freebsd-skq/sys/vm/vm_vmio.c

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/*
* Copyright (c) 1994 John S. Dyson
* All rights reserved.
*
* 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 immediately at the beginning of the file, without modification,
* 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. Absolutely no warranty of function or purpose is made by the author
* John S. Dyson.
* 4. Modifications may be freely made to this file if the above conditions
* are met.
*
* $Id$
*/
/*
* THIS IS PRELIMINARY, BUGGY AND NON-WORKING CODE
* WHEN THIS NOTICE IS REMOVED -- IT WILL WORK... :-).
*
* THINGS TO DO:
* COMMENTS, THE SYSTEM ALMOST RUNS WITH IT. THIS IS CURRENTLY MEANT
* ONLY AS A PLACEHOLDER!!!
*/
#define VMIO
#include "param.h"
#include "proc.h"
#include "malloc.h"
#include "vm_param.h"
#include "vm.h"
#include "lock.h"
#include "queue.h"
#include "vm_prot.h"
#include "vm_object.h"
#include "vm_page.h"
#include "vnode_pager.h"
#include "vm_map.h"
#include "vm_pageout.h"
#include "vnode.h"
#include "uio.h"
#include "mount.h"
/* #include "buf.h" */
#include "miscfs/specfs/specdev.h"
/* #include "vmio.h" */
int vnode_pager_initialized;
extern vm_map_t pager_map;
struct buf * getpbuf();
void relpbuf(struct buf *bp);
/*
* map an object into kva
* return 1 if all are in memory, and 0 if any are fake.
*/
int
vmio_alloc_pages( vm_object_t object, vm_offset_t start,
vm_offset_t size, vm_page_t *ms) {
int pagecount;
vm_page_t m;
int i,j;
int s;
vm_offset_t kva;
struct buf *bp;
int ioneeded=0;
pagecount = size / PAGE_SIZE;
for(i=0;i<pagecount;i++) {
vm_page_t m;
m = vm_page_lookup( object, start + i * PAGE_SIZE);
if( m) {
/*
* See if something else has already gotten this page
*/
if( m->busy || (m->flags & (PG_VMIO|PG_BUSY))) {
/*
* Something has the page, so we have to
* release all the pages we've gotten to
* this point, wait for the page to unbusy
* and then start over.
*/
int j;
for(j = 0; j < i; j++) {
vm_page_t n;
n = ms[j];
if( n) {
/*
* unbusy the page.
*/
PAGE_WAKEUP(n);
if( n->flags & PG_FAKE)
vm_page_free(n);
}
}
m->flags |= PG_WANTED;
tsleep((caddr_t)m, PVM, "vngpwt", 0);
return -1;
}
m->flags |= PG_REFERENCED;
} else {
m = (vm_page_t) vm_page_alloc( object,
start + i * PAGE_SIZE);
if( !m) {
VM_WAIT;
for(j=0;j<i;j++) {
vm_page_t n;
n = ms[j];
if( n) {
PAGE_WAKEUP(n);
if( n->flags & PG_FAKE)
vm_page_free(n);
}
}
return -1;
}
}
ms[i] = m;
}
/*
* hold the pages and assign them to the mapping
*/
for(i=0;i<pagecount;i++) {
m = ms[i];
vm_page_hold(m);
if( m->flags & PG_FAKE)
++ioneeded;
vm_page_deactivate(m);
if( (m->flags & PG_ACTIVE) == 0)
vm_page_activate(m);
m->flags |= PG_VMIO;
m->flags &= ~PG_BUSY;
++m->act_count;
pmap_page_protect( VM_PAGE_TO_PHYS(m), VM_PROT_READ);
}
return ioneeded;
}
void
vmio_rawiodone( struct buf *bp) {
int s;
int i;
