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From: Thomas Monjalon <thomas@monjalon.net>
To: dev@dpdk.org
Cc: stable@dpdk.org, Matan Azrad <matan@mellanox.com>,
	Shahaf Shuler <shahafs@mellanox.com>
Subject: [dpdk-dev] [PATCH v2 3/3] net/mlx4: fix build with -fno-common
Date: Wed,  8 Apr 2020 01:06:47 +0200	[thread overview]
Message-ID: <20200407230647.59478-4-thomas@monjalon.net> (raw)
In-Reply-To: <20200407230647.59478-1-thomas@monjalon.net>

The variable storages of the same name are merged together
if compiled with -fcommon. This is the default.
This default behaviour allows to declare a variable in a header file
and share the variable in every .o binaries thanks to merge at link-time.

In the case of dlopen linking of the glue library, the pointer mlx4_glue
is referencing the glue functions struct and is set after calling dlopen.

If compiling with -fno-common (default in GCC 10), the variables
must be declared as extern to avoid multiple re-definitions.
In case the glue layer is split in glue library, the variable mlx4_glue
needs to have its own storage for the rest of the PMD.

Cc: stable@dpdk.org

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Matan Azrad <matan@mellanox.com>
---
 drivers/net/mlx4/mlx4.c      | 4 ++++
 drivers/net/mlx4/mlx4_glue.h | 2 +-
 drivers/net/mlx4/mlx4_rxtx.h | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c
index 339a4d3ab6..ee15f28dff 100644
--- a/drivers/net/mlx4/mlx4.c
+++ b/drivers/net/mlx4/mlx4.c
@@ -49,6 +49,10 @@
 #include "mlx4_rxtx.h"
 #include "mlx4_utils.h"
 
+#ifdef MLX4_GLUE
+const struct mlx4_glue *mlx4_glue;
+#endif
+
 static const char *MZ_MLX4_PMD_SHARED_DATA = "mlx4_pmd_shared_data";
 
 /* Shared memory between primary and secondary processes. */
diff --git a/drivers/net/mlx4/mlx4_glue.h b/drivers/net/mlx4/mlx4_glue.h
index 668ca86700..5d9e985495 100644
--- a/drivers/net/mlx4/mlx4_glue.h
+++ b/drivers/net/mlx4/mlx4_glue.h
@@ -84,6 +84,6 @@ struct mlx4_glue {
 				   void *attr);
 };
 
-const struct mlx4_glue *mlx4_glue;
+extern const struct mlx4_glue *mlx4_glue;
 
 #endif /* MLX4_GLUE_H_ */
diff --git a/drivers/net/mlx4/mlx4_rxtx.h b/drivers/net/mlx4/mlx4_rxtx.h
index 8baf33fa94..9de6c59411 100644
--- a/drivers/net/mlx4/mlx4_rxtx.h
+++ b/drivers/net/mlx4/mlx4_rxtx.h
@@ -124,7 +124,7 @@ struct txq {
 
 /* mlx4_rxq.c */
 
-uint8_t mlx4_rss_hash_key_default[MLX4_RSS_HASH_KEY_SIZE];
+extern uint8_t mlx4_rss_hash_key_default[MLX4_RSS_HASH_KEY_SIZE];
 int mlx4_rss_init(struct mlx4_priv *priv);
 void mlx4_rss_deinit(struct mlx4_priv *priv);
 struct mlx4_rss *mlx4_rss_get(struct mlx4_priv *priv, uint64_t fields,
-- 
2.26.0


  parent reply	other threads:[~2020-04-07 23:07 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-10 10:32 [dpdk-dev] [PATCH 0/3] mlx: fix build with -fno-common (gcc 10) Thomas Monjalon
2020-02-10 10:32 ` [dpdk-dev] [PATCH 1/3] common/mlx5: split glue initialization Thomas Monjalon
2020-02-10 10:32 ` [dpdk-dev] [PATCH 2/3] common/mlx5: fix build with -fno-common Thomas Monjalon
2020-02-10 10:32 ` [dpdk-dev] [PATCH 3/3] net/mlx4: " Thomas Monjalon
2020-03-17  8:34 ` [dpdk-dev] [PATCH 0/3] mlx: fix build with -fno-common (gcc 10) Matan Azrad
2020-04-07  0:19   ` Thomas Monjalon
2020-04-07 23:06 ` [dpdk-dev] [PATCH v2 " Thomas Monjalon
2020-04-07 23:06   ` [dpdk-dev] [PATCH v2 1/3] common/mlx5: split glue initialization Thomas Monjalon
2020-04-07 23:06   ` [dpdk-dev] [PATCH v2 2/3] common/mlx5: fix build with -fno-common Thomas Monjalon
2020-04-07 23:06   ` Thomas Monjalon [this message]
2020-04-08  0:08 ` [dpdk-dev] [PATCH v3 0/3] mlx: fix build with -fno-common (gcc 10) Thomas Monjalon
2020-04-08  0:08   ` [dpdk-dev] [PATCH v3 1/3] common/mlx5: split glue initialization Thomas Monjalon
2020-04-08  0:08   ` [dpdk-dev] [PATCH v3 2/3] common/mlx5: fix build with -fno-common Thomas Monjalon
2020-04-08  0:09   ` [dpdk-dev] [PATCH v3 3/3] net/mlx4: " Thomas Monjalon
2020-04-12 15:51   ` [dpdk-dev] [PATCH v3 0/3] mlx: fix build with -fno-common (gcc 10) Raslan Darawsheh

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