static int zfcp_qdio_fill_sbals(struct zfcp_qdio *qdio,
struct zfcp_queue_req *q_req,
unsigned int sbtype, void *start_addr,
unsigned int total_length)
{
struct qdio_buffer_element *sbale;
unsigned long remaining, length;
void *addr;
/* split segment up */
for (addr = start_addr, remaining = total_length; remaining > 0;
addr += length, remaining -= length) {
sbale = zfcp_qdio_sbale_next(qdio, q_req, sbtype);
if (!sbale) {
atomic_inc(&qdio->req_q_full);
zfcp_qdio_undo_sbals(qdio, q_req);
return -EINVAL;
}
/* new piece must not exceed next page boundary */
length = min(remaining,
(PAGE_SIZE - ((unsigned long)addr &
(PAGE_SIZE - 1))));
sbale->addr = addr;
sbale->length = length;
}
return 0;
}
/**
* zfcp_qdio_sbals_from_segment - map memory segment to SBALE(s)
* @fsf_req: request to be processed
* @sbtype: SBALE flags
* @start_addr: address of memory segment
* @total_length: length of memory segment
*
* Alignment and length of the segment determine how many SBALEs are needed
* for the memory segment.
*/
static inline int
zfcp_qdio_sbals_from_segment(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
void *start_addr, unsigned long total_length)
{
unsigned long remaining, length;
void *addr;
/* split segment up heeding page boundaries */
for (addr = start_addr, remaining = total_length; remaining > 0;
addr += length, remaining -= length) {
/* get next free SBALE for new piece */
if (NULL == zfcp_qdio_sbale_next(fsf_req, sbtype)) {
/* no SBALE left, clean up and leave */
zfcp_qdio_sbals_wipe(fsf_req);
return -EINVAL;
}
/* calculate length of new piece */
length = min(remaining,
(PAGE_SIZE - ((unsigned long) addr &
(PAGE_SIZE - 1))));
/* fill current SBALE with calculated piece */
zfcp_qdio_sbale_fill(fsf_req, sbtype, addr, length);
}
return total_length;
}
/**
* zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
* @qdio: pointer to struct zfcp_qdio
* @q_req: pointer to struct zfcp_qdio_req
* @sg: scatter-gather list
* @max_sbals: upper bound for number of SBALs to be used
* Returns: number of bytes, or error (negativ)
*/
int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
struct scatterlist *sg)
{
struct qdio_buffer_element *sbale;
int bytes = 0;
/* set storage-block type for this request */
sbale = zfcp_qdio_sbale_req(qdio, q_req);
sbale->sflags |= q_req->sbtype;
for (; sg; sg = sg_next(sg)) {
sbale = zfcp_qdio_sbale_next(qdio, q_req);
if (!sbale) {
atomic_inc(&qdio->req_q_full);
zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
q_req->sbal_number);
return -EINVAL;
}
sbale->addr = sg_virt(sg);
sbale->length = sg->length;
bytes += sg->length;
}
return bytes;
}
