File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
new file mode 100644
index 0000000..8a10a7a
--- /dev/null
+++ b/drivers/acpi/pci_irq.c
@@ -0,0 +1,513 @@
+/*
+ *  pci_irq.c - ACPI PCI Interrupt Routing ($Revision: 11 $)
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *  Copyright (C) 2002       Dominik Brodowski <devel@brodo.de>
+ *  (c) Copyright 2008 Hewlett-Packard Development Company, L.P.
+ *	Bjorn Helgaas <bjorn.helgaas@hp.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+
+#include <linux/dmi.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/pm.h>
+#include <linux/pci.h>
+#include <linux/acpi.h>
+#include <linux/slab.h>
+
+#define PREFIX "ACPI: "
+
+#define _COMPONENT		ACPI_PCI_COMPONENT
+ACPI_MODULE_NAME("pci_irq");
+
+struct acpi_prt_entry {
+	struct acpi_pci_id	id;
+	u8			pin;
+	acpi_handle		link;
+	u32			index;		/* GSI, or link _CRS index */
+};
+
+static inline char pin_name(int pin)
+{
+	return 'A' + pin - 1;
+}
+
+/* --------------------------------------------------------------------------
+                         PCI IRQ Routing Table (PRT) Support
+   -------------------------------------------------------------------------- */
+
+/* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
+static const struct dmi_system_id medion_md9580[] = {
+	{
+		.ident = "Medion MD9580-F laptop",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "A555"),
+		},
+	},
+	{ }
+};
+
+/* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */
+static const struct dmi_system_id dell_optiplex[] = {
+	{
+		.ident = "Dell Optiplex GX1",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"),
+		},
+	},
+	{ }
+};
+
+/* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */
+static const struct dmi_system_id hp_t5710[] = {
+	{
+		.ident = "HP t5710",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"),
+			DMI_MATCH(DMI_BOARD_NAME, "098Ch"),
+		},
+	},
+	{ }
+};
+
+struct prt_quirk {
+	const struct dmi_system_id *system;
+	unsigned int		segment;
+	unsigned int		bus;
+	unsigned int		device;
+	unsigned char		pin;
+	const char		*source;	/* according to BIOS */
+	const char		*actual_source;
+};
+
+#define PCI_INTX_PIN(c)		(c - 'A' + 1)
+
+/*
+ * These systems have incorrect _PRT entries.  The BIOS claims the PCI
+ * interrupt at the listed segment/bus/device/pin is connected to the first
+ * link device, but it is actually connected to the second.
+ */
+static const struct prt_quirk prt_quirks[] = {
+	{ medion_md9580, 0, 0, 9, PCI_INTX_PIN('A'),
+		"\\_SB_.PCI0.ISA_.LNKA",
+		"\\_SB_.PCI0.ISA_.LNKB"},
+	{ dell_optiplex, 0, 0, 0xd, PCI_INTX_PIN('A'),
+		"\\_SB_.LNKB",
+		"\\_SB_.LNKA"},
+	{ hp_t5710, 0, 0, 1, PCI_INTX_PIN('A'),
+		"\\_SB_.PCI0.LNK1",
+		"\\_SB_.PCI0.LNK3"},
+};
+
+static void do_prt_fixups(struct acpi_prt_entry *entry,
+			  struct acpi_pci_routing_table *prt)
+{
+	int i;
+	const struct prt_quirk *quirk;
+
+	for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) {
+		quirk = &prt_quirks[i];
+
+		/* All current quirks involve link devices, not GSIs */
+		if (!prt->source)
+			continue;
+
+		if (dmi_check_system(quirk->system) &&
+		    entry->id.segment == quirk->segment &&
+		    entry->id.bus == quirk->bus &&
+		    entry->id.device == quirk->device &&
+		    entry->pin == quirk->pin &&
+		    !strcmp(prt->source, quirk->source) &&
+		    strlen(prt->source) >= strlen(quirk->actual_source)) {
+			printk(KERN_WARNING PREFIX "firmware reports "
+				"%04x:%02x:%02x PCI INT %c connected to %s; "
+				"changing to %s\n",
+				entry->id.segment, entry->id.bus,
+				entry->id.device, pin_name(entry->pin),
+				prt->source, quirk->actual_source);
+			strcpy(prt->source, quirk->actual_source);
+		}
+	}
+}
+
+static int acpi_pci_irq_check_entry(acpi_handle handle, struct pci_dev *dev,
+				  int pin, struct acpi_pci_routing_table *prt,
+				  struct acpi_prt_entry **entry_ptr)
+{
+	int segment = pci_domain_nr(dev->bus);
+	int bus = dev->bus->number;
+	int device = pci_ari_enabled(dev->bus) ? 0 : PCI_SLOT(dev->devfn);
+	struct acpi_prt_entry *entry;
+
+	if (((prt->address >> 16) & 0xffff) != device ||
+	    prt->pin + 1 != pin)
+		return -ENODEV;
+
+	entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
+	if (!entry)
+		return -ENOMEM;
+
+	/*
+	 * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
+	 * 1=INTA, 2=INTB.  We use the PCI encoding throughout, so convert
+	 * it here.
