From 5352a44a561d708f1a975a90f5ce16a054fe265c Mon Sep 17 00:00:00 2001
From: Mika Westerberg <mika.westerberg@linux.intel.com>
Date: Wed, 23 May 2018 17:24:08 -0500
Subject: [PATCH] PCI: pciehp: Make pciehp_is_native() stricter
Git-commit: 5352a44a561d708f1a975a90f5ce16a054fe265c
Patch-mainline: v4.18
References: FATE#326302
Previously pciehp_is_native() returned true for any PCI device in a
hierarchy where _OSC says we can use pciehp. This is incorrect because
bridges without PCI_EXP_SLTCAP_HPC capability should be managed by acpiphp
instead.
Improve pciehp_is_native() to return true only when PCI_EXP_SLTCAP_HPC is
set and the pciehp driver is present. In any other case return false
to let acpiphp handle those.
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[bhelgaas: remove NULL pointer check]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
drivers/pci/pci-acpi.c | 26 ++++++++++++++------------
drivers/pci/pcie/portdrv.h | 2 --
include/linux/pci.h | 2 ++
include/linux/pci_hotplug.h | 4 ++--
4 files changed, 18 insertions(+), 16 deletions(-)
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -370,26 +370,28 @@ EXPORT_SYMBOL_GPL(pci_get_hp_params);
/**
* pciehp_is_native - Check whether a hotplug port is handled by the OS
- * @pdev: Hotplug port to check
+ * @bridge: Hotplug port to check
*
- * Walk up from @pdev to the host bridge, obtain its cached _OSC Control Field
- * and return the value of the "PCI Express Native Hot Plug control" bit.
- * On failure to obtain the _OSC Control Field return %false.
+ * Returns true if the given @bridge is handled by the native PCIe hotplug
+ * driver.
*/
-bool pciehp_is_native(struct pci_dev *pdev)
+bool pciehp_is_native(struct pci_dev *bridge)
{
- struct acpi_pci_root *root;
- acpi_handle handle;
+ const struct pci_host_bridge *host;
+ u32 slot_cap;
- handle = acpi_find_root_bridge_handle(pdev);
- if (!handle)
+ if (!IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
return false;
- root = acpi_pci_find_root(handle);
- if (!root)
+ pcie_capability_read_dword(bridge, PCI_EXP_SLTCAP, &slot_cap);
+ if (!(slot_cap & PCI_EXP_SLTCAP_HPC))
return false;
- return root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
+ if (pcie_ports_native)
+ return true;
+
+ host = pci_find_host_bridge(bridge->bus);
+ return host->native_pcie_hotplug;
}
/**
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1465,9 +1465,11 @@ static inline int pci_irqd_intx_xlate(st
#ifdef CONFIG_PCIEPORTBUS
extern bool pcie_ports_disabled;
+extern bool pcie_ports_native;
extern bool pcie_ports_auto;
#else
#define pcie_ports_disabled true
+#define pcie_ports_native false
#define pcie_ports_auto false
#endif
--- a/include/linux/pci_hotplug.h
+++ b/include/linux/pci_hotplug.h
@@ -176,7 +176,7 @@ struct hotplug_params {
#ifdef CONFIG_ACPI
#include <linux/acpi.h>
int pci_get_hp_params(struct pci_dev *dev, struct hotplug_params *hpp);
-bool pciehp_is_native(struct pci_dev *pdev);
+bool pciehp_is_native(struct pci_dev *bridge);
int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags);
int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle);
int acpi_pci_detect_ejectable(acpi_handle handle);
@@ -186,6 +186,6 @@ static inline int pci_get_hp_params(stru
{
return -ENODEV;
}
-static inline bool pciehp_is_native(struct pci_dev *pdev) { return true; }
+static inline bool pciehp_is_native(struct pci_dev *bridge) { return true; }
#endif
#endif
--- a/drivers/pci/pcie/portdrv.h
+++ b/drivers/pci/pcie/portdrv.h
@@ -11,8 +11,6 @@
#include <linux/compiler.h>
-extern bool pcie_ports_native;
-
/* Service Type */
#define PCIE_PORT_SERVICE_PME_SHIFT 0 /* Power Management Event */
#define PCIE_PORT_SERVICE_PME (1 << PCIE_PORT_SERVICE_PME_SHIFT)