[PATCH v13 5/5] PCI: Centralize pci_aer_available() checking

[Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>]

From: Bjorn Helgaas <bhelgaas@google.com>

"pci=noaer" tells us not to use AER.  pci_aer_available() reports that,
and it also reports the other cases where the OS cannot use AER at all,
namely CONFIG_PCIEAER=n and MSI being unavailable.

Set host_bridge->native_aer from pci_aer_available() when we initialize
the host bridge, so callers only have to look at native_aer and we do not
have to test pci_aer_available() separately in each of them.

Do this in pci_init_host_bridge() rather than in acpi_pci_root_create()
so it also covers host bridges that are not described by ACPI and never
reach acpi_pci_root_create().

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Co-developed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---
Changes since v12

 * Rebased to v7.3-rc3.
 * Set native_aer from pci_aer_available() in pci_init_host_bridge()
   rather than clearing it in acpi_pci_root_create(), so "pci=noaer" also
   works on host bridges that ACPI does not describe.
 * pci_aer_available() stays in the DPC arm of
   get_port_device_capability(), where pcie_ports_dpc_native still needs
   it.

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

 drivers/pci/pcie/portdrv.c | 3 +--
 drivers/pci/probe.c        | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c
index 32fc623dd410..9f8c6dd434c5 100644
--- a/drivers/pci/pcie/portdrv.c
+++ b/drivers/pci/pcie/portdrv.c
@@ -239,8 +239,7 @@ static int get_port_device_capability(struct pci_dev *dev)
 #ifdef CONFIG_PCIEAER
 	if ((pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
              pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC) &&
-	    dev->aer_cap && pci_aer_available() &&
-	    host->native_aer)
+	    dev->aer_cap && host->native_aer)
 		services |= PCIE_PORT_SERVICE_AER;
 #endif
 
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 5f7eb6bc438b..0429f5671c63 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -669,7 +669,7 @@ static void pci_init_host_bridge(struct pci_host_bridge *bridge)
 	 * OS from interfering.
 	 */
 #ifdef CONFIG_PCIEPORTBUS
-	bridge->native_aer = 1;
+	bridge->native_aer = pci_aer_available();
 	bridge->native_pcie_hotplug = 1;
 	bridge->native_pme = 1;
 	bridge->native_dpc = 1;
-- 
2.43.0