![Christof Schmitt](/assets/img/avatar_default.png)
Instead of dealing with large segments in the scatter-gather lists in zfcp_qdio.c, report the limits to the upper layers. With these limits in place, the code for mapping large data blocks to multiple sbales can be removed. Reviewed-by: Swen Schillig <swen@vnet.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
112 lines
3 KiB
C
112 lines
3 KiB
C
/*
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* zfcp device driver
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*
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* Header file for zfcp qdio interface
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*
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* Copyright IBM Corporation 2010
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*/
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#ifndef ZFCP_QDIO_H
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#define ZFCP_QDIO_H
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#include <asm/qdio.h>
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#define ZFCP_QDIO_SBALE_LEN PAGE_SIZE
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/**
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* struct zfcp_qdio_queue - qdio queue buffer, zfcp index and free count
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* @sbal: qdio buffers
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* @first: index of next free buffer in queue
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* @count: number of free buffers in queue
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*/
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struct zfcp_qdio_queue {
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struct qdio_buffer *sbal[QDIO_MAX_BUFFERS_PER_Q];
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u8 first;
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atomic_t count;
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};
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/**
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* struct zfcp_qdio - basic qdio data structure
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* @resp_q: response queue
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* @req_q: request queue
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* @stat_lock: lock to protect req_q_util and req_q_time
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* @req_q_lock: lock to serialize access to request queue
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* @req_q_time: time of last fill level change
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* @req_q_util: used for accounting
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* @req_q_full: queue full incidents
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* @req_q_wq: used to wait for SBAL availability
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* @adapter: adapter used in conjunction with this qdio structure
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*/
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struct zfcp_qdio {
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struct zfcp_qdio_queue resp_q;
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struct zfcp_qdio_queue req_q;
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spinlock_t stat_lock;
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spinlock_t req_q_lock;
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unsigned long long req_q_time;
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u64 req_q_util;
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atomic_t req_q_full;
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wait_queue_head_t req_q_wq;
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struct zfcp_adapter *adapter;
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};
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/**
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* struct zfcp_qdio_req - qdio queue related values for a request
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* @sbal_number: number of free sbals
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* @sbal_first: first sbal for this request
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* @sbal_last: last sbal for this request
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* @sbal_limit: last possible sbal for this request
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* @sbale_curr: current sbale at creation of this request
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* @sbal_response: sbal used in interrupt
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* @qdio_outb_usage: usage of outbound queue
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* @qdio_inb_usage: usage of inbound queue
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*/
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struct zfcp_qdio_req {
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u8 sbal_number;
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u8 sbal_first;
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u8 sbal_last;
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u8 sbal_limit;
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u8 sbale_curr;
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u8 sbal_response;
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u16 qdio_outb_usage;
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u16 qdio_inb_usage;
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};
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/**
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* zfcp_qdio_sbale - return pointer to sbale in qdio queue
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* @q: queue where to find sbal
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* @sbal_idx: sbal index in queue
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* @sbale_idx: sbale index in sbal
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*/
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static inline struct qdio_buffer_element *
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zfcp_qdio_sbale(struct zfcp_qdio_queue *q, int sbal_idx, int sbale_idx)
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{
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return &q->sbal[sbal_idx]->element[sbale_idx];
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}
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/**
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* zfcp_qdio_sbale_req - return pointer to sbale on req_q for a request
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* @qdio: pointer to struct zfcp_qdio
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* @q_rec: pointer to struct zfcp_qdio_req
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* Returns: pointer to qdio_buffer_element (sbale) structure
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*/
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static inline struct qdio_buffer_element *
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zfcp_qdio_sbale_req(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
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{
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return zfcp_qdio_sbale(&qdio->req_q, q_req->sbal_last, 0);
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}
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/**
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* zfcp_qdio_sbale_curr - return current sbale on req_q for a request
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* @qdio: pointer to struct zfcp_qdio
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* @fsf_req: pointer to struct zfcp_fsf_req
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* Returns: pointer to qdio_buffer_element (sbale) structure
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*/
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static inline struct qdio_buffer_element *
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zfcp_qdio_sbale_curr(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
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{
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return zfcp_qdio_sbale(&qdio->req_q, q_req->sbal_last,
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q_req->sbale_curr);
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}
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#endif /* ZFCP_QDIO_H */
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