4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Arnd Bergmann arnd@arndb.de
commit 2f44e29cef006a4b0a4ecf7d4c5aac7d0fbb505c upstream.
A bug fix to the MSIx handling in vfio added references to functions that may not be defined if MSI is disabled in the kernel, resulting in this link error:
drivers/built-in.o: In function `vfio_msi_set_vector_signal': :(.text+0x450808): undefined reference to `get_cached_msi_msg' :(.text+0x45080c): undefined reference to `write_msi_msg'
As suggested by Alex Williamson, add stub implementations for get_cached_msi_msg() and pci_write_msi_msg().
In case this bugfix gets backported, please note that the #ifdef has changed over time, originally both functions were implemented in drivers/pci/msi.c and controlled by CONFIG_PCI_MSI, while nowadays get_cached_msi_msg() is part of the generic MSI support and can be used without PCI.
Fixes: b8f02af096b1 ("vfio/pci: Restore MSIx message prior to enabling") Signed-off-by: Arnd Bergmann arnd@arndb.de Cc: Marc Zyngier marc.zyngier@arm.com Cc: Alex Williamson alex.williamson@redhat.com Cc: Bjorn Helgaas bhelgaas@google.com Cc: Bart Van Assche bart.vanassche@sandisk.com Link: http://lkml.kernel.org/r/1413190208.4202.34.camel@ul30vt.home Link: http://lkml.kernel.org/r/20170214215343.3307861-1-arnd@arndb.de Signed-off-by: Thomas Gleixner tglx@linutronix.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- include/linux/msi.h | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
--- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -17,7 +17,13 @@ struct msi_desc; struct pci_dev; struct platform_msi_priv_data; void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg); +#ifdef CONFIG_GENERIC_MSI_IRQ void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg); +#else +static inline void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg) +{ +} +#endif
typedef void (*irq_write_msi_msg_t)(struct msi_desc *desc, struct msi_msg *msg); @@ -105,18 +111,21 @@ struct msi_desc {
struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc); void *msi_desc_to_pci_sysdata(struct msi_desc *desc); +void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg); #else /* CONFIG_PCI_MSI */ static inline void *msi_desc_to_pci_sysdata(struct msi_desc *desc) { return NULL; } +static inline void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg) +{ +} #endif /* CONFIG_PCI_MSI */
struct msi_desc *alloc_msi_entry(struct device *dev); void free_msi_entry(struct msi_desc *entry); void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg); void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg); -void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg);
u32 __pci_msix_desc_mask_irq(struct msi_desc *desc, u32 flag); u32 __pci_msi_desc_mask_irq(struct msi_desc *desc, u32 mask, u32 flag);