/* $OpenBSD: uvm_page.c,v 1.140 2015/07/19 22:52:30 beck Exp $ */ /* $NetBSD: uvm_page.c,v 1.44 2000/11/27 08:40:04 chs 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. 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.c 8.3 (Berkeley) 3/21/94 * from: Id: uvm_page.c,v 1.1.2.18 1998/02/06 05:24:42 chs 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. */ /* * uvm_page.c: page ops. */ #include #include #include #include #include #include #include /* * for object trees */ RB_GENERATE(uvm_objtree, vm_page, objt, uvm_pagecmp); int uvm_pagecmp(struct vm_page *a, struct vm_page *b) { return (a->offset < b->offset ? -1 : a->offset > b->offset); } /* * global vars... XXXCDC: move to uvm. structure. */ /* * physical memory config is stored in vm_physmem. */ struct vm_physseg vm_physmem[VM_PHYSSEG_MAX]; /* XXXCDC: uvm.physmem */ int vm_nphysseg = 0; /* XXXCDC: uvm.nphysseg */ /* * Some supported CPUs in a given architecture don't support all * of the things necessary to do idle page zero'ing efficiently. * We therefore provide a way to disable it from machdep code here. */ /* * local variables */ /* * these variables record the values returned by vm_page_bootstrap, * for debugging purposes. The implementation of uvm_pageboot_alloc * and pmap_startup here also uses them internally. */ static vaddr_t virtual_space_start; static vaddr_t virtual_space_end; /* * local prototypes */ static void uvm_pageinsert(struct vm_page *); static void uvm_pageremove(struct vm_page *); /* * inline functions */ /* * uvm_pageinsert: insert a page in the object * * => caller must lock page queues XXX questionable * => call should have already set pg's object and offset pointers * and bumped the version counter */ __inline static void uvm_pageinsert(struct vm_page *pg) { struct vm_page *dupe; KASSERT((pg->pg_flags & PG_TABLED) == 0); dupe = RB_INSERT(uvm_objtree, &pg->uobject->memt, pg); /* not allowed to insert over another page */ KASSERT(dupe == NULL); atomic_setbits_int(&pg->pg_flags, PG_TABLED); pg->uobject->uo_npages++; } /* * uvm_page_remove: remove page from object * * => caller must lock page queues */ static __inline void uvm_pageremove(struct vm_page *pg) { KASSERT(pg->pg_flags & PG_TABLED); RB_REMOVE(uvm_objtree, &pg->uobject->memt, pg); atomic_clearbits_int(&pg->pg_flags, PG_TABLED); pg->uobject->uo_npages--; pg->uobject = NULL; pg->pg_version++; } /* * uvm_page_init: init the page system. called from uvm_init(). * * => we return the range of kernel virtual memory in kvm_startp/kvm_endp */ void uvm_page_init(vaddr_t *kvm_startp, vaddr_t *kvm_endp) { vsize_t freepages, pagecount, n; vm_page_t pagearray, curpg; int lcv, i; paddr_t paddr, pgno; struct vm_physseg *seg; /* * init the page queues and page queue locks */ TAILQ_INIT(&uvm.page_active); TAILQ_INIT(&uvm.page_inactive_swp); TAILQ_INIT(&uvm.page_inactive_obj); mtx_init(&uvm.fpageqlock, IPL_VM); uvm_pmr_init(); /* * allocate vm_page structures. */ /* * sanity check: * before calling this function the MD code is expected to register * some free RAM with the uvm_page_physload() function. our job * now is to allocate vm_page structures for this memory. */ if (vm_nphysseg == 0) panic("uvm_page_bootstrap: no memory pre-allocated"); /* * first calculate the number of free pages... * * note that we use start/end rather than avail_start/avail_end. * this allows us to allocate extra vm_page structures in case we * want to return some memory to the pool after booting. */ freepages = 0; for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg ; lcv++, seg++) freepages += (seg->end - seg->start); /* * we now know we have (PAGE_SIZE * freepages) bytes of memory we can * use. for each page of memory we use we need a vm_page structure. * thus, the total number of pages we can use is the total size of * the memory divided by the PAGE_SIZE plus the size of the vm_page * structure. we add one to freepages as a fudge factor to avoid * truncation errors (since we can only allocate in terms of whole * pages). */ pagecount = (((paddr_t)freepages + 1) << PAGE_SHIFT) / (PAGE_SIZE + sizeof(struct vm_page)); pagearray = (vm_page_t)uvm_pageboot_alloc(pagecount * sizeof(struct vm_page)); memset(pagearray, 0, pagecount * sizeof(struct vm_page)); /* init the vm_page structures and put them in the correct place. */ for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg ; lcv++, seg++) { n = seg->end - seg->start; if (n > pagecount) { panic("uvm_page_init: lost %ld page(s) in init", (long)(n - pagecount)); /* XXXCDC: shouldn't happen? */ /* n = pagecount; */ } /* set up page array pointers */ seg->pgs = pagearray; pagearray += n; pagecount -= n; seg->lastpg = seg->pgs + (n - 1); /* init and free vm_pages (we've already zeroed them) */ pgno = seg->start; paddr = ptoa(pgno); for (i = 0, curpg = seg->pgs; i < n; i++, curpg++, pgno++, paddr += PAGE_SIZE) { curpg->phys_addr = paddr; VM_MDPAGE_INIT(curpg); if (pgno >= seg->avail_start && pgno <= seg->avail_end) { uvmexp.npages++; } } /* Add pages to free pool. */ uvm_pmr_freepages(&seg->pgs[seg->avail_start - seg->start], seg->avail_end - seg->avail_start); } /* * pass up the values of virtual_space_start and * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper * layers of the VM. */ *kvm_startp = round_page(virtual_space_start); *kvm_endp = trunc_page(virtual_space_end); /* init locks for kernel threads */ mtx_init(&uvm.aiodoned_lock, IPL_BIO); /* * init reserve thresholds * XXXCDC - values may need adjusting */ uvmexp.reserve_pagedaemon = 4; uvmexp.reserve_kernel = 6; uvmexp.anonminpct = 10; uvmexp.vnodeminpct = 10; uvmexp.vtextminpct = 5; uvmexp.anonmin = uvmexp.anonminpct * 256 / 100; uvmexp.vnodemin = uvmexp.vnodeminpct * 256 / 100; uvmexp.vtextmin = uvmexp.vtextminpct * 256 / 100; uvm.page_init_done = TRUE; } /* * uvm_setpagesize: set the page size * * => sets page_shift and page_mask from uvmexp.pagesize. */ void uvm_setpagesize(void) { if (uvmexp.pagesize == 0) uvmexp.pagesize = DEFAULT_PAGE_SIZE; uvmexp.pagemask = uvmexp.pagesize - 1; if ((uvmexp.pagemask & uvmexp.pagesize) != 0) panic("uvm_setpagesize: page size not a power of two"); for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) if ((1 << uvmexp.pageshift) == uvmexp.pagesize) break; } /* * uvm_pageboot_alloc: steal memory from physmem for bootstrapping */ vaddr_t uvm_pageboot_alloc(vsize_t size) { #if defined(PMAP_STEAL_MEMORY) vaddr_t addr; /* * defer bootstrap allocation to MD code (it may want to allocate * from a direct-mapped segment). pmap_steal_memory should round * off virtual_space_start/virtual_space_end. */ addr = pmap_steal_memory(size, &virtual_space_start, &virtual_space_end); return(addr); #else /* !PMAP_STEAL_MEMORY */ static boolean_t initialized = FALSE; vaddr_t addr, vaddr; paddr_t paddr; /* round to page size */ size = round_page(size); /* on first call to this function, initialize ourselves. */ if (initialized == FALSE) { pmap_virtual_space(&virtual_space_start, &virtual_space_end); /* round it the way we like it */ virtual_space_start = round_page(virtual_space_start); virtual_space_end = trunc_page(virtual_space_end); initialized = TRUE; } /* allocate virtual memory for this request */ if (virtual_space_start == virtual_space_end || (virtual_space_end - virtual_space_start) < size) panic("uvm_pageboot_alloc: out of virtual space"); addr = virtual_space_start; #ifdef PMAP_GROWKERNEL /* * If the kernel pmap can't map the requested space, * then allocate more resources for it. */ if (uvm_maxkaddr < (addr + size)) { uvm_maxkaddr = pmap_growkernel(addr + size); if (uvm_maxkaddr < (addr + size)) panic("uvm_pageboot_alloc: pmap_growkernel() failed"); } #endif virtual_space_start += size; /* allocate and mapin physical pages to back new virtual pages */ for (vaddr = round_page(addr) ; vaddr < addr + size ; vaddr += PAGE_SIZE) { if (!uvm_page_physget(&paddr)) panic("uvm_pageboot_alloc: