PCI/ACPI: Centralize pcie_ports_native checking

If the user booted with "pcie_ports=native", we take control of the PCIe
port services unconditionally, regardless of what _OSC says.

Centralize the testing of pcie_ports_native in acpi_pci_root_create(),
where we interpret the _OSC results, so other places only have to check
host_bridge->native_X and we don't have to sprinkle tests of
pcie_ports_native everywhere.

Rather than overriding the host_bridge->native_X flags after the fact, fold
"pcie_ports=native" into the _OSC control mask we evaluate, i.e., proceed
as though the platform had granted control of the port services.  That way
there is a single mechanism deciding each native_X flag, and we can report
exactly which features we are overriding _OSC for instead of just noting
that we are overriding something:

  acpi PNP0A08:00: _OSC: OS forcing control ("pcie_ports=native") of [PCIeHotplug PME AER DPC]

Forcing host_bridge->native_aer also restores DPC service binding under
"pcie_ports=native", which regressed in commit 97ca178c899d ("PCI/DPC:
Allow DPC on all Downstream Ports when OS controls AER").  That commit
replaced the AER service test in get_port_device_capability() with
host->native_aer, so DPC stayed off when host_bridge->native_aer was not
set.

This also extends "pcie_ports=native" to host_bridge->native_dpc, which had
no pcie_ports_native fallback before.  That effect is narrow.  native_dpc
is only consumed by pci_dpc_recovered(), where with CONFIG_PCIE_EDR=n it
previously gave up immediately and now lets pciehp wait for DPC recovery
before treating a Link Down as a hotplug event.

Fold "pcie_ports=dpc-native" into the control mask the same way, so
host_bridge->native_dpc reflects it as well, with the same narrow effect on
pci_dpc_recovered().  Move the pcie_ports_dpc_native declaration to
<linux/pci.h> so acpi_pci_root_create() can test it.

host_bridge->native_ltr is deliberately not forced.  "pcie_ports=" controls
PCIe port services and LTR is not one.  There is no PCIE_PORT_SERVICE_LTR,
and native_ltr is only used by pci_configure_ltr() to enable ASPM L1.2, so
forcing it would be an ASPM policy decision users did not ask for.

SHPC hotplug is left alone for a simpler reason: SHPC is a conventional PCI
feature rather than a PCIe one, so "pcie_ports=" has no bearing on it.

Fixes: 97ca178c899d ("PCI/DPC: Allow DPC on all Downstream Ports when OS controls AER")
Closes: https://lore.kernel.org/linux-pci/20260901064554.2178688-1-kanie@linux.alibaba.com/
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Guixin Liu <kanie@linux.alibaba.com>
Acked-by: Rafael J. Wysocki (Intel) <rafael@kernel.org> # ACPI core
Link: https://patch.msgid.link/20261002211828.1293177-4-sathyanarayanan.kuppuswamy@linux.intel.com

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/pci.h b/include/linux/pci.h
index d31a8d107b1e..f3e9c6c9c5e0 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1915,12 +1915,14 @@ static inline int pci_irqd_intx_xlate(struct irq_domain *d,
 #ifdef CONFIG_PCIEPORTBUS
 extern bool pcie_ports_disabled;
 extern bool pcie_ports_native;
+extern bool pcie_ports_dpc_native;
 
 int pcie_set_target_speed(struct pci_dev *port, enum pci_bus_speed speed_req,
 			  bool use_lt);
 #else
 #define pcie_ports_disabled	true
 #define pcie_ports_native	false
+#define pcie_ports_dpc_native	false
 
 static inline int pcie_set_target_speed(struct pci_dev *port,
 					enum pci_bus_speed speed_req,