/* $OpenBSD: uvm_glue.c,v 1.66 2014/07/11 16:35:40 jsg Exp $ */ /* $NetBSD: uvm_glue.c,v 1.44 2001/02/06 19:54:44 eeh 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_glue.c 8.6 (Berkeley) 1/5/94 * from: Id: uvm_glue.c,v 1.1.2.8 1998/02/07 01:16:54 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_glue.c: glue functions */ #include #include #include #include #include #include #ifdef SYSVSHM #include #endif #include #include /* * uvm_kernacc: can the kernel access a region of memory * * - called from malloc [DIAGNOSTIC], and /dev/kmem driver (mem.c) */ boolean_t uvm_kernacc(caddr_t addr, size_t len, int rw) { boolean_t rv; vaddr_t saddr, eaddr; vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE; saddr = trunc_page((vaddr_t)addr); eaddr = round_page((vaddr_t)addr + len); vm_map_lock_read(kernel_map); rv = uvm_map_checkprot(kernel_map, saddr, eaddr, prot); vm_map_unlock_read(kernel_map); return(rv); } #ifdef KGDB /* * Change protections on kernel pages from addr to addr+len * (presumably so debugger can plant a breakpoint). * * We force the protection change at the pmap level. If we were * to use vm_map_protect a change to allow writing would be lazily- * applied meaning we would still take a protection fault, something * we really don't want to do. It would also fragment the kernel * map unnecessarily. We cannot use pmap_protect since it also won't * enforce a write-enable request. Using pmap_enter is the only way * we can ensure the change takes place properly. */ void uvm_chgkprot(caddr_t addr, size_t len, int rw) { vm_prot_t prot; paddr_t pa; vaddr_t sva, eva; prot = rw == B_READ ? VM_PROT_READ : VM_PROT_READ|VM_PROT_WRITE; eva = round_page((vaddr_t)addr + len); for (sva = trunc_page((vaddr_t)addr); sva < eva; sva += PAGE_SIZE) { /* * Extract physical address for the page. * We use a cheezy hack to differentiate physical * page 0 from an invalid mapping, not that it * really matters... */ if (pmap_extract(pmap_kernel(), sva, &pa) == FALSE) panic("chgkprot: invalid page"); pmap_enter(pmap_kernel(), sva, pa, prot, PMAP_WIRED); } pmap_update(pmap_kernel()); } #endif /* * uvm_vslock: wire user memory for I/O * * - called from physio and sys___sysctl */ int uvm_vslock(struct proc *p, caddr_t addr, size_t len, vm_prot_t access_type) { struct vm_map *map; vaddr_t start, end; int rv; map = &p->p_vmspace->vm_map; start = trunc_page((vaddr_t)addr); end = round_page((vaddr_t)addr + len); if (end <= start) return (EINVAL); rv = uvm_fault_wire(map, start, end, access_type); return (rv); } /* * uvm_vsunlock: unwire user memory wired by uvm_vslock() * * - called from physio and sys___sysctl */ void uvm_vsunlock(struct proc *p, caddr_t addr, size_t len) { vaddr_t start, end; start = trunc_page((vaddr_t)addr); end = round_page((vaddr_t)addr + len); if (end <= start) return; uvm_fault_unwire(&p->p_vmspace->vm_map, start, end); } /* * uvm_vslock_device: wire user memory, make sure it's device reachable * and bounce if necessary. * Always bounces for now. */ int uvm_vslock_device(struct proc *p, void *addr, size_t len, vm_prot_t access_type, void **retp) { struct vm_page *pg; struct pglist pgl; int npages; vaddr_t start, end, off; vaddr_t sva, va; vsize_t sz; int error, i; start = trunc_page((vaddr_t)addr); end = round_page((vaddr_t)addr + len); sz = end - start; off = (vaddr_t)addr - start; if (end <= start) return (EINVAL); if ((error = uvm_fault_wire(&p->p_vmspace->vm_map, start, end, access_type))) { return (error); } npages = atop(sz); for (i = 0; i < npages; i++) { paddr_t pa; if (!pmap_extract(p->p_vmspace->vm_map.pmap, start + ptoa(i), &pa)) { error = EFAULT; goto out_unwire; } if (!PADDR_IS_DMA_REACHABLE(pa)) break; } if (i == npages) { *retp = NULL; return (0); } if ((va = uvm_km_valloc(kernel_map, sz)) == 0) { error = ENOMEM; goto out_unwire; } sva = va; TAILQ_INIT(&pgl); error = uvm_pglistalloc(npages * PAGE_SIZE, dma_constraint.ucr_low, dma_constraint.ucr_high, 0, 0, &pgl, npages, UVM_PLA_WAITOK); if (error) goto out_unmap; while ((pg = TAILQ_FIRST(&pgl)) != NULL) { TAILQ_REMOVE(&pgl, pg, pageq); pmap_kenter_pa(va, VM_PAGE_TO_PHYS(pg), VM_PROT_READ|VM_PROT_WRITE); va += PAGE_SIZE; } pmap_update(pmap_kernel()); KASSERT(va == sva + sz); *retp = (void *)(sva + off); if ((error = copyin(addr, *retp, len)) == 0) return 0; uvm_km_pgremove_intrsafe(sva, sva + sz); pmap_kremove(sva, sz); pmap_update(pmap_kernel()); out_unmap: