[adding CCs: Kukjin Kim, Shawn Guo, Magnus Damm, Rob Herring] Pushed out a branch containing the set @ git://linux-arm.org/linux-2.6-lp.git cache-louis for testing purposes. Thanks a lot, Lorenzo On Tue, Sep 18, 2012 at 05:35:30PM +0100, Lorenzo Pieralisi wrote: > This patch series provides an update of a previous posting: > > http://www.spinics.net/lists/arm-kernel/msg194946.html > > v2 updates: > - Dropped v7 dcache level patch > - Refactor the set to make it work on all processors with MULTI_CACHE > and !MULTI_CACHE > - Factor out label redefinition in v7_flush_dcache_all > - Updated some comments > > v7 ARM architecture introduced the concept of cache levels and relative > control registers to manage them. Cache operations that operate on set/way > require to define the cache level at which maintenance operations are carried > out by using coprocessor registers. > > Processors like A7/A15 integrates a unified L2 that is part of the cache > level hierarchy; this implies that cache operations operating on all levels > also end up cleaning the L2 unified cache which is a very time consuming > operation and it is not needed for some power-down operations like single CPU > shutdown. > > For v7, flush_kern_all() cleans all the cache levels up to the Level of > Coherency which includes L2 in it. This is suboptimal for code paths that end > up shutting-down a single processor like CPU hotplug and CPU idle, where only > per-CPU cache state (ie L1 integrated cache) has to be cleaned and invalidated. > > To fix this performance issue this patchset introduces cache LoUIS (Level of > Unification Inner Shareable) maintenance operations in the kernel. > > A new cache operations pointer is added to cpu_cache_fns > > void (*flush_kern_cache_louis)(void); > > that allows to clean and invalidate all data cache levels up to the LoUIS and > invalidate the instruction cache. This new API should provide a sufficiently > optimized API to be used in generic C code in the kernel for power management > operations on most v7 systems. > > For architecture versions previous to v7, flush_kern_cache_louis() falls back > to flush_kern_all() leaving the current behaviour unchanged. > > For A9/A5 processors Level of Unification Inner Shareable and Level of > Coherency are equivalent hence this patch should not affect current kernel > behaviour in any way when run on A9/A5 based systems, but should nonetheless > be thoroughly tested on them. > > Tested on: > - OMAP4 (S2R, cpuidle and hotplug) > - OMAP5 (out of tree code) (S2R, cpuidle and hotplug) > - TC2 big.LITTLE testchip (out of tree code) (cpuidle, on both A7 and A15 > clusters) > > Lorenzo Pieralisi (4): > ARM: mm: implement LoUIS API for cache maintenance ops > ARM: mm: rename jump labels in v7_flush_dcache_all function > ARM: kernel: update cpu_suspend code to use cache LoUIS operations > ARM: kernel: update __cpu_disable to use cache LoUIS maintenance API > > Santosh Shilimkar (1): > ARM: mm: update __v7_setup() to the new LoUIS cache maintenance API > > arch/arm/include/asm/cacheflush.h | 15 ++++++++++++ > arch/arm/include/asm/glue-cache.h | 1 + > arch/arm/kernel/smp.c | 5 +++- > arch/arm/kernel/suspend.c | 17 +++++++++++++- > arch/arm/mm/cache-fa.S | 3 +++ > arch/arm/mm/cache-v3.S | 3 +++ > arch/arm/mm/cache-v4.S | 3 +++ > arch/arm/mm/cache-v4wb.S | 3 +++ > arch/arm/mm/cache-v4wt.S | 3 +++ > arch/arm/mm/cache-v6.S | 3 +++ > arch/arm/mm/cache-v7.S | 48 ++++++++++++++++++++++++++++++++++----- > arch/arm/mm/proc-arm1020.S | 3 +++ > arch/arm/mm/proc-arm1020e.S | 3 +++ > arch/arm/mm/proc-arm1022.S | 3 +++ > arch/arm/mm/proc-arm1026.S | 3 +++ > arch/arm/mm/proc-arm920.S | 3 +++ > arch/arm/mm/proc-arm922.S | 3 +++ > arch/arm/mm/proc-arm925.S | 3 +++ > arch/arm/mm/proc-arm926.S | 3 +++ > arch/arm/mm/proc-arm940.S | 3 +++ > arch/arm/mm/proc-arm946.S | 3 +++ > arch/arm/mm/proc-feroceon.S | 3 +++ > arch/arm/mm/proc-macros.S | 1 + > arch/arm/mm/proc-mohawk.S | 3 +++ > arch/arm/mm/proc-v7.S | 2 +- > arch/arm/mm/proc-xsc3.S | 3 +++ > arch/arm/mm/proc-xscale.S | 3 +++ > 27 files changed, 140 insertions(+), 9 deletions(-) > > -- > 1.7.12 > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
