Merge branch 'pci/errors'

- Add PCI_ERROR_RESPONSE and related definitions for signaling and checking
  for transaction errors on PCI (Naveen Naidu)

- Fabricate PCI_ERROR_RESPONSE data (~0) in config read wrappers, instead
  of in host controller drivers, when transactions fail on PCI (Naveen
  Naidu)

- Use PCI_POSSIBLE_ERROR() to check for possible failure of config reads
  (Naveen Naidu)

* pci/errors:
  PCI: xgene: Use PCI_ERROR_RESPONSE to identify config read errors
  PCI: hv: Use PCI_ERROR_RESPONSE to identify config read errors
  PCI: keystone: Use PCI_ERROR_RESPONSE to identify config read errors
  PCI: Use PCI_ERROR_RESPONSE to identify config read errors
  PCI: cpqphp: Use PCI_POSSIBLE_ERROR() to check config reads
  PCI/PME: Use PCI_POSSIBLE_ERROR() to check config reads
  PCI/DPC: Use PCI_POSSIBLE_ERROR() to check config reads
  PCI: pciehp: Use PCI_POSSIBLE_ERROR() to check config reads
  PCI: vmd: Use PCI_POSSIBLE_ERROR() to check config reads
  PCI/ERR: Use PCI_POSSIBLE_ERROR() to check config reads
  PCI: rockchip-host: Drop error data fabrication when config read fails
  PCI: rcar-host: Drop error data fabrication when config read fails
  PCI: altera: Drop error data fabrication when config read fails
  PCI: mvebu: Drop error data fabrication when config read fails
  PCI: aardvark: Drop error data fabrication when config read fails
  PCI: kirin: Drop error data fabrication when config read fails
  PCI: histb: Drop error data fabrication when config read fails
  PCI: exynos: Drop error data fabrication when config read fails
  PCI: mediatek: Drop error data fabrication when config read fails
  PCI: iproc: Drop error data fabrication when config read fails
  PCI: thunder: Drop error data fabrication when config read fails
  PCI: Drop error data fabrication when config read fails
  PCI: Use PCI_SET_ERROR_RESPONSE() for disconnected devices
  PCI: Set error response data when config read fails
  PCI: Add PCI_ERROR_RESPONSE and related definitions

include/linux/pci.h

@@ -154,6 +154,15 @@ enum pci_interrupt_pin {
 /* The number of legacy PCI INTx interrupts */
 #define PCI_NUM_INTX	4
 
+/*
+ * Reading from a device that doesn't respond typically returns ~0.  A
+ * successful read from a device may also return ~0, so you need additional
+ * information to reliably identify errors.
+ */
+#define PCI_ERROR_RESPONSE		(~0ULL)
+#define PCI_SET_ERROR_RESPONSE(val)	(*(val) = ((typeof(*(val))) PCI_ERROR_RESPONSE))
+#define PCI_POSSIBLE_ERROR(val)		((val) == ((typeof(val)) PCI_ERROR_RESPONSE))
+
 /*
  * pci_power_t values must match the bits in the Capabilities PME_Support
  * and Control/Status PowerState fields in the Power Management capability.