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/*
 * 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 - 2000, 2001 by Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Copyright (C) 2001 MIPS Technologies, Inc.
 */
#include <linux/config.h>
#include <linux/init.h>
#include <linux/sys.h>

#include <asm/addrspace.h>
#include <asm/asm.h>
#include <asm/cacheops.h>
#include <asm/current.h>
#include <asm/errno.h>
#include <asm/mipsregs.h>
#include <asm/page.h>
#include <asm/pgtable-bits.h>
#include <asm/stackframe.h>
#include <asm/processor.h>
#include <asm/regdef.h>
#include <asm/fpregdef.h>
#include <asm/unistd.h>
#include <asm/isadep.h>


                .text
                .align  5
                .set    push
                .set    reorder
FEXPORT(ret_from_irq)
FEXPORT(ret_from_exception)
                lw      t0, PT_STATUS(sp)       # returning to kernel mode?
                andi    t0, t0, KU_USER
                beqz    t0, restore_all

FEXPORT(ret_from_sys_call)              # here to prevent code duplication
ret_from_schedule:
                mfc0    t0, CP0_STATUS  # need_resched and signals atomic test
                ori     t0, t0, 1
                xori    t0, t0, 1
                mtc0    t0, CP0_STATUS
                SSNOP; SSNOP; SSNOP

                lw      v0, TASK_NEED_RESCHED($28)
                lw      v1, TASK_SIGPENDING($28)
                bnez    v0, reschedule
                bnez    v1, signal_return
restore_all:    .set    noat
                RESTORE_ALL_AND_RET
                .set    at

/* Put this behind restore_all for the sake of the branch prediction.  */
signal_return:
                .type   signal_return, @function

                mfc0    t0, CP0_STATUS
                ori     t0, t0, 1
                mtc0    t0, CP0_STATUS

                move    a0, zero
                move    a1, sp
                jal     do_signal
                b       restore_all

reschedule:
                jal     schedule
                b       ret_from_schedule

/*
 * Common spurious interrupt handler.
 */
                .text
                .align  5
LEAF(spurious_interrupt)
                /*
                 * Someone tried to fool us by sending an interrupt but we
                 * couldn't find a cause for it.
                 */
                lui     t1,%hi(irq_err_count)
                lw      t0,%lo(irq_err_count)(t1)
                addiu   t0,1
                sw      t0,%lo(irq_err_count)(t1)
                j       ret_from_irq
END(spurious_interrupt)

                __INIT

                .set    reorder

NESTED(except_vec1_generic, 0, sp)
                PANIC("Exception vector 1 called")
END(except_vec1_generic)

                /*
                 * General exception vector.  Used for all CPUs except R4000
                 * and R4400 SC and MC versions.
                 */
NESTED(except_vec3_generic, 0, sp)
#if R5432_CP0_INTERRUPT_WAR
                mfc0    k0, CP0_INDEX
#endif
                mfc0    k1, CP0_CAUSE
                la      k0, exception_handlers
                andi    k1, k1, 0x7c
                addu    k0, k0, k1
                lw      k0, (k0)
                jr      k0
END(except_vec3_generic)
                .set    at

                /* General exception vector R4000 version. */
NESTED(except_vec3_r4000, 0, sp)
                .set    push
                .set    mips3
                .set    noat
                mfc0    k1, CP0_CAUSE
                li      k0, 31<<2
                andi    k1, k1, 0x7c
                .set    noreorder
                beq     k1, k0, handle_vced
                 li     k0, 14<<2
                beq     k1, k0, handle_vcei
                 la     k0, exception_handlers
                .set    reorder
                addu    k0, k0, k1
                lw      k0, (k0)
                jr      k0

                /*
                 * Big shit, we now may have two dirty primary cache lines for
                 * the same physical address.  We can savely invalidate the
                 * line pointed to by c0_badvaddr because after return from
                 * this exception handler the load / store will be re-executed.
                 */
handle_vced:
                mfc0    k0, CP0_BADVADDR
                li      k1, -4
                and     k0, k1
                mtc0    zero, CP0_TAGLO
                cache   Index_Store_Tag_D,(k0)
                cache   Hit_Writeback_Inv_SD,(k0)
#ifdef CONFIG_PROC_FS
                lui     k0, %hi(vced_count)
                lw      k1, %lo(vced_count)(k0)
                addiu   k1, 1
                sw      k1, %lo(vced_count)(k0)
#endif
                eret

handle_vcei:
                mfc0    k0, CP0_BADVADDR
                cache   Hit_Writeback_Inv_SD, (k0)      # also cleans pi
#ifdef CONFIG_PROC_FS
                lui     k0, %hi(vcei_count)
                lw      k1, %lo(vcei_count)(k0)
                addiu   k1, 1
                sw      k1, %lo(vcei_count)(k0)
#endif
                eret
                .set    pop
END(except_vec3_r4000)

