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

 static void tlb_refill_fail(struct exception_regdump *pstate);
 static void tlb_invalid_fail(struct exception_regdump *pstate);
 static void tlb_modified_fail(struct exception_regdump *pstate);
+static pte_t *find_mapping_and_check(__address badvaddr);
+static void prepare_entry_lo(struct entry_lo *lo, bool g, bool v, bool d, bool c, __address pfn);
 /** Initialize TLB
+ *
  * Initialize TLB.
  * Invalidate all entries and mark wired entries.
  */
+ *
  * @param pstate Interrupted register context.
  */
 void tlb_refill(struct exception_regdump *pstate)
+{
-    struct entry_hi hi;
+    struct entry_lo lo;
     __address badvaddr;
     pte_t *pte;
-    *((__u32 *) &hi) = cp0_entry_hi_read();
     badvaddr = cp0_badvaddr_read();
     spinlock_lock(&VM->lock);
-    /*
-     * Refill cannot succeed if the ASIDs don't match.
-     */
-    if (hi.asid != VM->asid)
-        goto fail;
-    /*
-     * Refill cannot succeed if badvaddr is not
-     * associated with any mapping.
-     */
-    pte = find_mapping(badvaddr, 0);
+    pte = find_mapping_and_check(badvaddr);
     if (!pte)
         goto fail;
     /*
-     * Refill cannot succeed if the mapping is marked as invalid.
+     * Record access to PTE.
      */
-    if (!pte->v)
+    pte->a = 1;
-        goto fail;
+    prepare_entry_lo(&lo, pte->g, pte->v, pte->d, pte->c, pte->pfn);
     /*
      * New entry is to be inserted into TLB
      */
-    cp0_pagemask_write(TLB_PAGE_MASK_16K);
     if ((badvaddr/PAGE_SIZE) % 2 == 0) {
-        cp0_entry_lo0_write(*((__u32 *) pte));
+        cp0_entry_lo0_write(*((__u32 *) &lo));
         cp0_entry_lo1_write(0);
+    }
     else {
         cp0_entry_lo0_write(0);
-        cp0_entry_lo1_write(*((__u32 *) pte));
+        cp0_entry_lo1_write(*((__u32 *) &lo));
+    }
     tlbwr();
     spinlock_unlock(&VM->lock);
     return;
 fail:
     spinlock_unlock(&VM->lock);
     tlb_refill_fail(pstate);
+}
+/** Process TLB Invalid Exception
+ *
+ * Process TLB Invalid Exception.
+ *
+ * @param pstate Interrupted register context.
+ */
 void tlb_invalid(struct exception_regdump *pstate)
+{
+    struct index index;
+    __address badvaddr;
+    struct entry_lo lo;
+    pte_t *pte;
+    badvaddr = cp0_badvaddr_read();
+    /*
+     * Locate the faulting entry in TLB.
+     */
+    tlbp();
+    *((__u32 *) &index) = cp0_index_read();
+    spinlock_lock(&VM->lock);
+    /*
+     * Fail if the entry is not in TLB.
+     */
+    if (index.p)
+        goto fail;
+    pte = find_mapping_and_check(badvaddr);
+    if (!pte)
+        goto fail;
+    /*
+     * Read the faulting TLB entry.
+     */
+    tlbr();
+    /*
+     * Record access to PTE.
+     */
+    pte->a = 1;
+    prepare_entry_lo(&lo, pte->g, pte->v, pte->d, pte->c, pte->pfn);
+    /*
+     * The entry is to be updated in TLB.
+     */
+    if ((badvaddr/PAGE_SIZE) % 2 == 0)
+        cp0_entry_lo0_write(*((__u32 *) &lo));
+    else
+        cp0_entry_lo1_write(*((__u32 *) &lo));
+    tlbwi();
+    spinlock_unlock(&VM->lock);
+    return;
+fail:
+    spinlock_unlock(&VM->lock);
     tlb_invalid_fail(pstate);
+}
+/** Process TLB Modified Exception
+ *
+ * Process TLB Modified Exception.
