freebsd-nq/sys/vm/vm_pager.h
Konstantin Belousov b730fd30b7 vm: Add KPI to dynamically register pagers
Pager is allowed to inherit part of its implementation from the existing
pager, which is done by copying non-NULL virtual method slots.

Reviewed by:	markj
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D30168
2021-05-13 20:12:29 +03:00

291 lines
9.7 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1990 University of Utah.
* 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 Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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.
* 3. 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.
*
* @(#)vm_pager.h 8.4 (Berkeley) 1/12/94
* $FreeBSD$
*/
/*
* Pager routine interface definition.
*/
#ifndef _VM_PAGER_
#define _VM_PAGER_
#include <sys/queue.h>
TAILQ_HEAD(pagerlst, vm_object);
struct vnode;
typedef void pgo_init_t(void);
typedef vm_object_t pgo_alloc_t(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t,
struct ucred *);
typedef void pgo_dealloc_t(vm_object_t);
typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int *, int *);
typedef void pgo_getpages_iodone_t(void *, vm_page_t *, int, int);
typedef int pgo_getpages_async_t(vm_object_t, vm_page_t *, int, int *, int *,
pgo_getpages_iodone_t, void *);
typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *);
typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *);
typedef int pgo_populate_t(vm_object_t, vm_pindex_t, int, vm_prot_t,
vm_pindex_t *, vm_pindex_t *);
typedef void pgo_pageunswapped_t(vm_page_t);
typedef void pgo_writecount_t(vm_object_t, vm_offset_t, vm_offset_t);
typedef void pgo_set_writeable_dirty_t(vm_object_t);
typedef bool pgo_mightbedirty_t(vm_object_t);
typedef void pgo_getvp_t(vm_object_t object, struct vnode **vpp,
bool *vp_heldp);
typedef void pgo_freespace_t(vm_object_t object, vm_pindex_t start,
vm_size_t size);
struct pagerops {
int pgo_kvme_type;
pgo_init_t *pgo_init; /* Initialize pager. */
pgo_alloc_t *pgo_alloc; /* Allocate pager. */
pgo_dealloc_t *pgo_dealloc; /* Disassociate. */
pgo_getpages_t *pgo_getpages; /* Get (read) page. */
pgo_getpages_async_t *pgo_getpages_async; /* Get page asyncly. */
pgo_putpages_t *pgo_putpages; /* Put (write) page. */
pgo_haspage_t *pgo_haspage; /* Query page. */
pgo_populate_t *pgo_populate; /* Bulk spec pagein. */
pgo_pageunswapped_t *pgo_pageunswapped;
pgo_writecount_t *pgo_update_writecount;
pgo_writecount_t *pgo_release_writecount;
pgo_set_writeable_dirty_t *pgo_set_writeable_dirty;
pgo_mightbedirty_t *pgo_mightbedirty;
pgo_getvp_t *pgo_getvp;
pgo_freespace_t *pgo_freespace;
};
extern const struct pagerops defaultpagerops;
extern const struct pagerops swappagerops;
extern const struct pagerops vnodepagerops;
extern const struct pagerops devicepagerops;
extern const struct pagerops physpagerops;
extern const struct pagerops sgpagerops;
extern const struct pagerops mgtdevicepagerops;
extern const struct pagerops swaptmpfspagerops;
/*
* get/put return values
* OK operation was successful
* BAD specified data was out of the accepted range
* FAIL specified data was in range, but doesn't exist
* PEND operations was initiated but not completed
* ERROR error while accessing data that is in range and exists
* AGAIN temporary resource shortage prevented operation from happening
*/
#define VM_PAGER_OK 0
#define VM_PAGER_BAD 1
#define VM_PAGER_FAIL 2
#define VM_PAGER_PEND 3
#define VM_PAGER_ERROR 4
#define VM_PAGER_AGAIN 5
#define VM_PAGER_PUT_SYNC 0x0001
#define VM_PAGER_PUT_INVAL 0x0002
#define VM_PAGER_PUT_NOREUSE 0x0004
#define VM_PAGER_CLUSTER_OK 0x0008
#ifdef _KERNEL
extern const struct pagerops *pagertab[] __read_mostly;
extern struct mtx_padalign pbuf_mtx;
/*
* Number of pages that pbuf buffer can store in b_pages.
* It is +1 to allow for unaligned data buffer of maxphys size.
