--- /dev/null
+/*
+ * Copyright (c) 2015 Oracle. All rights reserved.
+ * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
+ */
+
+/* Lightweight memory registration using Fast Registration Work
+ * Requests (FRWR). Also referred to sometimes as FRMR mode.
+ *
+ * FRWR features ordered asynchronous registration and deregistration
+ * of arbitrarily sized memory regions. This is the fastest and safest
+ * but most complex memory registration mode.
+ */
+
+#include "xprt_rdma.h"
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY RPCDBG_TRANS
+#endif
+
+static int
+__frwr_init(struct rpcrdma_mw *r, struct ib_pd *pd, struct ib_device *device,
+ unsigned int depth)
+{
+ struct rpcrdma_frmr *f = &r->r.frmr;
+ int rc;
+
+ f->fr_mr = ib_alloc_fast_reg_mr(pd, depth);
+ if (IS_ERR(f->fr_mr))
+ goto out_mr_err;
+ f->fr_pgl = ib_alloc_fast_reg_page_list(device, depth);
+ if (IS_ERR(f->fr_pgl))
+ goto out_list_err;
+ return 0;
+
+out_mr_err:
+ rc = PTR_ERR(f->fr_mr);
+ dprintk("RPC: %s: ib_alloc_fast_reg_mr status %i\n",
+ __func__, rc);
+ return rc;
+
+out_list_err:
+ rc = PTR_ERR(f->fr_pgl);
+ dprintk("RPC: %s: ib_alloc_fast_reg_page_list status %i\n",
+ __func__, rc);
+ ib_dereg_mr(f->fr_mr);
+ return rc;
+}
+
+static void
+__frwr_release(struct rpcrdma_mw *r)
+{
+ int rc;
+
+ rc = ib_dereg_mr(r->r.frmr.fr_mr);
+ if (rc)
+ dprintk("RPC: %s: ib_dereg_mr status %i\n",
+ __func__, rc);
+ ib_free_fast_reg_page_list(r->r.frmr.fr_pgl);
+}
+
+static int
+frwr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
+ struct rpcrdma_create_data_internal *cdata)
+{
+ struct ib_device_attr *devattr = &ia->ri_devattr;
+ int depth, delta;
+
+ ia->ri_max_frmr_depth =
+ min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
+ devattr->max_fast_reg_page_list_len);
+ dprintk("RPC: %s: device's max FR page list len = %u\n",
+ __func__, ia->ri_max_frmr_depth);
+
+ /* Add room for frmr register and invalidate WRs.
+ * 1. FRMR reg WR for head
+ * 2. FRMR invalidate WR for head
+ * 3. N FRMR reg WRs for pagelist
+ * 4. N FRMR invalidate WRs for pagelist
+ * 5. FRMR reg WR for tail
+ * 6. FRMR invalidate WR for tail
+ * 7. The RDMA_SEND WR
+ */
+ depth = 7;
+
+ /* Calculate N if the device max FRMR depth is smaller than
+ * RPCRDMA_MAX_DATA_SEGS.
+ */
+ if (ia->ri_max_frmr_depth < RPCRDMA_MAX_DATA_SEGS) {
+ delta = RPCRDMA_MAX_DATA_SEGS - ia->ri_max_frmr_depth;
+ do {
+ depth += 2; /* FRMR reg + invalidate */
+ delta -= ia->ri_max_frmr_depth;
+ } while (delta > 0);
+ }
+
+ ep->rep_attr.cap.max_send_wr *= depth;
+ if (ep->rep_attr.cap.max_send_wr > devattr->max_qp_wr) {
+ cdata->max_requests = devattr->max_qp_wr / depth;
+ if (!cdata->max_requests)
+ return -EINVAL;
+ ep->rep_attr.cap.max_send_wr = cdata->max_requests *
+ depth;
+ }
+
+ return 0;
+}
+
+/* FRWR mode conveys a list of pages per chunk segment. The
+ * maximum length of that list is the FRWR page list depth.
