r8169: use spinlock to protect access to registers Config2 and Config5

For disabling ASPM during NAPI poll we'll have to access both registers
in atomic context. Use a spinlock to protect access.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169_main.c

@@ -613,6 +613,7 @@ struct rtl8169_private {
 		struct work_struct work;
 	} wk;
 
+	spinlock_t config25_lock;
 	spinlock_t mac_ocp_lock;
 
 	unsigned supports_gmii:1;
@@ -677,6 +678,28 @@ static void rtl_pci_commit(struct rtl8169_private *tp)
 	RTL_R8(tp, ChipCmd);
 }
 
+static void rtl_mod_config2(struct rtl8169_private *tp, u8 clear, u8 set)
+{
+	unsigned long flags;
+	u8 val;
+
+	spin_lock_irqsave(&tp->config25_lock, flags);
+	val = RTL_R8(tp, Config2);
+	RTL_W8(tp, Config2, (val & ~clear) | set);
+	spin_unlock_irqrestore(&tp->config25_lock, flags);
+}
+
+static void rtl_mod_config5(struct rtl8169_private *tp, u8 clear, u8 set)
+{
+	unsigned long flags;
+	u8 val;
+
+	spin_lock_irqsave(&tp->config25_lock, flags);
+	val = RTL_R8(tp, Config5);
+	RTL_W8(tp, Config5, (val & ~clear) | set);
+	spin_unlock_irqrestore(&tp->config25_lock, flags);
+}
+
 static bool rtl_is_8125(struct rtl8169_private *tp)
 {
 	return tp->mac_version >= RTL_GIGA_MAC_VER_61;
@@ -1363,6 +1386,7 @@ static void __rtl8169_set_wol(struct rtl8169_private *tp, u32 wolopts)
 		{ WAKE_MAGIC, Config3, MagicPacket }
 	};
 	unsigned int i, tmp = ARRAY_SIZE(cfg);
+	unsigned long flags;
 	u8 options;
 
 	rtl_unlock_config_regs(tp);
@@ -1381,12 +1405,14 @@ static void __rtl8169_set_wol(struct rtl8169_private *tp, u32 wolopts)
 			r8168_mac_ocp_modify(tp, 0xc0b6, BIT(0), 0);
 	}
 
+	spin_lock_irqsave(&tp->config25_lock, flags);
 	for (i = 0; i < tmp; i++) {
 		options = RTL_R8(tp, cfg[i].reg) & ~cfg[i].mask;
 		if (wolopts & cfg[i].opt)
 			options |= cfg[i].mask;
 		RTL_W8(tp, cfg[i].reg, options);
 	}
+	spin_unlock_irqrestore(&tp->config25_lock, flags);
 
 	switch (tp->mac_version) {
 	case RTL_GIGA_MAC_VER_02 ... RTL_GIGA_MAC_VER_06:
@@ -1398,10 +1424,10 @@ static void __rtl8169_set_wol(struct rtl8169_private *tp, u32 wolopts)
 	case RTL_GIGA_MAC_VER_34:
 	case RTL_GIGA_MAC_VER_37:
 	case RTL_GIGA_MAC_VER_39 ... RTL_GIGA_MAC_VER_63:
-		options = RTL_R8(tp, Config2) & ~PME_SIGNAL;
 		if (wolopts)
-			options |= PME_SIGNAL;
-		RTL_W8(tp, Config2, options);
+			rtl_mod_config2(tp, 0, PME_SIGNAL);
+		else
+			rtl_mod_config2(tp, PME_SIGNAL, 0);
 		break;
 	default:
 		break;
@@ -2704,8 +2730,8 @@ static void rtl_hw_aspm_clkreq_enable(struct rtl8169_private *tp, bool enable)
 {
 	/* Don't enable ASPM in the chip if OS can't control ASPM */
 	if (enable && tp->aspm_manageable) {
-		RTL_W8(tp, Config5, RTL_R8(tp, Config5) | ASPM_en);
-		RTL_W8(tp, Config2, RTL_R8(tp, Config2) | ClkReqEn);
+		rtl_mod_config5(tp, 0, ASPM_en);
+		rtl_mod_config2(tp, 0, ClkReqEn);
 
 		switch (tp->mac_version) {
 		case RTL_GIGA_MAC_VER_46 ... RTL_GIGA_MAC_VER_48:
@@ -2728,8 +2754,8 @@ static void rtl_hw_aspm_clkreq_enable(struct rtl8169_private *tp, bool enable)
 			break;
 		}
 
-		RTL_W8(tp, Config2, RTL_R8(tp, Config2) & ~ClkReqEn);
-		RTL_W8(tp, Config5, RTL_R8(tp, Config5) & ~ASPM_en);
+		rtl_mod_config2(tp, ClkReqEn, 0);
+		rtl_mod_config5(tp, ASPM_en, 0);
 	}
 
 	udelay(10);
@@ -2890,7 +2916,7 @@ static void rtl_hw_start_8168e_1(struct rtl8169_private *tp)
 	RTL_W32(tp, MISC, RTL_R32(tp, MISC) | TXPLA_RST);
 	RTL_W32(tp, MISC, RTL_R32(tp, MISC) & ~TXPLA_RST);
 
-	RTL_W8(tp, Config5, RTL_R8(tp, Config5) & ~Spi_en);
+	rtl_mod_config5(tp, Spi_en, 0);
 }
 
 static void rtl_hw_start_8168e_2(struct rtl8169_private *tp)
@@ -2923,7 +2949,7 @@ static void rtl_hw_start_8168e_2(struct rtl8169_private *tp)
 
 	RTL_W8(tp, DLLPR, RTL_R8(tp, DLLPR) | PFM_EN);
 	RTL_W32(tp, MISC, RTL_R32(tp, MISC) | PWM_EN);
-	RTL_W8(tp, Config5, RTL_R8(tp, Config5) & ~Spi_en);
+	rtl_mod_config5(tp, Spi_en, 0);
 
 	rtl_hw_aspm_clkreq_enable(tp, true);
 }
@@ -2946,7 +2972,7 @@ static void rtl_hw_start_8168f(struct rtl8169_private *tp)
 	RTL_W8(tp, MCU, RTL_R8(tp, MCU) & ~NOW_IS_OOB);
 	RTL_W8(tp, DLLPR, RTL_R8(tp, DLLPR) | PFM_EN);
 	RTL_W32(tp, MISC, RTL_R32(tp, MISC) | PWM_EN);
-	RTL_W8(tp, Config5, RTL_R8(tp, Config5) & ~Spi_en);
+	rtl_mod_config5(tp, Spi_en, 0);
 
 	rtl8168_config_eee_mac(tp);
 }
@@ -5203,6 +5229,7 @@ static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	tp->eee_adv = -1;
 	tp->ocp_base = OCP_STD_PHY_BASE;
 
+	spin_lock_init(&tp->config25_lock);
 	spin_lock_init(&tp->mac_ocp_lock);
 
 	dev->tstats = devm_netdev_alloc_pcpu_stats(&pdev->dev,