Chuck Lever | a0ce85f | 2015-03-30 14:34:21 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2015 Oracle. All rights reserved. |
| 3 | * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved. |
| 4 | */ |
| 5 | |
| 6 | /* Lightweight memory registration using Fast Registration Work |
| 7 | * Requests (FRWR). Also referred to sometimes as FRMR mode. |
| 8 | * |
| 9 | * FRWR features ordered asynchronous registration and deregistration |
| 10 | * of arbitrarily sized memory regions. This is the fastest and safest |
| 11 | * but most complex memory registration mode. |
| 12 | */ |
| 13 | |
| 14 | #include "xprt_rdma.h" |
| 15 | |
| 16 | #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) |
| 17 | # define RPCDBG_FACILITY RPCDBG_TRANS |
| 18 | #endif |
| 19 | |
Chuck Lever | 91e70e7 | 2015-03-30 14:34:58 -0400 | [diff] [blame] | 20 | static int |
| 21 | __frwr_init(struct rpcrdma_mw *r, struct ib_pd *pd, struct ib_device *device, |
| 22 | unsigned int depth) |
| 23 | { |
| 24 | struct rpcrdma_frmr *f = &r->r.frmr; |
| 25 | int rc; |
| 26 | |
| 27 | f->fr_mr = ib_alloc_fast_reg_mr(pd, depth); |
| 28 | if (IS_ERR(f->fr_mr)) |
| 29 | goto out_mr_err; |
| 30 | f->fr_pgl = ib_alloc_fast_reg_page_list(device, depth); |
| 31 | if (IS_ERR(f->fr_pgl)) |
| 32 | goto out_list_err; |
| 33 | return 0; |
| 34 | |
| 35 | out_mr_err: |
| 36 | rc = PTR_ERR(f->fr_mr); |
| 37 | dprintk("RPC: %s: ib_alloc_fast_reg_mr status %i\n", |
| 38 | __func__, rc); |
| 39 | return rc; |
| 40 | |
| 41 | out_list_err: |
| 42 | rc = PTR_ERR(f->fr_pgl); |
| 43 | dprintk("RPC: %s: ib_alloc_fast_reg_page_list status %i\n", |
| 44 | __func__, rc); |
| 45 | ib_dereg_mr(f->fr_mr); |
| 46 | return rc; |
| 47 | } |
| 48 | |
Chuck Lever | 31a701a | 2015-03-30 14:35:07 -0400 | [diff] [blame] | 49 | static void |
| 50 | __frwr_release(struct rpcrdma_mw *r) |
| 51 | { |
| 52 | int rc; |
| 53 | |
| 54 | rc = ib_dereg_mr(r->r.frmr.fr_mr); |
| 55 | if (rc) |
| 56 | dprintk("RPC: %s: ib_dereg_mr status %i\n", |
| 57 | __func__, rc); |
| 58 | ib_free_fast_reg_page_list(r->r.frmr.fr_pgl); |
| 59 | } |
| 60 | |
Chuck Lever | 3968cb5 | 2015-03-30 14:35:26 -0400 | [diff] [blame] | 61 | static int |
| 62 | frwr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep, |
| 63 | struct rpcrdma_create_data_internal *cdata) |
| 64 | { |
| 65 | struct ib_device_attr *devattr = &ia->ri_devattr; |
| 66 | int depth, delta; |
| 67 | |
| 68 | ia->ri_max_frmr_depth = |
| 69 | min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS, |
| 70 | devattr->max_fast_reg_page_list_len); |
| 71 | dprintk("RPC: %s: device's max FR page list len = %u\n", |
| 72 | __func__, ia->ri_max_frmr_depth); |
| 73 | |
| 74 | /* Add room for frmr register and invalidate WRs. |
| 75 | * 1. FRMR reg WR for head |
| 76 | * 2. FRMR invalidate WR for head |
| 77 | * 3. N FRMR reg WRs for pagelist |
| 78 | * 4. N FRMR invalidate WRs for pagelist |
| 79 | * 5. FRMR reg WR for tail |
| 80 | * 6. FRMR invalidate WR for tail |
| 81 | * 7. The RDMA_SEND WR |
