freebsd-skq/sys/vm/vm_pager.h
Konstantin Belousov cd85379104 Make MAXPHYS tunable. Bump MAXPHYS to 1M.
Replace MAXPHYS by runtime variable maxphys. It is initialized from
MAXPHYS by default, but can be also adjusted with the tunable kern.maxphys.

Make b_pages[] array in struct buf flexible.  Size b_pages[] for buffer
cache buffers exactly to atop(maxbcachebuf) (currently it is sized to
atop(MAXPHYS)), and b_pages[] for pbufs is sized to atop(maxphys) + 1.
The +1 for pbufs allow several pbuf consumers, among them vmapbuf(),
to use unaligned buffers still sized to maxphys, esp. when such
buffers come from userspace (*).  Overall, we save significant amount
of otherwise wasted memory in b_pages[] for buffer cache buffers,
while bumping MAXPHYS to desired high value.

Eliminate all direct uses of the MAXPHYS constant in kernel and driver
sources, except a place which initialize maxphys.  Some random (and
arguably weird) uses of MAXPHYS, e.g. in linuxolator, are converted
straight.  Some drivers, which use MAXPHYS to size embeded structures,
get private MAXPHYS-like constant; their convertion is out of scope
for this work.

Changes to cam/, dev/ahci, dev/ata, dev/mpr, dev/mpt, dev/mvs,
dev/siis, where either submitted by, or based on changes by mav.

Suggested by: mav (*)
Reviewed by:	imp, mav, imp, mckusick, scottl (intermediate versions)
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D27225
2020-11-28 12:12:51 +00:00

255 lines
8.6 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);
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);
struct pagerops {
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;
/* Operations for specialized writecount handling */
pgo_writecount_t *pgo_update_writecount;
pgo_writecount_t *pgo_release_writecount;
};
extern struct pagerops defaultpagerops;
extern struct pagerops swappagerops;
extern struct pagerops vnodepagerops;
extern struct pagerops devicepagerops;
extern struct pagerops physpagerops;
extern struct pagerops sgpagerops;
extern struct pagerops mgtdevicepagerops;
/*
* 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 struct pagerops *pagertab[];
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)
{
if (pagertab[m->object->type]->pgo_pageunswapped)
(*pagertab[m->object->type]->pgo_pageunswapped)(m);
}
static __inline void
vm_pager_update_writecount(vm_object_t object, vm_offset_t start,
vm_offset_t end)
{
if (pagertab[object->type]->pgo_update_writecount)
pagertab[object->type]->pgo_update_writecount(object, start,
end);
}
static __inline void
vm_pager_release_writecount(vm_object_t object, vm_offset_t start,
vm_offset_t end)
{
if (pagertab[object->type]->pgo_release_writecount)
pagertab[object->type]->pgo_release_writecount(object, start,
end);
}
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,
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 struct phys_pager_ops default_phys_pg_ops;
vm_object_t phys_pager_allocate(void *handle, 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_ */