PCI/ACPI: Request _OSC control once for each root bridge (v3)

Move the evaluation of acpi_pci_osc_control_set() (to request control of
PCI Express native features) into acpi_pci_root_add() to avoid calling
it many times for the same root complex with the same arguments.
Additionally, check if all of the requisite _OSC support bits are set
before calling acpi_pci_osc_control_set() for a given root complex.

References: https://bugzilla.kernel.org/show_bug.cgi?id=20232
Reported-by: Ozan Caglayan <ozan@pardus.org.tr>
Tested-by: Ozan Caglayan <ozan@pardus.org.tr>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index c8b6473c5f42..479d9bb88e11 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -40,4 +40,10 @@ static inline acpi_handle acpi_find_root_bridge_handle(struct pci_dev *pdev)
 { return NULL; }
 #endif
 
+#ifdef CONFIG_ACPI_APEI
+extern bool aer_acpi_firmware_first(void);
+#else
+static inline bool aer_acpi_firmware_first(void) { return false; }
+#endif
+
 #endif  /* _PCI_ACPI_H_ */