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authorMatthew Wilcox <matthew@wil.cx>2009-02-08 20:27:47 -0700
committerJesse Barnes <jbarnes@virtuousgeek.org>2009-02-13 11:59:03 -0800
commit0b49ec37a20bc7eb7178105aadaa8d1ecba825f8 (patch)
tree4558a778c20048bd519b444a1d8381087592397f /drivers/pci/msi.c
parent37bed90094fdb1eea6e4afec6a200d4e60143e55 (diff)
PCI/MSI: fix msi_mask() shift fix
Hidetoshi Seto points out that commit bffac3c593eba1f9da3efd0199e49ea6558a40ce has wrong values in the array. Rather than correct the array, we can just use a bounds check and perform the calculation specified in the comment. As a bonus, this will not run off the end of the array if the device specifies an illegal value in the MSI capability. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci/msi.c')
-rw-r--r--drivers/pci/msi.c10
1 files changed, 4 insertions, 6 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 44f15ff70c1..baba2eb5367 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -103,14 +103,12 @@ static void msix_set_enable(struct pci_dev *dev, int enable)
}
}
-/*
- * Essentially, this is ((1 << (1 << x)) - 1), but without the
- * undefinedness of a << 32.
- */
static inline __attribute_const__ u32 msi_mask(unsigned x)
{
- static const u32 mask[] = { 1, 2, 4, 0xf, 0xff, 0xffff, 0xffffffff };
- return mask[x];
+ /* Don't shift by >= width of type */
+ if (x >= 5)
+ return 0xffffffff;
+ return (1 << (1 << x)) - 1;
}
static void msix_flush_writes(struct irq_desc *desc)