[PATCH 5.4 262/320] PCI: pci-bridge-emul: Correctly set PCIe capabilities

Greg Kroah-Hartman
2022-01-24T19:51:28Z

From: Pali Rohár <pali@kernel.org>

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@kernel.org
Fixes: 23a5fba4d941 ("PCI: Introduce PCI bridge emulated config space common logic")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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
@@ -863,7 +863,6 @@ 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);
@@ -944,6 +943,9 @@ 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
@@ -576,6 +576,8 @@ struct pci_bridge_emul_ops mvebu_pci_bri
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;
@@ -588,6 +590,12 @@ 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
@@ -288,10 +288,7 @@ 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),