Re: [PATCH] pci_regs: reintroduce PCI_MSIX_FLAGS_BIRMASK

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Jul 13, 2015 at 10:49:02AM -0500, Bjorn Helgaas wrote:
> On Mon, Jul 13, 2015 at 10:11 AM, Michael S. Tsirkin <mst@redhat.com> wrote:
> > On Wed, Jul 01, 2015 at 12:14:10PM +0200, Michael S. Tsirkin wrote:
> >> This partially reverts commit 09a2c73ddfc7f173237fc7209a65b34dd5bcb5ed.
> >>     PCI: Remove unused PCI_MSIX_FLAGS_BIRMASK definition
> >>
> >> That commit dropped a symbol from an exported header claiming "no one
> >> uses it". This isn't how Linux normally approaches userspace API though,
> >> and in fact QEMU build fails if trying to use updated headers from linux
> >> 3.12 and up.
> >>
> >> Sure, userspace can be fixed to use the new symbol, but the cost
> >> of keeping the old one around is fairly low, too.
> >>
> >> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> >
> > Ping. Can this be included upstream please?
> 
> Yes, I plan to merge it, and I'll mark it for stable.  This looks like
> a complete revert of 09a2c73ddfc7, not a partial revert.  Am I missing
> something?

Only that I redefine PCI_MSIX_FLAGS_BIRMASK in terms of PCI_MSIX_PBA_BIR
so that there's no duplication.

> 09a2c73ddfc7 appeared in v3.13 (not v3.12), so it wouldn't ordinarily
> be post-merge window material.  But it seems pretty safe, so I might
> put it in for v4.2 instead of waiting for v4.3.
> 
> >> ---
> >>  include/uapi/linux/pci_regs.h | 1 +
> >>  1 file changed, 1 insertion(+)
> >>
> >> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> >> index efe3443..66644ac 100644
> >> --- a/include/uapi/linux/pci_regs.h
> >> +++ b/include/uapi/linux/pci_regs.h
> >> @@ -319,6 +319,7 @@
> >>  #define PCI_MSIX_PBA         8       /* Pending Bit Array offset */
> >>  #define  PCI_MSIX_PBA_BIR    0x00000007 /* BAR index */
> >>  #define  PCI_MSIX_PBA_OFFSET 0xfffffff8 /* Offset into specified BAR */
> >> +#define  PCI_MSIX_FLAGS_BIRMASK      PCI_MSIX_PBA_BIR /* deprecated */
> >>  #define PCI_CAP_MSIX_SIZEOF  12      /* size of MSIX registers */
> >>
> >>  /* MSI-X Table entry format */
> >> --
> >> MST