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    SubjectRE: HELP: Is writeq an atomic operation??
    On Friday, May 02, 2008 5:22 PM,  Roland Dreier wrote:
    > > Yeah, I forgot I have a #ifndef writeq, then defined the
    > x86_64 version
    > > of that. I've not tested on x86, so I'm not sure whether
    > it works.
    > > How are you handling writeq when its not defined, as the
    > case in x86?
    > Write two writel() inside a spinlock to avoid any transactions in the
    > middle (the HW I'm dealing with can deal with two 32-bit transactions,
    > as long as nothing comes in the middle). If your hardware demands a
    > single 64-bit transaction, you may be in trouble, because I'm not sure
    > all 32-bit systems can generate such a PCIe transaction.
    > You can see include/linux/mlx4/doorbell.h for exactly what I did.

    Thanks for the code sample. Yes, I need to send a single atomic 64-bit


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