From ede62b5a56ff9c218b8a3eabdd6bbd466bcee903 Mon Sep 17 00:00:00 2001
From: Andrew Rybchenko <arybchenko@solarflare.com>
Date: Thu, 16 Nov 2017 08:04:12 +0000
Subject: [PATCH] net/sfc/base: more accurately calculate number of PS credits
Maximum number of packets per 64k buffer should be rounded up
when calculating number of credits by event queue size.
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
---
drivers/net/sfc/base/ef10_ev.c | 2 +-
drivers/net/sfc/base/efx.h | 3 +++
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/net/sfc/base/ef10_ev.c b/drivers/net/sfc/base/ef10_ev.c
index 946efeb6b8..2c6edf3f46 100644
--- a/drivers/net/sfc/base/ef10_ev.c
+++ b/drivers/net/sfc/base/ef10_ev.c
@@ -1370,7 +1370,7 @@ ef10_ev_rxlabel_init(
eersp->eers_rx_packed_stream = packed_stream;
if (packed_stream) {
eersp->eers_rx_packed_stream_credits = (eep->ee_mask + 1) /
- (EFX_RX_PACKED_STREAM_MEM_PER_CREDIT /
+ EFX_DIV_ROUND_UP(EFX_RX_PACKED_STREAM_MEM_PER_CREDIT,
EFX_RX_PACKED_STREAM_MIN_PACKET_SPACE);
EFSYS_ASSERT3U(eersp->eers_rx_packed_stream_credits, !=, 0);
/*
diff --git a/drivers/net/sfc/base/efx.h b/drivers/net/sfc/base/efx.h
index bf17aba371..d7ce0b56ae 100644
--- a/drivers/net/sfc/base/efx.h
+++ b/drivers/net/sfc/base/efx.h
@@ -48,6 +48,9 @@ extern "C" {
#define EFX_FIELD_OFFSET(_type, _field) \
((size_t) &(((_type *)0)->_field))
+/* The macro expands divider twice */
+#define EFX_DIV_ROUND_UP(_n, _d) (((_n) + (_d) - 1) / (_d))
+
/* Return codes */
typedef __success(return == 0) int efx_rc_t;
--
2.39.5