diff options
Diffstat (limited to 'drivers/s390/scsi/zfcp_qdio.h')
| -rw-r--r-- | drivers/s390/scsi/zfcp_qdio.h | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/drivers/s390/scsi/zfcp_qdio.h b/drivers/s390/scsi/zfcp_qdio.h index f2b5a363bb84..138fba577b48 100644 --- a/drivers/s390/scsi/zfcp_qdio.h +++ b/drivers/s390/scsi/zfcp_qdio.h @@ -13,6 +13,12 @@ #define ZFCP_QDIO_SBALE_LEN PAGE_SIZE +/* DMQ bug workaround: don't use last SBALE */ +#define ZFCP_QDIO_MAX_SBALES_PER_SBAL (QDIO_MAX_ELEMENTS_PER_BUFFER - 1) + +/* index of last SBALE (with respect to DMQ bug workaround) */ +#define ZFCP_QDIO_LAST_SBALE_PER_SBAL (ZFCP_QDIO_MAX_SBALES_PER_SBAL - 1) + /** * struct zfcp_qdio_queue - qdio queue buffer, zfcp index and free count * @sbal: qdio buffers @@ -51,6 +57,7 @@ struct zfcp_qdio { /** * struct zfcp_qdio_req - qdio queue related values for a request + * @sbtype: sbal type flags for sbale 0 * @sbal_number: number of free sbals * @sbal_first: first sbal for this request * @sbal_last: last sbal for this request @@ -61,6 +68,7 @@ struct zfcp_qdio { * @qdio_inb_usage: usage of inbound queue */ struct zfcp_qdio_req { + u32 sbtype; u8 sbal_number; u8 sbal_first; u8 sbal_last; @@ -108,4 +116,98 @@ zfcp_qdio_sbale_curr(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) q_req->sbale_curr); } +/** + * zfcp_qdio_req_init - initialize qdio request + * @qdio: request queue where to start putting the request + * @q_req: the qdio request to start + * @req_id: The request id + * @sbtype: type flags to set for all sbals + * @data: First data block + * @len: Length of first data block + * + * This is the start of putting the request into the queue, the last + * step is passing the request to zfcp_qdio_send. The request queue + * lock must be held during the whole process from init to send. + */ +static inline +void zfcp_qdio_req_init(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req, + unsigned long req_id, u32 sbtype, void *data, u32 len) +{ + struct qdio_buffer_element *sbale; + + q_req->sbal_first = q_req->sbal_last = qdio->req_q.first; + q_req->sbal_number = 1; + q_req->sbtype = sbtype; + + sbale = zfcp_qdio_sbale_req(qdio, q_req); + sbale->addr = (void *) req_id; + sbale->flags |= SBAL_FLAGS0_COMMAND; + sbale->flags |= sbtype; + + q_req->sbale_curr = 1; + sbale++; + sbale->addr = data; + if (likely(data)) + sbale->length = len; +} + +/** + * zfcp_qdio_fill_next - Fill next sbale, only for single sbal requests + * @qdio: pointer to struct zfcp_qdio + * @q_req: pointer to struct zfcp_queue_req + * + * This is only required for single sbal requests, calling it when + * wrapping around to the next sbal is a bug. + */ +static inline +void zfcp_qdio_fill_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req, + void *data, u32 len) +{ + struct qdio_buffer_element *sbale; + + BUG_ON(q_req->sbale_curr == ZFCP_QDIO_LAST_SBALE_PER_SBAL); + q_req->sbale_curr++; + sbale = zfcp_qdio_sbale_curr(qdio, q_req); + sbale->addr = data; + sbale->length = len; +} + +/** + * zfcp_qdio_set_sbale_last - set last entry flag in current sbale + * @qdio: pointer to struct zfcp_qdio + * @q_req: pointer to struct zfcp_queue_req + */ +static inline +void zfcp_qdio_set_sbale_last(struct zfcp_qdio *qdio, + struct zfcp_qdio_req *q_req) +{ + struct qdio_buffer_element *sbale; + + sbale = zfcp_qdio_sbale_curr(qdio, q_req); + sbale->flags |= SBAL_FLAGS_LAST_ENTRY; +} + +/** + * zfcp_qdio_sg_one_sbal - check if one sbale is enough for sg data + * @sg: The scatterlist where to check the data size + * + * Returns: 1 when one sbale is enough for the data in the scatterlist, + * 0 if not. + */ +static inline +int zfcp_qdio_sg_one_sbale(struct scatterlist *sg) +{ + return sg_is_last(sg) && sg->length <= ZFCP_QDIO_SBALE_LEN; +} + +/** + * zfcp_qdio_skip_to_last_sbale - skip to last sbale in sbal + * @q_req: The current zfcp_qdio_req + */ +static inline +void zfcp_qdio_skip_to_last_sbale(struct zfcp_qdio_req *q_req) +{ + q_req->sbale_curr = ZFCP_QDIO_LAST_SBALE_PER_SBAL; +} + #endif /* ZFCP_QDIO_H */ |