linux-sg2042/drivers/s390/scsi/zfcp_qdio.h

110 lines
2.9 KiB
C

/*
* zfcp device driver
*
* Header file for zfcp qdio interface
*
* Copyright IBM Corporation 2010
*/
#ifndef ZFCP_QDIO_H
#define ZFCP_QDIO_H
#include <asm/qdio.h>
/**
* struct zfcp_qdio_queue - qdio queue buffer, zfcp index and free count
* @sbal: qdio buffers
* @first: index of next free buffer in queue
* @count: number of free buffers in queue
*/
struct zfcp_qdio_queue {
struct qdio_buffer *sbal[QDIO_MAX_BUFFERS_PER_Q];
u8 first;
atomic_t count;
};
/**
* struct zfcp_qdio - basic qdio data structure
* @resp_q: response queue
* @req_q: request 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 zfcp_qdio_queue resp_q;
struct zfcp_qdio_queue req_q;
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;
};
/**
* struct zfcp_qdio_req - qdio queue related values for a request
* @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
* @sbal_response: sbal used in interrupt
* @qdio_outb_usage: usage of outbound queue
* @qdio_inb_usage: usage of inbound queue
*/
struct zfcp_qdio_req {
u8 sbal_number;
u8 sbal_first;
u8 sbal_last;
u8 sbal_limit;
u8 sbale_curr;
u8 sbal_response;
u16 qdio_outb_usage;
u16 qdio_inb_usage;
};
/**
* zfcp_qdio_sbale - return pointer to sbale in qdio queue
* @q: queue where to find sbal
* @sbal_idx: sbal index in queue
* @sbale_idx: sbale index in sbal
*/
static inline struct qdio_buffer_element *
zfcp_qdio_sbale(struct zfcp_qdio_queue *q, int sbal_idx, int sbale_idx)
{
return &q->sbal[sbal_idx]->element[sbale_idx];
}
/**
* 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 zfcp_qdio_sbale(&qdio->req_q, q_req->sbal_last, 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 zfcp_qdio_sbale(&qdio->req_q, q_req->sbal_last,
q_req->sbale_curr);
}
#endif /* ZFCP_QDIO_H */