uvm_km_free(kernel_map, sva, sz); out_unwire: uvm_fault_unwire(&p->p_vmspace->vm_map, start, end); return (error); } void uvm_vsunlock_device(struct proc *p, void *addr, size_t len, void *map) { vaddr_t start, end; vaddr_t kva; vsize_t sz; start = trunc_page((vaddr_t)addr); end = round_page((vaddr_t)addr + len); sz = end - start; if (end <= start) return; if (map) copyout(map, addr, len); uvm_fault_unwire(&p->p_vmspace->vm_map, start, end); if (!map) return; kva = trunc_page((vaddr_t)map); uvm_km_pgremove_intrsafe(kva, kva + sz); pmap_kremove(kva, sz); pmap_update(pmap_kernel()); uvm_km_free(kernel_map, kva, sz); } /* * uvm_uarea_alloc: allocate the u-area for a new thread */ vaddr_t uvm_uarea_alloc(void) { vaddr_t uaddr; uaddr = uvm_km_kmemalloc_pla(kernel_map, uvm.kernel_object, USPACE, USPACE_ALIGN, UVM_KMF_ZERO, no_constraint.ucr_low, no_constraint.ucr_high, 0, 0, USPACE/PAGE_SIZE); #ifdef PMAP_UAREA /* Tell the pmap this is a u-area mapping */ if (uaddr != 0) PMAP_UAREA(uaddr); #endif return (uaddr); } /* * uvm_uarea_free: free a dead thread's stack * * - the thread passed to us is a dead thread; we * are running on a different context now (the reaper). */ void uvm_uarea_free(struct proc *p) { uvm_km_free(kernel_map, (vaddr_t)p->p_addr, USPACE); p->p_addr = NULL; } /* * uvm_exit: exit a virtual address space */ void uvm_exit(struct process *pr) { uvmspace_free(pr->ps_vmspace); pr->ps_vmspace = NULL; } /* * uvm_init_limit: init per-process VM limits * * - called for process 0 and then inherited by all others. */ void uvm_init_limits(struct proc *p) { /* * Set up the initial limits on process VM. Set the maximum * resident set size to be all of (reasonably) available memory. * This causes any single, large process to start random page * replacement once it fills memory. */ p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ; p->p_rlimit[RLIMIT_STACK].rlim_max = MAXSSIZ; p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ; p->p_rlimit[RLIMIT_DATA].rlim_max = MAXDSIZ; p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(uvmexp.free); } #ifdef DEBUG int enableswap = 1; int swapdebug = 0; #define SDB_FOLLOW 1 #define SDB_SWAPIN 2 #define SDB_SWAPOUT 4 #endif /* * swapout_threads: find threads that can be swapped * * - called by the pagedaemon * - try and swap at least one processs * - processes that are sleeping or stopped for maxslp or more seconds * are swapped... otherwise the longest-sleeping or stopped process * is swapped, otherwise the longest resident process... */ void uvm_swapout_threads(void) { struct process *pr; struct proc *p, *slpp; struct process *outpr; int outpri; int didswap = 0; extern int maxslp; /* XXXCDC: should move off to uvmexp. or uvm., also in uvm_meter */ #ifdef DEBUG if (!enableswap) return; #endif /* * outpr/outpri : stop/sleep process whose most active thread has * the largest sleeptime < maxslp */ outpr = NULL; outpri = 0; LIST_FOREACH(pr, &allprocess, ps_list) { if (pr->ps_flags & (PS_SYSTEM | PS_EXITING)) continue; /* * slpp: the sleeping or stopped thread in pr with * the smallest p_slptime */ slpp = NULL; TAILQ_FOREACH(p, &pr->ps_threads, p_thr_link) { switch (p->p_stat) { case SRUN: case SONPROC: goto next_process; case SSLEEP: case SSTOP: if (slpp == NULL || slpp->p_slptime < p->p_slptime) slpp = p; continue; } } if (slpp != NULL) { if (slpp->p_slptime >= maxslp) { pmap_collect(pr->ps_vmspace->vm_map.pmap); didswap++; } else if (slpp->p_slptime > outpri) { outpr = pr; outpri = slpp->p_slptime; } } next_process: ; } /* * If we didn't get rid of any real duds, toss out the next most * likely sleeping/stopped or running candidate. We only do this * if we are real low on memory since we don't gain much by doing * it. */ if (didswap == 0 && uvmexp.free <= atop(round_page(USPACE)) && outpr != NULL) { #ifdef DEBUG if (swapdebug & SDB_SWAPOUT) printf("swapout_threads: no duds, try procpr %p\n", outpr); #endif pmap_collect(outpr->ps_vmspace->vm_map.pmap); } } /* * uvm_atopg: convert KVAs back to their page structures. */ struct vm_page * uvm_atopg(vaddr_t kva) { struct vm_page *pg; paddr_t pa; boolean_t rv; rv = pmap_extract(pmap_kernel(), kva, &pa); KASSERT(rv); pg = PHYS_TO_VM_PAGE(pa); KASSERT(pg != NULL); return (pg); } void uvm_pause(void) { KERNEL_UNLOCK(); KERNEL_LOCK(); if (curcpu()->ci_schedstate.spc_schedflags & SPCF_SHOULDYIELD) preempt(NULL); }