PCI: aardvark: Optimize writing PCI_EXP_RTCTL_PMEIE and PCI_EXP_RTSTA_PME on emulated...

BugLink: https://bugs.launchpad.net/bugs/1978240
commit 7122bcb33295228c882c0aa32a04b2547beba2c3 upstream.

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.

Link: https://lore.kernel.org/r/20220110015018.26359-16-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index b97ec2214148eaf57b19fff070e0d02c24bfe505..1d14bbe1cb60f80ccd5f024d6309d665759cd894 100644 (file)
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -924,19 +924,21 @@ advk_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge,
                        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: