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 <linux/interrupt.h> 14 #include <asm/qdio.h> 15 16 #define ZFCP_QDIO_SBALE_LEN PAGE_SIZE 17 18 /* Max SBALS for chaining */ 19 #define ZFCP_QDIO_MAX_SBALS_PER_REQ 36 20 21 /** 22 * struct zfcp_qdio - basic qdio data structure 23 * @res_q: response queue 24 * @req_q: request queue 25 * @req_q_idx: index of next free buffer 26 * @req_q_free: number of free buffers in queue 27 * @stat_lock: lock to protect req_q_util and req_q_time 28 * @req_q_lock: lock to serialize access to request queue 29 * @req_q_time: time of last fill level change 30 * @req_q_util: used for accounting 31 * @req_q_full: queue full incidents 32 * @req_q_wq: used to wait for SBAL availability 33 * @irq_tasklet: used for QDIO interrupt processing 34 * @request_tasklet: used for Request Queue completion processing 35 * @request_timer: used to trigger the Request Queue completion processing 36 * @adapter: adapter used in conjunction with this qdio structure 37 * @max_sbale_per_sbal: qdio limit per sbal 38 * @max_sbale_per_req: qdio limit per request 39 */ 40 struct zfcp_qdio { 41 struct qdio_buffer *res_q[QDIO_MAX_BUFFERS_PER_Q]; 42 struct qdio_buffer *req_q[QDIO_MAX_BUFFERS_PER_Q]; 43 u8 req_q_idx; 44 atomic_t req_q_free; 45 spinlock_t stat_lock; 46 spinlock_t req_q_lock; 47 unsigned long long req_q_time; 48 u64 req_q_util; 49 atomic_t req_q_full; 50 wait_queue_head_t req_q_wq; 51 struct tasklet_struct irq_tasklet; 52 struct tasklet_struct request_tasklet; 53 struct timer_list request_timer; 54 struct zfcp_adapter *adapter; 55 u16 max_sbale_per_sbal; 56 u16 max_sbale_per_req; 57 }; 58 59 /** 60 * struct zfcp_qdio_req - qdio queue related values for a request 61 * @sbtype: sbal type flags for sbale 0 62 * @sbal_number: number of free sbals 63 * @sbal_first: first sbal for this request 64 * @sbal_last: last sbal for this request 65 * @sbal_limit: last possible sbal for this request 66 * @sbale_curr: current sbale at creation of this request 67 * @qdio_outb_usage: usage of outbound queue 68 */ 69 struct zfcp_qdio_req { 70 u8 sbtype; 71 u8 sbal_number; 72 u8 sbal_first; 73 u8 sbal_last; 74 u8 sbal_limit; 75 u8 sbale_curr; 76 u16 qdio_outb_usage; 77 }; 78 79 /** 80 * zfcp_qdio_sbale_req - return pointer to sbale on req_q for a request 81 * @qdio: pointer to struct zfcp_qdio 82 * @q_req: pointer to struct zfcp_qdio_req 83 * Returns: pointer to qdio_buffer_element (sbale) structure 84 */ 85 static inline struct qdio_buffer_element * 86 zfcp_qdio_sbale_req(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) 87 { 88 return &qdio->req_q[q_req->sbal_last]->element[0]; 89 } 90 91 /** 92 * zfcp_qdio_sbale_curr - return current sbale on req_q for a request 93 * @qdio: pointer to struct zfcp_qdio 94 * @q_req: pointer to struct zfcp_qdio_req 95 * Returns: pointer to qdio_buffer_element (sbale) structure 96 */ 97 static inline struct qdio_buffer_element * 98 zfcp_qdio_sbale_curr(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) 99 { 100 return &qdio->req_q[q_req->sbal_last]->element[q_req->sbale_curr]; 101 } 102 103 /** 104 * zfcp_qdio_req_init - initialize qdio request 105 * @qdio: request queue where to start putting the request 106 * @q_req: the qdio request to start 107 * @req_id: The request id 108 * @sbtype: type flags to set for all sbals 109 * @data: First data block 110 * @len: Length of first data block 111 * 112 * This is the start of putting the request into the queue, the last 113 * step is passing the request to zfcp_qdio_send. The request queue 114 * lock must be held during the whole process from init to send. 115 */ 116 static inline 117 void zfcp_qdio_req_init(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req, 118 u64 req_id, u8 sbtype, void *data, u32 len) 119 { 120 struct qdio_buffer_element *sbale; 121 int count = min(atomic_read(&qdio->req_q_free), 122 ZFCP_QDIO_MAX_SBALS_PER_REQ); 123 124 q_req->sbal_first = q_req->sbal_last = qdio->req_q_idx; 125 q_req->sbal_number = 1; 126 q_req->sbtype = sbtype; 127 q_req->sbale_curr = 1; 128 q_req->sbal_limit = (q_req->sbal_first + count - 1) 129 % QDIO_MAX_BUFFERS_PER_Q; 130 131 sbale = zfcp_qdio_sbale_req(qdio, q_req); 132 sbale->addr = u64_to_dma64(req_id); 133 sbale->eflags = 0; 134 sbale->sflags = SBAL_SFLAGS0_COMMAND | sbtype; 135 136 if (unlikely(!data)) 137 return; 138 sbale++; 139 sbale->addr = virt_to_dma64(data); 140 sbale->length = len; 141 } 142 143 /** 144 * zfcp_qdio_fill_next - Fill next sbale, only for single sbal requests 145 * @qdio: pointer to struct zfcp_qdio 146 * @q_req: pointer to struct zfcp_queue_req 147 * @data: pointer to data 148 * @len: length of data 149 * 150 * This is only required for single sbal requests, calling it when 151 * wrapping around to the next sbal is a bug. 152 */ 153 static inline 154 void zfcp_qdio_fill_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req, 155 void *data, u32 len) 156 { 157 struct qdio_buffer_element *sbale; 158 159 BUG_ON(q_req->sbale_curr == qdio->max_sbale_per_sbal - 1); 160 q_req->sbale_curr++; 161 sbale = zfcp_qdio_sbale_curr(qdio, q_req); 162 sbale->addr = virt_to_dma64(data); 163 sbale->length = len; 164 } 165 166 /** 167 * zfcp_qdio_set_sbale_last - set last entry flag in current sbale 168 * @qdio: pointer to struct zfcp_qdio 169 * @q_req: pointer to struct zfcp_queue_req 170 */ 171 static inline 172 void zfcp_qdio_set_sbale_last(struct zfcp_qdio *qdio, 173 struct zfcp_qdio_req *q_req) 174 { 175 struct qdio_buffer_element *sbale; 176 177 sbale = zfcp_qdio_sbale_curr(qdio, q_req); 178 sbale->eflags |= SBAL_EFLAGS_LAST_ENTRY; 179 } 180 181 /** 182 * zfcp_qdio_sg_one_sbal - check if one sbale is enough for sg data 183 * @sg: The scatterlist where to check the data size 184 * 185 * Returns: 1 when one sbale is enough for the data in the scatterlist, 186 * 0 if not. 187 */ 188 static inline 189 int zfcp_qdio_sg_one_sbale(struct scatterlist *sg) 190 { 191 return sg_is_last(sg) && sg->length <= ZFCP_QDIO_SBALE_LEN; 192 } 193 194 /** 195 * zfcp_qdio_skip_to_last_sbale - skip to last sbale in sbal 196 * @qdio: pointer to struct zfcp_qdio 197 * @q_req: The current zfcp_qdio_req 198 */ 199 static inline 200 void zfcp_qdio_skip_to_last_sbale(struct zfcp_qdio *qdio, 201 struct zfcp_qdio_req *q_req) 202 { 203 q_req->sbale_curr = qdio->max_sbale_per_sbal - 1; 204 } 205 206 /** 207 * zfcp_qdio_sbal_limit - set the sbal limit for a request in q_req 208 * @qdio: pointer to struct zfcp_qdio 209 * @q_req: The current zfcp_qdio_req 210 * @max_sbals: maximum number of SBALs allowed 211 */ 212 static inline 213 void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio, 214 struct zfcp_qdio_req *q_req, int max_sbals) 215 { 216 int count = min(atomic_read(&qdio->req_q_free), max_sbals); 217 218 q_req->sbal_limit = (q_req->sbal_first + count - 1) % 219 QDIO_MAX_BUFFERS_PER_Q; 220 } 221 222 /** 223 * zfcp_qdio_set_data_div - set data division count 224 * @qdio: pointer to struct zfcp_qdio 225 * @q_req: The current zfcp_qdio_req 226 * @count: The data division count 227 */ 228 static inline 229 void zfcp_qdio_set_data_div(struct zfcp_qdio *qdio, 230 struct zfcp_qdio_req *q_req, u32 count) 231 { 232 struct qdio_buffer_element *sbale; 233 234 sbale = qdio->req_q[q_req->sbal_first]->element; 235 sbale->length = count; 236 } 237 238 /** 239 * zfcp_qdio_real_bytes - count bytes used 240 * @sg: pointer to struct scatterlist 241 */ 242 static inline 243 unsigned int zfcp_qdio_real_bytes(struct scatterlist *sg) 244 { 245 unsigned int real_bytes = 0; 246 247 for (; sg; sg = sg_next(sg)) 248 real_bytes += sg->length; 249 250 return real_bytes; 251 } 252 253 /** 254 * zfcp_qdio_set_scount - set SBAL count value 255 * @qdio: pointer to struct zfcp_qdio 256 * @q_req: The current zfcp_qdio_req 257 */ 258 static inline 259 void zfcp_qdio_set_scount(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) 260 { 261 struct qdio_buffer_element *sbale; 262 263 sbale = qdio->req_q[q_req->sbal_first]->element; 264 sbale->scount = q_req->sbal_number - 1; 265 } 266 267 #endif /* ZFCP_QDIO_H */ 268