merge vm_map.h into uvm_map.h, kinda matches netbsd's approach

1 files changed, 351 insertions, 1 deletions

diff --git a/sys/uvm/uvm_map.h b/sys/uvm/uvm_map.h
index 3747c4da8ff..11e94353dcd 100644
--- a/sys/uvm/uvm_map.h
+++ b/sys/uvm/uvm_map.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_map.h,v 1.9 2001/08/11 10:57:22 art Exp $	*/
+/*	$OpenBSD: uvm_map.h,v 1.10 2001/08/12 22:41:15 mickey Exp $	*/
 /*	$NetBSD: uvm_map.h,v 1.17 2000/03/29 04:05:47 simonb Exp $	*/
 
 /* 
@@ -108,6 +108,354 @@
 #define UVM_EXTRACT_QREF	0x4	/* use quick refs */
 #define UVM_EXTRACT_FIXPROT	0x8	/* set prot to maxprot as we go */
 
+#endif /* _KERNEL */
+
+#include <uvm/uvm_anon.h>
+
+/*
+ *	Types defined:
+ *
+ *	vm_map_t		the high-level address map data structure.
+ *	vm_map_entry_t		an entry in an address map.
+ *	vm_map_version_t	a timestamp of a map, for use with vm_map_lookup
+ */
+
+/*
+ *	Objects which live in maps may be either VM objects, or
+ *	another map (called a "sharing map") which denotes read-write
+ *	sharing with other maps.
+ *
+ * XXXCDC: private pager data goes here now
+ */
+
+union vm_map_object {
+	struct uvm_object	*uvm_obj;	/* UVM OBJECT */
+	struct vm_map		*sub_map;	/* belongs to another map */
+};
+
+/*
+ *	Address map entries consist of start and end addresses,
+ *	a VM object (or sharing map) and offset into that object,
+ *	and user-exported inheritance and protection information.
+ *	Also included is control information for virtual copy operations.
+ */
+struct vm_map_entry {
+	struct vm_map_entry	*prev;		/* previous entry */
+	struct vm_map_entry	*next;		/* next entry */
+	vaddr_t			start;		/* start address */
+	vaddr_t			end;		/* end address */
+	union vm_map_object	object;		/* object I point to */
+	voff_t			offset;		/* offset into object */
+	/* etype is a bitmap that replaces the following 4 items */
+	int			etype;		/* entry type */
+		/* Only in task maps: */
+	vm_prot_t		protection;	/* protection code */
+	vm_prot_t		max_protection;	/* maximum protection */
+	vm_inherit_t		inheritance;	/* inheritance */
+	int			wired_count;	/* can be paged if == 0 */
+	struct vm_aref		aref;		/* anonymous overlay */
+	int			advice;		/* madvise advice */
+#define uvm_map_entry_stop_copy flags
+	u_int8_t		flags;		/* flags */
+
+#define UVM_MAP_STATIC		0x01		/* static map entry */
+};
+
+#define		VM_MAPENT_ISWIRED(entry)	((entry)->wired_count != 0)
+
+/*
+ *	Maps are doubly-linked lists of map entries, kept sorted
+ *	by address.  A single hint is provided to start
+ *	searches again from the last successful search,
+ *	insertion, or removal.
+ *
+ *	LOCKING PROTOCOL NOTES:
+ *	-----------------------
+ *
+ *	VM map locking is a little complicated.  There are both shared
+ *	and exclusive locks on maps.  However, it is sometimes required
+ *	to downgrade an exclusive lock to a shared lock, and upgrade to
+ *	an exclusive lock again (to perform error recovery).  However,
+ *	another thread *must not* queue itself to receive an exclusive
+ *	lock while before we upgrade back to exclusive, otherwise the
+ *	error recovery becomes extremely difficult, if not impossible.
+ *
+ *	In order to prevent this scenario, we introduce the notion of
+ *	a `busy' map.  A `busy' map is read-locked, but other threads
+ *	attempting to write-lock wait for this flag to clear before
+ *	entering the lock manager.  A map may only be marked busy
+ *	when the map is write-locked (and then the map must be downgraded
+ *	to read-locked), and may only be marked unbusy by the thread
+ *	which marked it busy (holding *either* a read-lock or a
+ *	write-lock, the latter being gained by an upgrade).
+ *
+ *	Access to the map `flags' member is controlled by the `flags_lock'
