From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Wed, 25 Jul 2018 19:53:35 -0700
Subject: nfp: bpf: improve map offload info messages
Patch-mainline: v4.19-rc1
Git-commit: 17082566a9d2d05eefa3a5d6d968aa1d4b87c73d
References: bsc#1109837

FW can put constraints on map element size to maximize resource
use and efficiency.  When user attempts offload of a map which
does not fit into those constraints an informational message is
printed to kernel logs to inform user about the reason offload
failed.  Map offload does not have access to any advanced error
reporting like verifier log or extack.  There is also currently
no way for us to nicely expose the FW capabilities to user
space.  Given all those constraints we should make sure log
messages are as informative as possible.  Improve them.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/netronome/nfp/bpf/offload.c |   20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

--- a/drivers/net/ethernet/netronome/nfp/bpf/offload.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/offload.c
@@ -380,11 +380,23 @@ nfp_bpf_map_alloc(struct nfp_app_bpf *bp
 			bpf->maps.max_elems - bpf->map_elems_in_use);
 		return -ENOMEM;
 	}
-	if (offmap->map.key_size > bpf->maps.max_key_sz ||
-	    offmap->map.value_size > bpf->maps.max_val_sz ||
-	    round_up(offmap->map.key_size, 8) +
+
+	if (round_up(offmap->map.key_size, 8) +
 	    round_up(offmap->map.value_size, 8) > bpf->maps.max_elem_sz) {
-		pr_info("elements don't fit in device constraints\n");
+		pr_info("map elements too large: %u, FW max element size (key+value): %u\n",
+			round_up(offmap->map.key_size, 8) +
+			round_up(offmap->map.value_size, 8),
+			bpf->maps.max_elem_sz);
+		return -ENOMEM;
+	}
+	if (offmap->map.key_size > bpf->maps.max_key_sz) {
+		pr_info("map key size %u, FW max is %u\n",
+			offmap->map.key_size, bpf->maps.max_key_sz);
+		return -ENOMEM;
+	}
+	if (offmap->map.value_size > bpf->maps.max_val_sz) {
+		pr_info("map value size %u, FW max is %u\n",
+			offmap->map.value_size, bpf->maps.max_val_sz);
 		return -ENOMEM;
 	}