Changeset 313 for trunk/kernel/mm/vmm.h

Timestamp:

Aug 2, 2017, 3:24:57 PM (6 years ago)

Author:

alain

Message:

RSeveral modifs in the page-fault handling.

File:

• trunk/kernel/mm/vmm.h (modified) (3 diffs)

trunk/kernel/mm/vmm.h

@@ -272 +272 @@
                        intptr_t           vaddr );
 
+
 /*********************************************************************************************
  * This function is called by the generic exception handler when a page fault 
@@ -291 +292 @@
 /*********************************************************************************************
  * This function returns in the "attr" and "ppn" arguments the PTE associated to a given
- * VPN for a given process. This function must be called on the reference cluster.
- * To get the PTE from another cluster, use the RPC_VMM_GET_PTE.
+ * VPN for a given process. This function must be called by a thread running in the 
+ * reference cluster. To get the PTE from another cluster, use the RPC_VMM_GET_PTE.
  * The vseg containing the searched VPN should be registered in the reference VMM.
  * If the PTE in the reference page table is unmapped, this function allocates the missing
- * physical page from the target cluster defined by the vseg type, and update the reference
- * page table. It can call a RPC_PMEM_GET_PAGES to get the missing physical page,
- * if the target cluster is not the reference cluster.
+ * physical page from the target cluster defined by the vseg type, initilize it,
+ * and update the reference page table. It calls the RPC_PMEM_GET_PAGES to get and 
+ * initialize the missing physical page, if the target cluster is not the reference cluster.
  *********************************************************************************************
  * @ process   : [in] pointer on process descriptor.
@@ -309 +310 @@
                      uint32_t         * attr,
                      ppn_t            * ppn );
+
+/*********************************************************************************************
+ * This function is called by the vmm_get_pte() function.
+ * Depending on the vseg type, defined by the <vseg> argument, it returns the PPN 
+ * (Physical Page Number) associated to a missing page defined by the <vpn> argument.
+ * - For the VSEG_TYPE_FILE, it returns the physical page from the file mapper.
+ *   For all other types, it allocates a new physical page from the cluster defined
+ *   by the <vseg->cxy> field, or by the <vpn> MSB bits for a distributed vseg.
+ * - For the VSEG_TYPE_CODE and VSEG_TYPE_DATA types, the allocated page is initialized
+ *   from the .elf file mapper. For others vseg types it is not initialised.
+ *********************************************************************************************
+ * @ vseg   : local pointer on vseg containing the mising page.
+ * @ vpn    : Virtual Page Number identifying the missing page.
+ * @ ppn    : [out] returned Physical Page Number.
+ ********************************************************************************************/
+error_t vmm_get_one_ppn( vseg_t * vseg,
+                         vpn_t    vpn,
+                         ppn_t  * ppn );
 
 /*********************************************************************************************