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#include "all.h"
#include "io.h"
extern uint nhiob;
extern Hiob *hiob;
Iobuf*
getbuf(Device *d, Off addr, int flag)
{
Iobuf *p, *s;
Hiob *hp;
Off h;
if(chatty > 1)
fprint(2, "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);
fprint(2, "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);
fprint(2, "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;
unlock(hp);
if(iobufmap(p))
if(flag & Brd) {
if(!devread(p->dev, p->addr, p->iobuf))
return p;
iobufunmap(p);
} else
return p;
else
fprint(2, "iobuf cant map buffer %Z(%lld)\n", p->dev, (Wideoff)p->addr);
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;
long 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)
{
long i;
if(chatty)
fprint(2, "sync: %s\n", reason);
for(i=10*nhiob; i>0; i--)
if(!syncblock())
return;
}
void
putbuf(Iobuf *p)
{
if(canqlock(p))
fprint(2, "buffer not locked %Z(%lld)\n", p->dev, (Wideoff)p->addr);
if(p->flags & Bimm) {
if(!(p->flags & Bmod))
fprint(2, "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;
ulong pc;
qpath &= ~QPDIR;
t = (Tag*)(p->iobuf+BUFSIZE);
if((tag != t->tag) || ((qpath != QPNONE) && (qpath != t->path))){
pc = getcallerpc(&p);
if(qpath == QPNONE){
fprint(2, "checktag pc=%lux %Z(%llux) tag/path=%G/%llud; expected %G\n",
pc, p->dev, (Wideoff)p->addr, t->tag, (Wideoff)t->path, tag);
} else {
fprint(2, "checktag pc=%lux %Z(%llux) tag/path=%G/%llud; expected %G/%llud\n",
pc, p->dev, (Wideoff)p->addr, t->tag, (Wideoff)t->path, tag, qpath);
}
return 1;
}
return 0;
}
void
settag(Iobuf *p, int tag, long 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;
long h;
for(h=0; h<nhiob; h++) {
hp = &hiob[h];
lock(hp);
s = hp->link;
for(p=s;;) {
if(qlmatch(q, p)) {
unlock(hp);
return 1;
}
p = p->fore;
if(p == s)
break;
}
unlock(hp);
}
return 0;
}
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