[PATCH net-next 1/2] net: stmmac: dwmac4: Read the UC filter size from hardware capabilities

Maxime Chevallier maxime.chevallier at bootlin.com
Mon Aug 31 00:01:19 PDT 2026


dwmac4 has multiple banks of perfect filter entries, independently
configurable during IP integration.

The multi_addr bank reports a number between 0 and 31 corresponding to
the actual number of entries in that bank, while the 32 and 64 banks
are all-or-nothing.

Expose these caps over debugfs as well.

Signed-off-by: Maxime Chevallier <maxime.chevallier at bootlin.com>
---
 drivers/net/ethernet/stmicro/stmmac/common.h      |  2 ++
 drivers/net/ethernet/stmicro/stmmac/dwmac4.h      |  4 +++-
 drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c  |  2 ++
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 12 ++++++++++++
 4 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index 927ea6230073..77bd47a83357 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -419,6 +419,8 @@ struct dma_features {
 	unsigned int half_duplex;
 	unsigned int hash_filter;
 	unsigned int multi_addr;
+	unsigned int additional_32_addr;
+	unsigned int additional_64_addr;
 	unsigned int pcs;
 	unsigned int sma_mdio;
 	unsigned int pmt_remote_wake_up;
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
index 6382836828ba..89368e34a388 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
@@ -176,7 +176,9 @@ enum power_event {
 
 /* MAC HW features0 bitmap */
 #define GMAC_HW_FEAT_SAVLANINS		BIT(27)
-#define GMAC_HW_FEAT_ADDMAC		BIT(18)
+#define GMAC_HW_FEAT_MACADR64SEL	BIT(24)
+#define GMAC_HW_FEAT_MACADR32SEL	BIT(23)
+#define GMAC_HW_FEAT_ADDMAC		GENMASK(22, 18)
 #define GMAC_HW_FEAT_RXCOESEL		BIT(16)
 #define GMAC_HW_FEAT_TXCOSEL		BIT(14)
 #define GMAC_HW_FEAT_EEESEL		BIT(13)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
index 23ffe1adcd0d..14ac3f0e51f7 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
@@ -388,6 +388,8 @@ static int dwmac4_get_hw_feature(void __iomem *ioaddr,
 	dma_cap->half_duplex = (hw_cap & GMAC_HW_FEAT_HDSEL) >> 2;
 	dma_cap->vlhash = (hw_cap & GMAC_HW_FEAT_VLHASH) >> 4;
 	dma_cap->multi_addr = (hw_cap & GMAC_HW_FEAT_ADDMAC) >> 18;
+	dma_cap->additional_32_addr = (hw_cap & GMAC_HW_FEAT_MACADR32SEL) >> 23;
+	dma_cap->additional_64_addr = (hw_cap & GMAC_HW_FEAT_MACADR64SEL) >> 24;
 	dma_cap->pcs = (hw_cap & GMAC_HW_FEAT_PCSSEL) >> 3;
 	dma_cap->sma_mdio = (hw_cap & GMAC_HW_FEAT_SMASEL) >> 5;
 	dma_cap->pmt_remote_wake_up = (hw_cap & GMAC_HW_FEAT_RWKSEL) >> 6;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index f2fc89176654..a885f8cfef21 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -6580,6 +6580,18 @@ static int stmmac_dma_cap_show(struct seq_file *seq, void *v)
 		seq_printf(seq,
 			   "\tNumber of Additional MAC address registers: %d\n",
 			   priv->dma_cap.multi_addr);
+	} else if (priv->plat->core_type == DWMAC_CORE_GMAC4) {
+		seq_printf(seq,
+			   "\tNumber of MAC address registers (1-31): %d\n",
+			   priv->dma_cap.multi_addr);
+		seq_printf(seq,
+			   "\tAdditional 32 MAC address registers (32-63): %s\n",
+			   priv->dma_cap.additional_32_addr ? "Y" : "N");
+		seq_printf(seq,
+			   "\tAdditional 64 MAC address registers (64-127): %s\n",
+			   priv->dma_cap.additional_64_addr ? "Y" : "N");
+		seq_printf(seq, "\tHash Filter: %s\n",
+			   (priv->dma_cap.hash_filter) ? "Y" : "N");
 	} else {
 		seq_printf(seq, "\tHash Filter: %s\n",
 			   (priv->dma_cap.hash_filter) ? "Y" : "N");
-- 
2.55.0




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