xprtrdma: Add a "max_payload" op for each memreg mode
The max_payload computation is generalized to ensure that the
payload maximum is the lesser of RPC_MAX_DATA_SEGS and the number of
data segments that can be transmitted in an inline buffer.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Devesh Sharma <Devesh.Sharma@Emulex.Com>
Tested-by: Meghana Cheripady <Meghana.Cheripady@Emulex.Com>
Tested-by: Veeresh U. Kokatnur <veereshuk@chelsio.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/net/sunrpc/xprtrdma/fmr_ops.c b/net/sunrpc/xprtrdma/fmr_ops.c
index ffb7d93..eec2660 100644
--- a/net/sunrpc/xprtrdma/fmr_ops.c
+++ b/net/sunrpc/xprtrdma/fmr_ops.c
@@ -17,6 +17,19 @@
# define RPCDBG_FACILITY RPCDBG_TRANS
#endif
+/* Maximum scatter/gather per FMR */
+#define RPCRDMA_MAX_FMR_SGES (64)
+
+/* 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,
+ rpcrdma_max_segments(r_xprt) * RPCRDMA_MAX_FMR_SGES);
+}
+
const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops = {
+ .ro_maxpages = fmr_op_maxpages,
.ro_displayname = "fmr",
};