Subversion Repositories planix.SVN

/*
 * 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;
        ulong addr;

        if((b = ucalloc(sizeof(Block)+size+Hdrspc)) == nil)
                return nil;

        b->next = nil;
        b->list = nil;
        b->free = 0;
        b->flag = 0;
        b->ref = 0;
        _xinc(&b->ref);

        /* align start of data portion by rounding up */
        addr = (ulong)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 = (ulong)(b->lim);
        addr = 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;
        long ref;

        if(b == nil || (ref = _xdec(&b->ref)) > 0)
                return;

        if(ref < 0){
                dumpstack();
                panic("ucfreeb: 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(&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);
}