PCI MSI: Refactor interrupt masking code

Since most of the callers already know whether they have an MSI or
an MSI-X capability, split msi_set_mask_bits() into msi_mask_irq()
and msix_mask_irq().  The only callers which don't (mask_msi_irq()
and unmask_msi_irq()) can share code in msi_set_mask_bit().  This then
becomes the only caller of msix_flush_writes(), so we can inline it.
The flushing read can be to any address that belongs to the device,
so we can eliminate the calculation too.

We can also get rid of maskbits_mask from struct msi_desc and simply
recalculate it on the rare occasion that we need it.  The single-bit
'masked' element is replaced by a copy of the 32-bit 'masked' register,
so this patch does not affect the size of msi_desc.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 2 insertions, 3 deletions

diff --git a/include/linux/msi.h b/include/linux/msi.h
index 5025ca4d91e4..37c1bbe546e5 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -22,14 +22,13 @@ struct msi_desc {
         struct {
                 __u8    is_msix : 1;
                 __u8    maskbit : 1;    /* mask-pending bit supported ?   */
-                __u8    masked  : 1;
                 __u8    is_64   : 1;    /* Address size: 0=32bit 1=64bit  */
                 __u8    pos;            /* Location of the msi capability */
                 __u16   entry_nr;       /* specific enabled entry         */
-                __u32   maskbits_mask;  /* mask bits mask */
                 unsigned default_irq;   /* default pre-assigned irq       */
-        }msi_attrib;
+        } msi_attrib;
 
+        u32 masked;                     /* mask bits */
         unsigned int irq;
         struct list_head list;