Merge tag 'msi-3.12' of git://git.infradead.org/linux-mvebu into next/drivers

From Jason Cooper:
mvebu msi pci changes for v3.12

 - introduce support for MSI on PCI
 - fix s390 build breakage when !HAVE_GENERIC_HARDIRQS

NOTE: This branch is a dependency for changes going though arm-soc from both
Thomas Petazzoni and Thierry Reding.

* tag 'msi-3.12' of git://git.infradead.org/linux-mvebu:
  PCI: msi: add default MSI operations for !HAVE_GENERIC_HARDIRQS platforms
  ARM: pci: add ->add_bus() and ->remove_bus() hooks to hw_pci
  of: pci: add registry of MSI chips
  PCI: Introduce new MSI chip infrastructure
  PCI: remove ARCH_SUPPORTS_MSI kconfig option
  PCI: use weak functions for MSI arch-specific functions

Signed-off-by: Olof Johansson <olof@lixom.net>

22 files changed, 185 insertions, 81 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 43594d5..98538e1 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -441,7 +441,6 @@ config ARCH_NETX
 config ARCH_IOP13XX
 	bool "IOP13xx-based"
 	depends on MMU
-	select ARCH_SUPPORTS_MSI
 	select CPU_XSC3
 	select NEED_MACH_MEMORY_H
 	select NEED_RET_TO_USER
diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h
index a1c90d7..454d642 100644
--- a/arch/arm/include/asm/mach/pci.h
+++ b/arch/arm/include/asm/mach/pci.h
@@ -36,6 +36,8 @@ struct hw_pci {
 					  resource_size_t start,
 					  resource_size_t size,
 					  resource_size_t align);
+	void		(*add_bus)(struct pci_bus *bus);
+	void		(*remove_bus)(struct pci_bus *bus);
 };
 
 /*
@@ -63,6 +65,8 @@ struct pci_sys_data {
 					  resource_size_t start,
 					  resource_size_t size,
 					  resource_size_t align);
+	void		(*add_bus)(struct pci_bus *bus);
+	void		(*remove_bus)(struct pci_bus *bus);
 	void		*private_data;	/* platform controller private data	*/
 };
 
diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index 261fcc8..1ec9c87 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -363,6 +363,20 @@ void pcibios_fixup_bus(struct pci_bus *bus)
 }
 EXPORT_SYMBOL(pcibios_fixup_bus);
 
+void pcibios_add_bus(struct pci_bus *bus)
+{
+	struct pci_sys_data *sys = bus->sysdata;
+	if (sys->add_bus)
+		sys->add_bus(bus);
+}
+
+void pcibios_remove_bus(struct pci_bus *bus)
+{
+	struct pci_sys_data *sys = bus->sysdata;
+	if (sys->remove_bus)
+		sys->remove_bus(bus);
+}
+
 /*
  * Swizzle the device pin each time we cross a bridge.  If a platform does
  * not provide a swizzle function, we perform the standard PCI swizzling.
@@ -464,6 +478,8 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
 		sys->swizzle = hw->swizzle;
 		sys->map_irq = hw->map_irq;
 		sys->align_resource = hw->align_resource;
+		sys->add_bus = hw->add_bus;
+		sys->remove_bus = hw->remove_bus;
 		INIT_LIST_HEAD(&sys->resources);
 
 		if (hw->private_data)
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 5a768ad..098602b 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -9,7 +9,6 @@ config IA64
 	select PCI if (!IA64_HP_SIM)
 	select ACPI if (!IA64_HP_SIM)
 	select PM if (!IA64_HP_SIM)
-	select ARCH_SUPPORTS_MSI
 	select HAVE_UNSTABLE_SCHED_CLOCK
 	select HAVE_IDE
 	select HAVE_OPROFILE
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index e12764c..1e31fcb9 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -727,7 +727,6 @@ config CAVIUM_OCTEON_SOC
 	select SYS_HAS_CPU_CAVIUM_OCTEON
 	select SWAP_IO_SPACE
 	select HW_HAS_PCI
-	select ARCH_SUPPORTS_MSI
 	select ZONE_DMA32
 	select USB_ARCH_HAS_OHCI
 	select USB_ARCH_HAS_EHCI
@@ -763,7 +762,6 @@ config NLM_XLR_BOARD
 	select CEVT_R4K
 	select CSRC_R4K
 	select IRQ_CPU
-	select ARCH_SUPPORTS_MSI
 	select ZONE_DMA32 if 64BIT
 	select SYNC_R4K
 	select SYS_HAS_EARLY_PRINTK
diff --git a/arch/mips/include/asm/pci.h b/arch/mips/include/asm/pci.h
index fa8e0aa..f194c08 100644
--- a/arch/mips/include/asm/pci.h
+++ b/arch/mips/include/asm/pci.h
@@ -136,11 +136,6 @@ static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
 	return channel ? 15 : 14;
 }
 
