PCI: PCIe: Ask BIOS for control of all native services at once

After commit 852972acff8f10f3a15679be2059bb94916cba5d (ACPI: Disable
ASPM if the platform won't provide _OSC control for PCIe) control of
the PCIe Capability Structure is unconditionally requested by
acpi_pci_root_add(), which in principle may cause problems to
happen in two ways.  First, the BIOS may refuse to give control of
the PCIe Capability Structure if it is not asked for any of the
_OSC features depending on it at the same time.  Second, the BIOS may
assume that control of the _OSC features depending on the PCIe
Capability Structure will be requested in the future and may behave
incorrectly if that doesn't happen.  For this reason, control of
the PCIe Capability Structure should always be requested along with
control of any other _OSC features that may depend on it (ie. PCIe
native PME, PCIe native hot-plug, PCIe AER).

Rework the PCIe port driver so that (1) it checks which native PCIe
port services can be enabled, according to the BIOS, and (2) it
requests control of all these services simultaneously.  In
particular, this causes pcie_portdrv_probe() to fail if the BIOS
refuses to grant control of the PCIe Capability Structure, which
means that no native PCIe port services can be enabled for the PCIe
Root Complex the given port belongs to.  If that happens, ASPM is
disabled to avoid problems with mishandling it by the part of the
PCIe hierarchy for which control of the PCIe Capability Structure
has not been received.

Make it possible to override this behavior using 'pcie_ports=native'
(use the PCIe native services regardless of the BIOS response to the
control request), or 'pcie_ports=compat' (do not use the PCIe native
services at all).

Accordingly, rework the existing PCIe port service drivers so that
they don't request control of the services directly.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

2 files changed, 1 insertions, 49 deletions

diff --git a/drivers/pci/pcie/aer/aerdrv_acpi.c b/drivers/pci/pcie/aer/aerdrv_acpi.c
index 3a276a0cea9..2bb9b897221 100644
--- a/drivers/pci/pcie/aer/aerdrv_acpi.c
+++ b/drivers/pci/pcie/aer/aerdrv_acpi.c
@@ -19,42 +19,6 @@
 #include <acpi/apei.h>
 #include "aerdrv.h"
 
-/**
- * aer_osc_setup - run ACPI _OSC method
- * @pciedev: pcie_device which AER is being enabled on
- *
- * @return: Zero on success. Nonzero otherwise.
- *
- * Invoked when PCIe bus loads AER service driver. To avoid conflict with
- * BIOS AER support requires BIOS to yield AER control to OS native driver.
- **/
-int aer_osc_setup(struct pcie_device *pciedev)
-{
-	acpi_status status = AE_NOT_FOUND;
-	struct pci_dev *pdev = pciedev->port;
-	acpi_handle handle = NULL;
-
-	if (acpi_pci_disabled)
-		return -1;
-
-	handle = acpi_find_root_bridge_handle(pdev);
-	if (handle) {
-		u32 flags = OSC_PCI_EXPRESS_AER_CONTROL |
-				OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL;
-		status = acpi_pci_osc_control_set(handle, &flags, flags);
-	}
-
-	if (ACPI_FAILURE(status)) {
-		dev_printk(KERN_DEBUG, &pciedev->device, "AER service couldn't "
-			   "init device: %s\n",
-			   (status == AE_SUPPORT || status == AE_NOT_FOUND) ?
-			   "no _OSC support" : "_OSC failed");
-		return -1;
-	}
-
-	return 0;
-}
-
 #ifdef CONFIG_ACPI_APEI
 static inline int hest_match_pci(struct acpi_hest_aer_common *p,
 				 struct pci_dev *pci)
diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c
index fc0b5a93e1d..29e268fadf1 100644
--- a/drivers/pci/pcie/aer/aerdrv_core.c
+++ b/drivers/pci/pcie/aer/aerdrv_core.c
@@ -772,22 +772,10 @@ void aer_isr(struct work_struct *work)
  */
 int aer_init(struct pcie_device *dev)
 {
-	if (pcie_aer_get_firmware_first(dev->port)) {
-		dev_printk(KERN_DEBUG, &dev->device,
-			   "PCIe errors handled by platform firmware.\n");
-		goto out;
-	}
-
-	if (aer_osc_setup(dev))
-		goto out;
-
-	return 0;
-out:
 	if (forceload) {
 		dev_printk(KERN_DEBUG, &dev->device,
 			   "aerdrv forceload requested.\n");
 		pcie_aer_force_firmware_first(dev->port, 0);
-		return 0;
 	}
-	return -ENXIO;
+	return 0;
 }