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[net-next,1/3] net: ethernet: ti: am65-cpsw: Address __percpu Sparse warnings

Message ID 20240910-ti-warn-v1-1-afd1e404abbe@kernel.org
State New
Headers show
Series net: ethernet: ti: Address some warnings | expand

Commit Message

Simon Horman Sept. 10, 2024, 7:17 a.m. UTC
Sparse flags a mismatch between percpu stats data, and
it's use with actions which handle non-percpu data.

.../am65-cpsw-nuss.c:2658:55: warning: incorrect type in initializer (different address spaces)
.../am65-cpsw-nuss.c:2658:55:    expected struct am65_cpsw_ndev_stats [noderef] __percpu *stats
.../am65-cpsw-nuss.c:2658:55:    got void *data
.../am65-cpsw-nuss.c:2781:15: warning: incorrect type in argument 3 (different address spaces)
.../am65-cpsw-nuss.c:2781:15:    expected void *data
.../am65-cpsw-nuss.c:2781:15:    got struct am65_cpsw_ndev_stats [noderef] __percpu *stats

Address this using casts.

An alternate, approach would be to create a variant of
devm_add_action_or_reset() which expects __percpu data.  This would
avoid discarding the __percpu annotation, and any value it may have
between the casts added by this patch.  However, doing so appears to
require a significant amount of plumbing.  And, as far as I can see, the
code updated by this patch would be the only user of it.  So this patch
takes a simpler approach.

No functional change intended.
Compile tested only.

Signed-off-by: Simon Horman <horms@kernel.org>
---
 drivers/net/ethernet/ti/am65-cpsw-nuss.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

Comments

Jakub Kicinski Sept. 12, 2024, 12:06 a.m. UTC | #1
On Tue, 10 Sep 2024 08:17:56 +0100 Simon Horman wrote:
> An alternate, approach would be to create a variant of
> devm_add_action_or_reset() which expects __percpu data.  This would
> avoid discarding the __percpu annotation, and any value it may have
> between the casts added by this patch.  However, doing so appears to
> require a significant amount of plumbing.  And, as far as I can see, the
> code updated by this patch would be the only user of it.  So this patch
> takes a simpler approach.

Sorry if this was already discussed, but struct am65_cpsw_ndev_stats
appears to be identical to struct pcpu_sw_netstats but for ordering.
Can we let the core allocate the stats by setting
netdev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS?
diff mbox series

Patch

diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
index b7e5d0fb5d19..a4b0e4bb7529 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
@@ -2671,9 +2671,7 @@  static int am65_cpsw_nuss_init_slave_ports(struct am65_cpsw_common *common)
 
 static void am65_cpsw_pcpu_stats_free(void *data)
 {
-	struct am65_cpsw_ndev_stats __percpu *stats = data;
-
-	free_percpu(stats);
+	free_percpu((void __percpu *)data);
 }
 
 static void am65_cpsw_nuss_phylink_cleanup(struct am65_cpsw_common *common)
@@ -2794,7 +2792,7 @@  am65_cpsw_nuss_init_port_ndev(struct am65_cpsw_common *common, u32 port_idx)
 		return -ENOMEM;
 
 	ret = devm_add_action_or_reset(dev, am65_cpsw_pcpu_stats_free,
-				       ndev_priv->stats);
+				       (__force void *)ndev_priv->stats);
 	if (ret)
 		dev_err(dev, "failed to add percpu stat free action %d\n", ret);