static int
deccnt(Ref *r)
{
int x;
x = _xdec(&r->ref);
if(x < 0)
panic("deccnt pc=%#p", getcallerpc(&r));
return x;
}
void
freeb(Block *b)
{
void *dead = (void*)Bdead;
long ref;
if(b == nil)
return;
if(Bmagic && b->magic != Bmagic)
panic("freeb: bad magic %#lux in Block %#p; caller pc %#p",
b->magic, b, getcallerpc(&b));
if((ref = _xdec(&b->ref)) > 0)
return;
if(ref < 0){
dumpstack();
panic("freeb: ref %ld; caller pc %#p", ref, getcallerpc(&b));
}
/*
* drivers which perform non cache coherent DMA manage their own buffer
* pool of uncached buffers and provide their own free routine.
*/
if(b->free) {
b->free(b);
return;
}
if(b->flag & BINTR) {
ilock(&ialloc);
ialloc.bytes -= b->lim - b->base;
iunlock(&ialloc);
}
/* poison the block in case someone is still holding onto it */
b->next = dead;
b->rp = dead;
b->wp = dead;
b->lim = dead;
b->base = dead;
b->magic = 0;
free(b);
}