/* $NetBSD: uvm_page.h,v 1.59 2010/02/06 12:10:59 uebayasi 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 #include #include 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_PAGER1 0x1000 /* pager-specific flag */ #define UVM_PGFLAGBITS \ "\20\1BUSY\2WANTED\3TABLED\4CLEAN\5PAGEOUT\6RELEASED\7FAKE\10RDONLY" \ "\11ZERO\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_ */