8 files changed, 287 insertions, 147 deletions

diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 083a49fee56a..01c001f3b766 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -2,7 +2,7 @@
 # Makefile for the PCI bus specific drivers.
 #
 
-obj-y		+= access.o bus.o probe.o remove.o pci.o \
+obj-y		+= access.o bus.o probe.o host-bridge.o remove.o pci.o \
 			pci-driver.o search.o pci-sysfs.o rom.o setup-res.o \
 			irq.o vpd.o
 obj-$(CONFIG_PROC_FS) += proc.o
@@ -42,6 +42,7 @@ obj-$(CONFIG_UNICORE32) += setup-bus.o setup-irq.o
 obj-$(CONFIG_PARISC) += setup-bus.o
 obj-$(CONFIG_SUPERH) += setup-bus.o setup-irq.o
 obj-$(CONFIG_PPC) += setup-bus.o
+obj-$(CONFIG_FRV) += setup-bus.o
 obj-$(CONFIG_MIPS) += setup-bus.o setup-irq.o
 obj-$(CONFIG_X86_VISWS) += setup-irq.o
 obj-$(CONFIG_MN10300) += setup-bus.o
diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
new file mode 100644
index 000000000000..a68dc613a5be
--- /dev/null
+++ b/drivers/pci/host-bridge.c
@@ -0,0 +1,96 @@
+/*
+ * host bridge related code
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/module.h>
+
+#include "pci.h"
+
+static struct pci_bus *find_pci_root_bus(struct pci_dev *dev)
+{
+	struct pci_bus *bus;
+
+	bus = dev->bus;
+	while (bus->parent)
+		bus = bus->parent;
+
+	return bus;
+}
+
+static struct pci_host_bridge *find_pci_host_bridge(struct pci_dev *dev)
+{
+	struct pci_bus *bus = find_pci_root_bus(dev);
+
+	return to_pci_host_bridge(bus->bridge);
+}
+
+void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
+				 void (*release_fn)(struct pci_host_bridge *),
+				 void *release_data)
+{
+	bridge->release_fn = release_fn;
+	bridge->release_data = release_data;
+}
+
+static bool resource_contains(struct resource *res1, struct resource *res2)
+{
+	return res1->start <= res2->start && res1->end >= res2->end;
+}
+
+void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
+			     struct resource *res)
+{
+	struct pci_host_bridge *bridge = find_pci_host_bridge(dev);
+	struct pci_host_bridge_window *window;
+	resource_size_t offset = 0;
+
+	list_for_each_entry(window, &bridge->windows, list) {
+		if (resource_type(res) != resource_type(window->res))
+			continue;
+
+		if (resource_contains(window->res, res)) {
+			offset = window->offset;
+			break;
+		}
+	}
+
+	region->start = res->start - offset;
+	region->end = res->end - offset;
+}
+EXPORT_SYMBOL(pcibios_resource_to_bus);
+
+static bool region_contains(struct pci_bus_region *region1,
+			    struct pci_bus_region *region2)
+{
+	return region1->start <= region2->start && region1->end >= region2->end;
+}
+
+void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
+			     struct pci_bus_region *region)
+{
+	struct pci_host_bridge *bridge = find_pci_host_bridge(dev);
+	struct pci_host_bridge_window *window;
+	resource_size_t offset = 0;
+
+	list_for_each_entry(window, &bridge->windows, list) {
+		struct pci_bus_region bus_region;
+
+		if (resource_type(res) != resource_type(window->res))
+			continue;
+
+		bus_region.start = window->res->start - window->offset;
+		bus_region.end = window->res->end - window->offset;
+
+		if (region_contains(&bus_region, region)) {
+			offset = window->offset;
+			break;
+		}
+	}
+
+	res->start = region->start + offset;
+	res->end = region->end + offset;
+}
+EXPORT_SYMBOL(pcibios_bus_to_resource);
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 0f150f271c2a..61e2fefeedab 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -200,7 +200,7 @@ static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 		return PCI_D1;
 	case ACPI_STATE_D2:
 		return PCI_D2;
-	case ACPI_STATE_D3:
+	case ACPI_STATE_D3_HOT:
 		return PCI_D3hot;
 	case ACPI_STATE_D3_COLD:
 		return PCI_D3cold;
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 6b54b23b990b..bf0cee629b60 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -421,6 +421,12 @@ static void pci_device_shutdown(struct device *dev)
 	pci_msix_shutdown(pci_dev);
 
