WebSVN – HelenOS-historic – Diff – /kernel/trunk/arch/mips32/src/exception.c

 /*
  * Copyright (C) 2003-2004 Jakub Jermar
  * All rights reserved.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
+ *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  * - 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.
  * - The name of the author may not be used to endorse or promote products
  *   derived from this software without specific prior written permission.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
  */
 #include <arch/exception.h>
 #include <arch/interrupt.h>
 #include <panic.h>
 #include <arch/cp0.h>
 #include <arch/types.h>
 #include <arch.h>
 #include <debug.h>
 #include <proc/thread.h>
 #include <symtab.h>
 #include <print.h>
 #include <interrupt.h>
 #include <func.h>
 #include <console/kconsole.h>
 #include <arch/debugger.h>
 #include <syscall/syscall.h>
 static char * exctable[] = {
     "Interrupt","TLB Modified","TLB Invalid","TLB Invalid Store",
         "Address Error - load/instr. fetch",
         "Address Error - store",
         "Bus Error - fetch instruction",
         "Bus Error - data reference",
         "Syscall",
         "BreakPoint",
         "Reserved Instruction",
         "Coprocessor Unusable",
         "Arithmetic Overflow",
         "Trap",
         "Virtual Coherency - instruction",
         "Floating Point",
         NULL, NULL, NULL, NULL, NULL, NULL, NULL,
         "WatchHi/WatchLo", /* 23 */
         NULL, NULL, NULL, NULL, NULL, NULL, NULL,
         "Virtual Coherency - data",
 };
 static void print_regdump(istate_t *istate)
+{
     char *pcsymbol = "";
     char *rasymbol = "";
     char *s = get_symtab_entry(istate->epc);
     if (s)
         pcsymbol = s;
     s = get_symtab_entry(istate->ra);
     if (s)
         rasymbol = s;
     printf("PC: %X(%s) RA: %X(%s), SP(%P)\n",istate->epc,pcsymbol,
            istate->ra,rasymbol, istate->sp);
+}
 static void unhandled_exception(int n, istate_t *istate)
+{
     print_regdump(istate);
     panic("unhandled exception %s\n", exctable[n]);
+}
 static void breakpoint_exception(int n, istate_t *istate)
+{
 #ifdef CONFIG_DEBUG
     debugger_bpoint(istate);
 #else
     /* it is necessary to not re-execute BREAK instruction after
        returning from Exception handler
        (see page 138 in R4000 Manual for more information) */
     istate->epc += 4;
 #endif
+}
 static void tlbmod_exception(int n, istate_t *istate)
+{
     tlb_modified(istate);
+}
 static void tlbinv_exception(int n, istate_t *istate)
+{
     tlb_invalid(istate);
+}
 #ifdef CONFIG_FPU_LAZY
 static void cpuns_exception(int n, istate_t *istate)
+{
     if (cp0_cause_coperr(cp0_cause_read()) == fpu_cop_id)
         scheduler_fpu_lazy_request();
     else
         panic("unhandled Coprocessor Unusable Exception\n");
+}
 #endif
 static void interrupt_exception(int n, istate_t *istate)
+{
     __u32 cause;
     int i;
     /* decode interrupt number and process the interrupt */
     cause = (cp0_cause_read() >> 8) &0xff;
     for (i = 0; i < 8; i++)
         if (cause & (1 << i))
             exc_dispatch(i+INT_OFFSET, istate);
+}
-#include <debug.h>
-/** Handle syscall userspace call */
+__native syscall_handler(__native a0, __native a1, __native a2,
-static void syscall_exception(int n, istate_t *istate)
+             __native a3, __native sysnum)
+{
-    interrupts_enable();
-    if (istate->t0 < SYSCALL_END)
+    if (sysnum < SYSCALL_END)
-        istate->v0 = syscall_table[istate->t0](istate->a0,
+        return syscall_table[sysnum](a0,a1,a2,a3);
-                               istate->a1,
-                               istate->a2,
-                               istate->a3);
-    else
-        panic("Undefined syscall %d", istate->a3);
+    panic("Undefined syscall %d", sysnum);
-    istate->epc += 4;
-    interrupts_disable();
+}
+/** Handle syscall userspace call */
-void exception(istate_t *istate)
+static void syscall_exception(int n, istate_t *istate)
+{
-    int cause;
-    int excno;
-    ASSERT(CPU != NULL);
-    /*
-     * NOTE ON OPERATION ORDERING
-     *
-     * On entry, interrupts_disable() must be called before
-     * exception bit is cleared.
-     */
-    interrupts_disable();
-    cp0_status_write(cp0_status_read() & ~ (cp0_status_exl_exception_bit |
-                        cp0_status_um_bit));
-    /* Save istate so that the threads can access it */
+    panic("Syscall is handled through shortcut");
-    /* If THREAD->istate is set, this is nested exception,
-     * do not rewrite it
-     */
-    if (THREAD && !THREAD->istate)
-        THREAD->istate = istate;
-    cause = cp0_cause_read();
-    excno = cp0_cause_excno(cause);
-    /* Dispatch exception */
-    exc_dispatch(excno, istate);
-    /* Set to NULL, so that we can still support nested
-     * exceptions
-     * TODO: We should probably set EXL bit before this command,
-     * nesting. On the other hand, if some exception occurs between
-     * here and ERET, it won't set anything on the istate anyway.
-     */
-    if (THREAD)
-        THREAD->istate = NULL;
+}
 void exception_init(void)
+{
     int i;
     /* Clear exception table */
     for (i=0;i < IVT_ITEMS; i++)
         exc_register(i, "undef", (iroutine) unhandled_exception);
     exc_register(EXC_Bp, "bkpoint", (iroutine) breakpoint_exception);
     exc_register(EXC_Mod, "tlb_mod", (iroutine) tlbmod_exception);
     exc_register(EXC_TLBL, "tlbinvl", (iroutine) tlbinv_exception);
     exc_register(EXC_TLBS, "tlbinvl", (iroutine) tlbinv_exception);
     exc_register(EXC_Int, "interrupt", (iroutine) interrupt_exception);
 #ifdef CONFIG_FPU_LAZY
     exc_register(EXC_CpU, "cpunus", (iroutine) cpuns_exception);
 #endif
     exc_register(EXC_Sys, "syscall", (iroutine) syscall_exception);
+}

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/arch/mips32/src/exception.c – Rev 959 → 1096