NetBSD/sys/uvm/uvm_page.h
hannken c84e81cad1 Add vm page flag PG_MARKER and use it to tag dummy marker pages
in genfs_do_putpages() and uao_put().
Use 'v_uobj.uo_npages' to check for an empty memq.
Put some assertions where these marker pages may not appear.

Ok: YAMAMOTO Takashi <yamt@netbsd.org>
2010-07-29 10:54:50 +00:00

444 lines
14 KiB
C++

/* $NetBSD: uvm_page.h,v 1.60 2010/07/29 10:54:51 hannken Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Charles D. Cranor,
* Washington University, the University of California, Berkeley and
* its contributors.
* 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.
*
* @(#)vm_page.h 7.3 (Berkeley) 4/21/91
* from: Id: uvm_page.h,v 1.1.2.6 1998/02/04 02:31:42 chuck Exp
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* 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.
*/
#ifndef _UVM_UVM_PAGE_H_
#define _UVM_UVM_PAGE_H_
/*
* uvm_page.h
*/
/*
* Resident memory system definitions.
*/
/*
* Management of resident (logical) pages.
*
* A small structure is kept for each resident
* page, indexed by page number. Each structure
* is an element of several lists:
*
* A red-black tree rooted with the containing
* object is used to quickly perform object+
* offset lookups
*
* A list of all pages for a given object,
* so they can be quickly deactivated at
* time of deallocation.
*
* An ordered list of pages due for pageout.
*
* In addition, the structure contains the object
* and offset to which this page belongs (for pageout),
* and sundry status bits.
*
* Fields in this structure are locked either by the lock on the
* object that the page belongs to (O) or by the lock on the page
* queues (P) [or both].
*/
/*
* locking note: the mach version of this data structure had bit
* fields for the flags, and the bit fields were divided into two
* items (depending on who locked what). some time, in BSD, the bit
* fields were dumped and all the flags were lumped into one short.
* that is fine for a single threaded uniprocessor OS, but bad if you
* want to actual make use of locking. so, we've separated things
* back out again.
*
* note the page structure has no lock of its own.
*/
#include <uvm/uvm_extern.h>
#include <uvm/uvm_pglist.h>
#include <sys/rb.h>
struct vm_page {
struct rb_node rb_node; /* tree of pages in obj (O) */
union {
TAILQ_ENTRY(vm_page) queue;
LIST_ENTRY(vm_page) list;
} pageq; /* queue info for FIFO
* queue or free list (P) */
union {
TAILQ_ENTRY(vm_page) queue;
LIST_ENTRY(vm_page) list;
} listq; /* pages in same object (O)*/
struct vm_anon *uanon; /* anon (O,P) */
struct uvm_object *uobject; /* object (O,P) */
voff_t offset; /* offset into object (O,P) */
uint16_t flags; /* object flags [O] */
uint16_t loan_count; /* number of active loans
* to read: [O or P]
* to modify: [O _and_ P] */
uint16_t wire_count; /* wired down map refs [P] */
uint16_t pqflags; /* page queue flags [P] */
paddr_t phys_addr; /* physical address of page */
#ifdef __HAVE_VM_PAGE_MD
struct vm_page_md mdpage; /* pmap-specific data */
#endif
#if defined(UVM_PAGE_TRKOWN)
/* debugging fields to track page ownership */
pid_t owner; /* proc that set PG_BUSY */
lwpid_t lowner; /* lwp that set PG_BUSY */
const char *owner_tag; /* why it was set busy */
#endif
};
/*
* These are the flags defined for vm_page.
*/
/*
* locking rules:
* PG_ ==> locked by object lock
* PQ_ ==> lock by page queue lock
* PQ_FREE is locked by free queue lock and is mutex with all other PQs
*
* PG_ZERO is used to indicate that a page has been pre-zero'd. This flag
* is only set when the page is on no queues, and is cleared when the page
* is placed on the free list.
