Removed special-case utcb shared page from posix services.

Previously a so-called utcb shared page was used for transfering
data between posix services. This was a special shmat/get/dt case
allocating from its own virtual pool. Now the term utcb is renamed
as a shared page and integrated with the shm* handling routines.

Generic l4 threads will use long-ipc and not this method. Posix
services will continue to communicate on a shared page for now.
	modified:   tasks/libl4/include/l4lib/ipcdefs.h
	modified:   tasks/libl4/src/init.c
	new file:   tasks/libposix/init.c
	modified:   tasks/mm0/include/shm.h
	modified:   tasks/mm0/include/task.h
	deleted:    tasks/mm0/include/utcb.h
	modified:   tasks/mm0/main.c
	modified:   tasks/mm0/src/boot.c
	modified:   tasks/mm0/src/clone.c
	modified:   tasks/mm0/src/execve.c
	modified:   tasks/mm0/src/exit.c
	modified:   tasks/mm0/src/init.c
	modified:   tasks/mm0/src/shm.c
	modified:   tasks/mm0/src/task.c
	deleted:    tasks/mm0/src/utcb.c
	deleted:    tools/l4-qemu

tasks/mm0/src/boot.c

@@ -5,7 +5,6 @@
  */
 #include <boot.h>
 #include <mmap.h>
-#include <utcb.h>
 #include <shm.h>
 #include <l4/api/thread.h>
 #include <l4lib/arch/syslib.h>
@@ -74,11 +73,12 @@ int boottask_mmap_regions(struct tcb *task, struct vm_file *file)
 		return (int)mapped;
 	}
 
-	/* Task's utcb */
-	task->utcb = utcb_new_address();
+	/* Task's default shared page */
+	task->shared_page = shm_new_address(DEFAULT_SHPAGE_SIZE/PAGE_SIZE);
 
 	/* Create a shared memory segment available for shmat() */
-	if (IS_ERR(shm = shm_new((key_t)task->utcb, __pfn(DEFAULT_UTCB_SIZE))))
+	if (IS_ERR(shm = shm_new((key_t)task->shared_page,
+				 __pfn(DEFAULT_SHPAGE_SIZE))))
 		return (int)shm;
 
 	return 0;

tasks/mm0/src/clone.c

@@ -12,7 +12,6 @@
 #include <vm_area.h>
 #include <task.h>
 #include <mmap.h>
-#include <utcb.h>
 #include <shm.h>
 #include <test.h>
 #include <clone.h>
@@ -31,7 +30,7 @@ int vfs_notify_fork(struct tcb *child, struct tcb *parent, unsigned int flags)
 	/* Write parent and child information */
 	write_mr(L4SYS_ARG0, parent->tid);
 	write_mr(L4SYS_ARG1, child->tid);
-	write_mr(L4SYS_ARG2, (unsigned int)child->utcb);
+	write_mr(L4SYS_ARG2, (unsigned int)child->shared_page);
 	write_mr(L4SYS_ARG3, flags);
 
 	if ((err = l4_sendrecv(VFS_TID, VFS_TID,
@@ -85,8 +84,10 @@ int sys_fork(struct tcb *parent)
 		BUG();
 
 	/* Create and prefault a utcb for child and map it to vfs task */
-	utcb_map_to_task(child, find_task(VFS_TID),
-			 UTCB_NEW_ADDRESS | UTCB_NEW_SHM | UTCB_PREFAULT);
+	shpage_map_to_task(child, find_task(VFS_TID),
+			   SHPAGE_NEW_ADDRESS | SHPAGE_NEW_SHM |
+			   SHPAGE_PREFAULT);
+
 	// printf("Mapped 0x%p to vfs as utcb of %d\n", child->utcb, child->tid);
 
 	/* We can now notify vfs about forked process */
@@ -138,8 +139,9 @@ int do_clone(struct tcb *parent, unsigned long child_stack, unsigned int flags)
 		BUG();
 
 	/* Create and prefault a utcb for child and map it to vfs task */
-	utcb_map_to_task(child, find_task(VFS_TID),
-			 UTCB_NEW_ADDRESS | UTCB_NEW_SHM | UTCB_PREFAULT);
+	shpage_map_to_task(child, find_task(VFS_TID),
+			   SHPAGE_NEW_ADDRESS | SHPAGE_NEW_SHM |
+			   SHPAGE_PREFAULT);
 
