256 lines
6.8 KiB
C
256 lines
6.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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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 Corp. 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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/* Max SBALS for chaining */
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#define ZFCP_QDIO_MAX_SBALS_PER_REQ 36
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/**
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* struct zfcp_qdio - basic qdio data structure
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* @res_q: response queue
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* @req_q: request queue
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* @req_q_idx: index of next free buffer
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* @req_q_free: number of free buffers in 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 qdio_buffer *res_q[QDIO_MAX_BUFFERS_PER_Q];
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struct qdio_buffer *req_q[QDIO_MAX_BUFFERS_PER_Q];
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u8 req_q_idx;
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atomic_t req_q_free;
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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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u16 max_sbale_per_sbal;
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u16 max_sbale_per_req;
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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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* @sbtype: sbal type flags for sbale 0
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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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* @qdio_outb_usage: usage of outbound queue
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*/
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struct zfcp_qdio_req {
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u8 sbtype;
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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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u16 qdio_outb_usage;
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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 &qdio->req_q[q_req->sbal_last]->element[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 &qdio->req_q[q_req->sbal_last]->element[q_req->sbale_curr];
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}
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/**
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* zfcp_qdio_req_init - initialize qdio request
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* @qdio: request queue where to start putting the request
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* @q_req: the qdio request to start
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* @req_id: The request id
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* @sbtype: type flags to set for all sbals
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* @data: First data block
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* @len: Length of first data block
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*
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* This is the start of putting the request into the queue, the last
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* step is passing the request to zfcp_qdio_send. The request queue
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* lock must be held during the whole process from init to send.
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*/
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static inline
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void zfcp_qdio_req_init(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
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unsigned long req_id, u8 sbtype, void *data, u32 len)
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{
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struct qdio_buffer_element *sbale;
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int count = min(atomic_read(&qdio->req_q_free),
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ZFCP_QDIO_MAX_SBALS_PER_REQ);
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q_req->sbal_first = q_req->sbal_last = qdio->req_q_idx;
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q_req->sbal_number = 1;
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q_req->sbtype = sbtype;
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q_req->sbale_curr = 1;
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q_req->sbal_limit = (q_req->sbal_first + count - 1)
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% QDIO_MAX_BUFFERS_PER_Q;
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sbale = zfcp_qdio_sbale_req(qdio, q_req);
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sbale->addr = (void *) req_id;
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sbale->eflags = 0;
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sbale->sflags = SBAL_SFLAGS0_COMMAND | sbtype;
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if (unlikely(!data))
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return;
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sbale++;
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sbale->addr = data;
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sbale->length = len;
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}
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/**
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* zfcp_qdio_fill_next - Fill next sbale, only for single sbal requests
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* @qdio: pointer to struct zfcp_qdio
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* @q_req: pointer to struct zfcp_queue_req
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*
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* This is only required for single sbal requests, calling it when
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* wrapping around to the next sbal is a bug.
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*/
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static inline
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void zfcp_qdio_fill_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
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void *data, u32 len)
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{
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struct qdio_buffer_element *sbale;
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BUG_ON(q_req->sbale_curr == qdio->max_sbale_per_sbal - 1);
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q_req->sbale_curr++;
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sbale = zfcp_qdio_sbale_curr(qdio, q_req);
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sbale->addr = data;
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sbale->length = len;
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}
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/**
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* zfcp_qdio_set_sbale_last - set last entry flag in current sbale
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* @qdio: pointer to struct zfcp_qdio
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* @q_req: pointer to struct zfcp_queue_req
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*/
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static inline
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void zfcp_qdio_set_sbale_last(struct zfcp_qdio *qdio,
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struct zfcp_qdio_req *q_req)
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{
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struct qdio_buffer_element *sbale;
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sbale = zfcp_qdio_sbale_curr(qdio, q_req);
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sbale->eflags |= SBAL_EFLAGS_LAST_ENTRY;
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}
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/**
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* zfcp_qdio_sg_one_sbal - check if one sbale is enough for sg data
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* @sg: The scatterlist where to check the data size
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*
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* Returns: 1 when one sbale is enough for the data in the scatterlist,
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* 0 if not.
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*/
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static inline
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int zfcp_qdio_sg_one_sbale(struct scatterlist *sg)
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{
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return sg_is_last(sg) && sg->length <= ZFCP_QDIO_SBALE_LEN;
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}
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/**
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* zfcp_qdio_skip_to_last_sbale - skip to last sbale in sbal
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* @q_req: The current zfcp_qdio_req
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*/
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static inline
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void zfcp_qdio_skip_to_last_sbale(struct zfcp_qdio *qdio,
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struct zfcp_qdio_req *q_req)
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{
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q_req->sbale_curr = qdio->max_sbale_per_sbal - 1;
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}
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/**
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* zfcp_qdio_sbal_limit - set the sbal limit for a request in q_req
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* @qdio: pointer to struct zfcp_qdio
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* @q_req: The current zfcp_qdio_req
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* @max_sbals: maximum number of SBALs allowed
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*/
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static inline
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void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio,
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struct zfcp_qdio_req *q_req, int max_sbals)
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{
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int count = min(atomic_read(&qdio->req_q_free), max_sbals);
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q_req->sbal_limit = (q_req->sbal_first + count - 1) %
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QDIO_MAX_BUFFERS_PER_Q;
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}
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/**
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* zfcp_qdio_set_data_div - set data division count
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* @qdio: pointer to struct zfcp_qdio
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* @q_req: The current zfcp_qdio_req
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* @count: The data division count
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*/
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static inline
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void zfcp_qdio_set_data_div(struct zfcp_qdio *qdio,
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struct zfcp_qdio_req *q_req, u32 count)
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{
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struct qdio_buffer_element *sbale;
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sbale = qdio->req_q[q_req->sbal_first]->element;
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sbale->length = count;
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}
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/**
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* zfcp_qdio_real_bytes - count bytes used
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* @sg: pointer to struct scatterlist
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*/
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static inline
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unsigned int zfcp_qdio_real_bytes(struct scatterlist *sg)
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{
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unsigned int real_bytes = 0;
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for (; sg; sg = sg_next(sg))
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real_bytes += sg->length;
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return real_bytes;
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}
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/**
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* zfcp_qdio_set_scount - set SBAL count value
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* @qdio: pointer to struct zfcp_qdio
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* @q_req: The current zfcp_qdio_req
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*/
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static inline
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void zfcp_qdio_set_scount(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
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{
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struct qdio_buffer_element *sbale;
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sbale = qdio->req_q[q_req->sbal_first]->element;
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sbale->scount = q_req->sbal_number - 1;
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}
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#endif /* ZFCP_QDIO_H */
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