Changeset 909c6e3 in mainline for arch/mips/src

Timestamp:

2005-09-07T09:44:30Z (20 years ago)

Author:

Ondrej Palkovsky <ondrap@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

d246e7e

Parents:

24bd23a

Message:

MIPS exception now saves all necesssary information only on stack.

Location:

arch/mips/src

Files:

• context.S (modified) (1 diff)
• exception.c (modified) (4 diffs)
• mm/tlb.c (modified) (1 diff)
• start.S (modified) (7 diffs)

arch/mips/src/context.S

@@ -29 +29 @@
 #define __ASM__
 #include <arch/asm/regname.h>
-#include "context_offset.h"
+#include <arch/context_offset.h>
         
 .text   

arch/mips/src/exception.c

@@ -35 +35 @@
 #include <debug.h>
 
-void exception(void)
+void exception(struct exception_regdump *pstate)
 {
         int excno;
-        __u32 epc;
         __u32 epc_shift = 0;
 
@@ -46 +45 @@
          * NOTE ON OPERATION ORDERING
          *
-         * On entry, cpu_priority_high() must be called before exception bit is cleared.
-         * On exit, exception bit must be set before cpu_priority_restore() is called.
+         * On entry, cpu_priority_high() must be called before 
+         * exception bit is cleared.
          */
 
         cpu_priority_high();
-        epc = cp0_epc_read();
         cp0_status_write(cp0_status_read() & ~ (cp0_status_exl_exception_bit |
                                                 cp0_status_um_bit));
 
-        if (THREAD) {
-                THREAD->saved_epc = epc;
-        }
         /* decode exception number and process the exception */
         switch (excno = (cp0_cause_read() >> 2) & 0x1f) {
@@ -65 +60 @@
                 case EXC_TLBL:
                 case EXC_TLBS:
-                        tlb_invalid();
+                        tlb_invalid(pstate);
                         break;
                 case EXC_Mod:
@@ -115 +110 @@
         }
         
-        if (THREAD)
-                epc = THREAD->saved_epc;
-        
-        /* Raise EXL bit before epc_write, so that we support
-         * properly nested exceptions
-         */
-        cp0_status_write(cp0_status_read() | cp0_status_exl_exception_bit);
-        cp0_epc_write(epc + epc_shift);
+        pstate->epc += epc_shift;
 }

arch/mips/src/mm/tlb.c

@@ -36 +36 @@
 #include <symtab.h>
 
-void tlb_refill(void)
+void tlb_refill(struct exception_regdump *pstate)
 {
         panic("tlb_refill exception\n");
 }
 
-void tlb_invalid(void)
+void tlb_invalid(struct exception_regdump *pstate)
 {
         char *symbol = "";
 
         if (THREAD) {
-                char *s = get_symtab_entry(THREAD->saved_epc);
+                char *s = get_symtab_entry(pstate->epc);
                 if (s)
                         symbol = s;
         }
         panic("%X: TLB exception at %X(%s)\n", cp0_badvaddr_read(), 
-              THREAD ? THREAD->saved_epc : 0, symbol);
+              pstate->epc, symbol);
 }
 

arch/mips/src/start.S

@@ -32 +32 @@
 #include <arch/mm/page.h>
 #include <arch/asm/boot.h>
-#include <arch/context.h>
+#include <arch/context_offset.h>
         
 .text
@@ -56 +56 @@
         sw $a2,EOFFSET_A2(\r)
         sw $a3,EOFFSET_A3(\r)
-        sw $t0,EOFFSET_A4(\r)
+        sw $t0,EOFFSET_T0(\r)
         sw $t1,EOFFSET_T1(\r)
         sw $t2,EOFFSET_T2(\r)
@@ -87 +87 @@
         mfc0 $at, $status
         sw $at,EOFFSET_STATUS(\r)
+        mfc0 $at, $epc
+        sw $at,EOFFSET_EPC(\r)
 .endm
 
@@ -96 +98 @@
         lw $a2,EOFFSET_A2(\r)
         lw $a3,EOFFSET_A3(\r)
-        lw $t0,EOFFSET_A4(\r)
+        lw $t0,EOFFSET_T0(\r)
         lw $t1,EOFFSET_T1(\r)
         lw $t2,EOFFSET_T2(\r)
@@ -125 +127 @@
         lw $at,EOFFSET_STATUS(\r)
         mtc0 $at, $status
+        lw $at,EOFFSET_EPC(\r)
+        mtc0 $at, $epc
         
         lw $at,EOFFSET_AT(\r)
@@ -192 +196 @@
         add $sp, $k0, 0
 
-        jal exception
+        add $a0, $sp, 0 
+        jal exception /* exception(register_space) */
         nop
 
@@ -206 +211 @@
         add $sp, $k0, 0
 
-        jal tlb_refill
+        add $a0, $sp, 0 
+        jal tlb_refill /* tlb_refill(register_space) */
         nop