+ *	simple lock.  Note that some flags are static (set once at map
+ *	creation time, and never changed), and thus require no locking
+ *	to check those flags.  All flags which are r/w must be set or
+ *	cleared while the `flags_lock' is asserted.  Additional locking
+ *	requirements are:
+ *
+ *		VM_MAP_PAGEABLE		r/o static flag; no locking required
+ *
+ *		VM_MAP_INTRSAFE		r/o static flag; no locking required
+ *
+ *		VM_MAP_WIREFUTURE	r/w; may only be set or cleared when
+ *					map is write-locked.  may be tested
+ *					without asserting `flags_lock'.
+ *
+ *		VM_MAP_BUSY		r/w; may only be set when map is
+ *					write-locked, may only be cleared by
+ *					thread which set it, map read-locked
+ *					or write-locked.  must be tested
+ *					while `flags_lock' is asserted.
+ *
+ *		VM_MAP_WANTLOCK		r/w; may only be set when the map
+ *					is busy, and thread is attempting
+ *					to write-lock.  must be tested
+ *					while `flags_lock' is asserted.
+ */
+struct vm_map {
+	struct pmap *		pmap;		/* Physical map */
+	lock_data_t		lock;		/* Lock for map data */
+	struct vm_map_entry	header;		/* List of entries */
+	int			nentries;	/* Number of entries */
+	vsize_t			size;		/* virtual size */
+	int			ref_count;	/* Reference count */
+	simple_lock_data_t	ref_lock;	/* Lock for ref_count field */
+	vm_map_entry_t		hint;		/* hint for quick lookups */
+	simple_lock_data_t	hint_lock;	/* lock for hint storage */
+	vm_map_entry_t		first_free;	/* First free space hint */
+	int			flags;		/* flags */
+	simple_lock_data_t	flags_lock;	/* Lock for flags field */
+	unsigned int		timestamp;	/* Version number */
+#define	min_offset		header.start
+#define max_offset		header.end
+};
+
+/* vm_map flags */
+#define VM_MAP_PAGEABLE		0x01		/* ro: entries are pageable*/
+#define VM_MAP_INTRSAFE		0x02		/* ro: interrupt safe map */
+#define VM_MAP_WIREFUTURE	0x04		/* rw: wire future mappings */
+#define	VM_MAP_BUSY		0x08		/* rw: map is busy */
+#define	VM_MAP_WANTLOCK		0x10		/* rw: want to write-lock */
+
+#ifdef _KERNEL
+#define	vm_map_modflags(map, set, clear)				\
+do {									\
+	simple_lock(&(map)->flags_lock);				\
+	(map)->flags = ((map)->flags | (set)) & ~(clear);		\
+	simple_unlock(&(map)->flags_lock);				\
+} while (0)
+#endif /* _KERNEL */
+
+/*
+ *     Interrupt-safe maps must also be kept on a special list,
+ *     to assist uvm_fault() in avoiding locking problems.
+ */
+struct vm_map_intrsafe {
+	struct vm_map   vmi_map;
+	LIST_ENTRY(vm_map_intrsafe) vmi_list;
+};
+
+LIST_HEAD(vmi_list, vm_map_intrsafe);
+#ifdef _KERNEL
+extern simple_lock_data_t vmi_list_slock;
+extern struct vmi_list vmi_list;
+
+static __inline int vmi_list_lock __P((void));
+static __inline void vmi_list_unlock __P((int));
+
+static __inline int
+vmi_list_lock()
+{
+	int s;
+
+	s = splhigh();
+	simple_lock(&vmi_list_slock);
+	return (s);
+}
+
+static __inline void
+vmi_list_unlock(s)
+	int s;
+{
+
+	simple_unlock(&vmi_list_slock);
+	splx(s);
+}
+#endif /* _KERNEL */
+
+/*
+ * VM map locking operations:
+ *
+ *	These operations perform locking on the data portion of the
+ *	map.
+ *
+ *	vm_map_lock_try: try to lock a map, failing if it is already locked.
+ *
+ *	vm_map_lock: acquire an exclusive (write) lock on a map.
+ *
+ *	vm_map_lock_read: acquire a shared (read) lock on a map.
+ *
+ *	vm_map_unlock: release an exclusive lock on a map.
+ *
+ *	vm_map_unlock_read: release a shared lock on a map.
+ *
+ *	vm_map_downgrade: downgrade an exclusive lock to a shared lock.
+ *
+ *	vm_map_upgrade: upgrade a shared lock to an exclusive lock.
+ *
+ *	vm_map_busy: mark a map as busy.
+ *
+ *	vm_map_unbusy: clear busy status on a map.
+ *
+ * Note that "intrsafe" maps use only exclusive, spin locks.  We simply
