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