+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (c) 2015, 2017 Oracle. All rights reserved.
- * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
- */
-
-/* Lightweight memory registration using Fast Memory Regions (FMR).
- * Referred to sometimes as MTHCAFMR mode.
- *
- * FMR uses synchronous memory registration and deregistration.
- * FMR registration is known to be fast, but FMR deregistration
- * can take tens of usecs to complete.
- */
-
-/* Normal operation
- *
- * A Memory Region is prepared for RDMA READ or WRITE using the
- * ib_map_phys_fmr verb (fmr_op_map). When the RDMA operation is
- * finished, the Memory Region is unmapped using the ib_unmap_fmr
- * verb (fmr_op_unmap).
- */
-
-#include <linux/sunrpc/svc_rdma.h>
-
-#include "xprt_rdma.h"
-#include <trace/events/rpcrdma.h>
-
-#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
-# define RPCDBG_FACILITY RPCDBG_TRANS
-#endif
-
-/* Maximum scatter/gather per FMR */
-#define RPCRDMA_MAX_FMR_SGES (64)
-
-/* Access mode of externally registered pages */
-enum {
- RPCRDMA_FMR_ACCESS_FLAGS = IB_ACCESS_REMOTE_WRITE |
- IB_ACCESS_REMOTE_READ,
-};
-
-bool
-fmr_is_supported(struct rpcrdma_ia *ia)
-{
- if (!ia->ri_device->alloc_fmr) {
- pr_info("rpcrdma: 'fmr' mode is not supported by device %s\n",
- ia->ri_device->name);
- return false;
- }
- return true;
-}
-
-static void
-__fmr_unmap(struct rpcrdma_mr *mr)
-{
- LIST_HEAD(l);
- int rc;
-
- list_add(&mr->fmr.fm_mr->list, &l);
- rc = ib_unmap_fmr(&l);
- list_del(&mr->fmr.fm_mr->list);
- if (rc)
- pr_err("rpcrdma: final ib_unmap_fmr for %p failed %i\n",
- mr, rc);
-}
-
-/* Release an MR.
- */
-static void
-fmr_op_release_mr(struct rpcrdma_mr *mr)
-{
- int rc;
-
- kfree(mr->fmr.fm_physaddrs);
- kfree(mr->mr_sg);
-
- /* In case this one was left mapped, try to unmap it
- * to prevent dealloc_fmr from failing with EBUSY
- */
- __fmr_unmap(mr);
-
- rc = ib_dealloc_fmr(mr->fmr.fm_mr);
- if (rc)
- pr_err("rpcrdma: final ib_dealloc_fmr for %p returned %i\n",
- mr, rc);
-
- kfree(mr);
-}
-
-/* MRs are dynamically allocated, so simply clean up and release the MR.
- * A replacement MR will subsequently be allocated on demand.
- */
-static void
-fmr_mr_recycle_worker(struct work_struct *work)
-{
- struct rpcrdma_mr *mr = container_of(work, struct rpcrdma_mr, mr_recycle);
- struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
-
- trace_xprtrdma_mr_recycle(mr);
-
- trace_xprtrdma_mr_unmap(mr);
- ib_dma_unmap_sg(r_xprt->rx_ia.ri_device,
- mr->mr_sg, mr->mr_nents, mr->mr_dir);
-
- spin_lock(&r_xprt->rx_buf.rb_mrlock);