out of memory"); /* * Note this memory is no longer managed, so using * pmap_kenter is safe. */ pmap_kenter_pa(vaddr, paddr, PROT_READ | PROT_WRITE); } pmap_update(pmap_kernel()); return(addr); #endif /* PMAP_STEAL_MEMORY */ } #if !defined(PMAP_STEAL_MEMORY) /* * uvm_page_physget: "steal" one page from the vm_physmem structure. * * => attempt to allocate it off the end of a segment in which the "avail" * values match the start/end values. if we can't do that, then we * will advance both values (making them equal, and removing some * vm_page structures from the non-avail area). * => return false if out of memory. */ boolean_t uvm_page_physget(paddr_t *paddrp) { int lcv; struct vm_physseg *seg; /* pass 1: try allocating from a matching end */ #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) || \ (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) for (lcv = vm_nphysseg - 1, seg = vm_physmem + lcv; lcv >= 0; lcv--, seg--) #else for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg ; lcv++, seg++) #endif { if (uvm.page_init_done == TRUE) panic("uvm_page_physget: called _after_ bootstrap"); /* try from front */ if (seg->avail_start == seg->start && seg->avail_start < seg->avail_end) { *paddrp = ptoa(seg->avail_start); seg->avail_start++; seg->start++; /* nothing left? nuke it */ if (seg->avail_start == seg->end) { if (vm_nphysseg == 1) panic("uvm_page_physget: out of memory!"); vm_nphysseg--; for (; lcv < vm_nphysseg; lcv++, seg++) /* structure copy */ seg[0] = seg[1]; } return (TRUE); } /* try from rear */ if (seg->avail_end == seg->end && seg->avail_start < seg->avail_end) { *paddrp = ptoa(seg->avail_end - 1); seg->avail_end--; seg->end--; /* nothing left? nuke it */ if (seg->avail_end == seg->start) { if (vm_nphysseg == 1) panic("uvm_page_physget: out of memory!"); vm_nphysseg--; for (; lcv < vm_nphysseg ; lcv++, seg++) /* structure copy */ seg[0] = seg[1]; } return (TRUE); } } /* pass2: forget about matching ends, just allocate something */ #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) || \ (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) for (lcv = vm_nphysseg - 1, seg = vm_physmem + lcv; lcv >= 0; lcv--, seg--) #else for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg ; lcv++, seg++) #endif { /* any room in this bank? */ if (seg->avail_start >= seg->avail_end) continue; /* nope */ *paddrp = ptoa(seg->avail_start); seg->avail_start++; /* truncate! */ seg->start = seg->avail_start; /* nothing left? nuke it */ if (seg->avail_start == seg->end) { if (vm_nphysseg == 1) panic("uvm_page_physget: out of memory!"); vm_nphysseg--; for (; lcv < vm_nphysseg ; lcv++, seg++) /* structure copy */ seg[0] = seg[1]; } return (TRUE); } return (FALSE); /* whoops! */ } #endif /* PMAP_STEAL_MEMORY */ /* * uvm_page_physload: load physical memory into VM system * * => all args are PFs * => all pages in start/end get vm_page structures * => areas marked by avail_start/avail_end get added to the free page pool * => we are limited to VM_PHYSSEG_MAX physical memory segments */ void uvm_page_physload(paddr_t start, paddr_t end, paddr_t avail_start, paddr_t avail_end, int flags) { int preload, lcv; psize_t npages; struct vm_page *pgs; struct vm_physseg *ps, *seg; #ifdef DIAGNOSTIC if (uvmexp.pagesize == 0) panic("uvm_page_physload: page size not set!"); if (start >= end) panic("uvm_page_physload: start >= end"); #endif /* do we have room? */ if (vm_nphysseg == VM_PHYSSEG_MAX) { printf("uvm_page_physload: unable to load physical memory " "segment\n"); printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n", VM_PHYSSEG_MAX, (long long)start, (long long)end); printf("\tincrease VM_PHYSSEG_MAX\n"); return; } /* * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been * called yet, so malloc is not available). */ for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg; lcv++, seg++) { if (seg->pgs) break; } preload = (lcv == vm_nphysseg); /* if