diff options
Diffstat (limited to 'drivers/s390/scsi/zfcp_qdio.h')
| -rw-r--r-- | drivers/s390/scsi/zfcp_qdio.h | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/drivers/s390/scsi/zfcp_qdio.h b/drivers/s390/scsi/zfcp_qdio.h new file mode 100644 index 000000000..886c662cc --- /dev/null +++ b/drivers/s390/scsi/zfcp_qdio.h @@ -0,0 +1,255 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * zfcp device driver + * + * Header file for zfcp qdio interface + * + * Copyright IBM Corp. 2010 + */ + +#ifndef ZFCP_QDIO_H +#define ZFCP_QDIO_H + +#include <asm/qdio.h> + +#define ZFCP_QDIO_SBALE_LEN PAGE_SIZE + +/* Max SBALS for chaining */ +#define ZFCP_QDIO_MAX_SBALS_PER_REQ 36 + +/** + * struct zfcp_qdio - basic qdio data structure + * @res_q: response queue + * @req_q: request queue + * @req_q_idx: index of next free buffer + * @req_q_free: number of free buffers in queue + * @stat_lock: lock to protect req_q_util and req_q_time + * @req_q_lock: lock to serialize access to request queue + * @req_q_time: time of last fill level change + * @req_q_util: used for accounting + * @req_q_full: queue full incidents + * @req_q_wq: used to wait for SBAL availability + * @adapter: adapter used in conjunction with this qdio structure + */ +struct zfcp_qdio { + struct qdio_buffer *res_q[QDIO_MAX_BUFFERS_PER_Q]; + struct qdio_buffer *req_q[QDIO_MAX_BUFFERS_PER_Q]; + u8 req_q_idx; + atomic_t req_q_free; + spinlock_t stat_lock; + spinlock_t req_q_lock; + unsigned long long req_q_time; + u64 req_q_util; + atomic_t req_q_full; + wait_queue_head_t req_q_wq; + struct zfcp_adapter *adapter; + u16 max_sbale_per_sbal; + u16 max_sbale_per_req; +}; + +/** + * 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 + * @sbal_limit: last possible sbal for this request + * @sbale_curr: current sbale at creation of this request + * @qdio_outb_usage: usage of outbound queue + */ +struct zfcp_qdio_req { + u8 sbtype; + u8 sbal_number; + u8 sbal_first; + u8 sbal_last; + u8 sbal_limit; + u8 sbale_curr; + u16 qdio_outb_usage; +}; + +/** + * zfcp_qdio_sbale_req - return pointer to sbale on req_q for a request + * @qdio: pointer to struct zfcp_qdio + * @q_rec: pointer to struct zfcp_qdio_req + * Returns: pointer to qdio_buffer_element (sbale) structure + */ +static inline struct qdio_buffer_element * +zfcp_qdio_sbale_req(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) +{ + return &qdio->req_q[q_req->sbal_last]->element[0]; +} + +/** + * zfcp_qdio_sbale_curr - return current sbale on req_q for a request + * @qdio: pointer to struct zfcp_qdio + * @fsf_req: pointer to struct zfcp_fsf_req + * Returns: pointer to qdio_buffer_element (sbale) structure + */ +static inline struct qdio_buffer_element * +zfcp_qdio_sbale_curr(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) +{ + return &qdio->req_q[q_req->sbal_last]->element[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, u8 sbtype, void *data, u32 len) +{ + struct qdio_buffer_element *sbale; + int count = min(atomic_read(&qdio->req_q_free), + ZFCP_QDIO_MAX_SBALS_PER_REQ); + + q_req->sbal_first = q_req->sbal_last = qdio->req_q_idx; + q_req->sbal_number = 1; + q_req->sbtype = sbtype; + q_req->sbale_curr = 1; + q_req->sbal_limit = (q_req->sbal_first + count - 1) + % QDIO_MAX_BUFFERS_PER_Q; + + sbale = zfcp_qdio_sbale_req(qdio, q_req); + sbale->addr = (void *) req_id; + sbale->eflags = 0; + sbale->sflags = SBAL_SFLAGS0_COMMAND | sbtype; + + if (unlikely(!data)) + return; + sbale++; + sbale->addr = 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 == qdio->max_sbale_per_sbal - 1); + 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->eflags |= SBAL_EFLAGS_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 *qdio, + struct zfcp_qdio_req *q_req) +{ + q_req->sbale_curr = qdio->max_sbale_per_sbal - 1; +} + +/** + * zfcp_qdio_sbal_limit - set the sbal limit for a request in q_req + * @qdio: pointer to struct zfcp_qdio + * @q_req: The current zfcp_qdio_req + * @max_sbals: maximum number of SBALs allowed + */ +static inline +void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio, + struct zfcp_qdio_req *q_req, int max_sbals) +{ + int count = min(atomic_read(&qdio->req_q_free), max_sbals); + + q_req->sbal_limit = (q_req->sbal_first + count - 1) % + QDIO_MAX_BUFFERS_PER_Q; +} + +/** + * zfcp_qdio_set_data_div - set data division count + * @qdio: pointer to struct zfcp_qdio + * @q_req: The current zfcp_qdio_req + * @count: The data division count + */ +static inline +void zfcp_qdio_set_data_div(struct zfcp_qdio *qdio, + struct zfcp_qdio_req *q_req, u32 count) +{ + struct qdio_buffer_element *sbale; + + sbale = qdio->req_q[q_req->sbal_first]->element; + sbale->length = count; +} + +/** + * zfcp_qdio_real_bytes - count bytes used + * @sg: pointer to struct scatterlist + */ +static inline +unsigned int zfcp_qdio_real_bytes(struct scatterlist *sg) +{ + unsigned int real_bytes = 0; + + for (; sg; sg = sg_next(sg)) + real_bytes += sg->length; + + return real_bytes; +} + +/** + * zfcp_qdio_set_scount - set SBAL count value + * @qdio: pointer to struct zfcp_qdio + * @q_req: The current zfcp_qdio_req + */ +static inline +void zfcp_qdio_set_scount(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) +{ + struct qdio_buffer_element *sbale; + + sbale = qdio->req_q[q_req->sbal_first]->element; + sbale->scount = q_req->sbal_number - 1; +} + +#endif /* ZFCP_QDIO_H */ |