| Message ID | 1347986135-17979-5-git-send-email-lorenzo.pieralisi@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 18 Sep 2012, Lorenzo Pieralisi wrote: > When a CPU is hotplugged out caches that reside in its power domain > lose their contents and so must be cleaned to the next memory level. > > Currently, __cpu_disable calls flush_cache_all() that for new generation > processor like A15/A7 ends up cleaning and invalidating all cache levels > up to Level of Coherency, which includes the unified L2. > > This ends up being a waste of cycles since the L2 cache contents are not > lost on power down. > > This patch updates __cpu_disable to use the new LoUIS API cache operations. > > Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> > --- > arch/arm/kernel/smp.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c > index d3eb222..f44e9cd 100644 > --- a/arch/arm/kernel/smp.c > +++ b/arch/arm/kernel/smp.c > @@ -136,8 +136,11 @@ int __cpu_disable(void) > /* > * Flush user cache and TLB mappings, and then remove this CPU > * from the vm mask set of all processes. > + * > + * Caches are flushed to the Level of Unification Inner Shareable > + * to write-back dirty lines to unified caches shared by all CPUs. > */ > - flush_cache_all(); > + flush_cache_louis(); > local_flush_tlb_all(); > > clear_tasks_mm_cpumask(cpu); > -- > 1.7.12 > >
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index d3eb222..f44e9cd 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -136,8 +136,11 @@ int __cpu_disable(void) /* * Flush user cache and TLB mappings, and then remove this CPU * from the vm mask set of all processes. + * + * Caches are flushed to the Level of Unification Inner Shareable + * to write-back dirty lines to unified caches shared by all CPUs. */ - flush_cache_all(); + flush_cache_louis(); local_flush_tlb_all(); clear_tasks_mm_cpumask(cpu);