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;