xprtrdma: Unclutter struct rpcrdma_mr_seg

Clean ups:
 - make it obvious that the rl_mw field is a pointer -- allocated
   separately, not as part of struct rpcrdma_mr_seg
 - promote "struct {} frmr;" to a named type
 - promote the state enum to a named type
 - name the MW state field the same way other fields in
   rpcrdma_mw are named

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Shirley Ma <shirley.ma@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

2 files changed, 50 insertions, 28 deletions

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index e49cdc930dfd..dd1dabcd3a07 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -156,9 +156,9 @@ rpcrdma_sendcq_process_wc(struct ib_wc *wc)
                 return;
 
         if (wc->opcode == IB_WC_FAST_REG_MR)
-                frmr->r.frmr.state = FRMR_IS_VALID;
+                frmr->r.frmr.fr_state = FRMR_IS_VALID;
         else if (wc->opcode == IB_WC_LOCAL_INV)
-                frmr->r.frmr.state = FRMR_IS_INVALID;
+                frmr->r.frmr.fr_state = FRMR_IS_INVALID;
 }
 
 static int
@@ -1496,6 +1496,9 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
                         struct rpcrdma_xprt *r_xprt)
 {
         struct rpcrdma_mr_seg *seg1 = seg;
+        struct rpcrdma_mw *mw = seg1->mr_chunk.rl_mw;
+        struct rpcrdma_frmr *frmr = &mw->r.frmr;
+        struct ib_mr *mr = frmr->fr_mr;
         struct ib_send_wr invalidate_wr, frmr_wr, *bad_wr, *post_wr;
 
         u8 key;
@@ -1515,8 +1518,7 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
                 rpcrdma_map_one(ia, seg, writing);
                 pa = seg->mr_dma;
                 for (seg_len = seg->mr_len; seg_len > 0; seg_len -= PAGE_SIZE) {
-                        seg1->mr_chunk.rl_mw->r.frmr.fr_pgl->
-                                page_list[page_no++] = pa;
+                        frmr->fr_pgl->page_list[page_no++] = pa;
                         pa += PAGE_SIZE;
                 }
                 len += seg->mr_len;
@@ -1528,20 +1530,18 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
                         break;
         }
         dprintk("RPC:       %s: Using frmr %p to map %d segments\n",
-                __func__, seg1->mr_chunk.rl_mw, i);
+                __func__, mw, i);
 
-        if (unlikely(seg1->mr_chunk.rl_mw->r.frmr.state == FRMR_IS_VALID)) {
+        if (unlikely(frmr->fr_state == FRMR_IS_VALID)) {
                 dprintk("RPC:       %s: frmr %x left valid, posting invalidate.\n",
-                        __func__,
-                        seg1->mr_chunk.rl_mw->r.frmr.fr_mr->rkey);
+                        __func__, mr->rkey);
                 /* Invalidate before using. */
                 memset(&invalidate_wr, 0, sizeof invalidate_wr);
-                invalidate_wr.wr_id = (unsigned long)(void *)seg1->mr_chunk.rl_mw;
+                invalidate_wr.wr_id = (unsigned long)(void *)mw;
                 invalidate_wr.next = &frmr_wr;
                 invalidate_wr.opcode = IB_WR_LOCAL_INV;
                 invalidate_wr.send_flags = IB_SEND_SIGNALED;
-                invalidate_wr.ex.invalidate_rkey =
-                        seg1->mr_chunk.rl_mw->r.frmr.fr_mr->rkey;
+                invalidate_wr.ex.invalidate_rkey = mr->rkey;
                 DECR_CQCOUNT(&r_xprt->rx_ep);
                 post_wr = &invalidate_wr;
         } else
@@ -1549,11 +1549,11 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
 
         /* Prepare FRMR WR */
         memset(&frmr_wr, 0, sizeof frmr_wr);
-        frmr_wr.wr_id = (unsigned long)(void *)seg1->mr_chunk.rl_mw;
+        frmr_wr.wr_id = (unsigned long)(void *)mw;
         frmr_wr.opcode = IB_WR_FAST_REG_MR;
         frmr_wr.send_flags = IB_SEND_SIGNALED;
         frmr_wr.wr.fast_reg.iova_start = seg1->mr_dma;
-        frmr_wr.wr.fast_reg.page_list = seg1->mr_chunk.rl_mw->r.frmr.fr_pgl;
+        frmr_wr.wr.fast_reg.page_list = frmr->fr_pgl;
         frmr_wr.wr.fast_reg.page_list_len = page_no;
         frmr_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
         frmr_wr.wr.fast_reg.length = page_no << PAGE_SHIFT;
@@ -1563,13 +1563,13 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
         }
 
         /* Bump the key */
-        key = (u8)(seg1->mr_chunk.rl_mw->r.frmr.fr_mr->rkey & 0x000000FF);
-        ib_update_fast_reg_key(seg1->mr_chunk.rl_mw->r.frmr.fr_mr, ++key);
+        key = (u8)(mr->rkey & 0x000000FF);
+        ib_update_fast_reg_key(mr, ++key);
 
         frmr_wr.wr.fast_reg.access_flags = (writing ?
                                 IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
                                 IB_ACCESS_REMOTE_READ);
-        frmr_wr.wr.fast_reg.rkey = seg1->mr_chunk.rl_mw->r.frmr.fr_mr->rkey;
+        frmr_wr.wr.fast_reg.rkey = mr->rkey;
         DECR_CQCOUNT(&r_xprt->rx_ep);
 
         rc = ib_post_send(ia->ri_id->qp, post_wr, &bad_wr);
@@ -1579,7 +1579,7 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
                         " status %i\n", __func__, rc);
                 goto out_err;
         } else {
-                seg1->mr_rkey = seg1->mr_chunk.rl_mw->r.frmr.fr_mr->rkey;
+                seg1->mr_rkey = mr->rkey;
                 seg1->mr_base = seg1->mr_dma + pageoff;
                 seg1->mr_nsegs = i;
                 seg1->mr_len = len;
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index c270e59cf917..84c3455a9521 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -146,6 +146,38 @@ struct rpcrdma_rep {
 };
 
 /*
+ * struct rpcrdma_mw - external memory region metadata
+ *
+ * An external memory region is any buffer or page that is registered
+ * on the fly (ie, not pre-registered).
+ *
+ * Each rpcrdma_buffer has a list of these anchored in rb_mws. During
+ * call_allocate, rpcrdma_buffer_get() assigns one to each segment in
+ * an rpcrdma_req. Then rpcrdma_register_external() grabs these to keep
+ * track of registration metadata while each RPC is pending.
+ * rpcrdma_deregister_external() uses this metadata to unmap and
+ * release these resources when an RPC is complete.
+ */
+enum rpcrdma_frmr_state {
+        FRMR_IS_INVALID,        /* ready to be used */
+        FRMR_IS_VALID,          /* in use */
+};
+
+struct rpcrdma_frmr {
+        struct ib_fast_reg_page_list    *fr_pgl;
+        struct ib_mr                    *fr_mr;
+        enum rpcrdma_frmr_state         fr_state;
+};
+
+struct rpcrdma_mw {
+        union {
+                struct ib_fmr           *fmr;
+                struct rpcrdma_frmr     frmr;
+        } r;
+        struct list_head        mw_list;
+};
+
+/*
  * struct rpcrdma_req -- structure central to the request/reply sequence.
  *
  * N of these are associated with a transport instance, and stored in
@@ -172,17 +204,7 @@ struct rpcrdma_rep {
 struct rpcrdma_mr_seg {         /* chunk descriptors */
         union {                         /* chunk memory handles */
                 struct ib_mr    *rl_mr;         /* if registered directly */
-                struct rpcrdma_mw {             /* if registered from region */
-                        union {
-                                struct ib_fmr   *fmr;
-                                struct {
-                                        struct ib_fast_reg_page_list *fr_pgl;
-                                        struct ib_mr *fr_mr;
-                                        enum { FRMR_IS_INVALID, FRMR_IS_VALID  } state;
-                                } frmr;
-                        } r;
-                        struct list_head mw_list;
-                } *rl_mw;
+                struct rpcrdma_mw *rl_mw;       /* if registered from region */
         } mr_chunk;
         u64             mr_base;        /* registration result */
         u32             mr_rkey;        /* registration result */