*/
#define PBUF_PAGES (atop(maxphys) + 1)
vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t,
vm_ooffset_t, struct ucred *);
void vm_pager_bufferinit(void);
void vm_pager_deallocate(vm_object_t);
int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int *, int *);
int vm_pager_get_pages_async(vm_object_t, vm_page_t *, int, int *, int *,
pgo_getpages_iodone_t, void *);
void vm_pager_init(void);
vm_object_t vm_pager_object_lookup(struct pagerlst *, void *);
static __inline void
vm_pager_put_pages(vm_object_t object, vm_page_t *m, int count, int flags,
int *rtvals)
{
VM_OBJECT_ASSERT_WLOCKED(object);
(*pagertab[object->type]->pgo_putpages)
(object, m, count, flags, rtvals);
}
/*
* vm_pager_haspage
*
* Check to see if an object's pager has the requested page. The
* object's pager will also set before and after to give the caller
* some idea of the number of pages before and after the requested
* page can be I/O'd efficiently.
*
* The object must be locked.
*/
static __inline boolean_t
vm_pager_has_page(vm_object_t object, vm_pindex_t offset, int *before,
int *after)
{
boolean_t ret;
VM_OBJECT_ASSERT_LOCKED(object);
ret = (*pagertab[object->type]->pgo_haspage)
(object, offset, before, after);
return (ret);
}
static __inline int
vm_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type,
vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last)
{
MPASS((object->flags & OBJ_POPULATE) != 0);
MPASS(pidx < object->size);
MPASS(blockcount_read(&object->paging_in_progress) > 0);
return ((*pagertab[object->type]->pgo_populate)(object, pidx,
fault_type, max_prot, first, last));
}
/*
* vm_pager_page_unswapped
*
* Destroy swap associated with the page.
*
* XXX: A much better name would be "vm_pager_page_dirtied()"
* XXX: It is not obvious if this could be profitably used by any
* XXX: pagers besides the swap_pager or if it should even be a
* XXX: generic pager_op in the first place.
*/
static __inline void
vm_pager_page_unswapped(vm_page_t m)
{
pgo_pageunswapped_t *method;
method = pagertab[m->object->type]->pgo_pageunswapped;
if (method != NULL)
method(m);
}
static __inline void
vm_pager_update_writecount(vm_object_t object, vm_offset_t start,
vm_offset_t end)
{
pgo_writecount_t *method;
method = pagertab[object->type]->pgo_update_writecount;
if (method != NULL)
method(object, start, end);
}
static __inline void
vm_pager_release_writecount(vm_object_t object, vm_offset_t start,
vm_offset_t end)
{
pgo_writecount_t *method;
method = pagertab[object->type]->pgo_release_writecount;
if (method != NULL)
method(object, start, end);
}
static __inline void
vm_pager_getvp(vm_object_t object, struct vnode **vpp, bool *vp_heldp)
{
pgo_getvp_t *method;
*vpp = NULL;
if (vp_heldp != NULL)
*vp_heldp = false;
method = pagertab[object->type]->pgo_getvp;
if (method != NULL)
method(object, vpp, vp_heldp);
}
static __inline void
vm_pager_freespace(vm_object_t object, vm_pindex_t start,
vm_size_t size)
{
pgo_freespace_t *method;
method = pagertab[object->type]->pgo_freespace;
if (method != NULL)
method(object, start, size);
}
int vm_pager_alloc_dyn_type(struct pagerops *ops, int base_type);
void vm_pager_free_dyn_type(objtype_t type);
struct cdev_pager_ops {
int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset,
int prot, vm_page_t *mres);
int (*cdev_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx,
int fault_type, vm_prot_t max_prot, vm_pindex_t *first,
vm_pindex_t *last);
int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot,
vm_ooffset_t foff, struct ucred *cred, u_short *color);
void (*cdev_pg_dtor)(void *handle);
};
vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp,
const struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot,
vm_ooffset_t foff, struct ucred *cred);
vm_object_t cdev_pager_lookup(void *handle);
void cdev_pager_free_page(vm_object_t object, vm_page_t m);
struct phys_pager_ops {
int (*phys_pg_getpages)(vm_object_t vm_obj, vm_page_t *m, int count,
int *rbehind, int *rahead);
int (*phys_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx,
int fault_type, vm_prot_t max_prot, vm_pindex_t *first,
vm_pindex_t *last);
boolean_t (*phys_pg_haspage)(vm_object_t obj, vm_pindex_t pindex,
int *before, int *after);
void (*phys_pg_ctor)(vm_object_t vm_obj, vm_prot_t prot,
vm_ooffset_t foff, struct ucred *cred);
void (*phys_pg_dtor)(vm_object_t vm_obj);
};
extern const struct phys_pager_ops default_phys_pg_ops;
vm_object_t phys_pager_allocate(void *handle, const struct phys_pager_ops *ops,
void *data, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff,
struct ucred *cred);
#endif /* _KERNEL */
#endif /* _VM_PAGER_ */