Changeset e3c762cd in mainline for arch/mips32/src/mm/tlb.c

Timestamp:

2006-05-05T11:59:19Z (19 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

de07bcf

Parents:

22cf454d

Message:

Complete implementation of copy_from_uspace() and copy_to_uspace()
for amd64 and ia32. Other architectures still compile and run,
but need to implement their own assembly-only memcpy(), memcpy_from_uspace(),
memcpy_to_uspace() and their failover parts. For these architectures
only dummy implementations are provided.

File:

• arch/mips32/src/mm/tlb.c (modified) (11 diffs)

arch/mips32/src/mm/tlb.c

@@ -45 +45 @@
 static void tlb_modified_fail(istate_t *istate);
 
-static pte_t *find_mapping_and_check(__address badvaddr);
+static pte_t *find_mapping_and_check(__address badvaddr, istate_t *istate, int *pfrc);
 
 static void prepare_entry_lo(entry_lo_t *lo, bool g, bool v, bool d, bool cacheable, __address pfn);
@@ -92 +92 @@
         __address badvaddr;
         pte_t *pte;
+        int pfrc;
 
         badvaddr = cp0_badvaddr_read();
@@ -101 +102 @@
         page_table_lock(AS, true);
 
-        pte = find_mapping_and_check(badvaddr);
-        if (!pte)
-                goto fail;
+        pte = find_mapping_and_check(badvaddr, istate, &pfrc);
+        if (!pte) {
+                switch (pfrc) {
+                case AS_PF_FAULT:
+                        goto fail;
+                        break;
+                case AS_PF_DEFER:
+                        /*
+                         * The page fault came during copy_from_uspace()
+                         * or copy_to_uspace().
+                         */
+                        page_table_unlock(AS, true);
+                        return;
+                default:
+                        panic("unexpected pfrc (%d)\n", pfrc);
+                }
+        }
 
         /*
@@ -149 +164 @@
         entry_hi_t hi;
         pte_t *pte;
+        int pfrc;
 
         badvaddr = cp0_badvaddr_read();
@@ -171 +187 @@
         }
 
-        pte = find_mapping_and_check(badvaddr);
-        if (!pte)
-                goto fail;
+        pte = find_mapping_and_check(badvaddr, istate, &pfrc);
+        if (!pte) {
+                switch (pfrc) {
+                case AS_PF_FAULT:
+                        goto fail;
+                        break;
+                case AS_PF_DEFER:
+                        /*
+                         * The page fault came during copy_from_uspace()
+                         * or copy_to_uspace().
+                         */
+                        page_table_unlock(AS, true);                     
+                        return;
+                default:
+                        panic("unexpected pfrc (%d)\n", pfrc);
+                }
+        }
 
         /*
@@ -218 +248 @@
         entry_hi_t hi;
         pte_t *pte;
+        int pfrc;
 
         badvaddr = cp0_badvaddr_read();
@@ -240 +271 @@
         }
 
-        pte = find_mapping_and_check(badvaddr);
-        if (!pte)
-                goto fail;
+        pte = find_mapping_and_check(badvaddr, istate, &pfrc);
+        if (!pte) {
+                switch (pfrc) {
+                case AS_PF_FAULT:
+                        goto fail;
+                        break;
+                case AS_PF_DEFER:
+                        /*
+                         * The page fault came during copy_from_uspace()
+                         * or copy_to_uspace().
+                         */
+                        page_table_unlock(AS, true);                     
+                        return;
+                default:
+                        panic("unexpected pfrc (%d)\n", pfrc);
+                }
+        }
 
         /*
@@ -322 +367 @@
  *
  * @param badvaddr Faulting virtual address.
+ * @param istate Pointer to interrupted state.
+ * @param pfrc Pointer to variable where as_page_fault() return code will be stored.
  *
  * @return PTE on success, NULL otherwise.
  */
-pte_t *find_mapping_and_check(__address badvaddr)
+pte_t *find_mapping_and_check(__address badvaddr, istate_t *istate, int *pfrc)
 {
         entry_hi_t hi;
@@ -351 +398 @@
                 return pte;
         } else {
+                int rc;
+                
                 /*
                  * Mapping not found in page tables.
@@ -356 +405 @@
                  */
                 page_table_unlock(AS, true);
-                if (as_page_fault(badvaddr)) {
+                switch (rc = as_page_fault(badvaddr, istate)) {
+                case AS_PF_OK:
                         /*
                          * The higher-level page fault handler succeeded,
@@ -365 +415 @@
                         ASSERT(pte && pte->p);
                         return pte;
-                } else {
+                        break;
+                case AS_PF_DEFER:
+                        page_table_lock(AS, true);
+                        *pfrc = AS_PF_DEFER;
+                        return NULL;
+                        break;
+                case AS_PF_FAULT:
                         page_table_lock(AS, true);
                         printf("Page fault.\n");
+                        *pfrc = AS_PF_FAULT;
                         return NULL;
+                        break;
+                default:
+                        panic("unexpected rc (%d)\n", rc);
                 }