| 82 | */ |
| 83 | depth = 7; |
| 84 | |
| 85 | /* Calculate N if the device max FRMR depth is smaller than |
| 86 | * RPCRDMA_MAX_DATA_SEGS. |
| 87 | */ |
| 88 | if (ia->ri_max_frmr_depth < RPCRDMA_MAX_DATA_SEGS) { |
| 89 | delta = RPCRDMA_MAX_DATA_SEGS - ia->ri_max_frmr_depth; |
| 90 | do { |
| 91 | depth += 2; /* FRMR reg + invalidate */ |
| 92 | delta -= ia->ri_max_frmr_depth; |
| 93 | } while (delta > 0); |
| 94 | } |
| 95 | |
| 96 | ep->rep_attr.cap.max_send_wr *= depth; |
| 97 | if (ep->rep_attr.cap.max_send_wr > devattr->max_qp_wr) { |
| 98 | cdata->max_requests = devattr->max_qp_wr / depth; |
| 99 | if (!cdata->max_requests) |
| 100 | return -EINVAL; |
| 101 | ep->rep_attr.cap.max_send_wr = cdata->max_requests * |
| 102 | depth; |
| 103 | } |
| 104 | |
| 105 | return 0; |
| 106 | } |
| 107 | |
Chuck Lever | 1c9351e | 2015-03-30 14:34:30 -0400 | [diff] [blame] | 108 | /* FRWR mode conveys a list of pages per chunk segment. The |
| 109 | * maximum length of that list is the FRWR page list depth. |
| 110 | */ |
| 111 | static size_t |
| 112 | frwr_op_maxpages(struct rpcrdma_xprt *r_xprt) |
| 113 | { |
| 114 | struct rpcrdma_ia *ia = &r_xprt->rx_ia; |
| 115 | |
| 116 | return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS, |
| 117 | rpcrdma_max_segments(r_xprt) * ia->ri_max_frmr_depth); |
| 118 | } |
| 119 | |
Chuck Lever | e46ac34 | 2015-03-30 14:35:35 -0400 | [diff] [blame] | 120 | /* If FAST_REG or LOCAL_INV failed, indicate the frmr needs to be reset. */ |
| 121 | static void |
| 122 | frwr_sendcompletion(struct ib_wc *wc) |
| 123 | { |
| 124 | struct rpcrdma_mw *r; |
| 125 | |
| 126 | if (likely(wc->status == IB_WC_SUCCESS)) |
| 127 | return; |
| 128 | |
| 129 | /* WARNING: Only wr_id and status are reliable at this point */ |
| 130 | r = (struct rpcrdma_mw *)(unsigned long)wc->wr_id; |
Sagi Grimberg | 76357c7 | 2015-05-18 13:40:32 +0300 | [diff] [blame] | 131 | dprintk("RPC: %s: frmr %p (stale), status %s (%d)\n", |
| 132 | __func__, r, ib_wc_status_msg(wc->status), wc->status); |
Chuck Lever | e46ac34 | 2015-03-30 14:35:35 -0400 | [diff] [blame] | 133 | r->r.frmr.fr_state = FRMR_IS_STALE; |
| 134 | } |
| 135 | |
Chuck Lever | 91e70e7 | 2015-03-30 14:34:58 -0400 | [diff] [blame] | 136 | static int |
| 137 | frwr_op_init(struct rpcrdma_xprt *r_xprt) |
| 138 | { |
| 139 | struct rpcrdma_buffer *buf = &r_xprt->rx_buf; |
| 140 | struct ib_device *device = r_xprt->rx_ia.ri_id->device; |
| 141 | unsigned int depth = r_xprt->rx_ia.ri_max_frmr_depth; |
| 142 | struct ib_pd *pd = r_xprt->rx_ia.ri_pd; |
| 143 | int i; |
| 144 | |
| 145 | INIT_LIST_HEAD(&buf->rb_mws); |
| 146 | INIT_LIST_HEAD(&buf->rb_all); |
| 147 | |
| 148 | i = (buf->rb_max_requests + 1) * RPCRDMA_MAX_SEGS; |
Linus Torvalds | 59953fb | 2015-04-26 17:33:59 -0700 | [diff] [blame] | 149 | dprintk("RPC: %s: initializing %d FRMRs\n", __func__, i); |
Chuck Lever | 91e70e7 | 2015-03-30 14:34:58 -0400 | [diff] [blame] | 150 | |
| 151 | while (i--) { |
| 152 | struct rpcrdma_mw *r; |
