From mboxrd@z Thu Jan 1 00:00:00 1970 From: ashoks@broadcom.com (Ashok Kumar) Date: Tue, 15 Dec 2015 04:56:16 -0800 Subject: [PATCH v2 0/2] arm64: change PoC D-cache flush to PoU Message-ID: <1450184178-28257-1-git-send-email-ashoks@broadcom.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org For keeping I and D coherent, dcache flush till PoU(Point of Unification) should be sufficient instead of doing till PoC(Point of coherence). In SoC with more levels of cache, there could be a performance hit in doing flush till PoC as __flush_dcache_area does both flush and invalidate. Introduced new API __clean_dcache_area_pou which does only clean till PoU. Also deferred dcache flush in __cpu_copy_user_page to __sync_icache_dcache. changes since v1 [1]: Incorporated Mark Rutland's review comments of * renaming __flush_dcache_area_pou to __clean_dcache_area_pou * using inner shareable domain for dsb in __clean_dcache_area_pou * having a common macro for __flush_dcache_area and __clean_dcache_area_pou. Thanks, Ashok [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-December/393527.html Ashok Kumar (2): arm64: Defer dcache flush in __cpu_copy_user_page arm64: Use PoU cache instr for I/D coherency arch/arm64/include/asm/cacheflush.h | 1 + arch/arm64/mm/cache.S | 47 ++++++++++++++++++++++++++++++------- arch/arm64/mm/copypage.c | 3 ++- arch/arm64/mm/flush.c | 14 +++++++---- 4 files changed, 51 insertions(+), 14 deletions(-) -- 2.1.0