+ * use the sleep lock's interlock for this.
+ */
+
+#ifdef _KERNEL
+/* XXX: clean up later */
+#include <sys/time.h>
+#include <sys/proc.h>	/* for tsleep(), wakeup() */
+#include <sys/systm.h>	/* for panic() */
+
+static __inline boolean_t vm_map_lock_try __P((vm_map_t));
+static __inline void vm_map_lock __P((vm_map_t));
+
+static __inline boolean_t
+vm_map_lock_try(map)
+	vm_map_t map;
+{
+	boolean_t rv;
+
+	if (map->flags & VM_MAP_INTRSAFE)
+		rv = simple_lock_try(&map->lock.lk_interlock);
+	else {
+		simple_lock(&map->flags_lock);
+		if (map->flags & VM_MAP_BUSY) {
+			simple_unlock(&map->flags_lock);
+			return (FALSE);
+		}
+		rv = (lockmgr(&map->lock, LK_EXCLUSIVE|LK_NOWAIT|LK_INTERLOCK,
+		    &map->flags_lock, curproc) == 0);
+	}
+
+	if (rv)
+		map->timestamp++;
+
+	return (rv);
+}
+
+static __inline void
+vm_map_lock(map)
+	vm_map_t map;
+{
+	int error;
+
+	if (map->flags & VM_MAP_INTRSAFE) {
+		simple_lock(&map->lock.lk_interlock);
+		return;
+	}
+
+ try_again:
+	simple_lock(&map->flags_lock);
+	if (map->flags & VM_MAP_BUSY) {
+		map->flags |= VM_MAP_WANTLOCK;
+		simple_unlock(&map->flags_lock);
+		(void) tsleep(&map->flags, PVM, "vmmapbsy", 0);
+		goto try_again;
+	}
+
+	error = lockmgr(&map->lock, LK_EXCLUSIVE|LK_SLEEPFAIL|LK_INTERLOCK,
+	    &map->flags_lock, curproc);
+
+	if (error) {
+#ifdef DIAGNOSTIC
+		if (error != ENOLCK)
+			panic("vm_map_lock: failed to get lock");
+#endif
+		goto try_again;
+	}
+ 
+	(map)->timestamp++;
+}
+
+#ifdef DIAGNOSTIC
+#define	vm_map_lock_read(map)						\
+do {									\
+	if (map->flags & VM_MAP_INTRSAFE)				\
+		panic("vm_map_lock_read: intrsafe map");		\
+	(void) lockmgr(&(map)->lock, LK_SHARED, NULL, curproc);		\
+} while (0)
+#else
+#define	vm_map_lock_read(map)						\
+	(void) lockmgr(&(map)->lock, LK_SHARED, NULL, curproc)
+#endif
+
+#define	vm_map_unlock(map)						\
+do {									\
+	if ((map)->flags & VM_MAP_INTRSAFE)				\
+		simple_unlock(&(map)->lock.lk_interlock);		\
+	else								\
+		(void) lockmgr(&(map)->lock, LK_RELEASE, NULL, curproc);\
+} while (0)
+
+#define	vm_map_unlock_read(map)						\
+	(void) lockmgr(&(map)->lock, LK_RELEASE, NULL, curproc)
+
+#define	vm_map_downgrade(map)						\
+	(void) lockmgr(&(map)->lock, LK_DOWNGRADE, NULL, curproc)
+
+#ifdef DIAGNOSTIC
+#define	vm_map_upgrade(map)						\
+do {									\
+	if (lockmgr(&(map)->lock, LK_UPGRADE, NULL, curproc) != 0)	\
+		panic("vm_map_upgrade: failed to upgrade lock");	\
+} while (0)
+#else
+#define	vm_map_upgrade(map)						\
+	(void) lockmgr(&(map)->lock, LK_UPGRADE, NULL, curproc)
+#endif
+
+#define	vm_map_busy(map)						\
+do {									\
+	simple_lock(&(map)->flags_lock);				\
+	(map)->flags |= VM_MAP_BUSY;					\
+	simple_unlock(&(map)->flags_lock);				\
+} while (0)
+
+#define	vm_map_unbusy(map)						\
+do {									\
+	int oflags;							\
+									\
+	simple_lock(&(map)->flags_lock);				\
+	oflags = (map)->flags;						\
+	(map)->flags &= ~(VM_MAP_BUSY|VM_MAP_WANTLOCK);			\
+	simple_unlock(&(map)->flags_lock);				\
+	if (oflags & VM_MAP_WANTLOCK)					\
+		wakeup(&(map)->flags);					\
+} while (0)
+#endif /* _KERNEL */
+
+/*
+ *	Functions implemented as macros
+ */
+#define		vm_map_min(map)		((map)->min_offset)
+#define		vm_map_max(map)		((map)->max_offset)
+#define		vm_map_pmap(map)	((map)->pmap)
+
+/* XXX: number of kernel maps and entries to statically allocate */
+#ifndef	MAX_KMAP
+#define	MAX_KMAP	20
+#endif
+#ifndef	MAX_KMAPENT
+#if (50 + (2 * NPROC) > 1000)
+#define MAX_KMAPENT (50 + (2 * NPROC))
+#else
+#define	MAX_KMAPENT	1000  /* XXXCDC: no crash */
+#endif
+#endif
 
 /*
  * handle inline options
@@ -123,6 +471,8 @@
  * globals:
  */
 
+#ifdef _KERNEL
+
 #ifdef PMAP_GROWKERNEL
 extern vaddr_t	uvm_maxkaddr;
 #endif