From 54de4ef852b644c2eb2741ec338d1750196e3733 Mon Sep 17 00:00:00 2001 From: Alastair D'Silva Date: Wed, 21 Aug 2019 10:19:27 +1000 Subject: [PATCH] powerpc: Allow flush_(inval_)dcache_range to work across ranges >4GB The upstream commit: 22e9c88d486a ("powerpc/64: reuse PPC32 static inline flush_dcache_range()") has a similar effect, but since it is a rewrite of the assembler to C, is too invasive for stable. This patch is a minimal fix to address the issue in assembler. This patch applies cleanly to v5.2, v4.19 & v4.14. When calling flush_(inval_)dcache_range with a size >4GB, we were masking off the upper 32 bits, so we would incorrectly flush a range smaller than intended. This patch replaces the 32 bit shifts with 64 bit ones, so that the full size is accounted for. Signed-off-by: Alastair D'Silva Acked-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/misc_64.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S index 3280953a82cf..09af857ca099 100644 --- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -134,7 +134,7 @@ _GLOBAL_TOC(flush_dcache_range) subf r8,r6,r4 /* compute length */ add r8,r8,r5 /* ensure we get enough */ lwz r9,DCACHEL1LOGBLOCKSIZE(r10) /* Get log-2 of dcache block size */ - srw. r8,r8,r9 /* compute line count */ + srd. r8,r8,r9 /* compute line count */ beqlr /* nothing to do? */ mtctr r8 0: dcbst 0,r6 @@ -190,7 +190,7 @@ _GLOBAL(flush_inval_dcache_range) subf r8,r6,r4 /* compute length */ add r8,r8,r5 /* ensure we get enough */ lwz r9,DCACHEL1LOGBLOCKSIZE(r10)/* Get log-2 of dcache block size */ - srw. r8,r8,r9 /* compute line count */ + srd. r8,r8,r9 /* compute line count */ beqlr /* nothing to do? */ sync isync -- 2.20.1