[openib-general] 2.6.18-rc5-mm1: drivers/infiniband/hw/amso1100/c2.c compile error

Roland Dreier rdreier at cisco.com
Fri Sep 1 13:54:04 PDT 2006


    Russell> Sure, if you want a _non-atomic_ 64-bit write then that's
    Russell> possible, but many 32-bit architectures can't do a 64-bit
    Russell> atomic IO write and that isn't something they can "fix".

I agree completely.  And going one step further: if an architecture
cannot implement a 64-bit write atomically, then the precise
serialization that is required is device-specific knowledge that
belongs in the device driver.

(For example, in the mthca case, the only serialization required is
that no writes go to the same page of MMIO space between the two
32-bit halves of the 64-bit write)

 - R.




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