 	/*
+	 * Turn off Bus Master bit on the device to tell it to not
+	 * continue to do DMA
+	 */
+	pci_disable_device(pci_dev);
+
+	/*
 	 * Devices may be enabled to wake up by runtime PM, but they need not
 	 * be supposed to wake up the system from its "power off" state (e.g.
 	 * ACPI S5).  Therefore disable wakeup for all devices that aren't
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 815674415267..8f169002dc7e 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -22,6 +22,7 @@
 #include <linux/interrupt.h>
 #include <linux/device.h>
 #include <linux/pm_runtime.h>
+#include <asm-generic/pci-bridge.h>
 #include <asm/setup.h>
 #include "pci.h"
 
@@ -967,16 +968,59 @@ pci_save_state(struct pci_dev *dev)
 	return 0;
 }
 
+static void pci_restore_config_dword(struct pci_dev *pdev, int offset,
+				     u32 saved_val, int retry)
+{
+	u32 val;
+
+	pci_read_config_dword(pdev, offset, &val);
+	if (val == saved_val)
+		return;
+
+	for (;;) {
+		dev_dbg(&pdev->dev, "restoring config space at offset "
+			"%#x (was %#x, writing %#x)\n", offset, val, saved_val);
+		pci_write_config_dword(pdev, offset, saved_val);
+		if (retry-- <= 0)
+			return;
+
+		pci_read_config_dword(pdev, offset, &val);
+		if (val == saved_val)
+			return;
+
+		mdelay(1);
+	}
+}
+
+static void pci_restore_config_space_range(struct pci_dev *pdev,
+					   int start, int end, int retry)
+{
+	int index;
+
+	for (index = end; index >= start; index--)
+		pci_restore_config_dword(pdev, 4 * index,
+					 pdev->saved_config_space[index],
+					 retry);
+}
+
+static void pci_restore_config_space(struct pci_dev *pdev)
+{
+	if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
+		pci_restore_config_space_range(pdev, 10, 15, 0);
+		/* Restore BARs before the command register. */
+		pci_restore_config_space_range(pdev, 4, 9, 10);
+		pci_restore_config_space_range(pdev, 0, 3, 0);
+	} else {
+		pci_restore_config_space_range(pdev, 0, 15, 0);
+	}
+}
+
 /** 
  * pci_restore_state - Restore the saved state of a PCI device
  * @dev: - PCI device that we're dealing with
  */
 void pci_restore_state(struct pci_dev *dev)
 {
-	int i;
-	u32 val;
-	int tries;
-
 	if (!dev->state_saved)
 		return;
 
@@ -984,24 +1028,8 @@ void pci_restore_state(struct pci_dev *dev)
 	pci_restore_pcie_state(dev);
 	pci_restore_ats_state(dev);
 
-	/*
-	 * The Base Address register should be programmed before the command
-	 * register(s)
-	 */
-	for (i = 15; i >= 0; i--) {
-		pci_read_config_dword(dev, i * 4, &val);
-		tries = 10;		
-		while (tries && val != dev->saved_config_space[i]) {
-			dev_dbg(&dev->dev, "restoring config "
-				"space at offset %#x (was %#x, writing %#x)\n",
-				i, val, (int)dev->saved_config_space[i]);
-			pci_write_config_dword(dev,i * 4,
-				dev->saved_config_space[i]);
-			pci_read_config_dword(dev, i * 4, &val);
-			mdelay(10);
-			tries--;
-		}
-	}
+	pci_restore_config_space(dev);
+
 	pci_restore_pcix_state(dev);
 	pci_restore_msi_state(dev);
 	pci_restore_iov_state(dev);
@@ -3137,18 +3165,12 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
 	return 0;
 }
 
-static int pci_dev_reset(struct pci_dev *dev, int probe)
+static int __pci_dev_reset(struct pci_dev *dev, int probe)
 {
 	int rc;
 
 	might_sleep();
 