VM is already running, attempt to malloc() vm_page structures */ if (!preload) { /* * XXXCDC: need some sort of lockout for this case * right now it is only used by devices so it should be alright. */ paddr_t paddr; npages = end - start; /* # of pages */ pgs = (struct vm_page *)uvm_km_zalloc(kernel_map, npages * sizeof(*pgs)); if (pgs == NULL) { printf("uvm_page_physload: can not malloc vm_page " "structs for segment\n"); printf("\tignoring 0x%lx -> 0x%lx\n", start, end); return; } /* init phys_addr and free pages, XXX uvmexp.npages */ for (lcv = 0, paddr = ptoa(start); lcv < npages; lcv++, paddr += PAGE_SIZE) { pgs[lcv].phys_addr = paddr; VM_MDPAGE_INIT(&pgs[lcv]); if (atop(paddr) >= avail_start && atop(paddr) <= avail_end) { if (flags & PHYSLOAD_DEVICE) { atomic_setbits_int(&pgs[lcv].pg_flags, PG_DEV); pgs[lcv].wire_count = 1; } else { #if defined(VM_PHYSSEG_NOADD) panic("uvm_page_physload: tried to add RAM after vm_mem_init"); #endif } } } /* Add pages to free pool. */ if ((flags & PHYSLOAD_DEVICE) == 0) { uvm_pmr_freepages(&pgs[avail_start - start], avail_end - avail_start); } /* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */ } else { /* gcc complains if these don't get init'd */ pgs = NULL; npages = 0; } /* now insert us in the proper place in vm_physmem[] */ #if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM) /* random: put it at the end (easy!) */ ps = &vm_physmem[vm_nphysseg]; #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) { int x; /* sort by address for binary search */ for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg; lcv++, seg++) if (start < seg->start) break; ps = seg; /* move back other entries, if necessary ... */ for (x = vm_nphysseg, seg = vm_physmem + x - 1; x > lcv; x--, seg--) /* structure copy */ seg[1] = seg[0]; } #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) { int x; /* sort by largest segment first */ for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg; lcv++, seg++) if ((end - start) > (seg->end - seg->start)) break; ps = &vm_physmem[lcv]; /* move back other entries, if necessary ... */ for (x = vm_nphysseg, seg = vm_physmem + x - 1; x > lcv; x--, seg--) /* structure copy */ seg[1] = seg[0]; } #else panic("uvm_page_physload: unknown physseg strategy selected!"); #endif ps->start = start; ps->end = end; ps->avail_start = avail_start; ps->avail_end = avail_end; if (preload) { ps->pgs = NULL; } else { ps->pgs = pgs; ps->lastpg = pgs + npages - 1; } vm_nphysseg++; return; } #ifdef DDB /* XXXCDC: TMP TMP TMP DEBUG DEBUG DEBUG */ void uvm_page_physdump(void); /* SHUT UP GCC */ /* call from DDB */ void uvm_page_physdump(void) { int lcv; struct vm_physseg *seg; printf("uvm_page_physdump: physical memory config [segs=%d of %d]:\n", vm_nphysseg, VM_PHYSSEG_MAX); for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg ; lcv++, seg++) printf("0x%llx->0x%llx [0x%llx->0x%llx]\n", (long long)seg->start, (long long)seg->end, (long long)seg->avail_start, (long long)seg->avail_end); printf("STRATEGY = "); switch (VM_PHYSSEG_STRAT) { case VM_PSTRAT_RANDOM: printf("RANDOM\n"); break; case VM_PSTRAT_BSEARCH: printf("BSEARCH\n"); break; case VM_PSTRAT_BIGFIRST: printf("BIGFIRST\n"); break; default: printf("<>!!!!\n"); } } #endif void uvm_shutdown(void) { #ifdef UVM_SWAP_ENCRYPT uvm_swap_finicrypt_all(); #endif } /* * Perform insert of a given page in the specified anon of obj. * This is basically, uvm_pagealloc, but with the page already given. */ void uvm_pagealloc_pg(struct vm_page *pg, struct uvm_object *obj, voff_t off, struct vm_anon *anon) { int flags; flags = PG_BUSY | PG_FAKE; pg->offset = off; pg->uobject = obj; pg->uanon = anon; if (anon) { anon->an_page = pg; flags |= PQ_ANON; } else if (obj) uvm_pageinsert(pg); atomic_setbits_int(&pg->pg_flags, flags); #if defined(UVM_PAGE_TRKOWN) pg->owner_tag = NULL; #endif UVM_PAGE_OWN(pg, "new alloc"); } /* * uvm_pglistalloc: allocate a list of pages * * => allocated