1 /* 2 * zfcp device driver 3 * 4 * Header file for zfcp qdio interface 5 * 6 * Copyright IBM Corp. 2010 7 */ 8 9 #ifndef ZFCP_QDIO_H 10 #define ZFCP_QDIO_H 11 12 #include <asm/qdio.h> 13 14 #define ZFCP_QDIO_SBALE_LEN PAGE_SIZE 15 16 /* Max SBALS for chaining */ 17 #define ZFCP_QDIO_MAX_SBALS_PER_REQ 36 18 19 /** 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 32 */ 33 struct zfcp_qdio { 34 struct qdio_buffer *res_q[QDIO_MAX_BUFFERS_PER_Q]; 35 struct qdio_buffer *req_q[QDIO_MAX_BUFFERS_PER_Q]; 36 u8 req_q_idx; 37 atomic_t req_q_free; 38 spinlock_t stat_lock; 39 spinlock_t req_q_lock; 40 unsigned long long req_q_time; 41 u64 req_q_util; 42 atomic_t req_q_full; 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; 47 }; 48 49 /** 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 * @sbal_response: sbal used in interrupt 58 * @qdio_outb_usage: usage of outbound queue 59 */ 60 struct zfcp_qdio_req { 61 u8 sbtype; 62 u8 sbal_number; 63 u8 sbal_first; 64 u8 sbal_last; 65 u8 sbal_limit; 66 u8 sbale_curr; 67 u8 sbal_response; 68 u16 qdio_outb_usage; 69 }; 70 71 /** 72 * zfcp_qdio_sbale_req - return pointer to sbale on req_q for a request 73 * @qdio: pointer to struct zfcp_qdio 74 * @q_rec: pointer to struct zfcp_qdio_req 75 * Returns: pointer to qdio_buffer_element (sbale) structure 76 */ 77 static inline struct qdio_buffer_element * 78 zfcp_qdio_sbale_req(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) 79 { 80 return &qdio->req_q[q_req->sbal_last]->element[0]; 81 } 82 83 /** 84 * zfcp_qdio_sbale_curr - return current sbale on req_q for a request 85 * @qdio: pointer to struct zfcp_qdio 86 * @fsf_req: pointer to struct zfcp_fsf_req 87 * Returns: pointer to qdio_buffer_element (sbale) structure 88 */ 89 static inline struct qdio_buffer_element * 90 zfcp_qdio_sbale_curr(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) 91 { 92 return &qdio->req_q[q_req->sbal_last]->element[q_req->sbale_curr]; 93 } 94 95 /** 96 * zfcp_qdio_req_init - initialize qdio request 97 * @qdio: request queue where to start putting the request 98 * @q_req: the qdio request to start 99 * @req_id: The request id 100 * @sbtype: type flags to set for all sbals 101 * @data: First data block 102 * @len: Length of first data block 103 * 104 * This is the start of putting the request into the queue, the last 105 * step is passing the request to zfcp_qdio_send. The request queue 106 * lock must be held during the whole process from init to send. 107 */ 108 static inline 109 void zfcp_qdio_req_init(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req, 110 unsigned long req_id, u8 sbtype, void *data, u32 len) 111 { 112 struct qdio_buffer_element *sbale; 113 int count = min(atomic_read(&qdio->req_q_free), 114 ZFCP_QDIO_MAX_SBALS_PER_REQ); 115 116 q_req->sbal_first = q_req->sbal_last = qdio->req_q_idx; 117 q_req->sbal_number = 1; 118 q_req->sbtype = sbtype; 119 q_req->sbale_curr = 1; 120 q_req->sbal_limit = (q_req->sbal_first + count - 1) 121 % QDIO_MAX_BUFFERS_PER_Q; 122 123 sbale = zfcp_qdio_sbale_req(qdio, q_req); 124 sbale->addr = (void *) req_id; 125 sbale->eflags = 0; 126 sbale->sflags = SBAL_SFLAGS0_COMMAND | sbtype; 127 128 if (unlikely(!data)) 129 return; 130 sbale++; 131 sbale->addr = data; 132 sbale->length = len; 133 } 134 135 /** 136 * zfcp_qdio_fill_next - Fill next sbale, only for single sbal requests 137 * @qdio: pointer to struct zfcp_qdio 138 * @q_req: pointer to struct zfcp_queue_req 139 * 140 * This is only required for single sbal requests, calling it when 141 * wrapping around to the