-#ifdef CONFIG_CPU_CAVIUM_OCTEON
-/* MSI arch hook for OCTEON */
-#define arch_setup_msi_irqs arch_setup_msi_irqs
-#endif
-
 extern char * (*pcibios_plat_setup)(char *str);
 
 #ifdef CONFIG_OF
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index dbd9d3c..3a67869 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -727,7 +727,6 @@ config PCI
 	default y if !40x && !CPM2 && !8xx && !PPC_83xx \
 		&& !PPC_85xx && !PPC_86xx && !GAMECUBE_COMMON
 	default PCI_QSPAN if !4xx && !CPM2 && 8xx
-	select ARCH_SUPPORTS_MSI
 	select GENERIC_PCI_IOMAP
 	help
 	  Find out whether your system includes a PCI bus. PCI is the name of
diff --git a/arch/powerpc/include/asm/pci.h b/arch/powerpc/include/asm/pci.h
index 6653f27..95145a1 100644
--- a/arch/powerpc/include/asm/pci.h
+++ b/arch/powerpc/include/asm/pci.h
@@ -113,11 +113,6 @@ extern int pci_domain_nr(struct pci_bus *bus);
 /* Decide whether to display the domain number in /proc */
 extern int pci_proc_domain(struct pci_bus *bus);
 
-/* MSI arch hooks */
-#define arch_setup_msi_irqs arch_setup_msi_irqs
-#define arch_teardown_msi_irqs arch_teardown_msi_irqs
-#define arch_msi_check_device arch_msi_check_device
-
 struct vm_area_struct;
 /* Map a range of PCI memory or I/O space for a device into user space */
 int pci_mmap_page_range(struct pci_dev *pdev, struct vm_area_struct *vma,
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 8a4cae7..21e5c16 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -430,7 +430,6 @@ menuconfig PCI
 	bool "PCI support"
 	default n
 	depends on 64BIT
-	select ARCH_SUPPORTS_MSI
 	select PCI_MSI
 	help
 	  Enable PCI support.
diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index 6e577ba..262b91b 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -21,10 +21,6 @@ void pci_iounmap(struct pci_dev *, void __iomem *);
 int pci_domain_nr(struct pci_bus *);
 int pci_proc_domain(struct pci_bus *);
 
-/* MSI arch hooks */
-#define arch_setup_msi_irqs	arch_setup_msi_irqs
-#define arch_teardown_msi_irqs	arch_teardown_msi_irqs
-
 #define ZPCI_BUS_NR			0	/* default bus number */
 #define ZPCI_DEVFN			0	/* default device number */
 
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index a00cbd3..1570ad2 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -52,7 +52,6 @@ config SPARC32
 
 config SPARC64
 	def_bool 64BIT
-	select ARCH_SUPPORTS_MSI
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_GRAPH_FP_TEST
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 24565a7..74dff90 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -380,7 +380,6 @@ config PCI
 	select PCI_DOMAINS
 	select GENERIC_PCI_IOMAP
 	select TILE_GXIO_TRIO if TILEGX
-	select ARCH_SUPPORTS_MSI if TILEGX
 	select PCI_MSI if TILEGX
 	---help---
 	  Enable PCI root complex support, so PCIe endpoint devices can
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b32ebf9..5db62ef 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2014,7 +2014,6 @@ menu "Bus options (PCI etc.)"
 config PCI
 	bool "PCI support"
 	default y
-	select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
 	---help---
 	  Find out whether you have a PCI motherboard. PCI is the name of a
 	  bus system, i.e. the way the CPU talks to the other stuff inside
diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
index d9e9e6c..7d74432 100644
--- a/arch/x86/include/asm/pci.h
+++ b/arch/x86/include/asm/pci.h
@@ -100,29 +100,6 @@ static inline void early_quirks(void) { }
 extern void pci_iommu_alloc(void);
 