pages are placed at the tail of rlist. rlist is * assumed to be properly initialized by caller. * => returns 0 on success or errno on failure * => doesn't take into account clean non-busy pages on inactive list * that could be used(?) * => params: * size the size of the allocation, rounded to page size. * low the low address of the allowed allocation range. * high the high address of the allowed allocation range. * alignment memory must be aligned to this power-of-two boundary. * boundary no segment in the allocation may cross this * power-of-two boundary (relative to zero). * => flags: * UVM_PLA_NOWAIT fail if allocation fails * UVM_PLA_WAITOK wait for memory to become avail * UVM_PLA_ZERO return zeroed memory */ int uvm_pglistalloc(psize_t size, paddr_t low, paddr_t high, paddr_t alignment, paddr_t boundary, struct pglist *rlist, int nsegs, int flags) { KASSERT((alignment & (alignment - 1)) == 0); KASSERT((boundary & (boundary - 1)) == 0); KASSERT(!(flags & UVM_PLA_WAITOK) ^ !(flags & UVM_PLA_NOWAIT)); if (size == 0) return (EINVAL); size = atop(round_page(size)); /* * check to see if we need to generate some free pages waking * the pagedaemon. */ if ((uvmexp.free - BUFPAGES_DEFICIT) < uvmexp.freemin || ((uvmexp.free - BUFPAGES_DEFICIT) < uvmexp.freetarg && (uvmexp.inactive + BUFPAGES_INACT) < uvmexp.inactarg)) wakeup(&uvm.pagedaemon); /* * XXX uvm_pglistalloc is currently only used for kernel * objects. Unlike the checks in uvm_pagealloc, below, here * we are always allowed to use the kernel reserve. However, we * have to enforce the pagedaemon reserve here or allocations * via this path could consume everything and we can't * recover in the page daemon. */ again: if ((uvmexp.free <= uvmexp.reserve_pagedaemon + size && !((curproc == uvm.pagedaemon_proc) || (curproc == syncerproc)))) { if (flags & UVM_PLA_WAITOK) { uvm_wait("uvm_pglistalloc"); goto again; } return (ENOMEM); } if ((high & PAGE_MASK) != PAGE_MASK) { printf("uvm_pglistalloc: Upper boundary 0x%lx " "not on pagemask.\n", (unsigned long)high); } /* * Our allocations are always page granularity, so our alignment * must be, too. */ if (alignment < PAGE_SIZE) alignment = PAGE_SIZE; low = atop(roundup(low, alignment)); /* * high + 1 may result in overflow, in which case high becomes 0x0, * which is the 'don't care' value. * The only requirement in that case is that low is also 0x0, or the * low pages should already be unmapped */ void uvm_pglistfree(struct pglist *list) { uvm_pmr_freepageq(list); } /* * interface used by the buffer cache to allocate a buffer at a time. * The pages are allocated wired in DMA accessible memory */ int uvm_pagealloc_multi(struct uvm_object *obj, voff_t off, vsize_t size, int flags) { struct pglist plist; struct vm_page *pg; int i, r; TAILQ_INIT(&plist); r = uvm_pglistalloc(size, dma_constraint.ucr_low, dma_constraint.ucr_high, 0, 0, &plist, atop(round_page(size)), flags); if (r == 0) { i = 0; while ((pg = TAILQ_FIRST(&plist)) != NULL) { pg->wire_count = 1; atomic_setbits_int(&pg->pg_flags, PG_CLEAN | PG_FAKE); KASSERT((pg->pg_flags & PG_DEV) == 0); TAILQ_REMOVE(&plist, pg, pageq); uvm_pagealloc_pg(pg, obj, off + ptoa(i++), NULL); } } return r; } /* * interface used by the buffer cache to reallocate a buffer at a time. * The pages are reallocated wired outside the DMA accessible region. * */ int uvm_pagerealloc_multi(struct uvm_object *obj, voff_t off, vsize_t size, int flags, struct uvm_constraint_range *where) { struct pglist plist; struct vm_page *pg, *tpg; int i, r; voff_t offset; TAILQ_INIT(&plist); if (size == 0) panic("size 0 uvm_pagerealloc"); r = uvm_pglistalloc(size, where->ucr_low, where->ucr_high, 0, 0, &plist, atop(round_page(size)), flags); if (r == 0) { i = 0; while((pg = TAILQ_FIRST(&plist)) != NULL) { offset = off + ptoa(i++); tpg = uvm_pagelookup(obj, offset); pg->wire_count = 1; atomic_setbits_int(&pg->pg_flags, PG_CLEAN | PG_FAKE); KASSERT((pg->pg_flags & PG_DEV) == 0); TAILQ_REMOVE(&plist, pg, pageq); uvm_pagecopy(tpg, pg); uvm_pagefree(tpg); uvm_pagealloc_pg(pg, obj, offset, NULL); } } return r; } /* * uvm_pagealloc_strat: allocate vm_page from a particular free list. * * => return null if no pages free * => wake up pagedaemon if number of free pages drops below low water mark * => only one of obj or anon can be non-null * => caller must activate/deactivate page if it is not wired. */ struct vm_page * uvm_pagealloc(struct uvm_object *obj, voff_t off, struct vm_anon *anon, int flags) { struct vm_page *pg; struct pglist pgl; int pmr_flags; boolean_t use_reserve; KASSERT(obj == NULL || anon == NULL); KASSERT(off == trunc_page(off)); /* * check to see if we need to generate some free pages waking * the pagedaemon. */ if ((uvmexp.free - BUFPAGES_DEFICIT) < uvmexp.freemin || ((uvmexp.free - BUFPAGES_DEFICIT) < uvmexp.freetarg && (uvmexp.inactive + BUFPAGES_INACT) < uvmexp.inactarg)) wakeup(&uvm.pagedaemon); /* * fail if any of these conditions is true: * [1] there really are no free pages, or * [2] only kernel "reserved" pages remain and * the page isn't being allocated to a kernel object. * [3] only pagedaemon "reserved" pages remain and * the requestor isn't the pagedaemon. */ use_reserve = (flags & UVM_PGA_USERESERVE) || (obj && UVM_OBJ_IS_KERN_OBJECT(obj)); if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) || (uvmexp.free <= uvmexp.reserve_pagedaemon && !((curproc == uvm.pagedaemon_proc) || (curproc == syncerproc)))) goto fail; pmr_flags = UVM_PLA_NOWAIT; if (flags & UVM_PGA_ZERO) pmr_flags |= UVM_PLA_ZERO; TAILQ_INIT(&pgl); if (uvm_pmr_getpages(1, 0, 0, 1, 0, 1, pmr_flags, &pgl) != 0) goto fail; pg = TAILQ_FIRST(&pgl); KASSERT(pg != NULL && TAILQ_NEXT(pg, pageq) == NULL); uvm_pagealloc_pg(pg, obj, off, anon); KASSERT((pg->pg_flags & PG_DEV) == 0); if (flags & UVM_PGA_ZERO) atomic_clearbits_int(&pg->pg_flags, PG_CLEAN); else atomic_setbits_int(&pg->pg_flags, PG_CLEAN); return(pg); fail: return (NULL); } /* * uvm_pagerealloc: reallocate a page from one object to another */ void uvm_pagerealloc(struct vm_page *pg, struct uvm_object *newobj, voff_t newoff) { /* remove it from the old object */ if (pg->uobject) { uvm_pageremove(pg); } /* put it in the new object */ if (newobj) { pg->uobject = newobj; pg->offset = newoff; pg->pg_version++; uvm_pageinsert(pg); } } /* * uvm_pagefree: free page * * => erase page's identity (i.e. remove from object) * => put page on free list * => caller must lock page queues * => assumes all valid mappings of pg are gone */ void uvm_pagefree(struct vm_page *pg) { int saved_loan_count = pg->loan_count; u_int flags_to_clear = 0; #ifdef DEBUG if (pg->uobject == (void *)0xdeadbeef && pg->uanon == (void *)0xdeadbeef) { panic("uvm_pagefree: freeing free page %p", pg); } #endif KASSERT((pg->pg_flags & PG_DEV) == 0); /* * if the page was an object page (and thus "TABLED"), remove it * from the object. */ if (pg->pg_flags & PG_TABLED) { /* * if the object page is on loan we are going to drop ownership. * it is possible that an anon will take over as owner for this * page later on. the anon will want a !PG_CLEAN page so that * it knows it needs to allocate swap if it wants to page the * page out. */ /* in case an anon takes over */ if (saved_loan_count) atomic_clearbits_int(&pg->pg_flags, PG_CLEAN); uvm_pageremove(pg); /* * if our page was on loan, then we just lost control over it * (in fact, if it was loaned to an anon, the anon may have * already taken over ownership of the page by now and thus * changed the loan_count [e.g. in uvmfault_anonget()]) we just * return (when the last loan is dropped, then the page can be * freed by whatever was holding the last loan). */ if (saved_loan_count) return; } else if (saved_loan_count && pg->uanon) { /* * if our page is owned by an anon and is loaned out to the * kernel then we just want to drop ownership and return. * the kernel must free the page when