*/
#define PG_BUSY 0x0001 /* page is locked */
#define PG_WANTED 0x0002 /* someone is waiting for page */
#define PG_TABLED 0x0004 /* page is in VP table */
#define PG_CLEAN 0x0008 /* page has not been modified */
#define PG_PAGEOUT 0x0010 /* page to be freed for pagedaemon */
#define PG_RELEASED 0x0020 /* page to be freed when unbusied */
#define PG_FAKE 0x0040 /* page is not yet initialized */
#define PG_RDONLY 0x0080 /* page must be mapped read-only */
#define PG_ZERO 0x0100 /* page is pre-zero'd */
#define PG_MARKER 0x0200 /* dummy marker page */
#define PG_PAGER1 0x1000 /* pager-specific flag */
#define UVM_PGFLAGBITS \
"\20\1BUSY\2WANTED\3TABLED\4CLEAN\5PAGEOUT\6RELEASED\7FAKE\10RDONLY" \
"\11ZERO\12MARKER\15PAGER1"
#define PQ_FREE 0x0001 /* page is on free list */
#define PQ_ANON 0x0002 /* page is part of an anon, rather
than an uvm_object */
#define PQ_AOBJ 0x0004 /* page is part of an anonymous
uvm_object */
#define PQ_SWAPBACKED (PQ_ANON|PQ_AOBJ)
#define PQ_READAHEAD 0x0008 /* read-ahead but has not been "hit" yet */
#define PQ_PRIVATE1 0x0100
#define PQ_PRIVATE2 0x0200
#define PQ_PRIVATE3 0x0400
#define PQ_PRIVATE4 0x0800
#define PQ_PRIVATE5 0x1000
#define PQ_PRIVATE6 0x2000
#define PQ_PRIVATE7 0x4000
#define PQ_PRIVATE8 0x8000
#define UVM_PQFLAGBITS \
"\20\1FREE\2ANON\3AOBJ\4READAHEAD" \
"\11PRIVATE1\12PRIVATE2\13PRIVATE3\14PRIVATE4" \
"\15PRIVATE5\16PRIVATE6\17PRIVATE7\20PRIVATE8"
/*
* physical memory layout structure
*
* MD vmparam.h must #define:
* VM_PHYSEG_MAX = max number of physical memory segments we support
* (if this is "1" then we revert to a "contig" case)
* VM_PHYSSEG_STRAT: memory sort/search options (for VM_PHYSEG_MAX > 1)
* - VM_PSTRAT_RANDOM: linear search (random order)
* - VM_PSTRAT_BSEARCH: binary search (sorted by address)
* - VM_PSTRAT_BIGFIRST: linear search (sorted by largest segment first)
* - others?
* XXXCDC: eventually we should purge all left-over global variables...
*/
#define VM_PSTRAT_RANDOM 1
#define VM_PSTRAT_BSEARCH 2
#define VM_PSTRAT_BIGFIRST 3
/*
* vm_physseg: describes one segment of physical memory
*/
struct vm_physseg {
paddr_t start; /* PF# of first page in segment */
paddr_t end; /* (PF# of last page in segment) + 1 */
paddr_t avail_start; /* PF# of first free page in segment */
paddr_t avail_end; /* (PF# of last free page in segment) +1 */
int free_list; /* which free list they belong on */
struct vm_page *pgs; /* vm_page structures (from start) */
struct vm_page *lastpg; /* vm_page structure for end */
#ifdef __HAVE_PMAP_PHYSSEG
struct pmap_physseg pmseg; /* pmap specific (MD) data */
#endif
};
#ifdef _KERNEL
/*
* globals
*/
extern bool vm_page_zero_enable;
/*
* physical memory config is stored in vm_physmem.
*/
extern struct vm_physseg vm_physmem[VM_PHYSSEG_MAX];
extern int vm_nphysseg;
/*
* prototypes: the following prototypes define the interface to pages
*/
void uvm_page_init(vaddr_t *, vaddr_t *);
#if defined(UVM_PAGE_TRKOWN)
void uvm_page_own(struct vm_page *, const char *);
#endif
#if !defined(PMAP_STEAL_MEMORY)
bool uvm_page_physget(paddr_t *);
#endif
void uvm_page_recolor(int);
void uvm_pageidlezero(void);
void uvm_pageactivate(struct vm_page *);
vaddr_t uvm_pageboot_alloc(vsize_t);
void uvm_pagecopy(struct vm_page *, struct vm_page *);
void uvm_pagedeactivate(struct vm_page *);
void uvm_pagedequeue(struct vm_page *);
void uvm_pageenqueue(struct vm_page *);
void uvm_pagefree(struct vm_page *);
void uvm_page_unbusy(struct vm_page **, int);
struct vm_page *uvm_pagelookup(struct uvm_object *, voff_t);
void uvm_pageunwire(struct vm_page *);
void uvm_pagewait(struct vm_page *, int);
void uvm_pagewake(struct vm_page *);
void uvm_pagewire(struct vm_page *);
void uvm_pagezero(struct vm_page *);
bool uvm_pageismanaged(paddr_t);
int uvm_page_lookup_freelist(struct vm_page *);
static struct vm_page *PHYS_TO_VM_PAGE(paddr_t);
static int vm_physseg_find(paddr_t, int *);
/*
* macros
*/
#define UVM_PAGE_TREE_PENALTY 4 /* XXX: a guess */
#define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
/*
* Compute the page color bucket for a given page.
