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#define ZFCP_QDIO_MAX_SBALES_PER_SBAL (QDIO_MAX_ELEMENTS_PER_BUFFER - 1) 17 18#define ZFCP_QDIO_LAST_SBALE_PER_SBAL (ZFCP_QDIO_MAX_SBALES_PER_SBAL - 1) 19 20/* Max SBALS for chaining */ 21#define ZFCP_QDIO_MAX_SBALS_PER_REQ 36 22 23/* max. number of (data buffer) SBALEs in largest SBAL chain 24 * request ID + QTCB in SBALE 0 + 1 of first SBAL in chain */ 25#define ZFCP_QDIO_MAX_SBALES_PER_REQ \ 26 (ZFCP_QDIO_MAX_SBALS_PER_REQ * ZFCP_QDIO_MAX_SBALES_PER_SBAL - 2) 27 28/** 29 * struct zfcp_qdio - basic qdio data structure 30 * @res_q: response queue 31 * @req_q: request queue 32 * @req_q_idx: index of next free buffer 33 * @req_q_free: number of free buffers in queue 34 * @stat_lock: lock to protect req_q_util and req_q_time 35 * @req_q_lock: lock to serialize access to request queue 36 * @req_q_time: time of last fill level change 37 * @req_q_util: used for accounting 38 * @req_q_full: queue full incidents 39 * @req_q_wq: used to wait for SBAL availability 40 * @adapter: adapter used in conjunction with this qdio structure 41 */ 42struct zfcp_qdio { 43 struct qdio_buffer *res_q[QDIO_MAX_BUFFERS_PER_Q]; 44 struct qdio_buffer *req_q[QDIO_MAX_BUFFERS_PER_Q]; 45 u8 req_q_idx; 46 atomic_t req_q_free; 47 spinlock_t stat_lock; 48 spinlock_t req_q_lock; 49 unsigned long long req_q_time; 50 u64 req_q_util; 51 atomic_t req_q_full; 52 wait_queue_head_t req_q_wq; 53 struct zfcp_adapter *adapter; 54}; 55 56/** 57 * struct zfcp_qdio_req - qdio queue related values for a request 58 * @sbtype: sbal type flags for sbale 0 59 * @sbal_number: number of free sbals 60 * @sbal_first: first sbal for this request 61 * @sbal_last: last sbal for this request 62 * @sbal_limit: last possible sbal for this request 63 * @sbale_curr: current sbale at creation of this request 64 * @sbal_response: sbal used in interrupt 65 * @qdio_outb_usage: usage of outbound queue 66 */ 67struct zfcp_qdio_req { 68 u32 sbtype; 69 u8 sbal_number; 70 u8 sbal_first; 71 u8 sbal_last; 72 u8 sbal_limit; 73 u8 sbale_curr; 74 u8 sbal_response; 75 u16 qdio_outb_usage; 76}; 77 78/** 79 * zfcp_qdio_sbale_req - return pointer to sbale on req_q for a request 80 * @qdio: pointer to struct zfcp_qdio 81 * @q_rec: pointer to struct zfcp_qdio_req 82 * Returns: pointer to qdio_buffer_element (sbale) structure 83 */ 84static inline struct qdio_buffer_element * 85zfcp_qdio_sbale_req(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) 86{ 87 return &qdio->req_q[q_req->sbal_last]->element[0]; 88} 89 90/** 91 * zfcp_qdio_sbale_curr - return current sbale on req_q for a request 92 * @qdio: pointer to struct zfcp_qdio 93 * @fsf_req: pointer to struct zfcp_fsf_req 94 * Returns: pointer to qdio_buffer_element (sbale) structure 95 */ 96static inline struct qdio_buffer_element * 97zfcp_qdio_sbale_curr(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) 98{ 99 return &qdio->req_q[q_req->sbal_last]->element[q_req->sbale_curr]; 100} 101 102/** 103 * zfcp_qdio_req_init - initialize qdio request 104 * @qdio: request queue where to start putting the request 105 * @q_req: the qdio request to start 106 * @req_id: The request id 107 * @sbtype: type flags to set for all sbals 108 * @data: First data block 109 * @len: Length of first data block 110 * 111 * This is the start of putting the request into the queue, the last 112 * step is passing the request to zfcp_qdio_send. The request queue 113 * lock must be held during the whole process from init to send. 114 */ 115static