From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Sun, 8 Oct 2017 21:04:17 -0700
Subject: nfp: bpf: pass dst register to ld_field instruction
Patch-mainline: v4.15-rc1
Git-commit: 2de1be1db25d3285f514920230790be20db92887
References: bsc#1109837

ld_field instruction is a bit special because the encoding uses
two source registers and one of them becomes the output.  We do
need to pass the dst register to our encoding helpers though,
otherwise the "write both banks" flag will not be observed.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/netronome/nfp/bpf/jit.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
@@ -408,7 +408,8 @@ emit_ld_field_any(struct nfp_prog *nfp_p
 	struct nfp_insn_re_regs reg;
 	int err;
 
-	err = swreg_to_restricted(reg_none(), dst, src, &reg, true);
+	/* Note: ld_field is special as it uses one of the src regs as dst */
+	err = swreg_to_restricted(dst, dst, src, &reg, true);
 	if (err) {
 		nfp_prog->error = err;
 		return;