all its loans clear ... * note that the kernel can't change the loan status of our * page as long as we are holding PQ lock. */ atomic_clearbits_int(&pg->pg_flags, PQ_ANON); pg->uanon->an_page = NULL; pg->uanon = NULL; return; } KASSERT(saved_loan_count == 0); /* now remove the page from the queues */ if (pg->pg_flags & PQ_ACTIVE) { TAILQ_REMOVE(&uvm.page_active, pg, pageq); flags_to_clear |= PQ_ACTIVE; uvmexp.active--; } if (pg->pg_flags & PQ_INACTIVE) { if (pg->pg_flags & PQ_SWAPBACKED) TAILQ_REMOVE(&uvm.page_inactive_swp, pg, pageq); else TAILQ_REMOVE(&uvm.page_inactive_obj, pg, pageq); flags_to_clear |= PQ_INACTIVE; uvmexp.inactive--; } /* if the page was wired, unwire it now. */ if (pg->wire_count) { pg->wire_count = 0; uvmexp.wired--; } if (pg->uanon) { pg->uanon->an_page = NULL; pg->uanon = NULL; flags_to_clear |= PQ_ANON; } /* Clean page state bits. */ flags_to_clear |= PQ_AOBJ; /* XXX: find culprit */ flags_to_clear |= PQ_ENCRYPT|PG_ZERO|PG_FAKE|PG_BUSY|PG_RELEASED| PG_CLEAN|PG_CLEANCHK; atomic_clearbits_int(&pg->pg_flags, flags_to_clear); /* and put on free queue */ #ifdef DEBUG pg->uobject = (void *)0xdeadbeef; pg->offset = 0xdeadbeef; pg->uanon = (void *)0xdeadbeef; #endif uvm_pmr_freepages(pg, 1); } /* * uvm_page_unbusy: unbusy an array of pages. * * => pages must either all belong to the same object, or all belong to anons. * => if pages are anon-owned, anons must have 0 refcount. */ void uvm_page_unbusy(struct vm_page **pgs, int npgs) { struct vm_page *pg; struct uvm_object *uobj; int i; for (i = 0; i < npgs; i++) { pg = pgs[i]; if (pg == NULL || pg == PGO_DONTCARE) { continue; } if (pg->pg_flags & PG_WANTED) { wakeup(pg); } if (pg->pg_flags & PG_RELEASED) { uobj = pg->uobject; if (uobj != NULL) { uvm_lock_pageq(); pmap_page_protect(pg, PROT_NONE); /* XXX won't happen right now */ if (pg->pg_flags & PQ_AOBJ) uao_dropswap(uobj, pg->offset >> PAGE_SHIFT); uvm_pagefree(pg); uvm_unlock_pageq(); } else { atomic_clearbits_int(&pg->pg_flags, PG_BUSY); UVM_PAGE_OWN(pg, NULL); uvm_anfree(pg->uanon); } } else { atomic_clearbits_int(&pg->pg_flags, PG_WANTED|PG_BUSY); UVM_PAGE_OWN(pg, NULL); } } } #if defined(UVM_PAGE_TRKOWN) /* * uvm_page_own: set or release page ownership * * => this is a debugging function that keeps track of who sets PG_BUSY * and where they do it. it can be used to track down problems * such a process setting "PG_BUSY" and never releasing it. * => if "tag" is NULL then we are releasing page ownership */ void uvm_page_own(struct vm_page *pg, char *tag) { /* gain ownership? */ if (tag) { if (pg->owner_tag) { printf("uvm_page_own: page %p already owned " "by proc %d [%s]\n", pg, pg->owner, pg->owner_tag); panic("uvm_page_own"); } pg->owner = (curproc) ? curproc->p_pid : (pid_t) -1; pg->owner_tag = tag; return; } /* drop ownership */ if (pg->owner_tag == NULL) { printf("uvm_page_own: dropping ownership of an non-owned " "page (%p)\n", pg); panic("uvm_page_own"); } pg->owner_tag = NULL; return; } #endif /* * when VM_PHYSSEG_MAX is 1, we can simplify these functions */ #if VM_PHYSSEG_MAX > 1 /* * vm_physseg_find: find vm_physseg structure that belongs to a PA */ int vm_physseg_find(paddr_t pframe, int *offp) { struct vm_physseg *seg; #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) /* binary search for it */ int start, len, try; /* * if try is too large (thus target is less than 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 = vm_nphysseg ; len != 0 ; len = len / 2) { try = start + (len / 2); /* try in the middle */ seg = vm_physmem + try; /* start past our try? */ if (pframe >= seg->start) { /* was try correct? */ if (pframe < seg->end) { if (offp) *offp = pframe - seg->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 /* linear search for it */ int lcv; for (lcv = 0, seg = vm_physmem; lcv < vm_nphysseg ; lcv++, seg++) { if (pframe >= seg->start && pframe < seg->end) { if (offp) *offp = pframe - seg->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. */ 