+ *
+ * @param pstate Interrupted register context.
+ */
 void tlb_modified(struct exception_regdump *pstate)
+{
+    struct index index;
+    __address badvaddr;
+    struct entry_lo lo;
+    pte_t *pte;
+    badvaddr = cp0_badvaddr_read();
+    /*
+     * Locate the faulting entry in TLB.
+     */
+    tlbp();
+    *((__u32 *) &index) = cp0_index_read();
+    spinlock_lock(&VM->lock);
+    /*
+     * Fail if the entry is not in TLB.
+     */
+    if (index.p)
+        goto fail;
+    pte = find_mapping_and_check(badvaddr);
+    if (!pte)
+        goto fail;
+    /*
+     * Fail if the page is not writable.
+     */
+    if (!pte->w)
+        goto fail;
+    /*
+     * Read the faulting TLB entry.
+     */
+    tlbr();
+    /*
+     * Record access and write to PTE.
+     */
+    pte->a = 1;
+    pte->d = 1;
+    prepare_entry_lo(&lo, pte->g, pte->v, pte->w, pte->c, pte->pfn);
+    /*
+     * The entry is to be updated in TLB.
+     */
+    if ((badvaddr/PAGE_SIZE) % 2 == 0)
+        cp0_entry_lo0_write(*((__u32 *) &lo));
+    else
+        cp0_entry_lo1_write(*((__u32 *) &lo));
+    tlbwi();
+    spinlock_unlock(&VM->lock);
+    return;
+fail:
+    spinlock_unlock(&VM->lock);
     tlb_modified_fail(pstate);
+}
 void tlb_refill_fail(struct exception_regdump *pstate)
+{
     char *symbol = "";
     char *s = get_symtab_entry(pstate->epc);
     if (s)
         symbol = s;
-    panic("%X: TLB Invalid Exception at %X(%s)\n", cp0_badvaddr_read(),
+    panic("%X: TLB Invalid Exception at %X(%s)\n", cp0_badvaddr_read(), pstate->epc, symbol);
-          pstate->epc, symbol);
+}
 void tlb_modified_fail(struct exception_regdump *pstate)
+{
     char *symbol = "";
     char *s = get_symtab_entry(pstate->epc);
     if (s)
         symbol = s;
-    panic("%X: TLB Modified Exception at %X(%s)\n", cp0_badvaddr_read(),
+    panic("%X: TLB Modified Exception at %X(%s)\n", cp0_badvaddr_read(), pstate->epc, symbol);
-          pstate->epc, symbol);
+}
 void tlb_invalidate(int asid)
+{
     // TODO
     cpu_priority_restore(pri);
+}
+/** Try to find PTE for faulting address
+ *
+ * Try to find PTE for faulting address.
+ * The VM->lock must be held on entry to this function.
+ *
+ * @param badvaddr Faulting virtual address.
+ *
+ * @return PTE on success, NULL otherwise.
+ */
+pte_t *find_mapping_and_check(__address badvaddr)
+{
+    struct entry_hi hi;
+    pte_t *pte;
+    *((__u32 *) &hi) = cp0_entry_hi_read();
+    /*
+     * Handler cannot succeed if the ASIDs don't match.
+     */
+    if (hi.asid != VM->asid)
+        return NULL;
+    /*
+     * Handler cannot succeed if badvaddr has no mapping.
+     */
+    pte = find_mapping(badvaddr, 0);
+    if (!pte)
+        return NULL;
+    /*
+     * Handler cannot succeed if the mapping is marked as invalid.
+     */
+    if (!pte->v)
+        return NULL;
+    return pte;
+}
+void prepare_entry_lo(struct entry_lo *lo, bool g, bool v, bool d, bool c, __address pfn)
+{
+    lo->g = g;
+    lo->v = v;
+    lo->d = d;
+    lo->c = c;
+    lo->pfn = pfn;
+    lo->zero = 0;
+}

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/arch/mips32/src/mm/tlb.c @ 730 – Rev 391 → 394