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#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "error.h"
enum
{
Hdrspc = 64, /* leave room for high-level headers */
Tlrspc = 16, /* extra room at the end for pad/crc/mac */
Bdead = 0x51494F42, /* "QIOB" */
};
static Block*
_allocb(int size)
{
Block *b;
uintptr addr;
size += Tlrspc;
if((b = mallocz(sizeof(Block)+size+Hdrspc, 0)) == nil)
return nil;
b->next = nil;
b->list = nil;
b->free = nil;
b->flag = 0;
/* align start of data portion by rounding up */
addr = (uintptr)b;
addr = ROUND(addr + sizeof(Block), BLOCKALIGN);
b->base = (uchar*)addr;
/* align end of data portion by rounding down */
b->lim = (uchar*)b + msize(b);
addr = (uintptr)b->lim;
addr &= ~(BLOCKALIGN-1);
b->lim = (uchar*)addr;
/* leave sluff at beginning for added headers */
b->rp = b->lim - ROUND(size, BLOCKALIGN);
if(b->rp < b->base)
panic("_allocb");
b->wp = b->rp;
return b;
}
Block*
allocb(int size)
{
Block *b;
/*
* Check in a process and wait until successful.
*/
if(up == nil)
panic("allocb without up: %#p", getcallerpc(&size));
while((b = _allocb(size)) == nil){
if(up->nlocks || m->ilockdepth || !islo()){
xsummary();
mallocsummary();
panic("allocb: no memory for %d bytes", size);
}
if(!waserror()){
resrcwait("no memory for allocb");
poperror();
}
}
setmalloctag(b, getcallerpc(&size));
return b;
}
Block*
iallocb(int size)
{
Block *b;
if((b = _allocb(size)) == nil){
static ulong nerr;
if((nerr++%10000)==0){
if(nerr > 10000000){
xsummary();
mallocsummary();
panic("iallocb: out of memory");
}
iprint("iallocb: no memory for %d bytes\n", size);
}
return nil;
}
setmalloctag(b, getcallerpc(&size));
b->flag = BINTR;
return b;
}
void
freeb(Block *b)
{
void *dead = (void*)Bdead;
if(b == nil)
return;
/*
* drivers which perform non cache coherent DMA manage their own buffer
* pool of uncached buffers and provide their own free routine.
*/
if(b->free != nil) {
b->free(b);
return;
}
/* 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;
free(b);
}
void
checkb(Block *b, char *msg)
{
void *dead = (void*)Bdead;
if(b == dead)
panic("checkb b %s %#p", msg, b);
if(b->base == dead || b->lim == dead || b->next == dead
|| b->rp == dead || b->wp == dead){
print("checkb: base %#p lim %#p next %#p\n",
b->base, b->lim, b->next);
print("checkb: rp %#p wp %#p\n", b->rp, b->wp);
panic("checkb dead: %s", msg);
}
if(b->base > b->lim)
panic("checkb 0 %s %#p %#p", msg, b->base, b->lim);
if(b->rp < b->base)
panic("checkb 1 %s %#p %#p", msg, b->base, b->rp);
if(b->wp < b->base)
panic("checkb 2 %s %#p %#p", msg, b->base, b->wp);
if(b->rp > b->lim)
panic("checkb 3 %s %#p %#p", msg, b->rp, b->lim);
if(b->wp > b->lim)
panic("checkb 4 %s %#p %#p", msg, b->wp, b->lim);
}
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