+	 */
+	entry->id.segment = segment;
+	entry->id.bus = bus;
+	entry->id.device = (prt->address >> 16) & 0xFFFF;
+	entry->pin = prt->pin + 1;
+
+	do_prt_fixups(entry, prt);
+
+	entry->index = prt->source_index;
+
+	/*
+	 * Type 1: Dynamic
+	 * ---------------
+	 * The 'source' field specifies the PCI interrupt link device used to
+	 * configure the IRQ assigned to this slot|dev|pin.  The 'source_index'
+	 * indicates which resource descriptor in the resource template (of
+	 * the link device) this interrupt is allocated from.
+	 * 
+	 * NOTE: Don't query the Link Device for IRQ information at this time
+	 *       because Link Device enumeration may not have occurred yet
+	 *       (e.g. exists somewhere 'below' this _PRT entry in the ACPI
+	 *       namespace).
+	 */
+	if (prt->source[0])
+		acpi_get_handle(handle, prt->source, &entry->link);
+
+	/*
+	 * Type 2: Static
+	 * --------------
+	 * The 'source' field is NULL, and the 'source_index' field specifies
+	 * the IRQ value, which is hardwired to specific interrupt inputs on
+	 * the interrupt controller.
+	 */
+
+	ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
+			      "      %04x:%02x:%02x[%c] -> %s[%d]\n",
+			      entry->id.segment, entry->id.bus,
+			      entry->id.device, pin_name(entry->pin),
+			      prt->source, entry->index));
+
+	*entry_ptr = entry;
+
+	return 0;
+}
+
+static int acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
+			  int pin, struct acpi_prt_entry **entry_ptr)
+{
+	acpi_status status;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct acpi_pci_routing_table *entry;
+	acpi_handle handle = NULL;
+
+	if (dev->bus->bridge)
+		handle = ACPI_HANDLE(dev->bus->bridge);
+
+	if (!handle)
+		return -ENODEV;
+
+	/* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
+	status = acpi_get_irq_routing_table(handle, &buffer);
+	if (ACPI_FAILURE(status)) {
+		kfree(buffer.pointer);
+		return -ENODEV;
+	}
+
+	entry = buffer.pointer;
+	while (entry && (entry->length > 0)) {
+		if (!acpi_pci_irq_check_entry(handle, dev, pin,
+						 entry, entry_ptr))
+			break;
+		entry = (struct acpi_pci_routing_table *)
+		    ((unsigned long)entry + entry->length);
+	}
+
+	kfree(buffer.pointer);
+	return 0;
+}
+
+/* --------------------------------------------------------------------------
+                          PCI Interrupt Routing Support
+   -------------------------------------------------------------------------- */
+#ifdef CONFIG_X86_IO_APIC
+extern int noioapicquirk;
+extern int noioapicreroute;
+
+static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
+{
+	struct pci_bus *bus_it;
+
+	for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
+		if (!bus_it->self)
+			return 0;
+		if (bus_it->self->irq_reroute_variant)
+			return bus_it->self->irq_reroute_variant;
+	}
+	return 0;
+}
+
+/*
+ * Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ
+ * entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does
+ * during interrupt handling). When this INTx generation cannot be disabled,
+ * we reroute these interrupts to their legacy equivalent to get rid of
+ * spurious interrupts.
+ */
+static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
+				       struct acpi_prt_entry *entry)
+{
+	if (noioapicquirk || noioapicreroute) {
+		return 0;
+	} else {
+		switch (bridge_has_boot_interrupt_variant(dev->bus)) {
+		case 0:
+			/* no rerouting necessary */
+			return 0;
+		case INTEL_IRQ_REROUTE_VARIANT:
+			/*
+			 * Remap according to INTx routing table in 6700PXH
+			 * specs, intel order number 302628-002, section
+			 * 2.15.2. Other chipsets (80332, ...) have the same
+			 * mapping and are handled here as well.
+			 */
+			dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy "
+				 "IRQ %d\n", entry->index,
+				 (entry->index % 4) + 16);
+			entry->index = (entry->index % 4) + 16;
+			return 1;
+		default:
+			dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy "
+				 "IRQ: unknown mapping\n", entry->index);
+			return -1;
+		}
+	}
+}
+#endif /* CONFIG_X86_IO_APIC */
+
+static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
+{
+	struct acpi_prt_entry *entry = NULL;
+	struct pci_dev *bridge;
+	u8 bridge_pin, orig_pin = pin;
+	int ret;
+
+	ret = acpi_pci_irq_find_prt_entry(dev, pin, &entry);
+	if (!ret && entry) {
+#ifdef CONFIG_X86_IO_APIC
+		acpi_reroute_boot_interrupt(dev, entry);
+#endif /* CONFIG_X86_IO_APIC */
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
+				  pci_name(dev), pin_name(pin)));
+		return entry;
+	}
+
+	/*
+	 * Attempt to derive an IRQ for this device from a parent bridge's
+	 * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge).
+	 */
+	bridge = dev->bus->self;
+	while (bridge) {
+		pin = pci_swizzle_interrupt_pin(dev, pin);
+
+		if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
+			/* PC card has the same IRQ as its cardbridge */
+			bridge_pin = bridge->pin;
+			if (!bridge_pin) {
+				ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+						  "No interrupt pin configured for device %s\n",
+						  pci_name(bridge)));
+				return NULL;
+			}
+			pin = bridge_pin;
+		}
+
+		ret = acpi_pci_irq_find_prt_entry(bridge, pin, &entry);
+		if (!ret && entry) {
+			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+					 "Derived GSI for %s INT %c from %s\n",
+					 pci_name(dev), pin_name(orig_pin),
+					 pci_name(bridge)));
+			return entry;
+		}
+
+		dev = bridge;
+		bridge = dev->bus->self;
+	}
+
+	dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
+		 pin_name(orig_pin));
+	return NULL;
+}
+
+#if IS_ENABLED(CONFIG_ISA) || IS_ENABLED(CONFIG_EISA)
+static int acpi_isa_register_gsi(struct pci_dev *dev)
+{
+	u32 dev_gsi;
+
+	/* Interrupt Line values above 0xF are forbidden */
+	if (dev->irq > 0 && (dev->irq <= 0xF) &&
+	    acpi_isa_irq_available(dev->irq) &&
+	    (acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) {
+		dev_warn(&dev->dev, "PCI INT %c: no GSI - using ISA IRQ %d\n",
+			 pin_name(dev->pin), dev->irq);
+		acpi_register_gsi(&dev->dev, dev_gsi,
+				  ACPI_LEVEL_SENSITIVE,
+				  ACPI_ACTIVE_LOW);
+		return 0;
+	}
+	return -EINVAL;
+}
+#else
+static inline int acpi_isa_register_gsi(struct pci_dev *dev)
+{
+	return -ENODEV;
+}
+#endif
+
+int acpi_pci_irq_enable(struct pci_dev *dev)
+{
+	struct acpi_prt_entry *entry;
+	int gsi;
+	u8 pin;
+	int triggering = ACPI_LEVEL_SENSITIVE;
+	int polarity = ACPI_ACTIVE_LOW;
+	char *link = NULL;
+	char link_desc[16];
+	int rc;
+
+	pin = dev->pin;
+	if (!pin) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				  "No interrupt pin configured for device %s\n",
+				  pci_name(dev)));
+		return 0;
+	}
+
+	if (dev->irq_managed && dev->irq > 0)
+		return 0;
+
+	entry = acpi_pci_irq_lookup(dev, pin);
+	if (!entry) {
+		/*
+		 * IDE legacy mode controller IRQs are magic. Why do compat
+		 * extensions always make such a nasty mess.
+		 */
+		if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
+				(dev->class & 0x05) == 0)
+			return 0;
+	}
+
+	if (entry) {
+		if (entry->link)
+			gsi = acpi_pci_link_allocate_irq(entry->link,
+							 entry->index,
+							 &triggering, &polarity,
+							 &link);
+		else
+			gsi = entry->index;
+	} else
+		gsi = -1;
+
+	/*
+	 * No IRQ known to the ACPI subsystem - maybe the BIOS / 
+	 * driver reported one, then use it. Exit in any case.
+	 */
+	if (gsi < 0) {
+		if (acpi_isa_register_gsi(dev))
+			dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
+				 pin_name(pin));
+
+		kfree(entry);
+		return 0;
+	}
+
+	rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
+	if (rc < 0) {
+		dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
+			 pin_name(pin));
+		kfree(entry);
+		return rc;
+	}
+	dev->irq = rc;
+	dev->irq_managed = 1;
+
+	if (link)
+		snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
+	else
+		link_desc[0] = '\0';
+
+	dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
+		pin_name(pin), link_desc, gsi,
+		(triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
+		(polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);
+
+	kfree(entry);
+	return 0;
+}
+
+void acpi_pci_irq_disable(struct pci_dev *dev)
+{
+	struct acpi_prt_entry *entry;
+	int gsi;
+	u8 pin;
+
+	pin = dev->pin;
+	if (!pin || !dev->irq_managed || dev->irq <= 0)
+		return;
+
+	/* Keep IOAPIC pin configuration when suspending */
+	if (dev->dev.power.is_prepared)
+		return;
+#ifdef	CONFIG_PM
+	if (dev->dev.power.runtime_status == RPM_SUSPENDING)
+		return;
+#endif
+
+	entry = acpi_pci_irq_lookup(dev, pin);
+	if (!entry)
+		return;
+
+	if (entry->link)
+		gsi = acpi_pci_link_free_irq(entry->link);
+	else
+		gsi = entry->index;
+
+	kfree(entry);
+
+	/*
+	 * TBD: It might be worth clearing dev->irq by magic constant
+	 * (e.g. PCI_UNDEFINED_IRQ).
+	 */
+
+	dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
+	if (gsi >= 0) {
+		acpi_unregister_gsi(gsi);
+		dev->irq_managed = 0;
+	}
+}