- list_del(&mr->mr_all);
- r_xprt->rx_stats.mrs_recycled++;
- spin_unlock(&r_xprt->rx_buf.rb_mrlock);
- fmr_op_release_mr(mr);
-}
-
-static int
-fmr_op_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mr *mr)
-{
- static struct ib_fmr_attr fmr_attr = {
- .max_pages = RPCRDMA_MAX_FMR_SGES,
- .max_maps = 1,
- .page_shift = PAGE_SHIFT
- };
-
- mr->fmr.fm_physaddrs = kcalloc(RPCRDMA_MAX_FMR_SGES,
- sizeof(u64), GFP_KERNEL);
- if (!mr->fmr.fm_physaddrs)
- goto out_free;
-
- mr->mr_sg = kcalloc(RPCRDMA_MAX_FMR_SGES,
- sizeof(*mr->mr_sg), GFP_KERNEL);
- if (!mr->mr_sg)
- goto out_free;
-
- sg_init_table(mr->mr_sg, RPCRDMA_MAX_FMR_SGES);
-
- mr->fmr.fm_mr = ib_alloc_fmr(ia->ri_pd, RPCRDMA_FMR_ACCESS_FLAGS,
- &fmr_attr);
- if (IS_ERR(mr->fmr.fm_mr))
- goto out_fmr_err;
-
- INIT_LIST_HEAD(&mr->mr_list);
- INIT_WORK(&mr->mr_recycle, fmr_mr_recycle_worker);
- return 0;
-
-out_fmr_err:
- dprintk("RPC: %s: ib_alloc_fmr returned %ld\n", __func__,
- PTR_ERR(mr->fmr.fm_mr));
-
-out_free:
- kfree(mr->mr_sg);
- kfree(mr->fmr.fm_physaddrs);
- return -ENOMEM;
-}
-
-/* On success, sets:
- * ep->rep_attr.cap.max_send_wr
- * ep->rep_attr.cap.max_recv_wr
- * cdata->max_requests
- * ia->ri_max_segs
- */
-static int
-fmr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
- struct rpcrdma_create_data_internal *cdata)
-{
- int max_qp_wr;
-
- max_qp_wr = ia->ri_device->attrs.max_qp_wr;
- max_qp_wr -= RPCRDMA_BACKWARD_WRS;
- max_qp_wr -= 1;
- if (max_qp_wr < RPCRDMA_MIN_SLOT_TABLE)
- return -ENOMEM;
- if (cdata->max_requests > max_qp_wr)
- cdata->max_requests = max_qp_wr;
- ep->rep_attr.cap.max_send_wr = cdata->max_requests;
- ep->rep_attr.cap.max_send_wr += RPCRDMA_BACKWARD_WRS;
- ep->rep_attr.cap.max_send_wr += 1; /* for ib_drain_sq */
- ep->rep_attr.cap.max_recv_wr = cdata->max_requests;
- ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS;
- ep->rep_attr.cap.max_recv_wr += 1; /* for ib_drain_rq */
-
- ia->ri_max_segs = max_t(unsigned int, 1, RPCRDMA_MAX_DATA_SEGS /
- RPCRDMA_MAX_FMR_SGES);
- /* Reply chunks require segments for head and tail buffers */
- ia->ri_max_segs += 2;
- if (ia->ri_max_segs > RPCRDMA_MAX_HDR_SEGS)
- ia->ri_max_segs = RPCRDMA_MAX_HDR_SEGS;
- return 0;
-}
-
-/* FMR mode conveys up to 64 pages of payload per chunk segment.
- */
-static size_t
-fmr_op_maxpages(struct rpcrdma_xprt *r_xprt)
-{
- return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
- (r_xprt->rx_ia.ri_max_segs - 2) * RPCRDMA_MAX_FMR_SGES);
-}
-
-/* Use the ib_map_phys_fmr() verb to register a memory region
- * for remote access via RDMA READ or RDMA WRITE.
