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| Current File : //usr/src/sys/mips/mips/exception.S |
/* $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)