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); return ((psi == -1) ? NULL : &vm_physmem[psi].pgs[off]); } #endif /* VM_PHYSSEG_MAX > 1 */ /* * uvm_pagelookup: look up a page */ struct vm_page * uvm_pagelookup(struct uvm_object *obj, voff_t off) { /* XXX if stack is too much, handroll */ struct vm_page pg; pg.offset = off; return (RB_FIND(uvm_objtree, &obj->memt, &pg)); } /* * uvm_pagewire: wire the page, thus removing it from the daemon's grasp * * => caller must lock page queues */ void uvm_pagewire(struct vm_page *pg) { if (pg->wire_count == 0) { if (pg->pg_flags & PQ_ACTIVE) { TAILQ_REMOVE(&uvm.page_active, pg, pageq); atomic_clearbits_int(&pg->pg_flags, PQ_ACTIVE); uvmexp.active--; } if (pg->pg_flags & PQ_INACTIVE) { if (pg->pg_flags & PQ_SWAPBACKED) TAILQ_REMOVE(&uvm.page_inactive_swp, pg, pageq); else TAILQ_REMOVE(&uvm.page_inactive_obj, pg, pageq); atomic_clearbits_int(&pg->pg_flags, PQ_INACTIVE); uvmexp.inactive--; } uvmexp.wired++; } pg->wire_count++; } /* * uvm_pageunwire: unwire the page. * * => activate if wire count goes to zero. * => caller must lock page queues */ void uvm_pageunwire(struct vm_page *pg) { pg->wire_count--; if (pg->wire_count == 0) { TAILQ_INSERT_TAIL(&uvm.page_active, pg, pageq); uvmexp.active++; atomic_setbits_int(&pg->pg_flags, PQ_ACTIVE); uvmexp.wired--; } } /* * uvm_pagedeactivate: deactivate page -- no pmaps have access to page * * => caller must lock page queues * => caller must check to make sure page is not wired * => object that page belongs to must be locked (so we can adjust pg->flags) */ void uvm_pagedeactivate(struct vm_page *pg) { if (pg->pg_flags & PQ_ACTIVE) { TAILQ_REMOVE(&uvm.page_active, pg, pageq); atomic_clearbits_int(&pg->pg_flags, PQ_ACTIVE); uvmexp.active--; } if ((pg->pg_flags & PQ_INACTIVE) == 0) { KASSERT(pg->wire_count == 0); if (pg->pg_flags & PQ_SWAPBACKED) TAILQ_INSERT_TAIL(&uvm.page_inactive_swp, pg, pageq); else TAILQ_INSERT_TAIL(&uvm.page_inactive_obj, pg, pageq); atomic_setbits_int(&pg->pg_flags, PQ_INACTIVE); uvmexp.inactive++; pmap_clear_reference(pg); /* * update the "clean" bit. this isn't 100% * accurate, and doesn't have to be. we'll * re-sync it after we zap all mappings when * scanning the inactive list. */ if ((pg->pg_flags & PG_CLEAN) != 0 && pmap_is_modified(pg)) atomic_clearbits_int(&pg->pg_flags, PG_CLEAN); } } /* * uvm_pageactivate: activate page * * => caller must lock page queues */ void uvm_pageactivate(struct vm_page *pg) { if (pg->pg_flags & PQ_INACTIVE) { if (pg->pg_flags & PQ_SWAPBACKED) TAILQ_REMOVE(&uvm.page_inactive_swp, pg, pageq); else TAILQ_REMOVE(&uvm.page_inactive_obj, pg, pageq); atomic_clearbits_int(&pg->pg_flags, PQ_INACTIVE); uvmexp.inactive--; } if (pg->wire_count == 0) { /* * if page is already active, remove it from list so we * can put it at tail. if it wasn't active, then mark * it active and bump active count */ if (pg->pg_flags & PQ_ACTIVE) TAILQ_REMOVE(&uvm.page_active, pg, pageq); else { atomic_setbits_int(&pg->pg_flags, PQ_ACTIVE); uvmexp.active++; } TAILQ_INSERT_TAIL(&uvm.page_active, pg, pageq); } } /* * uvm_pagezero: zero fill a page */ void uvm_pagezero(struct vm_page *pg) { atomic_clearbits_int(&pg->pg_flags, PG_CLEAN); pmap_zero_page(pg); } /* * uvm_pagecopy: copy a page */ void uvm_pagecopy(struct vm_page *src, struct vm_page *dst) { atomic_clearbits_int(&dst->pg_flags, PG_CLEAN); pmap_copy_page(src, dst); } /* * uvm_pagecount: count the number of physical pages in the address range. */ psize_t uvm_pagecount(struct uvm_constraint_range* constraint) { int lcv; psize_t sz; paddr_t low, high; paddr_t ps_low, ps_high; /* Algorithm uses page numbers. */ low = atop(constraint->ucr_low); high = atop(constraint->ucr_high); sz = 0; for (lcv = 0; lcv < vm_nphysseg; lcv++) { ps_low = MAX(low, vm_physmem[lcv].avail_start); ps_high = MIN(high, vm_physmem[lcv].avail_end); if (ps_low < ps_high) sz += ps_high - ps_low; } return sz; }