diff options
| author | Matthew Wilcox <matthew@wil.cx> | 2009-02-08 20:27:47 -0700 |
|---|---|---|
| committer | Jesse Barnes <jbarnes@virtuousgeek.org> | 2009-02-13 11:59:03 -0800 |
| commit | 0b49ec37a20bc7eb7178105aadaa8d1ecba825f8 (patch) | |
| tree | 4558a778c20048bd519b444a1d8381087592397f /drivers/pci/msi.c | |
| parent | 37bed90094fdb1eea6e4afec6a200d4e60143e55 (diff) | |
| download | lwn-0b49ec37a20bc7eb7178105aadaa8d1ecba825f8.tar.gz lwn-0b49ec37a20bc7eb7178105aadaa8d1ecba825f8.zip | |
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.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 44f15ff70c1d..baba2eb5367d 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) |