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| H A D | process.c | diff d1d0d5ffb3006eaf9b5f41c89fe801e032cbbfe4 Fri Aug 11 18:39:07 CEST 2017 Nicholas Piggin <npiggin@gmail.com> powerpc/64: Optimise set/clear of CTRL[RUN] (runlatch)
On modern CPUs the CTRL register is read-only except bit 63 which is
the run latch control. This means it can be updated with a mtspr
rather than mfspr/mtspr.
To accomodate older CPUs (Cell at least), where there are other bits
in the register, we still do a read/modify/write on pre 2.06 CPUs.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Update change log to mention 2.06 workaround]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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