adds a couple print_vmcb()s for the write CR0 -> shutdown bug

[freebsd-src/fkvm-freebsd.git] / sys / vm / vm_kern.c

/*-
 * Copyright (c) 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * The Mach Operating System project at Carnegie-Mellon University.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      from: @(#)vm_kern.c     8.3 (Berkeley) 1/12/94
 *
 *
 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
 *
 * Permission to use, copy, modify and distribute this software and
 * its documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 */

/*
 *      Kernel memory management.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>         /* for ticks and hz */
#include <sys/eventhandler.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/malloc.h>

#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_extern.h>
#include <vm/uma.h>

vm_map_t kernel_map=0;
vm_map_t kmem_map=0;
vm_map_t exec_map=0;
vm_map_t pipe_map;
vm_map_t buffer_map=0;

/*
 *      kmem_alloc_nofault:
 *
 *      Allocate a virtual address range with no underlying object and
 *      no initial mapping to physical memory.  Any mapping from this
 *      range to physical memory must be explicitly created prior to
 *      its use, typically with pmap_qenter().  Any attempt to create
 *      a mapping on demand through vm_fault() will result in a panic. 
 */
vm_offset_t
kmem_alloc_nofault(map, size)
        vm_map_t map;
        vm_size_t size;
{
        vm_offset_t addr;
        int result;

        size = round_page(size);
        addr = vm_map_min(map);
        result = vm_map_find(map, NULL, 0, &addr, size, VMFS_ANY_SPACE,
            VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
        if (result != KERN_SUCCESS) {
                return (0);
        }
        return (addr);
}

/*
 *      Allocate wired-down memory in the kernel's address map
 *      or a submap.
 */
vm_offset_t
kmem_alloc(map, size)
        vm_map_t map;
        vm_size_t size;
{
        vm_offset_t addr;
        vm_offset_t offset;
        vm_offset_t i;

        size = round_page(size);

        /*
         * Use the kernel object for wired-down kernel pages. Assume that no
         * region of the kernel object is referenced more than once.
         */

        /*
         * Locate sufficient space in the map.  This will give us the final
         * virtual address for the new memory, and thus will tell us the
         * offset within the kernel map.
         */
        vm_map_lock(map);
        if (vm_map_findspace(map, vm_map_min(map), size, &addr)) {
                vm_map_unlock(map);
                return (0);
        }
        offset = addr - VM_MIN_KERNEL_ADDRESS;
        vm_object_reference(kernel_object);
        vm_map_insert(map, kernel_object, offset, addr, addr + size,
                VM_PROT_ALL, VM_PROT_ALL, 0);
        vm_map_unlock(map);

        /*
         * Guarantee that there are pages already in this object before
         * calling vm_map_wire.  This is to prevent the following
         * scenario:
         *
         * 1) Threads have swapped out, so that there is a pager for the
         * kernel_object. 2) The kmsg zone is empty, and so we are
         * kmem_allocing a new page for it. 3) vm_map_wire calls vm_fault;
         * there is no page, but there is a pager, so we call
         * pager_data_request.  But the kmsg zone is empty, so we must
         * kmem_alloc. 4) goto 1 5) Even if the kmsg zone is not empty: when
         * we get the data back from the pager, it will be (very stale)
         * non-zero data.  kmem_alloc is defined to return zero-filled memory.
         *
         * We're intentionally not activating the pages we allocate to prevent a
         * race with page-out.  vm_map_wire will wire the pages.
         */
        VM_OBJECT_LOCK(kernel_object);
        for (i = 0; i < size; i += PAGE_SIZE) {
                vm_page_t mem;

                mem = vm_page_grab(kernel_object, OFF_TO_IDX(offset + i),
                    VM_ALLOC_NOBUSY | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
                mem->valid = VM_PAGE_BITS_ALL;
                KASSERT((mem->flags & PG_UNMANAGED) != 0,
                    ("kmem_alloc: page %p is managed", mem));
        }
        VM_OBJECT_UNLOCK(kernel_object);

        /*
         * And finally, mark the data as non-pageable.
         */
        (void) vm_map_wire(map, addr, addr + size,
            VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);

        return (addr);
}

/*
 *      kmem_free:
 *
 *      Release a region of kernel virtual memory allocated
 *      with kmem_alloc, and return the physical pages
 *      associated with that region.
 *
 *      This routine may not block on kernel maps.
 */
void
kmem_free(map, addr, size)
        vm_map_t map;
        vm_offset_t addr;
        vm_size_t size;
{

