850-0015-PCI-aardvark-Optimize-writing-PCI_EXP_RTCTL_PMEIE-an.patch

From 3fe0073d116d9902df08761c1cf0d733dd4c38fc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
Date: Wed, 8 Dec 2021 06:03:50 +0100
Subject: [PATCH] PCI: aardvark: Optimize writing PCI_EXP_RTCTL_PMEIE and
 PCI_EXP_RTSTA_PME on emulated bridge
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To optimize advk_pci_bridge_emul_pcie_conf_write() code, touch
PCIE_ISR0_REG and PCIE_ISR0_MASK_REG registers only when it is really
needed, when processing PCI_EXP_RTCTL_PMEIE and PCI_EXP_RTSTA_PME bits.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
---
 drivers/pci/controller/pci-aardvark.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -932,19 +932,21 @@ advk_pci_bridge_emul_pcie_conf_write(str
 			advk_pcie_wait_for_retrain(pcie);
 		break;
 
-	case PCI_EXP_RTCTL: {
+	case PCI_EXP_RTCTL:
 		/* Only mask/unmask PME interrupt */
-		u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG) &
-			~PCIE_MSG_PM_PME_MASK;
-		if ((new & PCI_EXP_RTCTL_PMEIE) == 0)
-			val |= PCIE_MSG_PM_PME_MASK;
-		advk_writel(pcie, val, PCIE_ISR0_MASK_REG);
+		if (mask & PCI_EXP_RTCTL_PMEIE) {
+			u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG);
+			if (new & PCI_EXP_RTCTL_PMEIE)
+				val &= ~PCIE_MSG_PM_PME_MASK;
+			else
+				val |= PCIE_MSG_PM_PME_MASK;
+			advk_writel(pcie, val, PCIE_ISR0_MASK_REG);
+		}
 		break;
-	}
 
 	case PCI_EXP_RTSTA:
-		new = (new & PCI_EXP_RTSTA_PME) >> 9;
-		advk_writel(pcie, new, PCIE_ISR0_REG);
+		if (new & PCI_EXP_RTSTA_PME)
+			advk_writel(pcie, PCIE_MSG_PM_PME_MASK, PCIE_ISR0_REG);
 		break;
 
 	case PCI_EXP_DEVCTL: