diff options
| author | Bogdan Purcareata <bogdan.purcareata@freescale.com> | 2015-03-24 13:43:43 +0300 |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2015-04-01 06:23:20 +0300 |
| commit | 56302c53d3dc477b8360954fc92c1dfc4fc0ec54 (patch) | |
| tree | efdd635d93e59a6bc82b66515f0640295e56aa56 | |
| parent | 88b7936da39618be04a6e1c2fb052dc528633392 (diff) | |
| download | linux-56302c53d3dc477b8360954fc92c1dfc4fc0ec54.tar.xz | |
powerpc/mpic: Remove WHOAMI readback after EOI
After previous discussions regarding the subject [1][2], there's no clear
explanation or reason why the call was needed in the first place. The sensible
argument is some sort of synchronization between the CPU and the MPIC, which
hasn't been pointed out precisely and is no longer required (at least on BookE
platforms).
The benefit of this change is saving a MMIO trap per interrupt when running in a
KVM guest.
[1] https://patchwork.ozlabs.org/patch/429098/
[2] https://patchwork.ozlabs.org/patch/433557/
Signed-off-by: Bogdan Purcareata <bogdan.purcareata@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
| -rw-r--r-- | arch/powerpc/sysdev/mpic.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c index 2c817a736b77..fb19084c5860 100644 --- a/arch/powerpc/sysdev/mpic.c +++ b/arch/powerpc/sysdev/mpic.c @@ -655,7 +655,6 @@ static inline struct mpic * mpic_from_irq_data(struct irq_data *d) static inline void mpic_eoi(struct mpic *mpic) { mpic_cpu_write(MPIC_INFO(CPU_EOI), 0); - (void)mpic_cpu_read(MPIC_INFO(CPU_WHOAMI)); } /* |