-	if (!probe) {
-		pci_cfg_access_lock(dev);
-		/* block PM suspend, driver probe, etc. */
-		device_lock(&dev->dev);
-	}
-
 	rc = pci_dev_specific_reset(dev, probe);
 	if (rc != -ENOTTY)
 		goto done;
@@ -3167,14 +3189,27 @@ static int pci_dev_reset(struct pci_dev *dev, int probe)
 
 	rc = pci_parent_bus_reset(dev, probe);
 done:
+	return rc;
+}
+
+static int pci_dev_reset(struct pci_dev *dev, int probe)
+{
+	int rc;
+
+	if (!probe) {
+		pci_cfg_access_lock(dev);
+		/* block PM suspend, driver probe, etc. */
+		device_lock(&dev->dev);
+	}
+
+	rc = __pci_dev_reset(dev, probe);
+
 	if (!probe) {
 		device_unlock(&dev->dev);
 		pci_cfg_access_unlock(dev);
 	}
-
 	return rc;
 }
-
 /**
  * __pci_reset_function - reset a PCI device function
  * @dev: PCI device to reset
@@ -3219,7 +3254,7 @@ EXPORT_SYMBOL_GPL(__pci_reset_function);
  */
 int __pci_reset_function_locked(struct pci_dev *dev)
 {
-	return pci_dev_reset(dev, 1);
+	return __pci_dev_reset(dev, 0);
 }
 EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
 
@@ -3866,6 +3901,8 @@ static int __init pci_setup(char *str)
 				pcie_bus_config = PCIE_BUS_PERFORMANCE;
 			} else if (!strncmp(str, "pcie_bus_peer2peer", 18)) {
 				pcie_bus_config = PCIE_BUS_PEER2PEER;
+			} else if (!strncmp(str, "pcie_scan_all", 13)) {
+				pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
 			} else {
 				printk(KERN_ERR "PCI: Unknown option `%s'\n",
 						str);
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index 2f589a54f9bd..75915b30ad19 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -249,7 +249,7 @@ static int get_port_device_capability(struct pci_dev *dev)
 	int services = 0, pos;
 	u16 reg16;
 	u32 reg32;
-	int cap_mask;
+	int cap_mask = 0;
 	int err;
 
 	if (pcie_ports_disabled)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 5e1ca3c58a7d..658ac977cb56 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -10,18 +10,16 @@
 #include <linux/module.h>
 #include <linux/cpumask.h>
 #include <linux/pci-aspm.h>
+#include <asm-generic/pci-bridge.h>
 #include "pci.h"
 
 #define CARDBUS_LATENCY_TIMER	176	/* secondary latency timer */
 #define CARDBUS_RESERVE_BUSNR	3
 
-static LIST_HEAD(pci_host_bridges);
-
 /* Ugh.  Need to stop exporting this to modules. */
 LIST_HEAD(pci_root_buses);
 EXPORT_SYMBOL(pci_root_buses);
 
-
 static int find_anything(struct device *dev, void *data)
 {
 	return 1;
@@ -44,82 +42,6 @@ int no_pci_devices(void)
 }
 EXPORT_SYMBOL(no_pci_devices);
 
-static struct pci_host_bridge *pci_host_bridge(struct pci_dev *dev)
-{
-	struct pci_bus *bus;
-	struct pci_host_bridge *bridge;
-
-	bus = dev->bus;
-	while (bus->parent)
-		bus = bus->parent;
-
-	list_for_each_entry(bridge, &pci_host_bridges, list) {
-		if (bridge->bus == bus)
-			return bridge;
-	}
-
-	return NULL;
-}
-
-static bool resource_contains(struct resource *res1, struct resource *res2)
-{
-	return res1->start <= res2->start && res1->end >= res2->end;
-}
-
-void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
-			     struct resource *res)
-{
-	struct pci_host_bridge *bridge = pci_host_bridge(dev);
-	struct pci_host_bridge_window *window;
-	resource_size_t offset = 0;
-
-	list_for_each_entry(window, &bridge->windows, list) {
-		if (resource_type(res) != resource_type(window->res))
-			continue;
-
-		if (resource_contains(window->res, res)) {
-			offset = window->offset;
-			break;
-		}
-	}
-
-	region->start = res->start - offset;
-	region->end = res->end - offset;
-}
-EXPORT_SYMBOL(pcibios_resource_to_bus);
-
-static bool region_contains(struct pci_bus_region *region1,
-			    struct pci_bus_region *region2)
-{
-	return region1->start <= region2->start && region1->end >= region2->end;
-}
-
-void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
-			     struct pci_bus_region *region)
-{
-	struct pci_host_bridge *bridge = pci_host_bridge(dev);
-	struct pci_host_bridge_window *window;
-	struct pci_bus_region bus_region;
-	resource_size_t offset = 0;
-
-	list_for_each_entry(window, &bridge->windows, list) {
-		if (resource_type(res) != resource_type(window->res))
-			continue;
-
-		bus_region.start = window->res->start - window->offset;
-		bus_region.end = window->res->end - window->offset;
-
-		if (region_contains(&bus_region, region)) {
-			offset = window->offset;
-			break;
-		}
-	}
-
-	res->start = region->start + offset;
-	res->end = region->end + offset;
-}
-EXPORT_SYMBOL(pcibios_bus_to_resource);
-
 /*
  * PCI Bus Class
  */
@@ -501,6 +423,19 @@ static struct pci_bus * pci_alloc_bus(void)
 	return b;
 }
 
