1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
|
/*
* 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>
#define ZFCP_QDIO_SBALE_LEN PAGE_SIZE
/* DMQ bug workaround: don't use last SBALE */
#define ZFCP_QDIO_MAX_SBALES_PER_SBAL (QDIO_MAX_ELEMENTS_PER_BUFFER - 1)
/* index of last SBALE (with respect to DMQ bug workaround) */
#define ZFCP_QDIO_LAST_SBALE_PER_SBAL (ZFCP_QDIO_MAX_SBALES_PER_SBAL - 1)
/* Max SBALS for chaining */
#define ZFCP_QDIO_MAX_SBALS_PER_REQ 36
/* max. number of (data buffer) SBALEs in largest SBAL chain
* request ID + QTCB in SBALE 0 + 1 of first SBAL in chain */
#define ZFCP_QDIO_MAX_SBALES_PER_REQ \
(ZFCP_QDIO_MAX_SBALS_PER_REQ * ZFCP_QDIO_MAX_SBALES_PER_SBAL - 2)
/**
* 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
* @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
* @sbal_response: sbal used in interrupt
* @qdio_outb_usage: usage of outbound queue
* @qdio_inb_usage: usage of inbound queue
*/
struct zfcp_qdio_req {
u32 sbtype;
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);
}
/**
* 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, u32 sbtype, void *data, u32 len)
{
struct qdio_buffer_element *sbale;
int count = min(atomic_read(&qdio->req_q.count),
ZFCP_QDIO_MAX_SBALS_PER_REQ);
q_req->sbal_first = q_req->sbal_last = qdio->req_q.first;
q_req->sbal_number = 1;
q_req->sbtype = sbtype;
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->flags |= SBAL_FLAGS0_COMMAND;
sbale->flags |= sbtype;
q_req->sbale_curr = 1;
sbale++;
sbale->addr = data;
if (likely(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 == ZFCP_QDIO_LAST_SBALE_PER_SBAL);
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->flags |= SBAL_FLAGS_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_req *q_req)
{
q_req->sbale_curr = ZFCP_QDIO_LAST_SBALE_PER_SBAL;
}
/**
* 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.count), max_sbals);
q_req->sbal_limit = (q_req->sbal_first + count - 1) %
QDIO_MAX_BUFFERS_PER_Q;
}
#endif /* ZFCP_QDIO_H */
|
