On 7/14/25 4:00 PM, Sathyanarayanan Kuppuswamy wrote:
On 7/13/25 7:31 AM, Lukas Wunner wrote:
Bjorn suggests to "set host->native_pcie_hotplug up front based on
CONFIG_HOTPLUG_PCI_PCIE and pcie_ports_native, and pciehp_is_native()
would collapse to just an accessor for host->native_pcie_hotplug".
Unfortunately only half of this is possible:
The check for pcie_ports_native can indeed be moved out of
pciehp_is_native() and into acpi_pci_root_create().
The check for CONFIG_HOTPLUG_PCI_PCIE however cannot be eliminated:
get_port_device_capability() needs to know whether platform firmware has
granted PCIe Native Hot-Plug control to the operating system. If it has
and CONFIG_HOTPLUG_PCI_PCIE is disabled, the function disables hotplug
interrupts in case BIOS left them enabled.
If host->native_pcie_hotplug would be set up front based on
CONFIG_HOTPLUG_PCI_PCIE, it would later on be impossible for
get_port_device_capability() to tell whether it can safely disable hotplug
interrupts: It wouldn't know whether Native Hot-Plug control was granted.
Since pcie_ports_native is a PCI driver specific override option, I am not
sure it is worth referring to this option in ACPI driver, just to reduce the
number of pcie_ports_native checks from 2 to 1.
Never mind. It looks like the goal is to simplify the pciehp_is_native() call.
Since you cannot get rid of CONFIG_HOTPLUG_PCI_PCIE check, do you
still want to do this simplification?
Link: https://lore.kernel.org/r/20250627025607.GA1650254@bhelgaas/
Suggested-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
---
drivers/acpi/pci_root.c | 3 ++-
drivers/pci/pci-acpi.c | 3 ---
drivers/pci/pcie/portdrv.c | 2 +-
3 files changed, 3 insertions(+), 5 deletions(-)
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 74ade4160314..f3de0dc9c533 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -1028,7 +1028,8 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
goto out_release_info;
host_bridge = to_pci_host_bridge(bus->bridge);
- if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
+ if (!pcie_ports_native &&
+ !(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
host_bridge->native_pcie_hotplug = 0;
if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
host_bridge->native_shpc_hotplug = 0;
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index ed7ed66a595b..b513826ea293 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -820,9 +820,6 @@ bool pciehp_is_native(struct pci_dev *bridge)
if (!IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
return false;
- if (pcie_ports_native)
- return true;
-
host = pci_find_host_bridge(bridge->bus);
return host->native_pcie_hotplug;
}
diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c
index d1b68c18444f..fa83ebdcfecb 100644
--- a/drivers/pci/pcie/portdrv.c
+++ b/drivers/pci/pcie/portdrv.c
@@ -223,7 +223,7 @@ static int get_port_device_capability(struct pci_dev *dev)
if (dev->is_pciehp &&
(pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM) &&
- (pcie_ports_native || host->native_pcie_hotplug)) {
+ host->native_pcie_hotplug) {
services |= PCIE_PORT_SERVICE_HP;
/*
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
