From 3a07ae70fd052a2e6f4ae4856f88ff4c93f03ef8 Mon Sep 17 00:00:00 2001
From: Bahadir Balban <bbalban@b-labs.co.uk>
Date: Tue, 5 Feb 2008 01:21:55 +0000
Subject: [PATCH] Rearranged devzero. More bugs to fix.

---
 tasks/fs0/main.c                     |  1 +
 tasks/mm0/include/memory.h           |  3 ++-
 tasks/mm0/src/{zpage.c => devzero.c} | 16 ++++++++++++++++
 tasks/mm0/src/fault.c                |  3 ---
 tasks/mm0/src/init.c                 |  2 +-
 tasks/mm0/src/mmap.c                 |  6 ++----
 6 files changed, 22 insertions(+), 9 deletions(-)
 rename tasks/mm0/src/{zpage.c => devzero.c} (75%)

diff --git a/tasks/fs0/main.c b/tasks/fs0/main.c
index c77af73..4887467 100644
--- a/tasks/fs0/main.c
+++ b/tasks/fs0/main.c
@@ -71,6 +71,7 @@ void handle_fs_requests(void)
 
 void main(void)
 {
+	//	printf("\n%s: Started.\n", __FUNCTION__);
 	initialise();
 
 	wait_pager(PAGER_TID);
diff --git a/tasks/mm0/include/memory.h b/tasks/mm0/include/memory.h
index daf60d0..139919c 100644
--- a/tasks/mm0/include/memory.h
+++ b/tasks/mm0/include/memory.h
@@ -22,7 +22,8 @@ void init_mm_descriptors(struct page_bitmap *page_map,
 			 struct bootdesc *bootdesc, struct membank *membank);
 void init_physmem(struct initdata *initdata, struct membank *membank);
 
-void init_zero_page(void);
+void init_devzero(void);
+struct vm_file *get_devzero(void);
 void *get_zero_page(void);
 void put_zero_page(void);
 
diff --git a/tasks/mm0/src/zpage.c b/tasks/mm0/src/devzero.c
similarity index 75%
rename from tasks/mm0/src/zpage.c
rename to tasks/mm0/src/devzero.c
index e43379a..c003d37 100644
--- a/tasks/mm0/src/zpage.c
+++ b/tasks/mm0/src/devzero.c
@@ -15,6 +15,7 @@
 
 static void *zpage_p;
 static struct page *zpage;
+static struct vm_file devzero;
 
 void init_zero_page(void)
 {
@@ -35,6 +36,21 @@ void init_zero_page(void)
 	zpage->count++;
 }
 
+void init_devzero(void)
+{
+	init_zero_page();
+
+	INIT_LIST_HEAD(&devzero.list);
+	INIT_LIST_HEAD(&devzero.page_cache_list);
+	devzero.length = (unsigned int)-1;
+	devzero.inode.i_addr = -1;
+}
+
+struct vm_file *get_devzero(void)
+{
+	return &devzero;
+}
+
 void *get_zero_page(void)
 {
 	zpage->count++;
diff --git a/tasks/mm0/src/fault.c b/tasks/mm0/src/fault.c
index e0c95fa..bab8e64 100644
--- a/tasks/mm0/src/fault.c
+++ b/tasks/mm0/src/fault.c
@@ -317,7 +317,6 @@ int do_anon_page(struct fault_data *fault)
 
 		/* Add the page to it's owner's list of in-memory pages */
 		BUG_ON(!list_empty(&page->list));
-		BUG();
 		list_add(&page->list, &page->owner->page_cache_list);
 
 		/* The offset of this page in its owner file */
@@ -400,8 +399,6 @@ int do_page_fault(struct fault_data *fault)
 		err = do_file_page(fault);
 
 	/* Return the ipc and by doing so restart the faulty thread */
-	printf("Finished handling fault. Restarting thread by returning.\n");
-
 	l4_ipc_return(err);
 	return 0;
 }
diff --git a/tasks/mm0/src/init.c b/tasks/mm0/src/init.c
index 827dde8..e191b1e 100644
--- a/tasks/mm0/src/init.c
+++ b/tasks/mm0/src/init.c
@@ -33,7 +33,7 @@ void init_mm(struct initdata *initdata)
 	printf("%s: Initialised page allocator.\n", __TASKNAME__);
 
 	/* Initialise the zero page */
-	init_zero_page();
+	init_devzero();
 	printf("%s: Initialised zero page.\n", __TASKNAME__);
 
 	init_utcb();
diff --git a/tasks/mm0/src/mmap.c b/tasks/mm0/src/mmap.c
index 45c2cfc..9230138 100644
--- a/tasks/mm0/src/mmap.c
+++ b/tasks/mm0/src/mmap.c
@@ -9,10 +9,9 @@
 #include <posix/sys/types.h>
 #include <task.h>
 #include <mmap.h>
+#include <memory.h>
 #include <l4lib/arch/syscalls.h>
 
-static struct vm_file devzero;
-
 /* Swap related bookkeeping.
 static struct vm_file shm_swap_file;
 static struct id_pool *swap_file_offset_pool;
@@ -253,7 +252,6 @@ int vma_swapfile_realloc(struct vm_area *vma, unsigned long pfn_start,
 }
 
 
-
 /* This shrinks the vma from *one* end only, either start or end */
 int vma_shrink(struct vm_area *vma, struct tcb *task, unsigned long pfn_start,
 	       unsigned long pfn_end)
@@ -441,7 +439,7 @@ int do_mmap(struct vm_file *mapfile, unsigned long f_offset, struct tcb *t,
 
 	if (!mapfile) {
 	       if (flags & VMA_ANON) {
-			mapfile = &devzero;
+			mapfile = get_devzero();
 			f_offset = 0;
 	       } else
 			BUG();