*/
#define VM_PGCOLOR_BUCKET(pg) \
(atop(VM_PAGE_TO_PHYS((pg))) & uvmexp.colormask)
/*
* when VM_PHYSSEG_MAX is 1, we can simplify these functions
*/
#if VM_PHYSSEG_MAX == 1
static inline int vm_physseg_find_contig(struct vm_physseg *, int, paddr_t, int *);
#elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH)
static inline int vm_physseg_find_bsearch(struct vm_physseg *, int, paddr_t, int *);
#else
static inline int vm_physseg_find_linear(struct vm_physseg *, int, paddr_t, int *);
#endif
/*
* vm_physseg_find: find vm_physseg structure that belongs to a PA
*/
static inline int
vm_physseg_find(paddr_t pframe, int *offp)
{
#if VM_PHYSSEG_MAX == 1
return vm_physseg_find_contig(vm_physmem, vm_nphysseg, pframe, offp);
#elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH)
return vm_physseg_find_bsearch(vm_physmem, vm_nphysseg, pframe, offp);
#else
return vm_physseg_find_linear(vm_physmem, vm_nphysseg, pframe, offp);
#endif
}
#if VM_PHYSSEG_MAX == 1
static inline int
vm_physseg_find_contig(struct vm_physseg *segs, int nsegs, paddr_t pframe, int *offp)
{
/* 'contig' case */
if (pframe >= segs[0].start && pframe < segs[0].end) {
if (offp)
*offp = pframe - segs[0].start;
return(0);
}
return(-1);
}
#elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH)
static inline int
vm_physseg_find_bsearch(struct vm_physseg *segs, int nsegs, paddr_t pframe, int *offp)
{
/* binary search for it */
u_int start, len, try;
/*
* if try is too large (thus target is less than try) we reduce
* the length to trunc(len/2) [i.e. everything smaller than "try"]
*
* if the try is too small (thus target is greater than try) then
* we set the new start to be (try + 1). this means we need to
* reduce the length to (round(len/2) - 1).
*
* note "adjust" below which takes advantage of the fact that
* (round(len/2) - 1) == trunc((len - 1) / 2)
* for any value of len we may have
*/
for (start = 0, len = nsegs ; len != 0 ; len = len / 2) {
try = start + (len / 2); /* try in the middle */
/* start past our try? */
if (pframe >= segs[try].start) {
/* was try correct? */
if (pframe < segs[try].end) {
if (offp)
*offp = pframe - segs[try].start;
return(try); /* got it */
}
start = try + 1; /* next time, start here */
len--; /* "adjust" */
} else {
/*
* pframe before try, just reduce length of
* region, done in "for" loop
*/
}
}
return(-1);
}
#else
static inline int
vm_physseg_find_linear(struct vm_physseg *segs, int nsegs, paddr_t pframe, int *offp)
{
/* linear search for it */
int lcv;
for (lcv = 0; lcv < nsegs; lcv++) {
if (pframe >= segs[lcv].start &&
pframe < segs[lcv].end) {
if (offp)
*offp = pframe - segs[lcv].start;
return(lcv); /* got it */
}
}
return(-1);
}
#endif
/*
* PHYS_TO_VM_PAGE: find vm_page for a PA. used by MI code to get vm_pages
* back from an I/O mapping (ugh!). used in some MD code as well.
*/
static inline struct vm_page *
PHYS_TO_VM_PAGE(paddr_t pa)
{
paddr_t pf = atop(pa);
int off;
int psi;
psi = vm_physseg_find(pf, &off);
if (psi != -1)
return(&vm_physmem[psi].pgs[off]);
return(NULL);
}
#define VM_PAGE_IS_FREE(entry) ((entry)->pqflags & PQ_FREE)
#define VM_FREE_PAGE_TO_CPU(pg) ((struct uvm_cpu *)((uintptr_t)pg->offset))
#ifdef DEBUG
void uvm_pagezerocheck(struct vm_page *);
#endif /* DEBUG */
#endif /* _KERNEL */
#endif /* _UVM_UVM_PAGE_H_ */