        (void) vm_map_remove(map, trunc_page(addr), round_page(addr + size));
}

/*
 *      kmem_suballoc:
 *
 *      Allocates a map to manage a subrange
 *      of the kernel virtual address space.
 *
 *      Arguments are as follows:
 *
 *      parent          Map to take range from
 *      min, max        Returned endpoints of map
 *      size            Size of range to find
 *      superpage_align Request that min is superpage aligned
 */
vm_map_t
kmem_suballoc(vm_map_t parent, vm_offset_t *min, vm_offset_t *max,
    vm_size_t size, boolean_t superpage_align)
{
        int ret;
        vm_map_t result;

        size = round_page(size);

        *min = vm_map_min(parent);
        ret = vm_map_find(parent, NULL, 0, min, size, superpage_align ?
            VMFS_ALIGNED_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL, 0);
        if (ret != KERN_SUCCESS)
                panic("kmem_suballoc: bad status return of %d", ret);
        *max = *min + size;
        result = vm_map_create(vm_map_pmap(parent), *min, *max);
        if (result == NULL)
                panic("kmem_suballoc: cannot create submap");
        if (vm_map_submap(parent, *min, *max, result) != KERN_SUCCESS)
                panic("kmem_suballoc: unable to change range to submap");
        return (result);
}

/*
 *      kmem_malloc:
 *
 *      Allocate wired-down memory in the kernel's address map for the higher
 *      level kernel memory allocator (kern/kern_malloc.c).  We cannot use
 *      kmem_alloc() because we may need to allocate memory at interrupt
 *      level where we cannot block (canwait == FALSE).
 *
 *      This routine has its own private kernel submap (kmem_map) and object
 *      (kmem_object).  This, combined with the fact that only malloc uses
 *      this routine, ensures that we will never block in map or object waits.
 *
 *      We don't worry about expanding the map (adding entries) since entries
 *      for wired maps are statically allocated.
 *
 *      `map' is ONLY allowed to be kmem_map or one of the mbuf submaps to
 *      which we never free.
 */
vm_offset_t
kmem_malloc(map, size, flags)
        vm_map_t map;
        vm_size_t size;
        int flags;
{
        vm_offset_t offset, i;
        vm_map_entry_t entry;
        vm_offset_t addr;
        vm_page_t m;
        int pflags;

        size = round_page(size);
        addr = vm_map_min(map);

        /*
         * Locate sufficient space in the map.  This will give us the final
         * virtual address for the new memory, and thus will tell us the
         * offset within the kernel map.
         */
        vm_map_lock(map);
        if (vm_map_findspace(map, vm_map_min(map), size, &addr)) {
                vm_map_unlock(map);
                if ((flags & M_NOWAIT) == 0) {
                        for (i = 0; i < 8; i++) {
                                EVENTHANDLER_INVOKE(vm_lowmem, 0);
                                uma_reclaim();
                                vm_map_lock(map);
                                if (vm_map_findspace(map, vm_map_min(map),
                                    size, &addr) == 0) {
                                        break;
                                }
                                vm_map_unlock(map);
                                tsleep(&i, 0, "nokva", (hz / 4) * (i + 1));
                        }
                        if (i == 8) {
                                panic("kmem_malloc(%ld): kmem_map too small: %ld total allocated",
                                    (long)size, (long)map->size);
                        }
                } else {
                        return (0);
                }
        }
        offset = addr - VM_MIN_KERNEL_ADDRESS;
        vm_object_reference(kmem_object);
        vm_map_insert(map, kmem_object, offset, addr, addr + size,
                VM_PROT_ALL, VM_PROT_ALL, 0);

        if ((flags & (M_NOWAIT|M_USE_RESERVE)) == M_NOWAIT)
                pflags = VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED;
        else
                pflags = VM_ALLOC_SYSTEM | VM_ALLOC_WIRED;

        if (flags & M_ZERO)
                pflags |= VM_ALLOC_ZERO;

        VM_OBJECT_LOCK(kmem_object);
        for (i = 0; i < size; i += PAGE_SIZE) {
retry:
                m = vm_page_alloc(kmem_object, OFF_TO_IDX(offset + i), pflags);

                /*
                 * Ran out of space, free everything up and return. Don't need
                 * to lock page queues here as we know that the pages we got
                 * aren't on any queues.
                 */
                if (m == NULL) {
                        if ((flags & M_NOWAIT) == 0) {
                                VM_OBJECT_UNLOCK(kmem_object);
                                vm_map_unlock(map);
                                VM_WAIT;
                                vm_map_lock(map);
                                VM_OBJECT_LOCK(kmem_object);
                                goto retry;
                        }
                        /* 
                         * Free the pages before removing the map entry.
                         * They are already marked busy.  Calling
                         * vm_map_delete before the pages has been freed or
                         * unbusied will cause a deadlock.
                         */
                        while (i != 0) {
                                i -= PAGE_SIZE;
                                m = vm_page_lookup(kmem_object,
                                                   OFF_TO_IDX(offset + i));
                                vm_page_lock_queues();
                                vm_page_unwire(m, 0);
                                vm_page_free(m);
                                vm_page_unlock_queues();
                        }
                        VM_OBJECT_UNLOCK(kmem_object);
                        vm_map_delete(map, addr, addr + size);
                        vm_map_unlock(map);
                        return (0);
                }
                if (flags & M_ZERO && (m->flags & PG_ZERO) == 0)
                        pmap_zero_page(m);
                m->valid = VM_PAGE_BITS_ALL;
                KASSERT((m->flags & PG_UNMANAGED) != 0,
                    ("kmem_malloc: page %p is managed", m));
        }
        VM_OBJECT_UNLOCK(kmem_object);

