4 * Header file for zfcp qdio interface
6 * Copyright IBM Corp. 2010
14 #define ZFCP_QDIO_SBALE_LEN PAGE_SIZE
16 /* Max SBALS for chaining */
17 #define ZFCP_QDIO_MAX_SBALS_PER_REQ 36
20 * struct zfcp_qdio - basic qdio data structure
21 * @res_q: response queue
22 * @req_q: request queue
23 * @req_q_idx: index of next free buffer
24 * @req_q_free: number of free buffers in queue
25 * @stat_lock: lock to protect req_q_util and req_q_time
26 * @req_q_lock: lock to serialize access to request queue
27 * @req_q_time: time of last fill level change
28 * @req_q_util: used for accounting
29 * @req_q_full: queue full incidents
30 * @req_q_wq: used to wait for SBAL availability
31 * @adapter: adapter used in conjunction with this qdio structure
34 struct qdio_buffer *res_q[QDIO_MAX_BUFFERS_PER_Q];
35 struct qdio_buffer *req_q[QDIO_MAX_BUFFERS_PER_Q];
39 spinlock_t req_q_lock;
40 unsigned long long req_q_time;
43 wait_queue_head_t req_q_wq;
44 struct zfcp_adapter *adapter;
45 u16 max_sbale_per_sbal;
46 u16 max_sbale_per_req;
50 * struct zfcp_qdio_req - qdio queue related values for a request
51 * @sbtype: sbal type flags for sbale 0
52 * @sbal_number: number of free sbals
53 * @sbal_first: first sbal for this request
54 * @sbal_last: last sbal for this request
55 * @sbal_limit: last possible sbal for this request
56 * @sbale_curr: current sbale at creation of this request
57 * @qdio_outb_usage: usage of outbound queue
59 struct zfcp_qdio_req {
70 * zfcp_qdio_sbale_req - return pointer to sbale on req_q for a request
71 * @qdio: pointer to struct zfcp_qdio
72 * @q_rec: pointer to struct zfcp_qdio_req
73 * Returns: pointer to qdio_buffer_element (sbale) structure
75 static inline struct qdio_buffer_element *
76 zfcp_qdio_sbale_req(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
78 return &qdio->req_q[q_req->sbal_last]->element[0];
82 * zfcp_qdio_sbale_curr - return current sbale on req_q for a request
83 * @qdio: pointer to struct zfcp_qdio
84 * @fsf_req: pointer to struct zfcp_fsf_req
85 * Returns: pointer to qdio_buffer_element (sbale) structure
87 static inline struct qdio_buffer_element *
88 zfcp_qdio_sbale_curr(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
90 return &qdio->req_q[q_req->sbal_last]->element[q_req->sbale_curr];
94 * zfcp_qdio_req_init - initialize qdio request
95 * @qdio: request queue where to start putting the request
96 * @q_req: the qdio request to start
97 * @req_id: The request id
98 * @sbtype: type flags to set for all sbals
99 * @data: First data block
100 * @len: Length of first data block
102 * This is the start of putting the request into the queue, the last
103 * step is passing the request to zfcp_qdio_send. The request queue
104 * lock must be held during the whole process from init to send.
107 void zfcp_qdio_req_init(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
108 unsigned long req_id, u8 sbtype, void *data, u32 len)
110 struct qdio_buffer_element *sbale;
111 int count = min(atomic_read(&qdio->req_q_free),
112 ZFCP_QDIO_MAX_SBALS_PER_REQ);
114 q_req->sbal_first = q_req->sbal_last = qdio->req_q_idx;
115 q_req->sbal_number = 1;
116 q_req->sbtype = sbtype;
117 q_req->sbale_curr = 1;
118 q_req->sbal_limit = (q_req->sbal_first + count - 1)
119 % QDIO_MAX_BUFFERS_PER_Q;
121 sbale = zfcp_qdio_sbale_req(qdio, q_req);
122 sbale->addr = (void *) req_id;
124 sbale->sflags = SBAL_SFLAGS0_COMMAND | sbtype;
134 * zfcp_qdio_fill_next - Fill next sbale, only for single sbal requests
135 * @qdio: pointer to struct zfcp_qdio
136 * @q_req: pointer to struct zfcp_queue_req
138 * This is only required for single sbal requests, calling it when
139 * wrapping around to the next sbal is a bug.
