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Commit 0b49ec37a20bc7eb7178105aadaa8d1ecba825f8

Authored by Matthew Wilcox
Committed by Jesse Barnes
1 parent 37bed90094
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

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>

Showing 1 changed file with 4 additions and 6 deletions Side-by-side Diff

... ... @@ -103,14 +103,12 @@
103 103 }
104 104 }
105 105  
106   -/*
107   - * Essentially, this is ((1 << (1 << x)) - 1), but without the
108   - * undefinedness of a << 32.
109   - */
110 106 static inline __attribute_const__ u32 msi_mask(unsigned x)
111 107 {
112   - static const u32 mask[] = { 1, 2, 4, 0xf, 0xff, 0xffff, 0xffffffff };
113   - return mask[x];
  108 + /* Don't shift by >= width of type */
  109 + if (x >= 5)
  110 + return 0xffffffff;
  111 + return (1 << (1 << x)) - 1;
114 112 }
115 113  
116 114 static void msix_flush_writes(struct irq_desc *desc)