+static struct pci_host_bridge *pci_alloc_host_bridge(struct pci_bus *b)
+{
+	struct pci_host_bridge *bridge;
+
+	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
+	if (bridge) {
+		INIT_LIST_HEAD(&bridge->windows);
+		bridge->bus = b;
+	}
+
+	return bridge;
+}
+
 static unsigned char pcix_bus_speed[] = {
 	PCI_SPEED_UNKNOWN,		/* 0 */
 	PCI_SPEED_66MHz_PCIX,		/* 1 */
@@ -1201,7 +1136,14 @@ int pci_cfg_space_size(struct pci_dev *dev)
 
 static void pci_release_bus_bridge_dev(struct device *dev)
 {
-	kfree(dev);
+	struct pci_host_bridge *bridge = to_pci_host_bridge(dev);
+
+	if (bridge->release_fn)
+		bridge->release_fn(bridge);
+
+	pci_free_resource_list(&bridge->windows);
+
+	kfree(bridge);
 }
 
 struct pci_dev *alloc_pci_dev(void)
@@ -1395,10 +1337,13 @@ static unsigned no_next_fn(struct pci_dev *dev, unsigned fn)
 static int only_one_child(struct pci_bus *bus)
 {
 	struct pci_dev *parent = bus->self;
+
 	if (!parent || !pci_is_pcie(parent))
 		return 0;
-	if (parent->pcie_type == PCI_EXP_TYPE_ROOT_PORT ||
-	    parent->pcie_type == PCI_EXP_TYPE_DOWNSTREAM)
+	if (parent->pcie_type == PCI_EXP_TYPE_ROOT_PORT)
+		return 1;
+	if (parent->pcie_type == PCI_EXP_TYPE_DOWNSTREAM &&
+	    !pci_has_flag(PCI_SCAN_ALL_PCIE_DEVS))
 		return 1;
 	return 0;
 }
@@ -1650,28 +1595,19 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 	int error;
 	struct pci_host_bridge *bridge;
 	struct pci_bus *b, *b2;
-	struct device *dev;
 	struct pci_host_bridge_window *window, *n;
 	struct resource *res;
 	resource_size_t offset;
 	char bus_addr[64];
 	char *fmt;
 
-	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
-	if (!bridge)
-		return NULL;
 
 	b = pci_alloc_bus();
 	if (!b)
-		goto err_bus;
-
-	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
-	if (!dev)
-		goto err_dev;
+		return NULL;
 
 	b->sysdata = sysdata;
 	b->ops = ops;
-
 	b2 = pci_find_bus(pci_domain_nr(b), bus);
 	if (b2) {
 		/* If we already got to this bus through a different bridge, ignore it */
@@ -1679,13 +1615,17 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 		goto err_out;
 	}
 
-	dev->parent = parent;
-	dev->release = pci_release_bus_bridge_dev;
-	dev_set_name(dev, "pci%04x:%02x", pci_domain_nr(b), bus);
-	error = device_register(dev);
+	bridge = pci_alloc_host_bridge(b);
+	if (!bridge)
+		goto err_out;
+
+	bridge->dev.parent = parent;
+	bridge->dev.release = pci_release_bus_bridge_dev;
+	dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus);
+	error = device_register(&bridge->dev);
 	if (error)
-		goto dev_reg_err;
-	b->bridge = get_device(dev);
+		goto bridge_dev_reg_err;
+	b->bridge = get_device(&bridge->dev);
 	device_enable_async_suspend(b->bridge);
 	pci_set_bus_of_node(b);
 
@@ -1704,9 +1644,6 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 
 	b->number = b->secondary = bus;
 