vm_object_t object;
vm_page_t m;
if( bp->b_bufsize != bp->b_bcount)
bzero( bp->b_data + bp->b_bcount, bp->b_bufsize - bp->b_bcount);
printf("rawdone: (blk: %d, count: %d)\n",
bp->b_blkno, bp->b_bcount);
s = splbio();
object = bp->b_pages[0]->object;
for( i = 0; i < bp->b_npages; i++) {
m = bp->b_pages[i];
if( m) {
--m->busy;
if( m->busy == 0) {
m->flags |= PG_CLEAN;
m->flags &= ~(PG_LAUNDRY|PG_FAKE);
PAGE_WAKEUP(m);
}
} else {
panic("vmio_rawiodone: page is gone!!!");
}
}
HOLDRELE(bp->b_vp);
relpbuf(bp);
--object->paging_in_progress;
if( object->paging_in_progress == 0)
wakeup((caddr_t)object);
splx(s);
return;
}
void
vmio_get_pager(struct vnode *vp) {
if( vp->v_type == VREG) {
vm_object_t object;
vm_pager_t pager;
if((vp->v_vmdata == NULL) || (vp->v_flag & VVMIO) == 0) {
pager = (vm_pager_t) vnode_pager_alloc(vp, 0, 0, 0);
object = (vm_object_t) vp->v_vmdata;
if( object->pager != pager)
panic("vmio_get_pager: pager/object mismatch");
(void) vm_object_lookup( pager);
pager_cache( object, TRUE);
vp->v_flag |= VVMIO;
} else {
object = (vm_object_t) vp->v_vmdata;
pager = object->pager;
if( pager == NULL) {
panic("vmio_get_pager: pager missing");
}
(void) vm_object_lookup( pager);
}
}
}
void
vmio_free_pager( struct vnode *vp) {
if( vp->v_vmdata == NULL)
panic("vmio_free_pager: object missing");
vm_object_deallocate( (vm_object_t) vp->v_vmdata);
}
void
vmio_aread( struct buf *lbp) {
struct vnode *vp, *dp;
vm_object_t object;
vm_offset_t offset;
vm_offset_t size;
vm_offset_t off;
int forcemore;
int runp;
int s;
s = splbio();
vp = lbp->b_vp;
object = (vm_object_t) vp->v_vmdata;
offset = trunc_page(lbp->b_lblkno * vp->v_mount->mnt_stat.f_iosize);
size = round_page(lbp->b_bcount);
forcemore = 0;
printf("queueing read: iosize: %d, b_lblkno: %d, offset: %d, size: %d:",
vp->v_mount->mnt_stat.f_iosize,
lbp->b_lblkno, offset, size);
for(off = 0; off < size; ) {
vm_offset_t curoff;
int pgidx, pgcnt, i;
struct buf *bp;
pgidx = off / PAGE_SIZE;
if( !forcemore) {
while( (off < size) &&
(lbp->b_pages[pgidx]->flags & PG_FAKE) == 0) {
off = trunc_page(off) + PAGE_SIZE;
pgidx += 1;
}
}
if( off >= size)
break;
bp = getpbuf();
++object->paging_in_progress;
curoff = offset + off;
VOP_BMAP( vp, curoff / vp->v_mount->mnt_stat.f_iosize,
&dp, &bp->b_blkno, &runp);
bp->b_bcount = (runp + 1) * vp->v_mount->mnt_stat.f_iosize;
if( off + bp->b_bcount > size)
bp->b_bcount = size - off;
bp->b_bufsize = round_page(bp->b_bcount);
pgcnt = bp->b_bufsize / PAGE_SIZE;
for(i=0;i<pgcnt;i++) {
++lbp->b_pages[pgidx+i]->busy;
bp->b_pages[i] = lbp->b_pages[pgidx+i];
bp->b_pages[i]->flags |= PG_BUSY;
}
bp->b_npages = pgcnt;
pmap_qenter((vm_offset_t) bp->b_data, &lbp->b_pages[pgidx], pgcnt);
bp->b_data += curoff - trunc_page(curoff);
off += bp->b_bcount;
if( off & (PAGE_SIZE - 1))
forcemore = 1;
else
forcemore = 0;
/*
