1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * zfcp device driver 4 * 5 * Header file for zfcp qdio interface 6 * 7 * Copyright IBM Corp. 2010 8 */ 9 10 #ifndef ZFCP_QDIO_H 11 #define ZFCP_QDIO_H 12 13 #include <asm/qdio.h> 14 15 #define ZFCP_QDIO_SBALE_LEN PAGE_SIZE 16 17 /* Max SBALS for chaining */ 18 #define ZFCP_QDIO_MAX_SBALS_PER_REQ 36 19 20 /** 21 * struct zfcp_qdio - basic qdio data structure 22 * @res_q: response queue 23 * @req_q: request queue 24 * @req_q_idx: index of next free buffer 25 * @req_q_free: number of free buffers in queue 26 * @stat_lock: lock to protect req_q_util and req_q_time 27 * @req_q_lock: lock to serialize access to request queue 28 * @req_q_time: time of last fill level change 29 * @req_q_util: used for accounting 30 * @req_q_full: queue full incidents 31 * @req_q_wq: used to wait for SBAL availability 32 * @adapter: adapter used in conjunction with this qdio structure 33 * @max_sbale_per_sbal: qdio limit per sbal 34 * @max_sbale_per_req: qdio limit per request 35 */ 36 struct zfcp_qdio { 37 struct qdio_buffer *res_q[QDIO_MAX_BUFFERS_PER_Q]; 38 struct qdio_buffer *req_q[QDIO_MAX_BUFFERS_PER_Q]; 39 u8 req_q_idx; 40 atomic_t req_q_free; 41 spinlock_t stat_lock; 42 spinlock_t req_q_lock; 43 unsigned long long req_q_time; 44 u64 req_q_util; 45 atomic_t req_q_full; 46 wait_queue_head_t req_q_wq; 47 struct zfcp_adapter *adapter; 48 u16 max_sbale_per_sbal; 49 u16 max_sbale_per_req; 50 }; 51 52 /** 53 * struct zfcp_qdio_req - qdio queue related values for a request 54 * @sbtype: sbal type flags for sbale 0 55 * @sbal_number: number of free sbals 56 * @sbal_first: first sbal for this request 57 * @sbal_last: last sbal for this request 58 * @sbal_limit: last possible sbal for this request 59 * @sbale_curr: current sbale at creation of this request 60 * @qdio_outb_usage: usage of outbound queue 61 */ 62 struct zfcp_qdio_req { 63 u8 sbtype; 64 u8 sbal_number; 65 u8 sbal_first; 66 u8 sbal_last; 67 u8 sbal_limit; 68 u8 sbale_curr; 69 u16 qdio_outb_usage; 70 }; 71 72 /** 73 * zfcp_qdio_sbale_req - return pointer to sbale on req_q for a request 74 * @qdio: pointer to struct zfcp_qdio 75 * @q_req: pointer to struct zfcp_qdio_req 76 * Returns: pointer to qdio_buffer_element (sbale) structure 77 */ 78 static inline struct qdio_buffer_element * 79 zfcp_qdio_sbale_req(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) 80 { 81 return &qdio->req_q[q_req->sbal_last]->element[0]; 82 } 83 84 /** 85 * zfcp_qdio_sbale_curr - return current sbale on req_q for a request 86 * @qdio: pointer to struct zfcp_qdio 87 * @q_req: pointer to struct zfcp_qdio_req 88 * Returns: pointer to qdio_buffer_element (sbale) structure 89 */ 90 static inline struct qdio_buffer_element * 91 zfcp_qdio_sbale_curr(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) 92 { 93 return &qdio->req_q[q_req->sbal_last]->element[q_req->sbale_curr]; 94 } 95 96 /** 97 * zfcp_qdio_req_init - initialize qdio request 98 * @qdio: request queue where to start putting the request 99 * @q_req: the qdio request to start 100 * @req_id: The request id 101 * @sbtype: type flags to set for all sbals 102 * @data: First data block 103 * @len: Length of first data block 104 * 105 * This is the start of putting the request into the queue, the last 106 * step is passing the request to zfcp_qdio_send. The request queue 107 * lock must be held during the whole process from init to send. 108 */ 109 static inline 110 void zfcp_qdio_req_init(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req, 111 unsigned long req_id, u8 sbtype, void *data, u32 len) 112 { 113 struct qdio_buffer_element *sbale; 114 int count = min(atomic_read(&qdio->req_q_free), 115 ZFCP_QDIO_MAX_SBALS_PER_REQ); 116 117 q_req->sbal_first = q_req->sbal_last = qdio->req_q_idx; 118 q_req->sbal_number = 1; 119 q_req->sbtype = sbtype; 120 q_req->sbale_curr = 1; 121 q_req->sbal_limit = (q_req->sbal_first + count - 1) 122 % QDIO_MAX_BUFFERS_PER_Q; 123 124 sbale = zfcp_qdio_sbale_req(qdio, q_req); 125 sbale->addr = (void *) req_id; 126 sbale->eflags = 0; 127 sbale->sflags = SBAL_SFLAGS0_COMMAND | sbtype; 128 129 if (unlikely(!data)) 130 return; 131 sbale++; 132 sbale->addr = data; 133 sbale->length = len; 134 } 135 136 /** 137 * zfcp_qdio_fill_next - Fill next sbale, only for single sbal requests 138 * @qdio: pointer to struct zfcp_qdio 139 * @q_req: pointer to struct zfcp_queue_req 140 * @data: pointer to data 141 * @len: length of data 142 * 143 * This is only required for single sbal requests, calling it when 144 * wrapping around to the next sbal is a bug. 145 */ 146 static inline 147 void zfcp_qdio_fill_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req, 148 void *data, u32 len) 149 { 150 struct qdio_buffer_element *sbale; 151 152 BUG_ON(q_req->sbale_curr == qdio->max_sbale_per_sbal - 1); 153 q_req->sbale_curr++; 154 sbale = zfcp_qdio_sbale_curr(qdio, q_req); 155 sbale->addr = data; 156 sbale->length = len; 157 } 158 159 /** 160 * zfcp_qdio_set_sbale_last - set last entry flag in current sbale 161 * @qdio: pointer to struct zfcp_qdio 162 * @q_req: pointer to struct zfcp_queue_req 163 */ 164 static inline 165 void zfcp_qdio_set_sbale_last(struct zfcp_qdio *qdio, 166 struct zfcp_qdio_req *q_req) 167 { 168 struct qdio_buffer_element *sbale; 169 170 sbale = zfcp_qdio_sbale_curr(qdio, q_req); 171 sbale->eflags |= SBAL_EFLAGS_LAST_ENTRY; 172 } 173 174 /** 175 * zfcp_qdio_sg_one_sbal - check if one sbale is enough for sg data 176 * @sg: The scatterlist where to check the data size 177 * 178 * Returns: 1 when one sbale is enough for the data in the scatterlist, 179 * 0 if not. 180 */ 181 static inline 182 int zfcp_qdio_sg_one_sbale(struct scatterlist *sg) 183 { 184 return sg_is_last(sg) && sg->length <= ZFCP_QDIO_SBALE_LEN; 185 } 186 187 /** 188 * zfcp_qdio_skip_to_last_sbale - skip to last sbale in sbal 189 * @qdio: pointer to struct zfcp_qdio 190 * @q_req: The current zfcp_qdio_req 191 */ 192 static inline 193 void zfcp_qdio_skip_to_last_sbale(struct zfcp_qdio *qdio, 194 struct zfcp_qdio_req *q_req) 195 { 196 q_req->sbale_curr = qdio->max_sbale_per_sbal - 1; 197 } 198 199 /** 200 * zfcp_qdio_sbal_limit - set the sbal limit for a request in q_req 201 * @qdio: pointer to struct zfcp_qdio 202 * @q_req: The current zfcp_qdio_req 203 * @max_sbals: maximum number of SBALs allowed 204 */ 205 static inline 206 void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio, 207 struct zfcp_qdio_req *q_req, int max_sbals) 208 { 209 int count = min(atomic_read(&qdio->req_q_free), max_sbals); 210 211 q_req->sbal_limit = (q_req->sbal_first + count - 1) % 212 QDIO_MAX_BUFFERS_PER_Q; 213 } 214 215 /** 216 * zfcp_qdio_set_data_div - set data division count 217 * @qdio: pointer to struct zfcp_qdio 218 * @q_req: The current zfcp_qdio_req 219 * @count: The data division count 220 */ 221 static inline 222 void zfcp_qdio_set_data_div(struct zfcp_qdio *qdio, 223 struct zfcp_qdio_req *q_req, u32 count) 224 { 225 struct qdio_buffer_element *sbale; 226 227 sbale = qdio->req_q[q_req->sbal_first]->element; 228 sbale->length = count; 229 } 230 231 /** 232 * zfcp_qdio_real_bytes - count bytes used 233 * @sg: pointer to struct scatterlist 234 */ 235 static inline 236 unsigned int zfcp_qdio_real_bytes(struct scatterlist *sg) 237 { 238 unsigned int real_bytes = 0; 239 240 for (; sg; sg = sg_next(sg)) 241 real_bytes += sg->length; 242 243 return real_bytes; 244 } 245 246 /** 247 * zfcp_qdio_set_scount - set SBAL count value 248 * @qdio: pointer to struct zfcp_qdio 249 * @q_req: The current zfcp_qdio_req 250 */ 251 static inline 252 void zfcp_qdio_set_scount(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) 253 { 254 struct qdio_buffer_element *sbale; 255 256 sbale = qdio->req_q[q_req->sbal_first]->element; 257 sbale->scount = q_req->sbal_number - 1; 258 } 259 260 #endif /* ZFCP_QDIO_H */ 261