-	bridge->bus = b;
-	INIT_LIST_HEAD(&bridge->windows);
-
 	if (parent)
 		dev_info(parent, "PCI host bridge to bus %s\n", dev_name(&b->dev));
 	else
@@ -1732,25 +1669,18 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 	}
 
 	down_write(&pci_bus_sem);
-	list_add_tail(&bridge->list, &pci_host_bridges);
 	list_add_tail(&b->node, &pci_root_buses);
 	up_write(&pci_bus_sem);
 
 	return b;
 
 class_dev_reg_err:
-	device_unregister(dev);
-dev_reg_err:
-	down_write(&pci_bus_sem);
-	list_del(&bridge->list);
-	list_del(&b->node);
-	up_write(&pci_bus_sem);
+	put_device(&bridge->dev);
+	device_unregister(&bridge->dev);
+bridge_dev_reg_err:
+	kfree(bridge);
 err_out:
-	kfree(dev);
-err_dev:
 	kfree(b);
-err_bus:
-	kfree(bridge);
 	return NULL;
 }
 
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 4bf71028556b..2a7521677541 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2626,6 +2626,18 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x4374,
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x4375,
 			quirk_msi_intx_disable_bug);
 
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATTANSIC, 0x1062,
+			quirk_msi_intx_disable_bug);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATTANSIC, 0x1063,
+			quirk_msi_intx_disable_bug);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATTANSIC, 0x2060,
+			quirk_msi_intx_disable_bug);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATTANSIC, 0x2062,
+			quirk_msi_intx_disable_bug);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATTANSIC, 0x1073,
+			quirk_msi_intx_disable_bug);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATTANSIC, 0x1083,
+			quirk_msi_intx_disable_bug);
 #endif /* CONFIG_PCI_MSI */
 
 /* Allow manual resource allocation for PCI hotplug bridges
@@ -3085,16 +3097,74 @@ static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, int probe)
 	return 0;
 }
 
+#include "../gpu/drm/i915/i915_reg.h"
+#define MSG_CTL			0x45010
+#define NSDE_PWR_STATE		0xd0100
+#define IGD_OPERATION_TIMEOUT	10000     /* set timeout 10 seconds */
+
+static int reset_ivb_igd(struct pci_dev *dev, int probe)
+{
+	void __iomem *mmio_base;
+	unsigned long timeout;
+	u32 val;
+
+	if (probe)
+		return 0;
+
+	mmio_base = pci_iomap(dev, 0, 0);
+	if (!mmio_base)
+		return -ENOMEM;
+
+	iowrite32(0x00000002, mmio_base + MSG_CTL);
+
+	/*
+	 * Clobbering SOUTH_CHICKEN2 register is fine only if the next
+	 * driver loaded sets the right bits. However, this's a reset and
+	 * the bits have been set by i915 previously, so we clobber
+	 * SOUTH_CHICKEN2 register directly here.
+	 */
+	iowrite32(0x00000005, mmio_base + SOUTH_CHICKEN2);
+
+	val = ioread32(mmio_base + PCH_PP_CONTROL) & 0xfffffffe;
+	iowrite32(val, mmio_base + PCH_PP_CONTROL);
+
+	timeout = jiffies + msecs_to_jiffies(IGD_OPERATION_TIMEOUT);
+	do {
+		val = ioread32(mmio_base + PCH_PP_STATUS);
+		if ((val & 0xb0000000) == 0)
+			goto reset_complete;
+		msleep(10);
+	} while (time_before(jiffies, timeout));
+	dev_warn(&dev->dev, "timeout during reset\n");
+
+reset_complete:
+	iowrite32(0x00000002, mmio_base + NSDE_PWR_STATE);
+
+	pci_iounmap(dev, mmio_base);
+	return 0;
+}
+
 #define PCI_DEVICE_ID_INTEL_82599_SFP_VF   0x10ed
+#define PCI_DEVICE_ID_INTEL_IVB_M_VGA      0x0156
+#define PCI_DEVICE_ID_INTEL_IVB_M2_VGA     0x0166
 
 static const struct pci_dev_reset_methods pci_dev_reset_methods[] = {
 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82599_SFP_VF,
 		 reset_intel_82599_sfp_virtfn },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IVB_M_VGA,
+		reset_ivb_igd },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IVB_M2_VGA,
+		reset_ivb_igd },
 	{ PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
 		reset_intel_generic_dev },
 	{ 0 }
 };
 
+/*
+ * These device-specific reset methods are here rather than in a driver
+ * because when a host assigns a device to a guest VM, the host may need
+ * to reset the device but probably doesn't have a driver for it.
+ */
 int pci_dev_specific_reset(struct pci_dev *dev, int probe)
 {
 	const struct pci_dev_reset_methods *i;