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