Changeset 5c2af75 in mainline for kernel/generic/src/mm/backend_user.c

Timestamp:

2016-08-30T16:10:26Z (8 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

2f6ad06

Parents:

072607b

Message:

Implement user_backend page fault handler

File:

• kernel/generic/src/mm/backend_user.c (modified) (2 diffs)

kernel/generic/src/mm/backend_user.c

@@ -39 +39 @@
 #include <mm/as.h>
 #include <mm/page.h>
+#include <abi/ipc/methods.h>
+#include <ipc/sysipc.h>
 #include <synch/mutex.h>
 #include <typedefs.h>
 #include <align.h>
 #include <debug.h>
+#include <errno.h>
+#include <log.h>
 
 static bool user_create(as_area_t *);
@@ -125 +129 @@
         ASSERT(IS_ALIGNED(upage, PAGE_SIZE));
 
-        return AS_PF_FAULT;
+        if (!as_area_check_access(area, access))
+                return AS_PF_FAULT;
+
+        ipc_data_t data = {};
+        IPC_SET_IMETHOD(data, IPC_M_PAGE_IN);
+        IPC_SET_ARG1(data, upage - area->base);
+        IPC_SET_ARG2(data, PAGE_SIZE);
+
+        int rc = ipc_req_internal(area->backend_data.pager, &data);
+
+        if (rc != EOK) {
+                log(LF_USPACE, LVL_FATAL,
+                    "Page-in request for page %#" PRIxn
+                    " at pager %d failed with error %d.",
+                    upage, area->backend_data.pager, rc);
+                return AS_PF_FAULT;
+        }
+
+        if (IPC_GET_RETVAL(data) != EOK)
+                return AS_PF_FAULT;
+
+        /*
+         * A successful reply will contain the physical frame in ARG1.
+         * The physical frame will have the reference count already
+         * incremented.
+         */
+
+        uintptr_t frame = IPC_GET_ARG1(data);
+        page_mapping_insert(AS, upage, frame, as_area_get_flags(area));
+        if (!used_space_insert(area, upage, 1))
+                panic("Cannot insert used space.");
+
+        return AS_PF_OK;
 }