[PATCH net] net: stmmac: Correct byte order of perfect_match

Simon Horman
2024-07-23T13:29:51Z

The perfect_match parameter of the update_vlan_hash operation is __le16,
and is correctly converted from host byte-order in the lone caller,
stmmac_vlan_update().

However, the implementations of this caller, dwxgmac2_update_vlan_hash()
and dwxgmac2_update_vlan_hash(), both treat this parameter as host byte
order, using the following pattern:

u32 value = ...
...
writel(value | perfect_match, ...);

This is not correct because both:
1) value is host byte order; and
2) writel expects a host byte order value as it's first argument

I believe that this will break on big endian systems. And I expect it
has gone unnoticed by only being exercised on little endian systems.

The approach taken by this patch is to update the callback, and it's
caller to simply use a host byte order value.

Flagged by Sparse.
Compile tested only.

Fixes: c7ab0b8088d7 ("net: stmmac: Fallback to VLAN Perfect filtering if HASH is not available")
Signed-off-by: Simon Horman <horms@kernel.org>
---
drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c | 2 +-
drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c | 2 +-
drivers/net/ethernet/stmicro/stmmac/hwif.h | 2 +-
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 4 ++--
4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index dbd9f93b2460..f98741d2607e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -977,7 +977,7 @@ static void dwmac4_set_mac_loopback(void __iomem *ioaddr, bool enable)
}

static void dwmac4_update_vlan_hash(struct mac_device_info *hw, u32 hash,
- __le16 perfect_match, bool is_double)
+ u16 perfect_match, bool is_double)
{
void __iomem *ioaddr = hw->pcsr;
u32 value;
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
index 6a987cf598e4..f196cd99d510 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
@@ -615,7 +615,7 @@ static int dwxgmac2_rss_configure(struct mac_device_info *hw,
}

static void dwxgmac2_update_vlan_hash(struct mac_device_info *hw, u32 hash,
- __le16 perfect_match, bool is_double)
+ u16 perfect_match, bool is_double)
{
void __iomem *ioaddr = hw->pcsr;

diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
index 97934ccba5b1..e53c32362774 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h
@@ -393,7 +393,7 @@ struct stmmac_ops {
struct stmmac_rss *cfg, u32 num_rxq);
/* VLAN */
void (*update_vlan_hash)(struct mac_device_info *hw, u32 hash,
- __le16 perfect_match, bool is_double);
+ u16 perfect_match, bool is_double);
void (*enable_vlan)(struct mac_device_info *hw, u32 type);
void (*rx_hw_vlan)(struct mac_device_info *hw, struct dma_desc *rx_desc,
struct sk_buff *skb);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 4b6a359e5a94..12689774d755 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -6641,7 +6641,7 @@ static u32 stmmac_vid_crc32_le(__le16 vid_le)
static int stmmac_vlan_update(struct stmmac_priv *priv, bool is_double)
{
u32 crc, hash = 0;
- __le16 pmatch = 0;
+ u16 pmatch = 0;
int count = 0;
u16 vid = 0;

@@ -6656,7 +6656,7 @@ static int stmmac_vlan_update(struct stmmac_priv *priv, bool is_double)
if (count > 2) /* VID = 0 always passes filter */
return -EOPNOTSUPP;

- pmatch = cpu_to_le16(vid);
+ pmatch = vid;
hash = 0;
}