 	/* We can now notify vfs about forked process */
 	vfs_notify_fork(child, parent, flags);

tasks/mm0/src/execve.c

@@ -37,16 +37,16 @@ int vfs_open_bypath(const char *pathname, unsigned long *vnum, unsigned long *le
 		return -ESRCH;
 
 	/*
-	 * Copy string to vfs utcb.
+	 * Copy string to vfs shared page.
 	 *
 	 * FIXME: There's a chance we're overwriting other tasks'
-	 * ipc information that is on the vfs utcb.
+	 * ipc information that is on the vfs shared page.
 	 */
-	strcpy(vfs->utcb, pathname);
+	strcpy(vfs->shared_page, pathname);
 
 	l4_save_ipcregs();
 
-	write_mr(L4SYS_ARG0, (unsigned long)vfs->utcb);
+	write_mr(L4SYS_ARG0, (unsigned long)vfs->shared_page);
 
 	if ((err = l4_sendrecv(VFS_TID, VFS_TID,
 			       L4_IPC_TAG_PAGER_OPEN_BYPATH)) < 0) {

tasks/mm0/src/exit.c

@@ -3,9 +3,9 @@
  *
  * Copyright (C) 2008 Bahadir Balban
  */
+#include <shm.h>
 #include <task.h>
 #include <file.h>
-#include <utcb.h>
 #include <exit.h>
 #include <test.h>
 #include <vm_area.h>
@@ -90,7 +90,7 @@ int execve_recycle_task(struct tcb *new, struct tcb *orig)
 	new->pagerid = orig->pagerid;
 
 	/* Copy utcb */
-	new->utcb = orig->utcb;
+	new->shared_page = orig->shared_page;
 
 	/* Copy parent relationship */
 	BUG_ON(new->parent);
@@ -131,9 +131,9 @@ void do_exit(struct tcb *task, int status)
 	/* Tell vfs that task is exiting */
 	vfs_notify_exit(task, status);
 
-	/* Remove utcb shm areas from vfs */
-	// printf("Unmapping 0x%p from vfs as utcb of %d\n", task->utcb, task->tid);
-	utcb_unmap_from_task(task, find_task(VFS_TID));
+	/* Remove default shared page shm areas from vfs */
+	// printf("Unmapping 0x%p from vfs as shared-page of %d\n", task->shared_page, task->tid);
+	shpage_unmap_from_task(task, find_task(VFS_TID));
 
 	/* Free task's local tcb */
 	tcb_destroy(task);

tasks/mm0/src/init.c

@@ -15,7 +15,6 @@
 #include <shm.h>
 #include <file.h>
 #include <init.h>
-#include <utcb.h>
 #include <test.h>
 #include <boot.h>
 
@@ -168,12 +167,8 @@ void init_mm(struct initdata *initdata)
 		printf("SHM initialisation failed.\n");
 		BUG();
 	}
-	// printf("%s: Initialised shm structures.\n", __TASKNAME__);
+	printf("%s: Initialised shm structures.\n", __TASKNAME__);
 
-	if (utcb_pool_init() < 0) {
-		printf("UTCB initialisation failed.\n");
-		BUG();
-	}
 
 	/* For supplying contiguous virtual addresses to pager */
 	pager_address_pool_init();

tasks/mm0/src/shm.c

@@ -7,7 +7,6 @@
 #include <stdio.h>
 #include <task.h>
 #include <mmap.h>
-#include <utcb.h>
 #include <vm_area.h>
 #include <globals.h>
 #include <lib/malloc.h>
@@ -181,15 +180,8 @@ void shm_destroy_priv_data(struct vm_file *shm_file)
 	struct shm_descriptor *shm_desc = shm_file_to_desc(shm_file);
 
 	/* Release the shared memory address */
-	if ((unsigned long)shm_desc->shm_addr >= UTCB_AREA_START &&
-	    (unsigned long)shm_desc->shm_addr < UTCB_AREA_END) {
-		BUG_ON(utcb_delete_address(shm_desc->shm_addr) < 0);
-	} else if ((unsigned long)shm_desc->shm_addr >= SHM_AREA_START &&
-	    	   (unsigned long)shm_desc->shm_addr < SHM_AREA_END) {
-		BUG_ON(shm_delete_address(shm_desc->shm_addr,
-					  shm_file->vm_obj.npages) < 0);
-	} else
-		BUG();
+	BUG_ON(shm_delete_address(shm_desc->shm_addr,
+				  shm_file->vm_obj.npages) < 0);
 
