[PATCH 5.15 706/846] PCI: pci-bridge-emul: Correctly set PCIe capabilities

[Greg Kroah-Hartman]

From: Pali Rohár <pali@xxxxxxxxxx>

commit 1f1050c5e1fefb34ac90a506b43e9da803b5f8f7 upstream.

Older mvebu hardware provides PCIe Capability structure only in version 1.
New mvebu and aardvark hardware provides it in version 2. So do not force
version to 2 in pci_bridge_emul_init() and rather allow drivers to set
correct version. Drivers need to set version in pcie_conf.cap field without
overwriting PCI_CAP_LIST_ID register. Both drivers (mvebu and aardvark) do
not provide slot support yet, so do not set PCI_EXP_FLAGS_SLOT flag.

Link: https://lore.kernel.org/r/20211124155944.1290-6-pali@xxxxxxxxxx
Fixes: 23a5fba4d941 ("PCI: Introduce PCI bridge emulated config space common logic")
Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/pci/controller/pci-aardvark.c |    4 +++-
 drivers/pci/controller/pci-mvebu.c    |    8 ++++++++
 drivers/pci/pci-bridge-emul.c         |    5 +----
 3 files changed, 12 insertions(+), 5 deletions(-)

--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -872,7 +872,6 @@ advk_pci_bridge_emul_pcie_conf_read(stru
 		return PCI_BRIDGE_EMUL_HANDLED;
 	}
 
-	case PCI_CAP_LIST_ID:
 	case PCI_EXP_DEVCAP:
 	case PCI_EXP_DEVCTL:
 		*value = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + reg);
@@ -953,6 +952,9 @@ static int advk_sw_pci_bridge_init(struc
 	/* Support interrupt A for MSI feature */
 	bridge->conf.intpin = PCIE_CORE_INT_A_ASSERT_ENABLE;
 
+	/* Aardvark HW provides PCIe Capability structure in version 2 */
+	bridge->pcie_conf.cap = cpu_to_le16(2);
+
 	/* Indicates supports for Completion Retry Status */
 	bridge->pcie_conf.rootcap = cpu_to_le16(PCI_EXP_RTCAP_CRSVIS);
 
--- a/drivers/pci/controller/pci-mvebu.c
+++ b/drivers/pci/controller/pci-mvebu.c
@@ -573,6 +573,8 @@ static struct pci_bridge_emul_ops mvebu_
 static void mvebu_pci_bridge_emul_init(struct mvebu_pcie_port *port)
 {
 	struct pci_bridge_emul *bridge = &port->bridge;
+	u32 pcie_cap = mvebu_readl(port, PCIE_CAP_PCIEXP);
+	u8 pcie_cap_ver = ((pcie_cap >> 16) & PCI_EXP_FLAGS_VERS);
 
 	bridge->conf.vendor = PCI_VENDOR_ID_MARVELL;
 	bridge->conf.device = mvebu_readl(port, PCIE_DEV_ID_OFF) >> 16;
@@ -585,6 +587,12 @@ static void mvebu_pci_bridge_emul_init(s
 		bridge->conf.iolimit = PCI_IO_RANGE_TYPE_32;
 	}
 
+	/*
+	 * Older mvebu hardware provides PCIe Capability structure only in
+	 * version 1. New hardware provides it in version 2.
+	 */
+	bridge->pcie_conf.cap = cpu_to_le16(pcie_cap_ver);
+
 	bridge->has_pcie = true;
 	bridge->data = port;
 	bridge->ops = &mvebu_pci_bridge_emul_ops;
--- a/drivers/pci/pci-bridge-emul.c
+++ b/drivers/pci/pci-bridge-emul.c
@@ -297,10 +297,7 @@ int pci_bridge_emul_init(struct pci_brid
 	if (bridge->has_pcie) {
 		bridge->conf.capabilities_pointer = PCI_CAP_PCIE_START;
 		bridge->pcie_conf.cap_id = PCI_CAP_ID_EXP;
-		/* Set PCIe v2, root port, slot support */
-		bridge->pcie_conf.cap =
-			cpu_to_le16(PCI_EXP_TYPE_ROOT_PORT << 4 | 2 |
-				    PCI_EXP_FLAGS_SLOT);
+		bridge->pcie_conf.cap |= cpu_to_le16(PCI_EXP_TYPE_ROOT_PORT << 4);
 		bridge->pcie_cap_regs_behavior =
 			kmemdup(pcie_cap_regs_behavior,
 				sizeof(pcie_cap_regs_behavior),