                __FINIT

/*
 * Build a default exception handler for the exceptions that don't need
 * special handlers.  If you didn't know yet - I *like* playing games with
 * the C preprocessor ...
 */
#define __BUILD_clear_none(exception)
#define __BUILD_clear_sti(exception)                                    \
                STI
#define __BUILD_clear_cli(exception)                                    \
                CLI
#define __BUILD_clear_fpe(exception)                                    \
                cfc1    a1,fcr31;                                       \
                li      a2,~(0x3f<<12);                                 \
                and     a2,a1;                                          \
                ctc1    a2,fcr31;                                       \
                STI
#define __BUILD_clear_ade(exception)                                    \
                .set    reorder;                                        \
                MFC0    t0,CP0_BADVADDR;                                \
                .set    noreorder;                                      \
                REG_S   t0,PT_BVADDR(sp);                               \
                KMODE
#define __BUILD_silent(exception)

#define fmt "Got %s at %08lx.\n"

#define __BUILD_verbose(exception)                                      \
                la      a1,8f;                                          \
                TEXT    (#exception);                                   \
                REG_L   a2,PT_EPC(sp);                                  \
                PRINT(fmt)
#define __BUILD_count(exception)                                        \
                .set    reorder;                                        \
                lw      t0,exception_count_##exception;                 \
                .set    noreorder;                                      \
                addiu   t0, 1;                                          \
                sw      t0,exception_count_##exception;                 \
                .data;                                                  \
EXPORT(exception_count_##exception);                                    \
                .word   0;                                              \
                .previous;
#define BUILD_HANDLER(exception,handler,clear,verbose)                  \
                .align  5;                                              \
NESTED(handle_##exception, PT_SIZE, sp);                                \
                .set    noat;                                           \
                SAVE_ALL;                                               \
FEXPORT(handle_##exception##_int);                                      \
                __BUILD_clear_##clear(exception);                       \
                .set    at;                                             \
                __BUILD_##verbose(exception);                           \
                jal     do_##handler;                                   \
                 move   a0, sp;                                         \
                j       ret_from_exception;                             \
                 nop;                                                   \
END(handle_##exception)

                BUILD_HANDLER(adel,ade,ade,silent)              /* #4  */
                BUILD_HANDLER(ades,ade,ade,silent)              /* #5  */
                BUILD_HANDLER(ibe,be,cli,silent)                /* #6  */
                BUILD_HANDLER(dbe,be,cli,silent)                /* #7  */
                BUILD_HANDLER(bp,bp,sti,silent)                 /* #9  */
                BUILD_HANDLER(ri,ri,sti,silent)                 /* #10 */
                BUILD_HANDLER(cpu,cpu,sti,silent)               /* #11 */
                BUILD_HANDLER(ov,ov,sti,silent)                 /* #12 */
                BUILD_HANDLER(tr,tr,sti,silent)                 /* #13 */
                BUILD_HANDLER(fpe,fpe,fpe,silent)               /* #15 */
                BUILD_HANDLER(mdmx,mdmx,sti,silent)             /* #22 */
                BUILD_HANDLER(watch,watch,sti,silent)           /* #23 */
                BUILD_HANDLER(mcheck,mcheck,cli,silent)         /* #24 */
                BUILD_HANDLER(reserved,reserved,sti,silent)     /* others */

                .set    pop

/*
 * Table of syscalls
 */
                .data
                .align  PTRLOG
EXPORT(sys_call_table)
#define SYS(call, narg) PTR call

                /* Reserved space for all SVR4 syscalls. */
                .space  (1000)*PTRSIZE

#ifdef CONFIG_BINFMT_IRIX
                /* 32bit IRIX5 system calls. */
#include "irix5sys.h"
#else
                .space  (1000)*PTRSIZE          /* No IRIX syscalls */
#endif

                /* Reserved space for all the BSD43 and POSIX syscalls. */
                .space  (2000)*PTRSIZE

                /* Linux flavoured syscalls. */
#include "syscalls.h"

/*
 * Number of arguments of each syscall
 */
EXPORT(sys_narg_table)
#undef SYS
#define SYS(call, narg) .byte narg

                /* Reserved space for all SVR4 flavoured syscalls. */
                .space  (1000)

#ifdef CONFIG_BINFMT_IRIX
                /* 32bit IRIX5 system calls. */
#include "irix5sys.h"
#else
                .space  (1000)                  /* No IRIX syscalls */
#endif

                /* Reserved space for all the BSD43 and POSIX syscalls. */
                .space  (2000)

                /* Linux flavoured syscalls. */
#include "syscalls.h"