 #ifdef CONFIG_PCI_MSI
-/* MSI arch specific hooks */
-static inline int x86_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
-{
-	return x86_msi.setup_msi_irqs(dev, nvec, type);
-}
-
-static inline void x86_teardown_msi_irqs(struct pci_dev *dev)
-{
-	x86_msi.teardown_msi_irqs(dev);
-}
-
-static inline void x86_teardown_msi_irq(unsigned int irq)
-{
-	x86_msi.teardown_msi_irq(irq);
-}
-static inline void x86_restore_msi_irqs(struct pci_dev *dev, int irq)
-{
-	x86_msi.restore_msi_irqs(dev, irq);
-}
-#define arch_setup_msi_irqs x86_setup_msi_irqs
-#define arch_teardown_msi_irqs x86_teardown_msi_irqs
-#define arch_teardown_msi_irq x86_teardown_msi_irq
-#define arch_restore_msi_irqs x86_restore_msi_irqs
 /* implemented in arch/x86/kernel/apic/io_apic. */
 struct msi_desc;
 int native_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);
@@ -130,16 +107,9 @@ void native_teardown_msi_irq(unsigned int irq);
 void native_restore_msi_irqs(struct pci_dev *dev, int irq);
 int setup_msi_irq(struct pci_dev *dev, struct msi_desc *msidesc,
 		  unsigned int irq_base, unsigned int irq_offset);
-/* default to the implementation in drivers/lib/msi.c */
-#define HAVE_DEFAULT_MSI_TEARDOWN_IRQS
-#define HAVE_DEFAULT_MSI_RESTORE_IRQS
-void default_teardown_msi_irqs(struct pci_dev *dev);
-void default_restore_msi_irqs(struct pci_dev *dev, int irq);
 #else
 #define native_setup_msi_irqs		NULL
 #define native_teardown_msi_irq		NULL
-#define default_teardown_msi_irqs	NULL
-#define default_restore_msi_irqs	NULL
 #endif
 
 #define PCI_DMA_BUS_IS_PHYS (dma_ops->is_phys)
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index 5f24c71..8ce0072 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -107,6 +107,8 @@ struct x86_platform_ops x86_platform = {
 };
 
 EXPORT_SYMBOL_GPL(x86_platform);
+
+#if defined(CONFIG_PCI_MSI)
 struct x86_msi_ops x86_msi = {
 	.setup_msi_irqs		= native_setup_msi_irqs,
 	.compose_msi_msg	= native_compose_msi_msg,
@@ -116,6 +118,28 @@ struct x86_msi_ops x86_msi = {
 	.setup_hpet_msi		= default_setup_hpet_msi,
 };
 