| 153 | int rc; |
| 154 | |
| 155 | r = kzalloc(sizeof(*r), GFP_KERNEL); |
| 156 | if (!r) |
| 157 | return -ENOMEM; |
| 158 | |
| 159 | rc = __frwr_init(r, pd, device, depth); |
| 160 | if (rc) { |
| 161 | kfree(r); |
| 162 | return rc; |
| 163 | } |
| 164 | |
| 165 | list_add(&r->mw_list, &buf->rb_mws); |
| 166 | list_add(&r->mw_all, &buf->rb_all); |
Chuck Lever | e46ac34 | 2015-03-30 14:35:35 -0400 | [diff] [blame] | 167 | r->mw_sendcompletion = frwr_sendcompletion; |
Chuck Lever | 91e70e7 | 2015-03-30 14:34:58 -0400 | [diff] [blame] | 168 | } |
| 169 | |
| 170 | return 0; |
| 171 | } |
| 172 | |
Chuck Lever | 9c1b4d7 | 2015-03-30 14:34:39 -0400 | [diff] [blame] | 173 | /* Post a FAST_REG Work Request to register a memory region |
| 174 | * for remote access via RDMA READ or RDMA WRITE. |
| 175 | */ |
| 176 | static int |
| 177 | frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg, |
| 178 | int nsegs, bool writing) |
| 179 | { |
| 180 | struct rpcrdma_ia *ia = &r_xprt->rx_ia; |
Chuck Lever | d654788 | 2015-03-30 14:35:44 -0400 | [diff] [blame] | 181 | struct ib_device *device = ia->ri_id->device; |
| 182 | enum dma_data_direction direction = rpcrdma_data_dir(writing); |
Chuck Lever | 9c1b4d7 | 2015-03-30 14:34:39 -0400 | [diff] [blame] | 183 | struct rpcrdma_mr_seg *seg1 = seg; |
| 184 | struct rpcrdma_mw *mw = seg1->rl_mw; |
| 185 | struct rpcrdma_frmr *frmr = &mw->r.frmr; |
| 186 | struct ib_mr *mr = frmr->fr_mr; |
| 187 | struct ib_send_wr fastreg_wr, *bad_wr; |
| 188 | u8 key; |
| 189 | int len, pageoff; |
| 190 | int i, rc; |
| 191 | int seg_len; |
| 192 | u64 pa; |
| 193 | int page_no; |
| 194 | |
| 195 | pageoff = offset_in_page(seg1->mr_offset); |
| 196 | seg1->mr_offset -= pageoff; /* start of page */ |
| 197 | seg1->mr_len += pageoff; |
| 198 | len = -pageoff; |
| 199 | if (nsegs > ia->ri_max_frmr_depth) |
| 200 | nsegs = ia->ri_max_frmr_depth; |
| 201 | for (page_no = i = 0; i < nsegs;) { |
Chuck Lever | d654788 | 2015-03-30 14:35:44 -0400 | [diff] [blame] | 202 | rpcrdma_map_one(device, seg, direction); |
Chuck Lever | 9c1b4d7 | 2015-03-30 14:34:39 -0400 | [diff] [blame] | 203 | pa = seg->mr_dma; |
| 204 | for (seg_len = seg->mr_len; seg_len > 0; seg_len -= PAGE_SIZE) { |
| 205 | frmr->fr_pgl->page_list[page_no++] = pa; |
| 206 | pa += PAGE_SIZE; |
| 207 | } |
| 208 | len += seg->mr_len; |
| 209 | ++seg; |
| 210 | ++i; |
| 211 | /* Check for holes */ |
| 212 | if ((i < nsegs && offset_in_page(seg->mr_offset)) || |
| 213 | offset_in_page((seg-1)->mr_offset + (seg-1)->mr_len)) |
| 214 | break; |
| 215 | } |
| 216 | dprintk("RPC: %s: Using frmr %p to map %d segments (%d bytes)\n", |
| 217 | __func__, mw, i, len); |
| 218 | |
| 219 | frmr->fr_state = FRMR_IS_VALID; |
| 220 | |
| 221 | memset(&fastreg_wr, 0, sizeof(fastreg_wr)); |
| 222 | fastreg_wr.wr_id = (unsigned long)(void *)mw; |
| 223 | fastreg_wr.opcode = IB_WR_FAST_REG_MR; |
| 224 | fastreg_wr.wr.fast_reg.iova_start = seg1->mr_dma + pageoff; |
| 225 | fastreg_wr.wr.fast_reg.page_list = frmr->fr_pgl; |