 	/* Release the shared memory id */
 	BUG_ON(id_del(shm_ids, shm_desc->shmid) < 0);
@@ -320,3 +312,76 @@ int sys_shmget(key_t key, int size, int shmflg)
 		return -ENOENT;
 }
 
+
+
+/*
+ * Currently, a default shm page is allocated to every thread in the system
+ * for efficient ipc communication. This part below provides the allocation
+ * and mapping of this page using shmat/get/dt call semantics.
+ */
+
+/*
+ * Sends shpage address information to requester. The requester then uses
+ * this address as a shm key and maps it via shmget/shmat.
+ */
+void *task_send_shpage_address(struct tcb *sender, l4id_t taskid)
+{
+	struct tcb *task = find_task(taskid);
+
+	/* Is the task asking for its own utcb address */
+	if (sender->tid == taskid) {
+		/* It hasn't got one allocated. */
+		BUG_ON(!task->shared_page);
+
+		/* Return it to requester */
+		return task->shared_page;
+
+	/* A task is asking for someone else's utcb */
+	} else {
+		/* Only vfs is allowed to do so yet, because its a server */
+		if (sender->tid == VFS_TID) {
+			/*
+			 * Return shpage address to requester. Note if there's
+			 * none allocated so far, requester gets 0. We don't
+			 * allocate one here.
+			 */
+			return task->shared_page;
+		}
+	}
+	return 0;
+}
+
+int shpage_map_to_task(struct tcb *owner, struct tcb *mapper, unsigned int flags)
+{
+	struct vm_file *default_shm;
+
+	/* Allocate a new utcb address */
+	if (flags & SHPAGE_NEW_ADDRESS)
+		owner->shared_page =
+			shm_new_address(DEFAULT_SHPAGE_SIZE/PAGE_SIZE);
+	else if (!owner->shared_page)
+		BUG();
+
+	/* Create a new shared memory segment for utcb */
+	if (flags & SHPAGE_NEW_SHM)
+		if (IS_ERR(default_shm = shm_new((key_t)owner->shared_page,
+					      __pfn(DEFAULT_SHPAGE_SIZE))))
+		return (int)default_shm;
+
+	/* Map the utcb to mapper */
+	if (IS_ERR(shmat_shmget_internal(mapper, (key_t)owner->shared_page,
+					 owner->shared_page)))
+		BUG();
+
+	/* Prefault the owner's utcb to mapper's address space */
+	if (flags & SHPAGE_PREFAULT)
+		for (int i = 0; i < __pfn(DEFAULT_SHPAGE_SIZE); i++)
+			prefault_page(mapper, (unsigned long)owner->shared_page +
+				      __pfn_to_addr(i), VM_READ | VM_WRITE);
+	return 0;
+}
+
+int shpage_unmap_from_task(struct tcb *owner, struct tcb *mapper)
+{
+	return sys_shmdt(mapper, owner->shared_page);
+}

tasks/mm0/src/task.c

@@ -24,7 +24,6 @@
 #include <vm_area.h>
 #include <memory.h>
 #include <file.h>
-#include <utcb.h>
 #include <task.h>
 #include <exec.h>
 #include <shm.h>
@@ -611,13 +610,13 @@ int vfs_send_task_data(struct tcb *vfs)
 	}
 
 	BUG_ON(!(self = find_task(self_tid())));
-	BUG_ON(!vfs->utcb);
+	BUG_ON(!vfs->shared_page);
 
 	/* Attach mm0 to vfs's utcb segment just like a normal task */
-	utcb_map_to_task(vfs, self, UTCB_PREFAULT);
+	shpage_map_to_task(vfs, self, SHPAGE_PREFAULT);
 
-	/* Write all requested task information to utcb's user buffer area */
-	tdata_head = (struct task_data_head *)vfs->utcb;
+	/* Write all requested task information to shared pages's user buffer area */
+	tdata_head = (struct task_data_head *)vfs->shared_page;
 
