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