- */
-static struct rpcrdma_mr_seg *
-fmr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
- int nsegs, bool writing, struct rpcrdma_mr **out)
-{
- struct rpcrdma_mr_seg *seg1 = seg;
- int len, pageoff, i, rc;
- struct rpcrdma_mr *mr;
- u64 *dma_pages;
-
- mr = rpcrdma_mr_get(r_xprt);
- if (!mr)
- return ERR_PTR(-EAGAIN);
-
- pageoff = offset_in_page(seg1->mr_offset);
- seg1->mr_offset -= pageoff; /* start of page */
- seg1->mr_len += pageoff;
- len = -pageoff;
- if (nsegs > RPCRDMA_MAX_FMR_SGES)
- nsegs = RPCRDMA_MAX_FMR_SGES;
- for (i = 0; i < nsegs;) {
- if (seg->mr_page)
- sg_set_page(&mr->mr_sg[i],
- seg->mr_page,
- seg->mr_len,
- offset_in_page(seg->mr_offset));
- else
- sg_set_buf(&mr->mr_sg[i], seg->mr_offset,
- seg->mr_len);
- 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;
- }
- mr->mr_dir = rpcrdma_data_dir(writing);
-
- mr->mr_nents = ib_dma_map_sg(r_xprt->rx_ia.ri_device,
- mr->mr_sg, i, mr->mr_dir);
- if (!mr->mr_nents)
- goto out_dmamap_err;
- trace_xprtrdma_mr_map(mr);
-
- for (i = 0, dma_pages = mr->fmr.fm_physaddrs; i < mr->mr_nents; i++)
- dma_pages[i] = sg_dma_address(&mr->mr_sg[i]);
- rc = ib_map_phys_fmr(mr->fmr.fm_mr, dma_pages, mr->mr_nents,
- dma_pages[0]);
- if (rc)
- goto out_maperr;
-
- mr->mr_handle = mr->fmr.fm_mr->rkey;
- mr->mr_length = len;
- mr->mr_offset = dma_pages[0] + pageoff;
-
- *out = mr;
- return seg;
-
-out_dmamap_err:
- pr_err("rpcrdma: failed to DMA map sg %p sg_nents %d\n",
- mr->mr_sg, i);
- rpcrdma_mr_put(mr);
- return ERR_PTR(-EIO);
-
-out_maperr:
- pr_err("rpcrdma: ib_map_phys_fmr %u@0x%llx+%i (%d) status %i\n",
- len, (unsigned long long)dma_pages[0],
- pageoff, mr->mr_nents, rc);
- rpcrdma_mr_unmap_and_put(mr);
- return ERR_PTR(-EIO);
-}
-
-/* Post Send WR containing the RPC Call message.
- */
-static int
-fmr_op_send(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
-{
- return ib_post_send(ia->ri_id->qp, &req->rl_sendctx->sc_wr, NULL);
-}
-
-/* Invalidate all memory regions that were registered for "req".
- *
- * Sleeps until it is safe for the host CPU to access the
- * previously mapped memory regions.
- *
- * Caller ensures that @mrs is not empty before the call. This
- * function empties the list.
- */
-static void
-fmr_op_unmap_sync(struct rpcrdma_xprt *r_xprt, struct list_head *mrs)
-{
- struct rpcrdma_mr *mr;
- LIST_HEAD(unmap_list);
- int rc;
-
- /* ORDER: Invalidate all of the req's MRs first
- *
- * ib_unmap_fmr() is slow, so use a single call instead
- * of one call per mapped FMR.
- */
- list_for_each_entry(mr, mrs, mr_list) {
- dprintk("RPC: %s: unmapping fmr %p\n",
- __func__, &mr->fmr);
- trace_xprtrdma_mr_localinv(mr);
- list_add_tail(&mr->fmr.fm_mr->list, &unmap_list);
- }
- r_xprt->rx_stats.local_inv_needed++;
- rc = ib_unmap_fmr(&unmap_list);
- if (rc)
- goto out_release;
-
- /* ORDER: Now DMA unmap all of the req's MRs, and return
- * them to the free MW list.
- */
- while (!list_empty(mrs)) {
- mr = rpcrdma_mr_pop(mrs);
- list_del(&mr->fmr.fm_mr->list);
- rpcrdma_mr_unmap_and_put(mr);
- }
-
- return;
-
-out_release:
- pr_err("rpcrdma: ib_unmap_fmr failed (%i)\n", rc);
-
- while (!list_empty(mrs)) {
- mr = rpcrdma_mr_pop(mrs);
- list_del(&mr->fmr.fm_mr->list);
- rpcrdma_mr_recycle(mr);
- }
-}
-
-const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops = {
- .ro_map = fmr_op_map,
- .ro_send = fmr_op_send,
- .ro_unmap_sync = fmr_op_unmap_sync,
- .ro_open = fmr_op_open,
- .ro_maxpages = fmr_op_maxpages,
- .ro_init_mr = fmr_op_init_mr,
- .ro_release_mr = fmr_op_release_mr,
- .ro_displayname = "fmr",
- .ro_send_w_inv_ok = 0,
-};
projects / users / hch / configfs.git / commitdiff