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| author | Nicholas Piggin <npiggin@gmail.com> | 2017-08-12 02:39:07 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-08-23 23:48:38 +1000 |
| commit | d1d0d5ffb3006eaf9b5f41c89fe801e032cbbfe4 (patch) | |
| tree | cfb1d7cec1dc0e7e3382efc64a2beb54f041799d /arch/powerpc/sysdev/xive/common.c | |
| parent | 7b76a1f5ed9c7233cfdd35b6f77310ccec293921 (diff) | |
| download | linux-d1d0d5ffb3006eaf9b5f41c89fe801e032cbbfe4.tar.gz linux-d1d0d5ffb3006eaf9b5f41c89fe801e032cbbfe4.tar.xz | |
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>
Diffstat (limited to 'arch/powerpc/sysdev/xive/common.c')
0 files changed, 0 insertions, 0 deletions