+/* MSI arch specific hooks */
+int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+	return x86_msi.setup_msi_irqs(dev, nvec, type);
+}
+
+void arch_teardown_msi_irqs(struct pci_dev *dev)
+{
+	x86_msi.teardown_msi_irqs(dev);
+}
+
+void arch_teardown_msi_irq(unsigned int irq)
+{
+	x86_msi.teardown_msi_irq(irq);
+}
+
+void arch_restore_msi_irqs(struct pci_dev *dev, int irq)
+{
+	x86_msi.restore_msi_irqs(dev, irq);
+}
+#endif
+
 struct x86_io_apic_ops x86_io_apic_ops = {
 	.init			= native_io_apic_init_mappings,
 	.read			= native_io_apic_read,
diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
index 42c687a..e5ca008 100644
--- a/drivers/of/of_pci.c
+++ b/drivers/of/of_pci.c
@@ -89,3 +89,48 @@ int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
 	return 0;
 }
 EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
+
+#ifdef CONFIG_PCI_MSI
+
+static LIST_HEAD(of_pci_msi_chip_list);
+static DEFINE_MUTEX(of_pci_msi_chip_mutex);
+
+int of_pci_msi_chip_add(struct msi_chip *chip)
+{
+	if (!of_property_read_bool(chip->of_node, "msi-controller"))
+		return -EINVAL;
+
+	mutex_lock(&of_pci_msi_chip_mutex);
+	list_add(&chip->list, &of_pci_msi_chip_list);
+	mutex_unlock(&of_pci_msi_chip_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_pci_msi_chip_add);
+
+void of_pci_msi_chip_remove(struct msi_chip *chip)
+{
+	mutex_lock(&of_pci_msi_chip_mutex);
+	list_del(&chip->list);
+	mutex_unlock(&of_pci_msi_chip_mutex);
+}
+EXPORT_SYMBOL_GPL(of_pci_msi_chip_remove);
+
+struct msi_chip *of_pci_find_msi_chip_by_node(struct device_node *of_node)
+{
+	struct msi_chip *c;
+
+	mutex_lock(&of_pci_msi_chip_mutex);
+	list_for_each_entry(c, &of_pci_msi_chip_list, list) {
+		if (c->of_node == of_node) {
+			mutex_unlock(&of_pci_msi_chip_mutex);
+			return c;
+		}
+	}
+	mutex_unlock(&of_pci_msi_chip_mutex);
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(of_pci_find_msi_chip_by_node);
+
+#endif /* CONFIG_PCI_MSI */
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 81944fb..b6a99f7 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -1,13 +1,9 @@
 #
 # PCI configuration
 #
-config ARCH_SUPPORTS_MSI
-	bool
-
 config PCI_MSI
 	bool "Message Signaled Interrupts (MSI and MSI-X)"
 	depends on PCI
-	depends on ARCH_SUPPORTS_MSI
 	help
 	   This allows device drivers to enable MSI (Message Signaled
 	   Interrupts).  Message Signaled Interrupts enable a device to
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index aca7578..b35f93c 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -30,20 +30,60 @@ static int pci_msi_enable = 1;
 
 /* Arch hooks */
 
-#ifndef arch_msi_check_device
-int arch_msi_check_device(struct pci_dev *dev, int nvec, int type)
+#if defined(CONFIG_GENERIC_HARDIRQS)
+int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
 {
+	struct msi_chip *chip = dev->bus->msi;
+	int err;
+
+	if (!chip || !chip->setup_irq)
+		return -EINVAL;
+
+	err = chip->setup_irq(chip, dev, desc);
+	if (err < 0)
+		return err;
+
+	irq_set_chip_data(desc->irq, chip);
+
 	return 0;
 }
-#endif
 
-#ifndef arch_setup_msi_irqs
-# define arch_setup_msi_irqs default_setup_msi_irqs
-# define HAVE_DEFAULT_MSI_SETUP_IRQS
-#endif
+void __weak arch_teardown_msi_irq(unsigned int irq)
+{
+	struct msi_chip *chip = irq_get_chip_data(irq);
 
-#ifdef HAVE_DEFAULT_MSI_SETUP_IRQS
-int default_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+	if (!chip || !chip->teardown_irq)
+		return;
+
+	chip->teardown_irq(chip, irq);
+}
+
+int __weak arch_msi_check_device(struct pci_dev *dev, int nvec, int type)
+{
+	struct msi_chip *chip = dev->bus->msi;
+
+	if (!chip || !chip->check_device)
+		return 0;
+
+	return chip->check_device(chip, dev, nvec, type);
+}
+#else
+int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
+{
+	return -ENOSYS;
+}
+
+void __weak arch_teardown_msi_irq(unsigned int irq)
+{
+}
+
+int __weak arch_msi_check_device(struct pci_dev *dev, int nvec, int type)
+{
+	return 0;
+}
+#endif /* CONFIG_GENERIC_HARDIRQS */
+
+int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 {
 	struct msi_desc *entry;
 	int ret;
@@ -65,14 +105,11 @@ int default_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 
 	return 0;
 }
-#endif
-
-#ifndef arch_teardown_msi_irqs
-# define arch_teardown_msi_irqs default_teardown_msi_irqs
-# define HAVE_DEFAULT_MSI_TEARDOWN_IRQS
-#endif
 
-#ifdef HAVE_DEFAULT_MSI_TEARDOWN_IRQS
+/*
+ * We have a default implementation available as a separate non-weak
+ * function, as it is used by the Xen x86 PCI code
+ */
 void default_teardown_msi_irqs(struct pci_dev *dev)
 {
 	struct msi_desc *entry;
@@ -89,14 +126,12 @@ void default_teardown_msi_irqs(struct pci_dev *dev)
 			arch_teardown_msi_irq(entry->irq + i);
 	}
 }
-#endif
 