 	/* First word is total number of tcbs */
 	tdata_head->total = global_tasks.total;
@@ -625,7 +624,7 @@ int vfs_send_task_data(struct tcb *vfs)
 	/* Write per-task data for all tasks */
 	list_for_each_entry(t, &global_tasks.list, list) {
 		tdata_head->tdata[li].tid = t->tid;
-		tdata_head->tdata[li].utcb_address = (unsigned long)t->utcb;
+		tdata_head->tdata[li].utcb_address = (unsigned long)t->shared_page;
 		li++;
 	}
 

tasks/mm0/src/utcb.c

@@ -1,107 +0,0 @@
-/*
- * utcb address allocation for user tasks.
- *
- * Copyright (C) 2008 Bahadir Balban
- */
-#include <stdio.h>
-#include <utcb.h>
-#include <lib/addr.h>
-#include <l4/macros.h>
-#include <l4lib/arch/syscalls.h>
-#include <l4lib/arch/syslib.h>
-#include <task.h>
-#include <shm.h>
-#include <vm_area.h>
-#include <syscalls.h>
-#include INC_GLUE(memlayout.h)
-
-static struct address_pool utcb_vaddr_pool;
-
-int utcb_pool_init()
-{
-	int err;
-	if ((err = address_pool_init(&utcb_vaddr_pool,
-				     UTCB_AREA_START,
-				     UTCB_AREA_END)) < 0) {
-		printf("UTCB address pool initialisation failed: %d\n", err);
-		return err;
-	}
-	return 0;
-}
-
-void *utcb_new_address(void)
-{
-	return address_new(&utcb_vaddr_pool, 1);
-}
-
-int utcb_delete_address(void *utcb_addr)
-{
-	return address_del(&utcb_vaddr_pool, utcb_addr, 1);
-}
-
-/*
- * Sends utcb address information to requester task, allocates
- * an address if it doesn't exist and the requester is asking
- * for its own. The requester then uses this address as a shm key and
- * maps its own utcb via shmget/shmat.
- */
-void *task_send_utcb_address(struct tcb *sender, l4id_t taskid)
-{
-	struct tcb *task = find_task(taskid);
-
-	/* Is the task asking for its own utcb address */
-	if (sender->tid == taskid) {
-		/* It hasn't got one allocated. */
-		BUG_ON(!task->utcb);
-
-		/* Return it to requester */
-		return task->utcb;
-
-	/* A task is asking for someone else's utcb */
-	} else {
-		/* Only vfs is allowed to do so yet, because its a server */
-		if (sender->tid == VFS_TID) {
-			/*
-			 * Return utcb address to requester. Note if there's
-			 * none allocated so far, requester gets 0. We don't
-			 * allocate one here.
-			 */
-			return task->utcb;
-		}
-	}
-	return 0;
-}
-
-int utcb_map_to_task(struct tcb *owner, struct tcb *mapper, unsigned int flags)
-{
-	struct vm_file *utcb_shm;
-
-	/* Allocate a new utcb address */
-	if (flags & UTCB_NEW_ADDRESS)
-		owner->utcb = utcb_new_address();
-	else if (!owner->utcb)
-		BUG();
-
-	/* Create a new shared memory segment for utcb */
-	if (flags & UTCB_NEW_SHM)
-		if (IS_ERR(utcb_shm = shm_new((key_t)owner->utcb,
-					      __pfn(DEFAULT_UTCB_SIZE))))
-		return (int)utcb_shm;
-
-	/* Map the utcb to mapper */
-	if (IS_ERR(shmat_shmget_internal(mapper, (key_t)owner->utcb,
-					 owner->utcb)))
-		BUG();
-
-	/* Prefault the owner's utcb to mapper's address space */
-	if (flags & UTCB_PREFAULT)
-		for (int i = 0; i < __pfn(DEFAULT_UTCB_SIZE); i++)
-			prefault_page(mapper, (unsigned long)owner->utcb +
-				      __pfn_to_addr(i), VM_READ | VM_WRITE);
-	return 0;
-}
-
-int utcb_unmap_from_task(struct tcb *owner, struct tcb *mapper)
-{
-	return sys_shmdt(mapper, owner->utcb);
-}