plan9fox/sys/src/9/port/ucallocb.c

144 lines
2.5 KiB
C

/*
* allocate Blocks from uncached memory
*/
#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 */
Bdead = 0x51494F42, /* "QIOB" */
};
struct
{
Lock;
ulong bytes;
} ucialloc;
static Block*
_ucallocb(int size)
{
Block *b;
uintptr addr;
if((b = ucalloc(sizeof(Block)+size+Hdrspc)) == 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("_ucallocb");
b->wp = b->rp;
return b;
}
Block*
ucallocb(int size)
{
Block *b;
/*
* Check in a process and wait until successful.
* Can still error out of here, though.
*/
if(up == nil)
panic("ucallocb without up: %#p", getcallerpc(&size));
if((b = _ucallocb(size)) == nil)
panic("ucallocb: no memory for %d bytes", size);
setmalloctag(b, getcallerpc(&size));
return b;
}
Block*
uciallocb(int size)
{
Block *b;
static int m1, m2, mp;
if(0 && ucialloc.bytes > conf.ialloc){
if((m1++%10000)==0){
if(mp++ > 1000){
active.exiting = 1;
exit(0);
}
iprint("uciallocb: limited %lud/%lud\n",
ucialloc.bytes, conf.ialloc);
}
return nil;
}
if((b = _ucallocb(size)) == nil){
if(0 && (m2++%10000)==0){
if(mp++ > 1000){
active.exiting = 1;
exit(0);
}
iprint("uciallocb: no memory %lud/%lud\n",
ucialloc.bytes, conf.ialloc);
}
return nil;
}
setmalloctag(b, getcallerpc(&size));
b->flag = BINTR;
ilock(&ucialloc);
ucialloc.bytes += b->lim - b->base;
iunlock(&ucialloc);
return b;
}
void
ucfreeb(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;
}
if(b->flag & BINTR) {
ilock(&ucialloc);
ucialloc.bytes -= b->lim - b->base;
iunlock(&ucialloc);
}
/* 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;
ucfree(b);
}