+ */
+static size_t
+frwr_op_maxpages(struct rpcrdma_xprt *r_xprt)
+{
+ struct rpcrdma_ia *ia = &r_xprt->rx_ia;
+
+ return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
+ rpcrdma_max_segments(r_xprt) * ia->ri_max_frmr_depth);
+}
+
+/* If FAST_REG or LOCAL_INV failed, indicate the frmr needs to be reset. */
+static void
+frwr_sendcompletion(struct ib_wc *wc)
+{
+ struct rpcrdma_mw *r;
+
+ if (likely(wc->status == IB_WC_SUCCESS))
+ return;
+
+ /* WARNING: Only wr_id and status are reliable at this point */
+ r = (struct rpcrdma_mw *)(unsigned long)wc->wr_id;
+ dprintk("RPC: %s: frmr %p (stale), status %d\n",
+ __func__, r, wc->status);
+ r->r.frmr.fr_state = FRMR_IS_STALE;
+}
+
+static int
+frwr_op_init(struct rpcrdma_xprt *r_xprt)
+{
+ struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+ struct ib_device *device = r_xprt->rx_ia.ri_id->device;
+ unsigned int depth = r_xprt->rx_ia.ri_max_frmr_depth;
+ struct ib_pd *pd = r_xprt->rx_ia.ri_pd;
+ int i;
+
+ INIT_LIST_HEAD(&buf->rb_mws);
+ INIT_LIST_HEAD(&buf->rb_all);
+
+ i = (buf->rb_max_requests + 1) * RPCRDMA_MAX_SEGS;
+ dprintk("RPC: %s: initializing %d FRMRs\n", __func__, i);
+
+ while (i--) {
+ struct rpcrdma_mw *r;
+ int rc;
+
+ r = kzalloc(sizeof(*r), GFP_KERNEL);
+ if (!r)
+ return -ENOMEM;
+
+ rc = __frwr_init(r, pd, device, depth);
+ if (rc) {
+ kfree(r);
+ return rc;
+ }
+
+ list_add(&r->mw_list, &buf->rb_mws);
+ list_add(&r->mw_all, &buf->rb_all);
+ r->mw_sendcompletion = frwr_sendcompletion;
+ }
+
+ return 0;
+}
+
+/* Post a FAST_REG Work Request to register a memory region
+ * for remote access via RDMA READ or RDMA WRITE.
+ */
+static int
+frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
+ int nsegs, bool writing)
+{
+ struct rpcrdma_ia *ia = &r_xprt->rx_ia;
+ struct ib_device *device = ia->ri_id->device;
+ enum dma_data_direction direction = rpcrdma_data_dir(writing);
+ struct rpcrdma_mr_seg *seg1 = seg;
+ struct rpcrdma_mw *mw = seg1->rl_mw;
+ struct rpcrdma_frmr *frmr = &mw->r.frmr;
+ struct ib_mr *mr = frmr->fr_mr;
+ struct ib_send_wr fastreg_wr, *bad_wr;
+ u8 key;
+ int len, pageoff;
+ int i, rc;
+ int seg_len;
+ u64 pa;
+ int page_no;
+
+ pageoff = offset_in_page(seg1->mr_offset);
+ seg1->mr_offset -= pageoff; /* start of page */
+ seg1->mr_len += pageoff;
+ len = -pageoff;
+ if (nsegs > ia->ri_max_frmr_depth)
+ nsegs = ia->ri_max_frmr_depth;
+ for (page_no = i = 0; i < nsegs;) {
+ rpcrdma_map_one(device, seg, direction);
+ pa = seg->mr_dma;
+ for (seg_len = seg->mr_len; seg_len > 0; seg_len -= PAGE_SIZE) {
+ frmr->fr_pgl->page_list[page_no++] = pa;
+ pa += PAGE_SIZE;
+ }
+ len += seg->mr_len;
+ ++seg;
+ ++i;
+ /* Check for holes */
+ if ((i < nsegs && offset_in_page(seg->mr_offset)) ||
+ offset_in_page((seg-1)->mr_offset + (seg-1)->mr_len))
+ break;
+ }
+ dprintk("RPC: %s: Using frmr %p to map %d segments (%d bytes)\n",
+ __func__, mw, i, len);
+
+ frmr->fr_state = FRMR_IS_VALID;
+
+ memset(&fastreg_wr, 0, sizeof(fastreg_wr));
+ fastreg_wr.wr_id = (unsigned long)(void *)mw;
+ fastreg_wr.opcode = IB_WR_FAST_REG_MR;
+ fastreg_wr.wr.fast_reg.iova_start = seg1->mr_dma + pageoff;
+ fastreg_wr.wr.fast_reg.page_list = frmr->fr_pgl;
+ fastreg_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
+ fastreg_wr.wr.fast_reg.page_list_len = page_no;
+ fastreg_wr.wr.fast_reg.length = len;
+ fastreg_wr.wr.fast_reg.access_flags = writing ?
+ IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
+ IB_ACCESS_REMOTE_READ;
+ key = (u8)(mr->rkey & 0x000000FF);
+ ib_update_fast_reg_key(mr, ++key);
+ fastreg_wr.wr.fast_reg.rkey = mr->rkey;
+
+ DECR_CQCOUNT(&r_xprt->rx_ep);
+ rc = ib_post_send(ia->ri_id->qp, &fastreg_wr, &bad_wr);
+ if (rc)
+ goto out_senderr;
+
+ seg1->mr_rkey = mr->rkey;
+ seg1->mr_base = seg1->mr_dma + pageoff;
+ seg1->mr_nsegs = i;
+ seg1->mr_len = len;
+ return i;
+
+out_senderr:
+ dprintk("RPC: %s: ib_post_send status %i\n", __func__, rc);
+ ib_update_fast_reg_key(mr, --key);
+ frmr->fr_state = FRMR_IS_INVALID;
+ while (i--)
+ rpcrdma_unmap_one(device, --seg);
+ return rc;
+}
+
+/* Post a LOCAL_INV Work Request to prevent further remote access
+ * via RDMA READ or RDMA WRITE.
+ */
+static int
+frwr_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
+{
+ struct rpcrdma_mr_seg *seg1 = seg;
+ struct rpcrdma_ia *ia = &r_xprt->rx_ia;
+ struct ib_send_wr invalidate_wr, *bad_wr;
+ int rc, nsegs = seg->mr_nsegs;
+ struct ib_device *device;
+
+ seg1->rl_mw->r.frmr.fr_state = FRMR_IS_INVALID;
+
+ memset(&invalidate_wr, 0, sizeof(invalidate_wr));
+ invalidate_wr.wr_id = (unsigned long)(void *)seg1->rl_mw;
+ invalidate_wr.opcode = IB_WR_LOCAL_INV;
+ invalidate_wr.ex.invalidate_rkey = seg1->rl_mw->r.frmr.fr_mr->rkey;
+ DECR_CQCOUNT(&r_xprt->rx_ep);
+
+ read_lock(&ia->ri_qplock);
+ device = ia->ri_id->device;
+ while (seg1->mr_nsegs--)
+ rpcrdma_unmap_one(device, seg++);
+ rc = ib_post_send(ia->ri_id->qp, &invalidate_wr, &bad_wr);
+ read_unlock(&ia->ri_qplock);
+ if (rc)
+ goto out_err;
+ return nsegs;
+
+out_err:
+ /* Force rpcrdma_buffer_get() to retry */
+ seg1->rl_mw->r.frmr.fr_state = FRMR_IS_STALE;
+ dprintk("RPC: %s: ib_post_send status %i\n", __func__, rc);
+ return nsegs;
+}
+
+/* After a disconnect, a flushed FAST_REG_MR can leave an FRMR in
+ * an unusable state. Find FRMRs in this state and dereg / reg
+ * each. FRMRs that are VALID and attached to an rpcrdma_req are
+ * also torn down.
+ *
+ * This gives all in-use FRMRs a fresh rkey and leaves them INVALID.
+ *
+ * This is invoked only in the transport connect worker in order
+ * to serialize with rpcrdma_register_frmr_external().
+ */
+static void
+frwr_op_reset(struct rpcrdma_xprt *r_xprt)
+{
+ struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+ struct ib_device *device = r_xprt->rx_ia.ri_id->device;
+ unsigned int depth = r_xprt->rx_ia.ri_max_frmr_depth;
+ struct ib_pd *pd = r_xprt->rx_ia.ri_pd;
+ struct rpcrdma_mw *r;
+ int rc;
+
+ list_for_each_entry(r, &buf->rb_all, mw_all) {
+ if (r->r.frmr.fr_state == FRMR_IS_INVALID)
+ continue;
+
+ __frwr_release(r);
+ rc = __frwr_init(r, pd, device, depth);
+ if (rc) {
+ dprintk("RPC: %s: mw %p left %s\n",
+ __func__, r,
+ (r->r.frmr.fr_state == FRMR_IS_STALE ?
+ "stale" : "valid"));
+ continue;
+ }
+
+ r->r.frmr.fr_state = FRMR_IS_INVALID;
+ }
+}
+
+static void
+frwr_op_destroy(struct rpcrdma_buffer *buf)
+{
+ struct rpcrdma_mw *r;
+
+ while (!list_empty(&buf->rb_all)) {
+ r = list_entry(buf->rb_all.next, struct rpcrdma_mw, mw_all);
+ list_del(&r->mw_all);
+ __frwr_release(r);
+ kfree(r);
+ }
+}
+
+const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops = {
+ .ro_map = frwr_op_map,
+ .ro_unmap = frwr_op_unmap,
+ .ro_open = frwr_op_open,
+ .ro_maxpages = frwr_op_maxpages,
+ .ro_init = frwr_op_init,
+ .ro_reset = frwr_op_reset,
+ .ro_destroy = frwr_op_destroy,
+ .ro_displayname = "frwr",
+};
Code Review / kvmfornfv.git / blobdiff