x86/PCI: VMD: Request userspace control of PCIe hotplug indicators

Add set_dev_domain_options() to set PCI domain-specific options as devices
are added.  The first usage is to request exclusive userspace control of
PCIe hotplug indicators in VMD domains.

Devices in a VMD domain use PCIe hotplug Attention and Power Indicators in
a non-standard way; tell pciehp to ignore the indicators so userspace can
control them via the sysfs "attention" file.

To determine whether a bus is within a VMD domain, add a bool to the
pci_sysdata structure that the VMD driver sets during initialization.

[bhelgaas: changelog]
Requested-by: Kapil Karkra <kapil.karkra@intel.com>
Tested-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
index 9ab7507..1411dbe 100644
--- a/arch/x86/include/asm/pci.h
+++ b/arch/x86/include/asm/pci.h
@@ -23,6 +23,9 @@
 #ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
 	void		*fwnode;	/* IRQ domain for MSI assignment */
 #endif
+#if IS_ENABLED(CONFIG_VMD)
+	bool vmd_domain;		/* True if in Intel VMD domain */
+#endif
 };
 
 extern int pci_routeirq;
@@ -56,6 +59,17 @@
 #define pci_root_bus_fwnode	_pci_root_bus_fwnode
 #endif
 
+static inline bool is_vmd(struct pci_bus *bus)
+{
+#if IS_ENABLED(CONFIG_VMD)
+	struct pci_sysdata *sd = bus->sysdata;
+
+	return sd->vmd_domain;
+#else
+	return false;
+#endif
+}
+
 /* Can be used to override the logic in pci_scan_bus for skipping
    already-configured bus numbers - to be used for buggy BIOSes
    or architectures with incomplete PCI setup by the loader */