142 void zfcp_qdio_fill_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
145 struct qdio_buffer_element *sbale;
147 BUG_ON(q_req->sbale_curr == qdio->max_sbale_per_sbal - 1);
149 sbale = zfcp_qdio_sbale_curr(qdio, q_req);
155 * zfcp_qdio_set_sbale_last - set last entry flag in current sbale
156 * @qdio: pointer to struct zfcp_qdio
157 * @q_req: pointer to struct zfcp_queue_req
160 void zfcp_qdio_set_sbale_last(struct zfcp_qdio *qdio,
161 struct zfcp_qdio_req *q_req)
163 struct qdio_buffer_element *sbale;
165 sbale = zfcp_qdio_sbale_curr(qdio, q_req);
166 sbale->eflags |= SBAL_EFLAGS_LAST_ENTRY;
170 * zfcp_qdio_sg_one_sbal - check if one sbale is enough for sg data
171 * @sg: The scatterlist where to check the data size
173 * Returns: 1 when one sbale is enough for the data in the scatterlist,
177 int zfcp_qdio_sg_one_sbale(struct scatterlist *sg)
179 return sg_is_last(sg) && sg->length <= ZFCP_QDIO_SBALE_LEN;
183 * zfcp_qdio_skip_to_last_sbale - skip to last sbale in sbal
184 * @q_req: The current zfcp_qdio_req
187 void zfcp_qdio_skip_to_last_sbale(struct zfcp_qdio *qdio,
188 struct zfcp_qdio_req *q_req)
190 q_req->sbale_curr = qdio->max_sbale_per_sbal - 1;
194 * zfcp_qdio_sbal_limit - set the sbal limit for a request in q_req
195 * @qdio: pointer to struct zfcp_qdio
196 * @q_req: The current zfcp_qdio_req
197 * @max_sbals: maximum number of SBALs allowed
200 void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio,
201 struct zfcp_qdio_req *q_req, int max_sbals)
203 int count = min(atomic_read(&qdio->req_q_free), max_sbals);
205 q_req->sbal_limit = (q_req->sbal_first + count - 1) %
206 QDIO_MAX_BUFFERS_PER_Q;
210 * zfcp_qdio_set_data_div - set data division count
211 * @qdio: pointer to struct zfcp_qdio
212 * @q_req: The current zfcp_qdio_req
213 * @count: The data division count
216 void zfcp_qdio_set_data_div(struct zfcp_qdio *qdio,
217 struct zfcp_qdio_req *q_req, u32 count)
219 struct qdio_buffer_element *sbale;
221 sbale = qdio->req_q[q_req->sbal_first]->element;
222 sbale->length = count;
226 * zfcp_qdio_real_bytes - count bytes used
227 * @sg: pointer to struct scatterlist
230 unsigned int zfcp_qdio_real_bytes(struct scatterlist *sg)
232 unsigned int real_bytes = 0;
234 for (; sg; sg = sg_next(sg))
235 real_bytes += sg->length;
241 * zfcp_qdio_set_scount - set SBAL count value
242 * @qdio: pointer to struct zfcp_qdio
243 * @q_req: The current zfcp_qdio_req
246 void zfcp_qdio_set_scount(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
248 struct qdio_buffer_element *sbale;
250 sbale = qdio->req_q[q_req->sbal_first]->element;
251 sbale->scount = q_req->sbal_number - 1;
254 #endif /* ZFCP_QDIO_H */