/**
* zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
* @fsf_req: request to be processed
* @sbtype: SBALE flags
* @sg: scatter-gather list
* @sg_count: number of elements in scatter-gather list
* @max_sbals: upper bound for number of SBALs to be used
*/
int
zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
struct scatterlist *sgl, int sg_count, int max_sbals)
{
int sg_index;
struct scatterlist *sg_segment;
int retval;
volatile struct qdio_buffer_element *sbale;
int bytes = 0;
/* figure out last allowed SBAL */
zfcp_qdio_sbal_limit(fsf_req, max_sbals);
/* set storage-block type for current SBAL */
sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
sbale->flags |= sbtype;
/* process all segements of scatter-gather list */
for_each_sg(sgl, sg_segment, sg_count, sg_index) {
retval = zfcp_qdio_sbals_from_segment(
fsf_req,
sbtype,
zfcp_sg_to_address(sg_segment),
sg_segment->length);
if (retval < 0) {
bytes = retval;
goto out;
} else
bytes += retval;
}
/**
* zfcp_qdio_sbal_chain - chain SBALs if more than one SBAL is needed for a
* request
* @fsf_req: zfcp_fsf_req to be processed
* @sbtype: SBAL flags which have to be set in first SBALE of new SBAL
*
* This function changes sbal_curr, sbale_curr, sbal_number of fsf_req.
*/
static inline volatile struct qdio_buffer_element *
zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
{
volatile struct qdio_buffer_element *sbale;
/* set last entry flag in current SBALE of current SBAL */
sbale = zfcp_qdio_sbale_curr(fsf_req);
sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
/* don't exceed last allowed SBAL */
if (fsf_req->sbal_curr == fsf_req->sbal_last)
return NULL;
/* set chaining flag in first SBALE of current SBAL */
sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
/* calculate index of next SBAL */
fsf_req->sbal_curr++;
fsf_req->sbal_curr %= QDIO_MAX_BUFFERS_PER_Q;
/* keep this requests number of SBALs up-to-date */
fsf_req->sbal_number++;
/* start at first SBALE of new SBAL */
fsf_req->sbale_curr = 0;
/* set storage-block type for new SBAL */
sbale = zfcp_qdio_sbale_curr(fsf_req);
sbale->flags |= sbtype;
return sbale;
}
static struct qdio_buffer_element *
zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
{
struct qdio_buffer_element *sbale;
/* set last entry flag in current SBALE of current SBAL */
sbale = zfcp_qdio_sbale_curr(qdio, q_req);
sbale->eflags |= SBAL_EFLAGS_LAST_ENTRY;
/* don't exceed last allowed SBAL */
if (q_req->sbal_last == q_req->sbal_limit)
return NULL;
/* set chaining flag in first SBALE of current SBAL */
sbale = zfcp_qdio_sbale_req(qdio, q_req);
sbale->sflags |= SBAL_SFLAGS0_MORE_SBALS;
/* calculate index of next SBAL */
q_req->sbal_last++;
q_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
/* keep this requests number of SBALs up-to-date */
q_req->sbal_number++;
BUG_ON(q_req->sbal_number > ZFCP_QDIO_MAX_SBALS_PER_REQ);
/* start at first SBALE of new SBAL */
q_req->sbale_curr = 0;
/* set storage-block type for new SBAL */
sbale = zfcp_qdio_sbale_curr(qdio, q_req);
sbale->sflags |= q_req->sbtype;
return sbale;
}
/**
* zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
* @fsf_req: request to be processed
* @sbtype: SBALE flags
* @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_queue_req *q_req,
unsigned long sbtype, struct scatterlist *sg,
int max_sbals)
{
struct qdio_buffer_element *sbale;
int retval, bytes = 0;
/* figure out last allowed SBAL */
zfcp_qdio_sbal_limit(qdio, q_req, max_sbals);
/* set storage-block type for this request */
sbale = zfcp_qdio_sbale_req(qdio, q_req);
sbale->flags |= sbtype;
for (; sg; sg = sg_next(sg)) {
retval = zfcp_qdio_fill_sbals(qdio, q_req, sbtype,
sg_virt(sg), sg->length);
if (retval < 0)
return retval;
bytes += sg->length;
}
/* assume that no other SBALEs are to follow in the same SBAL */
sbale = zfcp_qdio_sbale_curr(qdio, q_req);
sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
return bytes;
}
/**
* 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;
}
/**
* zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
* @fsf_req: request to be processed
* @sbtype: SBALE flags
* @sg: scatter-gather list
* @sg_count: number of elements in scatter-gather list
* @max_sbals: upper bound for number of SBALs to be used
*/
inline int
zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
struct scatterlist *sg, int sg_count, int max_sbals)
{
int sg_index;
struct scatterlist *sg_segment;
int retval;
volatile struct qdio_buffer_element *sbale;
int bytes = 0;
/* figure out last allowed SBAL */
zfcp_qdio_sbal_limit(fsf_req, max_sbals);
/* set storage-block type for current SBAL */
sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
sbale->flags |= sbtype;
/* process all segements of scatter-gather list */
for (sg_index = 0, sg_segment = sg, bytes = 0;
sg_index < sg_count;
sg_index++, sg_segment++) {
retval = zfcp_qdio_sbals_from_segment(
fsf_req,
sbtype,
zfcp_sg_to_address(sg_segment),
sg_segment->length);
if (retval < 0) {
bytes = retval;
goto out;
} else
bytes += retval;
}
/* assume that no other SBALEs are to follow in the same SBAL */
sbale = zfcp_qdio_sbale_curr(fsf_req);
sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
out:
#ifdef ZFCP_STAT_REQSIZES
if (sbtype == SBAL_FLAGS0_TYPE_READ) {
zfcp_statistics_inc(&zfcp_data.read_sguse_head, sg_count);
zfcp_statistics_inc(&zfcp_data.read_req_head, bytes);
} else {
zfcp_statistics_inc(&zfcp_data.write_sguse_head, sg_count);
zfcp_statistics_inc(&zfcp_data.write_req_head, bytes);
}
#endif
return bytes;
}
/**
* zfcp_qdio_determine_pci - set PCI flag in first SBALE on qdio queue if needed
*/
int
zfcp_qdio_determine_pci(struct zfcp_qdio_queue *req_queue,
struct zfcp_fsf_req *fsf_req)
{
int new_distance_from_int;
int pci_pos;
volatile struct qdio_buffer_element *sbale;
new_distance_from_int = req_queue->distance_from_int +
fsf_req->sbal_number;
if (unlikely(new_distance_from_int >= ZFCP_QDIO_PCI_INTERVAL)) {
new_distance_from_int %= ZFCP_QDIO_PCI_INTERVAL;
pci_pos = fsf_req->sbal_first;
pci_pos += fsf_req->sbal_number;
pci_pos -= new_distance_from_int;
pci_pos -= 1;
pci_pos %= QDIO_MAX_BUFFERS_PER_Q;
sbale = zfcp_qdio_sbale_req(fsf_req, pci_pos, 0);
sbale->flags |= SBAL_FLAGS0_PCI;
}
return new_distance_from_int;
}
/**
* zfcp_qdio_sbale_curr - return current SBALE on request_queue for
* a struct zfcp_fsf_req
*/
inline volatile struct qdio_buffer_element *
zfcp_qdio_sbale_curr(struct zfcp_fsf_req *fsf_req)
{
return zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr,
fsf_req->sbale_curr);
}