next sbal is a bug. 142 */ 143 static inline 144 void zfcp_qdio_fill_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req, 145 void *data, u32 len) 146 { 147 struct qdio_buffer_element *sbale; 148 149 BUG_ON(q_req->sbale_curr == qdio->max_sbale_per_sbal - 1); 150 q_req->sbale_curr++; 151 sbale = zfcp_qdio_sbale_curr(qdio, q_req); 152 sbale->addr = data; 153 sbale->length = len; 154 } 155 156 /** 157 * zfcp_qdio_set_sbale_last - set last entry flag in current sbale 158 * @qdio: pointer to struct zfcp_qdio 159 * @q_req: pointer to struct zfcp_queue_req 160 */ 161 static inline 162 void zfcp_qdio_set_sbale_last(struct zfcp_qdio *qdio, 163 struct zfcp_qdio_req *q_req) 164 { 165 struct qdio_buffer_element *sbale; 166 167 sbale = zfcp_qdio_sbale_curr(qdio, q_req); 168 sbale->eflags |= SBAL_EFLAGS_LAST_ENTRY; 169 } 170 171 /** 172 * zfcp_qdio_sg_one_sbal - check if one sbale is enough for sg data 173 * @sg: The scatterlist where to check the data size 174 * 175 * Returns: 1 when one sbale is enough for the data in the scatterlist, 176 * 0 if not. 177 */ 178 static inline 179 int zfcp_qdio_sg_one_sbale(struct scatterlist *sg) 180 { 181 return sg_is_last(sg) && sg->length <= ZFCP_QDIO_SBALE_LEN; 182 } 183 184 /** 185 * zfcp_qdio_skip_to_last_sbale - skip to last sbale in sbal 186 * @q_req: The current zfcp_qdio_req 187 */ 188 static inline 189 void zfcp_qdio_skip_to_last_sbale(struct zfcp_qdio *qdio, 190 struct zfcp_qdio_req *q_req) 191 { 192 q_req->sbale_curr = qdio->max_sbale_per_sbal - 1; 193 } 194 195 /** 196 * zfcp_qdio_sbal_limit - set the sbal limit for a request in q_req 197 * @qdio: pointer to struct zfcp_qdio 198 * @q_req: The current zfcp_qdio_req 199 * @max_sbals: maximum number of SBALs allowed 200 */ 201 static inline 202 void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio, 203 struct zfcp_qdio_req *q_req, int max_sbals) 204 { 205 int count = min(atomic_read(&qdio->req_q_free), max_sbals); 206 207 q_req->sbal_limit = (q_req->sbal_first + count - 1) % 208 QDIO_MAX_BUFFERS_PER_Q; 209 } 210 211 /** 212 * zfcp_qdio_set_data_div - set data division count 213 * @qdio: pointer to struct zfcp_qdio 214 * @q_req: The current zfcp_qdio_req 215 * @count: The data division count 216 */ 217 static inline 218 void zfcp_qdio_set_data_div(struct zfcp_qdio *qdio, 219 struct zfcp_qdio_req *q_req, u32 count) 220 { 221 struct qdio_buffer_element *sbale; 222 223 sbale = qdio->req_q[q_req->sbal_first]->element; 224 sbale->length = count; 225 } 226 227 /** 228 * zfcp_qdio_sbale_count - count sbale used 229 * @sg: pointer to struct scatterlist 230 */ 231 static inline 232 unsigned int zfcp_qdio_sbale_count(struct scatterlist *sg) 233 { 234 unsigned int count = 0; 235 236 for (; sg; sg = sg_next(sg)) 237 count++; 238 239 return count; 240 } 241 242 /** 243 * zfcp_qdio_real_bytes - count bytes used 244 * @sg: pointer to struct scatterlist 245 */ 246 static inline 247 unsigned int zfcp_qdio_real_bytes(struct scatterlist *sg) 248 { 249 unsigned int real_bytes = 0; 250 251 for (; sg; sg = sg_next(sg)) 252 real_bytes += sg->length; 253 254 return real_bytes; 255 } 256 257 /** 258 * zfcp_qdio_set_scount - set SBAL count value 259 * @qdio: pointer to struct zfcp_qdio 260 * @q_req: The current zfcp_qdio_req 261 */ 262 static inline 263 void zfcp_qdio_set_scount(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) 264 { 265 struct qdio_buffer_element *sbale; 266 267 sbale = qdio->req_q[q_req->sbal_first]->element; 268 sbale->scount = q_req->sbal_number - 1; 269 } 270 271 #endif /* ZFCP_QDIO_H */ 272