void freef(char *p)
{
printf("freef called with p=%p\n", (void *) p);
if(p!=0){
/* you write the code for the freef function here */
struct blockl *temp = (struct blockl *)p;
temp->tag = FREETAG;
char *temp2 = p;
temp2 += temp->size;
temp2 += (TAGSIZE*2);
struct blockr *temp3 = (struct blockr *)temp2;
temp3->tag = FREETAG;
struct blockr *temp4 = (struct blockr *)(p - TAGSIZE);
//temp4 -= 1;
if (temp4->tag == FREETAG) {
struct blockl *temp5 = (struct blockl *)(temp4 - temp4->size-(TAGSIZE));
coalesce(temp5, temp);
}
else{
enchain(temp);
}
temp2 += TAGSIZE;
struct blockl *temp6 = (struct blockl *)temp2;
if (temp6->tag == FREETAG){
unchain(temp6);
coalesce(temp, temp6);
}
}
}
void freef(void *f)
{
struct blockl *q;
struct blockr *r;
struct blockl *s;
char *p = (char *)f;
printf("freef called with p=%p\n", p);
if (p < allocbuf || p > allocbuf + ALLOCSIZE) {
printf("freef: bad pointer to block to be freed, %p\n", (void *) p);
return;
}
p = p - TAGSIZE; /* undo offset added by alloc() */
q = (struct blockl *) p; /* make pointer to struct blockl */
if (q->tag != USEDTAG) {
printf("freef: block being freed is not in use, %p\n", (void *) p);
return;
}
r = (struct blockr *) (p + q->size - TAGSIZE); /* point to blockr */
if (r->tag != USEDTAG) {
printf("freef: block being freed is not in use, %p\n", (void *) p);
return;
}
q->tag = (r->tag = FREETAG); /* set tags to show it is free */
r->size = q->size; /* set size in blockr */
/* look for opportunity to coalesce */
/* with next lower block */
r = (struct blockr *) (p - TAGSIZE);
if ((char *) r >= allocbuf && r->tag == FREETAG) {
s = (struct blockl *) (p - r->size);
p = p - r->size;
coalesce(s,q);
q = s;
} else
enchain(q); /* return to the free list */
/* look for opportunity to coalesce */
/* with next higher block */
s = (struct blockl *) (p + q->size);
if ((char *) s < allocbuf + ALLOCSIZE && s->tag == FREETAG) {
unchain(s);
coalesce(q,s);
}
}
/*
* ccw_req_t *ccw_alloc_request ( int cplength, int datasize )
* allocates a ccw_req_t, that
* - can hold a CP of cplength CCWS
* - can hold additional data up to datasize
*/
ccw_req_t *
ccw_alloc_request ( char *magic, int cplength, int datasize )
{
ccw_req_t * request = NULL;
int size_needed;
int data_offset, ccw_offset;
int cachind;
/* Sanity checks */
if ( magic == NULL || datasize > PAGE_SIZE ||
cplength == 0 || (cplength*sizeof(ccw1_t)) > PAGE_SIZE)
BUG();
debug_text_event ( debug_area, 1, "ALLC");
debug_text_event ( debug_area, 1, magic);
debug_int_event ( debug_area, 1, cplength);
debug_int_event ( debug_area, 1, datasize);
/* We try to keep things together in memory */
size_needed = (sizeof (ccw_req_t) + 7) & -8;
data_offset = ccw_offset = 0;
if (size_needed + datasize <= PAGE_SIZE) {
/* Keep data with the request */
data_offset = size_needed;
size_needed += (datasize + 7) & -8;
}
if (size_needed + cplength*sizeof(ccw1_t) <= PAGE_SIZE) {
/* Keep CCWs with request */
ccw_offset = size_needed;
size_needed += cplength*sizeof(ccw1_t);
}
/* determine cache index for the requested size */
for (cachind = 0; cachind < CCW_NUMBER_CACHES; cachind ++ )
if ( size_needed < (SMALLEST_SLAB << cachind) )
break;
/* Try to fulfill the request from a cache */
if ( ccw_cache[cachind] == NULL )
BUG();
request = kmem_cache_alloc ( ccw_cache[cachind], CCW_CACHE_TYPE );
if (request == NULL)
return NULL;
memset ( request, 0, (SMALLEST_SLAB << cachind));
request->cache = ccw_cache[cachind];
/* Allocate memory for the extra data */
if (data_offset == 0) {
/* Allocated memory for extra data with kmalloc */
request->data = (void *) kmalloc(datasize, CCW_CACHE_TYPE );
if (request->data == NULL) {
printk(KERN_WARNING PRINTK_HEADER
"Couldn't allocate data area\n");
kmem_cache_free(request->cache, request);
return NULL;
}
} else
/* Extra data already allocated with the request */
request->data = (void *) ((addr_t) request + data_offset);
/* Allocate memory for the channel program */
if (ccw_offset == 0) {
/* Allocated memory for the channel program with kmalloc */
request->cpaddr = (ccw1_t *) kmalloc(cplength*sizeof(ccw1_t),
CCW_CACHE_TYPE);
if (request->cpaddr == NULL) {
printk (KERN_DEBUG PRINTK_HEADER
"Couldn't allocate ccw area\n");
if (data_offset == 0)
kfree(request->data);
kmem_cache_free(request->cache, request);
return NULL;
}
} else
/* Channel program already allocated with the request */
request->cpaddr = (ccw1_t *) ((addr_t) request + ccw_offset);
memset ( request->data, 0, datasize );
memset ( request->cpaddr, 0, cplength*sizeof(ccw1_t) );
strncpy ( (char *)(&request->magic), magic, 4);
ASCEBC((char *)(&request->magic),4);
request -> cplength = cplength;
request -> datasize = datasize;
/* enqueue request to list of allocated requests */
enchain(request);
debug_int_event ( debug_area, 1, (long)request);
return request;
}
