openwrt/target/linux/bcm4908/patches-5.4/075-v5.13-0004-net-dsa-bcm_sf2-add-function-finding-RGMII-register.patch

From 55cfeb396965c3906a84d09a9c487d065e37773b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <[email protected]>
Date: Thu, 18 Mar 2021 09:01:42 +0100
Subject: [PATCH 1/2] net: dsa: bcm_sf2: add function finding RGMII register
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Simple macro like REG_RGMII_CNTRL_P() is insufficient as:
1. It doesn't validate port argument
2. It doesn't support chipsets with non-lineral RGMII regs layout

Missing port validation could result in getting register offset from out
of array. Random memory -> random offset -> random reads/writes. It
affected e.g. BCM4908 for REG_RGMII_CNTRL_P(7).

Fixes: a78e86ed586d ("net: dsa: bcm_sf2: Prepare for different register layouts")
Signed-off-by: Rafał Miłecki <[email protected]>
Acked-by: Florian Fainelli <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
---
 drivers/net/dsa/bcm_sf2.c      | 49 +++++++++++++++++++++++++++++-----
 drivers/net/dsa/bcm_sf2_regs.h |  2 --
 2 files changed, 42 insertions(+), 9 deletions(-)

--- a/drivers/net/dsa/bcm_sf2.c
+++ b/drivers/net/dsa/bcm_sf2.c
@@ -31,6 +31,31 @@
 #include "b53/b53_priv.h"
 #include "b53/b53_regs.h"
 
+static u16 bcm_sf2_reg_rgmii_cntrl(struct bcm_sf2_priv *priv, int port)
+{
+	switch (priv->type) {
+	case BCM4908_DEVICE_ID:
+		/* TODO */
+		break;
+	default:
+		switch (port) {
+		case 0:
+			return REG_RGMII_0_CNTRL;
+		case 1:
+			return REG_RGMII_1_CNTRL;
+		case 2:
+			return REG_RGMII_2_CNTRL;
+		default:
+			break;
+		}
+	}
+
+	WARN_ONCE(1, "Unsupported port %d\n", port);
+
+	/* RO fallback reg */
+	return REG_SWITCH_STATUS;
+}
+
 static void bcm_sf2_imp_setup(struct dsa_switch *ds, int port)
 {
 	struct bcm_sf2_priv *priv = bcm_sf2_to_priv(ds);
@@ -586,6 +611,7 @@ static void bcm_sf2_sw_mac_config(struct
 {
 	struct bcm_sf2_priv *priv = bcm_sf2_to_priv(ds);
 	u32 id_mode_dis = 0, port_mode;
+	u32 reg_rgmii_ctrl;
 	u32 reg, offset;
 
 	if (port == core_readl(priv, CORE_IMP0_PRT_ID))
@@ -615,10 +641,12 @@ static void bcm_sf2_sw_mac_config(struct
 		goto force_link;
 	}
 
+	reg_rgmii_ctrl = bcm_sf2_reg_rgmii_cntrl(priv, port);
+
 	/* Clear id_mode_dis bit, and the existing port mode, let
 	 * RGMII_MODE_EN bet set by mac_link_{up,down}
 	 */
-	reg = reg_readl(priv, REG_RGMII_CNTRL_P(port));
+	reg = reg_readl(priv, reg_rgmii_ctrl);
 	reg &= ~ID_MODE_DIS;
 	reg &= ~(PORT_MODE_MASK << PORT_MODE_SHIFT);
 	reg &= ~(RX_PAUSE_EN | TX_PAUSE_EN);
@@ -633,7 +661,7 @@ static void bcm_sf2_sw_mac_config(struct
 		reg |= RX_PAUSE_EN;
 	}
 
-	reg_writel(priv, reg, REG_RGMII_CNTRL_P(port));
+	reg_writel(priv, reg, reg_rgmii_ctrl);
 
 force_link:
 	/* Force link settings detected from the PHY */
@@ -659,6 +687,7 @@ static void bcm_sf2_sw_mac_link_set(stru
 				    phy_interface_t interface, bool link)
 {
 	struct bcm_sf2_priv *priv = bcm_sf2_to_priv(ds);
+	u32 reg_rgmii_ctrl;
 	u32 reg;
 
 	if (!phy_interface_mode_is_rgmii(interface) &&
@@ -666,13 +695,15 @@ static void bcm_sf2_sw_mac_link_set(stru
 	    interface != PHY_INTERFACE_MODE_REVMII)
 		return;
 
+	reg_rgmii_ctrl = bcm_sf2_reg_rgmii_cntrl(priv, port);
+
 	/* If the link is down, just disable the interface to conserve power */
-	reg = reg_readl(priv, REG_RGMII_CNTRL_P(port));
+	reg = reg_readl(priv, reg_rgmii_ctrl);
 	if (link)
 		reg |= RGMII_MODE_EN;
 	else
 		reg &= ~RGMII_MODE_EN;
-	reg_writel(priv, reg, REG_RGMII_CNTRL_P(port));
+	reg_writel(priv, reg, reg_rgmii_ctrl);
 }
 
 static void bcm_sf2_sw_mac_link_down(struct dsa_switch *ds, int port,
--- a/drivers/net/dsa/bcm_sf2_regs.h
+++ b/drivers/net/dsa/bcm_sf2_regs.h
@@ -55,8 +55,6 @@ enum bcm_sf2_reg_offs {
 #define CROSSBAR_BCM4908_EXT_GPHY4	1
 #define CROSSBAR_BCM4908_EXT_RGMII	2
 
-#define REG_RGMII_CNTRL_P(x)		(REG_RGMII_0_CNTRL + (x))
-
 /* Relative to REG_RGMII_CNTRL */
 #define  RGMII_MODE_EN			(1 << 0)
 #define  ID_MODE_DIS			(1 << 1)