123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298 |
- /*
- * This file is part of the UCB release of Plan 9. It is subject to the license
- * terms in the LICENSE file found in the top-level directory of this
- * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
- * part of the UCB release of Plan 9, including this file, may be copied,
- * modified, propagated, or distributed except according to the terms contained
- * in the LICENSE file.
- */
- #include "all.h"
- #include "io.h"
- enum { DEBUG = 0 };
- extern int32_t nhiob;
- extern Hiob *hiob;
- Iobuf*
- getbuf(Device *d, Off addr, int flag)
- {
- Iobuf *p, *s;
- Hiob *hp;
- Off h;
- if(DEBUG)
- print("getbuf %Z(%lld) f=%x\n", d, (Wideoff)addr, flag);
- h = addr + (Off)(uintptr)d*1009;
- if(h < 0)
- h = ~h;
- h %= nhiob;
- hp = &hiob[h];
- loop:
- lock(hp);
- /*
- * look for it in the active list
- */
- s = hp->link;
- for(p=s;;) {
- if(p->addr == addr && p->dev == d) {
- if(p != s) {
- p->back->fore = p->fore;
- p->fore->back = p->back;
- p->fore = s;
- p->back = s->back;
- s->back = p;
- p->back->fore = p;
- hp->link = p;
- }
- unlock(hp);
- qlock(p);
- if(p->addr != addr || p->dev != d || iobufmap(p) == 0) {
- qunlock(p);
- goto loop;
- }
- p->flags |= flag;
- return p;
- }
- p = p->fore;
- if(p == s)
- break;
- }
- if(flag & Bprobe) {
- unlock(hp);
- return 0;
- }
- /*
- * not found
- * take oldest unlocked entry in this queue
- */
- xloop:
- p = s->back;
- if(!canqlock(p)) {
- if(p == hp->link) {
- unlock(hp);
- print("iobuf all locked\n");
- goto loop;
- }
- s = p;
- goto xloop;
- }
- /*
- * its dangerous to flush the pseudo
- * devices since they recursively call
- * getbuf/putbuf. deadlock!
- */
- if(p->flags & Bres) {
- qunlock(p);
- if(p == hp->link) {
- unlock(hp);
- print("iobuf all reserved\n");
- goto loop;
- }
- s = p;
- goto xloop;
- }
- if(p->flags & Bmod) {
- unlock(hp);
- if(iobufmap(p)) {
- if(!devwrite(p->dev, p->addr, p->iobuf))
- p->flags &= ~(Bimm|Bmod);
- iobufunmap(p);
- }
- qunlock(p);
- goto loop;
- }
- hp->link = p;
- p->addr = addr;
- p->dev = d;
- p->flags = flag;
- // p->pc = getcallerpc(&d);
- unlock(hp);
- if(iobufmap(p))
- if(flag & Brd) {
- if(!devread(p->dev, p->addr, p->iobuf))
- return p;
- iobufunmap(p);
- } else
- return p;
- else
- print("iobuf cant map buffer\n");
- p->flags = 0;
- p->dev = devnone;
- p->addr = -1;
- qunlock(p);
- return 0;
- }
- /*
- * syncblock tries to put out a block per hashline
- * returns 0 all done,
- * returns 1 if it missed something
- */
- int
- syncblock(void)
- {
- Iobuf *p, *s, *q;
- Hiob *hp;
- int32_t h;
- int flag;
- flag = 0;
- for(h=0; h<nhiob; h++) {
- q = 0;
- hp = &hiob[h];
- lock(hp);
- s = hp->link;
- for(p=s;;) {
- if(p->flags & Bmod) {
- if(q)
- flag = 1; /* more than 1 mod/line */
- q = p;
- }
- p = p->fore;
- if(p == s)
- break;
- }
- unlock(hp);
- if(q) {
- if(!canqlock(q)) {
- flag = 1; /* missed -- was locked */
- continue;
- }
- if(!(q->flags & Bmod)) {
- qunlock(q);
- continue;
- }
- if(iobufmap(q)) {
- if(!devwrite(q->dev, q->addr, q->iobuf))
- q->flags &= ~(Bmod|Bimm);
- iobufunmap(q);
- } else
- flag = 1;
- qunlock(q);
- }
- }
- return flag;
- }
- void
- sync(char *reason)
- {
- int32_t i;
- print("sync: %s\n", reason);
- for(i=10*nhiob; i>0; i--)
- if(!syncblock())
- return;
- print("sync shorted\n");
- }
- void
- putbuf(Iobuf *p)
- {
- if(canqlock(p))
- print("buffer not locked %Z(%lld)\n", p->dev, (Wideoff)p->addr);
- if(p->flags & Bimm) {
- if(!(p->flags & Bmod))
- print("imm and no mod %Z(%lld)\n",
- p->dev, (Wideoff)p->addr);
- if(!devwrite(p->dev, p->addr, p->iobuf))
- p->flags &= ~(Bmod|Bimm);
- }
- iobufunmap(p);
- qunlock(p);
- }
- int
- checktag(Iobuf *p, int tag, Off qpath)
- {
- Tag *t;
- static Off lastaddr;
- t = (Tag*)(p->iobuf+BUFSIZE);
- if(t->tag != tag) {
- if(p->flags & Bmod) {
- print("\ttag = %d/%llu; expected %lld/%d -- not flushed\n",
- t->tag, (Wideoff)t->path, (Wideoff)qpath, tag);
- return 2;
- }
- if(p->dev != nil && p->dev->type == Devcw)
- cwfree(p->dev, p->addr);
- if(p->addr != lastaddr)
- print("\ttag = %G/%llu; expected %G/%lld -- flushed (%lld)\n",
- t->tag, (Wideoff)t->path, tag, (Wideoff)qpath,
- (Wideoff)p->addr);
- lastaddr = p->addr;
- p->dev = devnone;
- p->addr = -1;
- p->flags = 0;
- return 2;
- }
- if(qpath != QPNONE) {
- if((qpath ^ t->path) & ~QPDIR) {
- if(1 || CHAT(0))
- print("\ttag/path = %llu; expected %d/%llux\n",
- (Wideoff)t->path, tag, (Wideoff)qpath);
- return 0;
- }
- }
- return 0;
- }
- void
- settag(Iobuf *p, int tag, int32_t qpath)
- {
- Tag *t;
- t = (Tag*)(p->iobuf+BUFSIZE);
- t->tag = tag;
- if(qpath != QPNONE)
- t->path = qpath & ~QPDIR;
- p->flags |= Bmod;
- }
- int
- qlmatch(QLock *q1, QLock *q2)
- {
- return q1 == q2;
- }
- int
- iobufql(QLock *q)
- {
- Iobuf *p, *s;
- Hiob *hp;
- Tag *t;
- int32_t h;
- int tag;
- for(h=0; h<nhiob; h++) {
- hp = &hiob[h];
- lock(hp);
- s = hp->link;
- for(p=s;;) {
- if(qlmatch(q, p)) {
- t = (Tag*)(p->iobuf+BUFSIZE);
- tag = t->tag;
- if(tag < 0 || tag >= MAXTAG)
- tag = Tnone;
- print("\tIobuf %Z(%lld) t=%s\n",
- p->dev, (Wideoff)p->addr, tagnames[tag]);
- unlock(hp);
- return 1;
- }
- p = p->fore;
- if(p == s)
- break;
- }
- unlock(hp);
- }
- return 0;
- }
|