* round up physical size for real devices
*/
if( dp->v_type == VBLK || dp->v_type == VCHR) {
bp->b_bcount = (bp->b_bcount + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1);
}
/*
* and map the pages to be read into the kva
*/
VHOLD(vp);
/* build a minimal buffer header */
bp->b_flags = B_BUSY | B_READ | B_CALL | B_ASYNC;
bp->b_iodone = vmio_rawiodone;
/* B_PHYS is not set, but it is nice to fill this in */
bp->b_proc = curproc;
bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred;
if( bp->b_rcred != NOCRED)
crhold(bp->b_rcred);
if( bp->b_wcred != NOCRED)
crhold(bp->b_wcred);
bp->b_lblkno = bp->b_blkno;
/* bp->b_vp = dp; */
bgetvp( dp, bp);
printf(" p: (blk: %d, coff: %d, off: %d, count: %d)",
bp->b_blkno, curoff, off, bp->b_bcount);
/* Should be a BLOCK or character DEVICE if we get here */
bp->b_dev = dp->v_rdev;
/* do the input */
VOP_STRATEGY(bp);
}
printf("\n");
splx(s);
}
int
vmio_getblk( struct buf *bp) {
struct vnode *vp;
vm_object_t object;
vm_offset_t offset;
vm_offset_t size;
vm_page_t ms[(MAXBSIZE + PAGE_SIZE - 1)/PAGE_SIZE];
int rtval;
vp = bp->b_vp;
if( (object = (vm_object_t) vp->v_vmdata) == NULL)
panic("vmio_build_bp: object missing");
offset = trunc_page(bp->b_lblkno * vp->v_mount->mnt_stat.f_iosize);
size = round_page(bp->b_bcount);
printf("vmio_getblk: off:%d(0x%x) blk: %d, size: %d",
offset, offset, bp->b_lblkno, size);
bp->b_flags &= ~B_CACHE;
if( (rtval = vmio_alloc_pages( object, offset, size, ms)) == 0) {
bp->b_flags |= B_CACHE;
printf("(cached)\n");
} else {
printf("(ioneeded:%d)\n", rtval);
}
if( rtval < 0) {
printf("vmio_getblk: vmio_alloc_pages busy\n");
return 0;
}
bp->b_npages = size / PAGE_SIZE;
pmap_qenter((vm_offset_t) bp->b_data, ms, bp->b_npages);
bp->b_flags |= B_VMIO;
bp->b_bufsize = size;
bcopy( ms, bp->b_pages, bp->b_npages * sizeof(vm_page_t));
return 1;
}
int
vmio_biowait( struct buf *lbp) {
int i;
int s;
printf("vmio_biowait -->");
restart:
s = splbio();
for(i=lbp->b_npages-1;i >= 0; --i) {
if( lbp->b_pages[i]->busy || (lbp->b_pages[i]->flags & PG_BUSY)) {
lbp->b_pages[i]->flags |= PG_WANTED;
printf(" waiting on page %d of xfer at %d, flags: 0x%x\n",
i, lbp->b_blkno, lbp->b_pages[i]->flags);
tsleep( (caddr_t) lbp->b_pages[i], PVM, "vbiowt", 0);
splx(s);
goto restart;
}
}
splx(s);
printf("vmio_biowait: finished\n");
return 1;
}
void
vmio_brelse( struct buf *lbp) {
int i;
int nfullpages = lbp->b_bcount / PAGE_SIZE;
pmap_qremove((vm_offset_t) lbp->b_data, lbp->b_npages);
for(i=0;i<lbp->b_npages;i++) {
if( (i < nfullpages) && ((lbp->b_flags & B_DELWRI) == 0))
lbp->b_pages[i]->flags |= PG_CLEAN;
if( lbp->b_flags & B_DELWRI)
lbp->b_pages[i]->flags &= ~PG_CLEAN;
lbp->b_pages[i]->flags &= ~PG_VMIO;
vm_page_unhold(lbp->b_pages[i]);
PAGE_WAKEUP(lbp->b_pages[i]);
}
lbp->b_flags &= ~B_VMIO;
lbp->b_flags |= B_INVAL;
lbp->b_bufsize = 0;
}