Patch "PCI: mvebu: Fix support for DEVCAP2, DEVCTL2 and LNKCTL2 registers on emulated bridge" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    PCI: mvebu: Fix support for DEVCAP2, DEVCTL2 and LNKCTL2 registers on emulated bridge

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     pci-mvebu-fix-support-for-devcap2-devctl2-and-lnkctl.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 3f0266995f3f4cab2d36e5211a27f52dfda9dc69
Author: Pali Rohár <pali@xxxxxxxxxx>
Date:   Thu Nov 25 13:46:05 2021 +0100

    PCI: mvebu: Fix support for DEVCAP2, DEVCTL2 and LNKCTL2 registers on emulated bridge
    
    [ Upstream commit 4ab34548c55fbbb3898306a47dfaccd4860e1ccb ]
    
    Armada XP and new hardware supports access to DEVCAP2, DEVCTL2 and LNKCTL2
    configuration registers of PCIe core via PCIE_CAP_PCIEXP. So export them
    via emulated software root bridge.
    
    Pre-XP hardware does not support these registers and returns zeros.
    
    Link: https://lore.kernel.org/r/20211125124605.25915-16-pali@xxxxxxxxxx
    Fixes: 1f08673eef12 ("PCI: mvebu: Convert to PCI emulated bridge config space")
    Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
    Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c
index b690768d5a413..357e9a293edf7 100644
--- a/drivers/pci/controller/pci-mvebu.c
+++ b/drivers/pci/controller/pci-mvebu.c
@@ -524,6 +524,18 @@ mvebu_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge,
 		*value = mvebu_readl(port, PCIE_RC_RTSTA);
 		break;
 
+	case PCI_EXP_DEVCAP2:
+		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCAP2);
+		break;
+
+	case PCI_EXP_DEVCTL2:
+		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL2);
+		break;
+
+	case PCI_EXP_LNKCTL2:
+		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL2);
+		break;
+
 	default:
 		return PCI_BRIDGE_EMUL_NOT_HANDLED;
 	}
@@ -615,6 +627,17 @@ mvebu_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge,
 		if (new & PCI_EXP_RTSTA_PME)
 			mvebu_writel(port, ~PCIE_INT_PM_PME, PCIE_INT_CAUSE_OFF);
 		break;
+
+	case PCI_EXP_DEVCTL2:
+		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL2);
+		break;
+
+	case PCI_EXP_LNKCTL2:
+		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL2);
+		break;
+
+	default:
+		break;
 	}
 }