        /*
         * Mark map entry as non-pageable. Assert: vm_map_insert() will never
         * be able to extend the previous entry so there will be a new entry
         * exactly corresponding to this address range and it will have
         * wired_count == 0.
         */
        if (!vm_map_lookup_entry(map, addr, &entry) ||
            entry->start != addr || entry->end != addr + size ||
            entry->wired_count != 0)
                panic("kmem_malloc: entry not found or misaligned");
        entry->wired_count = 1;

        /*
         * At this point, the kmem_object must be unlocked because
         * vm_map_simplify_entry() calls vm_object_deallocate(), which
         * locks the kmem_object.
         */
        vm_map_simplify_entry(map, entry);

        /*
         * Loop thru pages, entering them in the pmap.
         */
        VM_OBJECT_LOCK(kmem_object);
        for (i = 0; i < size; i += PAGE_SIZE) {
                m = vm_page_lookup(kmem_object, OFF_TO_IDX(offset + i));
                /*
                 * Because this is kernel_pmap, this call will not block.
                 */
                pmap_enter(kernel_pmap, addr + i, VM_PROT_ALL, m, VM_PROT_ALL,
                    TRUE);
                vm_page_wakeup(m);
        }
        VM_OBJECT_UNLOCK(kmem_object);
        vm_map_unlock(map);

        return (addr);
}

/*
 *      kmem_alloc_wait:
 *
 *      Allocates pageable memory from a sub-map of the kernel.  If the submap
 *      has no room, the caller sleeps waiting for more memory in the submap.
 *
 *      This routine may block.
 */
vm_offset_t
kmem_alloc_wait(map, size)
        vm_map_t map;
        vm_size_t size;
{
        vm_offset_t addr;

        size = round_page(size);

        for (;;) {
                /*
                 * To make this work for more than one map, use the map's lock
                 * to lock out sleepers/wakers.
                 */
                vm_map_lock(map);
                if (vm_map_findspace(map, vm_map_min(map), size, &addr) == 0)
                        break;
                /* no space now; see if we can ever get space */
                if (vm_map_max(map) - vm_map_min(map) < size) {
                        vm_map_unlock(map);
                        return (0);
                }
                map->needs_wakeup = TRUE;
                vm_map_unlock_and_wait(map, 0);
        }
        vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_ALL, VM_PROT_ALL, 0);
        vm_map_unlock(map);
        return (addr);
}

/*
 *      kmem_free_wakeup:
 *
 *      Returns memory to a submap of the kernel, and wakes up any processes
 *      waiting for memory in that map.
 */
void
kmem_free_wakeup(map, addr, size)
        vm_map_t map;
        vm_offset_t addr;
        vm_size_t size;
{

        vm_map_lock(map);
        (void) vm_map_delete(map, trunc_page(addr), round_page(addr + size));
        if (map->needs_wakeup) {
                map->needs_wakeup = FALSE;
                vm_map_wakeup(map);
        }
        vm_map_unlock(map);
}

/*
 *      kmem_init:
 *
 *      Create the kernel map; insert a mapping covering kernel text, 
 *      data, bss, and all space allocated thus far (`boostrap' data).  The 
 *      new map will thus map the range between VM_MIN_KERNEL_ADDRESS and 
 *      `start' as allocated, and the range between `start' and `end' as free.
 */
void
kmem_init(start, end)
        vm_offset_t start, end;
{
        vm_map_t m;

        m = vm_map_create(kernel_pmap, VM_MIN_KERNEL_ADDRESS, end);
        m->system_map = 1;
        vm_map_lock(m);
        /* N.B.: cannot use kgdb to debug, starting with this assignment ... */
        kernel_map = m;
        (void) vm_map_insert(m, NULL, (vm_ooffset_t) 0,
#ifdef __amd64__
            KERNBASE,
#else                
            VM_MIN_KERNEL_ADDRESS,
#endif
            start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
        /* ... and ending with the completion of the above `insert' */
        vm_map_unlock(m);
}