[PATCH v13 3/5] PCI/ACPI: Tidy _OSC control bit checking

From: Kuppuswamy Sathyanarayanan

Date: Sat Sep 19 2026 - 12:27:25 EST


Add OSC_OWNER() helper to prettify checking the _OSC control bits to learn
whether the platform has granted us control of PCI features. No functional
change intended.

[bhelgaas: split to separate patch, commit log]
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
Changes since v12

* Rebased to v7.3-rc3. Parenthesized the OSC_OWNER() arguments, as
checkpatch --strict asks.
* Also convert native_cxl_error, which v12 left open coded. Its bit comes
from the extended control word, so that word gets its own ext_ctrl
local.

v12 posting
https://lore.kernel.org/all/20201126011816.711106-1-helgaas@xxxxxxxxxx/

drivers/acpi/pci_root.c | 37 ++++++++++++++++++++++---------------
1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 88c65f34e305..756dc2f055f5 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -993,6 +993,12 @@ static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
__acpi_pci_root_release_info(bridge->release_data);
}

+#define OSC_OWNER(ctrl, bit, flag) \
+ do { \
+ if (!((ctrl) & (bit))) \
+ flag = 0; \
+ } while (0)
+
struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
struct acpi_pci_root_ops *ops,
struct acpi_pci_root_info *info,
@@ -1003,6 +1009,7 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
int node = acpi_get_node(device->handle);
struct pci_bus *bus;
struct pci_host_bridge *host_bridge;
+ u32 ctrl, ext_ctrl;

info->root = root;
info->bridge = device;
@@ -1028,21 +1035,21 @@ 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))
- host_bridge->native_pcie_hotplug = 0;
- if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
- host_bridge->native_shpc_hotplug = 0;
- if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL))
- host_bridge->native_aer = 0;
- if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL))
- host_bridge->native_pme = 0;
- if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
- host_bridge->native_ltr = 0;
- if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
- host_bridge->native_dpc = 0;
-
- if (!(root->osc_ext_control_set & OSC_CXL_ERROR_REPORTING_CONTROL))
- host_bridge->native_cxl_error = 0;
+
+ ctrl = root->osc_control_set;
+ ext_ctrl = root->osc_ext_control_set;
+
+ OSC_OWNER(ctrl, OSC_PCI_EXPRESS_NATIVE_HP_CONTROL,
+ host_bridge->native_pcie_hotplug);
+ OSC_OWNER(ctrl, OSC_PCI_SHPC_NATIVE_HP_CONTROL,
+ host_bridge->native_shpc_hotplug);
+ OSC_OWNER(ctrl, OSC_PCI_EXPRESS_AER_CONTROL, host_bridge->native_aer);
+ OSC_OWNER(ctrl, OSC_PCI_EXPRESS_PME_CONTROL, host_bridge->native_pme);
+ OSC_OWNER(ctrl, OSC_PCI_EXPRESS_LTR_CONTROL, host_bridge->native_ltr);
+ OSC_OWNER(ctrl, OSC_PCI_EXPRESS_DPC_CONTROL, host_bridge->native_dpc);
+
+ OSC_OWNER(ext_ctrl, OSC_CXL_ERROR_REPORTING_CONTROL,
+ host_bridge->native_cxl_error);

acpi_dev_power_up_children_with_adr(device);

--
2.43.0