| 226 | fastreg_wr.wr.fast_reg.page_shift = PAGE_SHIFT; |
| 227 | fastreg_wr.wr.fast_reg.page_list_len = page_no; |
| 228 | fastreg_wr.wr.fast_reg.length = len; |
| 229 | fastreg_wr.wr.fast_reg.access_flags = writing ? |
| 230 | IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE : |
| 231 | IB_ACCESS_REMOTE_READ; |
| 232 | key = (u8)(mr->rkey & 0x000000FF); |
| 233 | ib_update_fast_reg_key(mr, ++key); |
| 234 | fastreg_wr.wr.fast_reg.rkey = mr->rkey; |
| 235 | |
| 236 | DECR_CQCOUNT(&r_xprt->rx_ep); |
| 237 | rc = ib_post_send(ia->ri_id->qp, &fastreg_wr, &bad_wr); |
| 238 | if (rc) |
| 239 | goto out_senderr; |
| 240 | |
| 241 | seg1->mr_rkey = mr->rkey; |
| 242 | seg1->mr_base = seg1->mr_dma + pageoff; |
| 243 | seg1->mr_nsegs = i; |
| 244 | seg1->mr_len = len; |
| 245 | return i; |
| 246 | |
| 247 | out_senderr: |
| 248 | dprintk("RPC: %s: ib_post_send status %i\n", __func__, rc); |
| 249 | ib_update_fast_reg_key(mr, --key); |
| 250 | frmr->fr_state = FRMR_IS_INVALID; |
| 251 | while (i--) |
Chuck Lever | d654788 | 2015-03-30 14:35:44 -0400 | [diff] [blame] | 252 | rpcrdma_unmap_one(device, --seg); |
Chuck Lever | 9c1b4d7 | 2015-03-30 14:34:39 -0400 | [diff] [blame] | 253 | return rc; |
| 254 | } |
| 255 | |
Chuck Lever | 6814bae | 2015-03-30 14:34:48 -0400 | [diff] [blame] | 256 | /* Post a LOCAL_INV Work Request to prevent further remote access |
| 257 | * via RDMA READ or RDMA WRITE. |
| 258 | */ |
| 259 | static int |
| 260 | frwr_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg) |
| 261 | { |
| 262 | struct rpcrdma_mr_seg *seg1 = seg; |
| 263 | struct rpcrdma_ia *ia = &r_xprt->rx_ia; |
| 264 | struct ib_send_wr invalidate_wr, *bad_wr; |
| 265 | int rc, nsegs = seg->mr_nsegs; |
Chuck Lever | d654788 | 2015-03-30 14:35:44 -0400 | [diff] [blame] | 266 | struct ib_device *device; |
Chuck Lever | 6814bae | 2015-03-30 14:34:48 -0400 | [diff] [blame] | 267 | |
| 268 | seg1->rl_mw->r.frmr.fr_state = FRMR_IS_INVALID; |
| 269 | |
| 270 | memset(&invalidate_wr, 0, sizeof(invalidate_wr)); |
| 271 | invalidate_wr.wr_id = (unsigned long)(void *)seg1->rl_mw; |
| 272 | invalidate_wr.opcode = IB_WR_LOCAL_INV; |
| 273 | invalidate_wr.ex.invalidate_rkey = seg1->rl_mw->r.frmr.fr_mr->rkey; |
| 274 | DECR_CQCOUNT(&r_xprt->rx_ep); |
| 275 | |
| 276 | read_lock(&ia->ri_qplock); |
Chuck Lever | d654788 | 2015-03-30 14:35:44 -0400 | [diff] [blame] | 277 | device = ia->ri_id->device; |
Chuck Lever | 6814bae | 2015-03-30 14:34:48 -0400 | [diff] [blame] | 278 | while (seg1->mr_nsegs--) |
Chuck Lever | d654788 | 2015-03-30 14:35:44 -0400 | [diff] [blame] | 279 | rpcrdma_unmap_one(device, seg++); |
Chuck Lever | 6814bae | 2015-03-30 14:34:48 -0400 | [diff] [blame] | 280 | rc = ib_post_send(ia->ri_id->qp, &invalidate_wr, &bad_wr); |
| 281 | read_unlock(&ia->ri_qplock); |
| 282 | if (rc) |
| 283 | goto out_err; |
| 284 | return nsegs; |
| 285 | |
| 286 | out_err: |
| 287 | /* Force rpcrdma_buffer_get() to retry */ |
| 288 | seg1->rl_mw->r.frmr.fr_state = FRMR_IS_STALE; |
