTRCNT_COUNT * (MAXCOMLEN + 1) * 2 #endif .align 4 intrcnt: .space INTRCNT_COUNT * 4 * 2 sintrcnt: #ifdef __mips_n64 .quad INTRCNT_COUNT * 4 * 2 #else .int INTRCNT_COUNT * 4 * 2 #endif /* * Vector to real handler in KSEG1. */ .text VECTOR(MipsCache, unknown) PTR_LA k0, _C_LABEL(MipsCacheException) li k1, MIPS_KSEG0_PHYS_MASK and k0, k1 PTR_LI k1, MIPS_KSEG1_START or k0, k1 j k0 nop VECTOR_END(MipsCache) .set at /* * Panic on cache errors. A lot more could be done to recover * from some types of errors but it is tricky. */ NESTED_NOPROFILE(MipsCacheException, KERN_EXC_FRAME_SIZE, ra) .set noat .mask 0x80000000, -4 PTR_LA k0, _C_LABEL(panic) # return to panic PTR_LA a0, 9f # panicstr MFC0 a1, MIPS_COP_0_ERROR_PC mfc0 a2, MIPS_COP_0_CACHE_ERR # 3rd arg cache error MTC0 k0, MIPS_COP_0_ERROR_PC # set return address mfc0 k0, MIPS_COP_0_STATUS # restore status li k1, MIPS_SR_DIAG_PE # ignore further errors or k0, k1 mtc0 k0, MIPS_COP_0_STATUS # restore status COP0_SYNC eret MSG("cache error @ EPC 0x%x CachErr 0x%x"); .set at END(MipsCacheException)