-#ifndef arch_restore_msi_irqs
-# define arch_restore_msi_irqs default_restore_msi_irqs
-# define HAVE_DEFAULT_MSI_RESTORE_IRQS
-#endif
+void __weak arch_teardown_msi_irqs(struct pci_dev *dev)
+{
+	return default_teardown_msi_irqs(dev);
+}
 
-#ifdef HAVE_DEFAULT_MSI_RESTORE_IRQS
 void default_restore_msi_irqs(struct pci_dev *dev, int irq)
 {
 	struct msi_desc *entry;
@@ -114,7 +149,11 @@ void default_restore_msi_irqs(struct pci_dev *dev, int irq)
 	if (entry)
 		write_msi_msg(irq, &entry->msg);
 }
-#endif
+
+void __weak arch_restore_msi_irqs(struct pci_dev *dev, int irq)
+{
+	return default_restore_msi_irqs(dev, irq);
+}
 
 static void msi_set_enable(struct pci_dev *dev, int enable)
 {
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 46ada5c..b8eaa81 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -666,6 +666,7 @@ static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
 
 	child->parent = parent;
 	child->ops = parent->ops;
+	child->msi = parent->msi;
 	child->sysdata = parent->sysdata;
 	child->bus_flags = parent->bus_flags;
 
diff --git a/include/linux/msi.h b/include/linux/msi.h
index ee66f3a..b17ead8 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -51,12 +51,31 @@ struct msi_desc {
 };
 
 /*
- * The arch hook for setup up msi irqs
+ * The arch hooks to setup up msi irqs. Those functions are
+ * implemented as weak symbols so that they /can/ be overriden by
+ * architecture specific code if needed.
  */
 int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc);
 void arch_teardown_msi_irq(unsigned int irq);
 int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);
 void arch_teardown_msi_irqs(struct pci_dev *dev);
 int arch_msi_check_device(struct pci_dev* dev, int nvec, int type);
+void arch_restore_msi_irqs(struct pci_dev *dev, int irq);
+
+void default_teardown_msi_irqs(struct pci_dev *dev);
+void default_restore_msi_irqs(struct pci_dev *dev, int irq);
+
+struct msi_chip {
+	struct module *owner;
+	struct device *dev;
+	struct device_node *of_node;
+	struct list_head list;
+
+	int (*setup_irq)(struct msi_chip *chip, struct pci_dev *dev,
+			 struct msi_desc *desc);
+	void (*teardown_irq)(struct msi_chip *chip, unsigned int irq);
+	int (*check_device)(struct msi_chip *chip, struct pci_dev *dev,
+			    int nvec, int type);
+};
 
 #endif /* LINUX_MSI_H */
diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
index 7a04826..fd9c408 100644
--- a/include/linux/of_pci.h
+++ b/include/linux/of_pci.h
@@ -2,6 +2,7 @@
 #define __OF_PCI_H
 
 #include <linux/pci.h>
+#include <linux/msi.h>
 
 struct pci_dev;
 struct of_irq;
@@ -13,4 +14,15 @@ struct device_node *of_pci_find_child_device(struct device_node *parent,
 int of_pci_get_devfn(struct device_node *np);
 int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
 
+#if defined(CONFIG_OF) && defined(CONFIG_PCI_MSI)
+int of_pci_msi_chip_add(struct msi_chip *chip);
+void of_pci_msi_chip_remove(struct msi_chip *chip);
+struct msi_chip *of_pci_find_msi_chip_by_node(struct device_node *of_node);
+#else
+static inline int of_pci_msi_chip_add(struct msi_chip *chip) { return -EINVAL; }
+static inline void of_pci_msi_chip_remove(struct msi_chip *chip) { }
+static inline struct msi_chip *
+of_pci_find_msi_chip_by_node(struct device_node *of_node) { return NULL; }
+#endif
+
 #endif
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 0fd1f15..4044e3c 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -433,6 +433,7 @@ struct pci_bus {
 	struct resource busn_res;	/* bus numbers routed to this bus */
 
 	struct pci_ops	*ops;		/* configuration access functions */
+	struct msi_chip	*msi;		/* MSI controller */
 	void		*sysdata;	/* hook for sys-specific extension */
 	struct proc_dir_entry *procdir;	/* directory entry in /proc/bus/pci */