inline 116void zfcp_qdio_req_init(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req, 117 unsigned long req_id, u32 sbtype, void *data, u32 len) 118{ 119 struct qdio_buffer_element *sbale; 120 int count = min(atomic_read(&qdio->req_q_free), 121 ZFCP_QDIO_MAX_SBALS_PER_REQ); 122 123 q_req->sbal_first = q_req->sbal_last = qdio->req_q_idx; 124 q_req->sbal_number = 1; 125 q_req->sbtype = sbtype; 126 q_req->sbale_curr = 1; 127 q_req->sbal_limit = (q_req->sbal_first + count - 1) 128 % QDIO_MAX_BUFFERS_PER_Q; 129 130 sbale = zfcp_qdio_sbale_req(qdio, q_req); 131 sbale->addr = (void *) req_id; 132 sbale->flags = SBAL_FLAGS0_COMMAND | sbtype; 133 134 if (unlikely(!data)) 135 return; 136 sbale++; 137 sbale->addr = data; 138 sbale->length = len; 139} 140 141/** 142 * zfcp_qdio_fill_next - Fill next sbale, only for single sbal requests 143 * @qdio: pointer to struct zfcp_qdio 144 * @q_req: pointer to struct zfcp_queue_req 145 * 146 * This is only required for single sbal requests, calling it when 147 * wrapping around to the next sbal is a bug. 148 */ 149static inline 150void zfcp_qdio_fill_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req, 151 void *data, u32 len) 152{ 153 struct qdio_buffer_element *sbale; 154 155 BUG_ON(q_req->sbale_curr == ZFCP_QDIO_LAST_SBALE_PER_SBAL); 156 q_req->sbale_curr++; 157 sbale = zfcp_qdio_sbale_curr(qdio, q_req); 158 sbale->addr = data; 159 sbale->length = len; 160} 161 162/** 163 * zfcp_qdio_set_sbale_last - set last entry flag in current sbale 164 * @qdio: pointer to struct zfcp_qdio 165 * @q_req: pointer to struct zfcp_queue_req 166 */ 167static inline 168void zfcp_qdio_set_sbale_last(struct zfcp_qdio *qdio, 169 struct zfcp_qdio_req *q_req) 170{ 171 struct qdio_buffer_element *sbale; 172 173 sbale = zfcp_qdio_sbale_curr(qdio, q_req); 174 sbale->flags |= SBAL_FLAGS_LAST_ENTRY; 175} 176 177/** 178 * zfcp_qdio_sg_one_sbal - check if one sbale is enough for sg data 179 * @sg: The scatterlist where to check the data size 180 * 181 * Returns: 1 when one sbale is enough for the data in the scatterlist, 182 * 0 if not. 183 */ 184static inline 185int zfcp_qdio_sg_one_sbale(struct scatterlist *sg) 186{ 187 return sg_is_last(sg) && sg->length <= ZFCP_QDIO_SBALE_LEN; 188} 189 190/** 191 * zfcp_qdio_skip_to_last_sbale - skip to last sbale in sbal 192 * @q_req: The current zfcp_qdio_req 193 */ 194static inline 195void zfcp_qdio_skip_to_last_sbale(struct zfcp_qdio_req *q_req) 196{ 197 q_req->sbale_curr = ZFCP_QDIO_LAST_SBALE_PER_SBAL; 198} 199 200/** 201 * zfcp_qdio_sbal_limit - set the sbal limit for a request in q_req 202 * @qdio: pointer to struct zfcp_qdio 203 * @q_req: The current zfcp_qdio_req 204 * @max_sbals: maximum number of SBALs allowed 205 */ 206static inline 207void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio, 208 struct zfcp_qdio_req *q_req, int max_sbals) 209{ 210 int count = min(atomic_read(&qdio->req_q_free), max_sbals); 211 212 q_req->sbal_limit = (q_req->sbal_first + count - 1) % 213 QDIO_MAX_BUFFERS_PER_Q; 214} 215 216/** 217 * zfcp_qdio_set_data_div - set data division count 218 * @qdio: pointer to struct zfcp_qdio 219 * @q_req: The current zfcp_qdio_req 220 * @count: The data division count 221 */ 222static inline 223void zfcp_qdio_set_data_div(struct zfcp_qdio *qdio, 224 struct zfcp_qdio_req *q_req, u32 count) 225{ 226 struct qdio_buffer_element *sbale; 227 228 sbale = &qdio->req_q[q_req->sbal_first]->element[0]; 229 sbale->length = count; 230} 231 232#endif /* ZFCP_QDIO_H */ 233