[PATCH] msi: sanely support hardware level msi disabling
In some cases when we are not using msi we need a way to ensure that the
hardware does not have an msi capability enabled. Currently the code has been
calling disable_msi_mode to try and achieve that. However disable_msi_mode
has several other side effects and is only available when msi support is
compiled in so it isn't really appropriate.
Instead this patch implements pci_msi_off which disables all msi and msix
capabilities unconditionally with no additional side effects.
pci_disable_device was redundantly clearing the bus master enable flag and
clearing the msi enable bit. A device that is not allowed to perform bus
mastering operations cannot generate intx or msi interrupt messages as those
are essentially a special case of dma, and require bus mastering. So the call
in pci_disable_device to disable msi capabilities was redundant.
quirk_pcie_pxh also called disable_msi_mode and is updated to use pci_msi_off.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 2c4b684..78417e4 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -543,6 +543,7 @@
int __must_check pci_set_mwi(struct pci_dev *dev);
void pci_clear_mwi(struct pci_dev *dev);
void pci_intx(struct pci_dev *dev, int enable);
+void pci_msi_off(struct pci_dev *dev);
int pci_set_dma_mask(struct pci_dev *dev, u64 mask);
int pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask);
void pci_update_resource(struct pci_dev *dev, struct resource *res, int resno);
diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h
index 7a6d34e..f09cce2 100644
--- a/include/linux/pci_regs.h
+++ b/include/linux/pci_regs.h
@@ -292,9 +292,10 @@
#define PCI_MSI_DATA_64 12 /* 16 bits of data for 64-bit devices */
#define PCI_MSI_MASK_BIT 16 /* Mask bits register */
-/* MSI-X registers (these are at offset PCI_MSI_FLAGS) */
-#define PCI_MSIX_FLAGS_QSIZE 0x7FF
-#define PCI_MSIX_FLAGS_ENABLE (1 << 15)
+/* MSI-X registers (these are at offset PCI_MSIX_FLAGS) */
+#define PCI_MSIX_FLAGS 2
+#define PCI_MSIX_FLAGS_QSIZE 0x7FF
+#define PCI_MSIX_FLAGS_ENABLE (1 << 15)
#define PCI_MSIX_FLAGS_BIRMASK (7 << 0)
#define PCI_MSIX_FLAGS_BITMASK (1 << 0)