| 289 | dprintk("RPC: %s: ib_post_send status %i\n", __func__, rc); |
| 290 | return nsegs; |
| 291 | } |
| 292 | |
Chuck Lever | 31a701a | 2015-03-30 14:35:07 -0400 | [diff] [blame] | 293 | /* After a disconnect, a flushed FAST_REG_MR can leave an FRMR in |
| 294 | * an unusable state. Find FRMRs in this state and dereg / reg |
| 295 | * each. FRMRs that are VALID and attached to an rpcrdma_req are |
| 296 | * also torn down. |
| 297 | * |
| 298 | * This gives all in-use FRMRs a fresh rkey and leaves them INVALID. |
| 299 | * |
| 300 | * This is invoked only in the transport connect worker in order |
| 301 | * to serialize with rpcrdma_register_frmr_external(). |
| 302 | */ |
| 303 | static void |
| 304 | frwr_op_reset(struct rpcrdma_xprt *r_xprt) |
| 305 | { |
| 306 | struct rpcrdma_buffer *buf = &r_xprt->rx_buf; |
| 307 | struct ib_device *device = r_xprt->rx_ia.ri_id->device; |
| 308 | unsigned int depth = r_xprt->rx_ia.ri_max_frmr_depth; |
| 309 | struct ib_pd *pd = r_xprt->rx_ia.ri_pd; |
| 310 | struct rpcrdma_mw *r; |
| 311 | int rc; |
| 312 | |
| 313 | list_for_each_entry(r, &buf->rb_all, mw_all) { |
| 314 | if (r->r.frmr.fr_state == FRMR_IS_INVALID) |
| 315 | continue; |
| 316 | |
| 317 | __frwr_release(r); |
| 318 | rc = __frwr_init(r, pd, device, depth); |
| 319 | if (rc) { |
| 320 | dprintk("RPC: %s: mw %p left %s\n", |
| 321 | __func__, r, |
| 322 | (r->r.frmr.fr_state == FRMR_IS_STALE ? |
| 323 | "stale" : "valid")); |
| 324 | continue; |
| 325 | } |
| 326 | |
| 327 | r->r.frmr.fr_state = FRMR_IS_INVALID; |
| 328 | } |
| 329 | } |
| 330 | |
Chuck Lever | 4561f34 | 2015-03-30 14:35:17 -0400 | [diff] [blame] | 331 | static void |
| 332 | frwr_op_destroy(struct rpcrdma_buffer *buf) |
| 333 | { |
| 334 | struct rpcrdma_mw *r; |
| 335 | |
| 336 | while (!list_empty(&buf->rb_all)) { |
| 337 | r = list_entry(buf->rb_all.next, struct rpcrdma_mw, mw_all); |
| 338 | list_del(&r->mw_all); |
| 339 | __frwr_release(r); |
| 340 | kfree(r); |
| 341 | } |
| 342 | } |
| 343 | |
Chuck Lever | a0ce85f | 2015-03-30 14:34:21 -0400 | [diff] [blame] | 344 | const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops = { |
Chuck Lever | 9c1b4d7 | 2015-03-30 14:34:39 -0400 | [diff] [blame] | 345 | .ro_map = frwr_op_map, |
Chuck Lever | 6814bae | 2015-03-30 14:34:48 -0400 | [diff] [blame] | 346 | .ro_unmap = frwr_op_unmap, |
Chuck Lever | 3968cb5 | 2015-03-30 14:35:26 -0400 | [diff] [blame] | 347 | .ro_open = frwr_op_open, |
Chuck Lever | 1c9351e | 2015-03-30 14:34:30 -0400 | [diff] [blame] | 348 | .ro_maxpages = frwr_op_maxpages, |
Chuck Lever | 91e70e7 | 2015-03-30 14:34:58 -0400 | [diff] [blame] | 349 | .ro_init = frwr_op_init, |
Chuck Lever | 31a701a | 2015-03-30 14:35:07 -0400 | [diff] [blame] | 350 | .ro_reset = frwr_op_reset, |
Chuck Lever | 4561f34 | 2015-03-30 14:35:17 -0400 | [diff] [blame] | 351 | .ro_destroy = frwr_op_destroy, |
Chuck Lever | a0ce85f | 2015-03-30 14:34:21 -0400 | [diff] [blame] | 352 | .ro_displayname = "frwr", |
| 353 | }; |