From: Alastair D'Silva alastair@d-silva.org
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.
Changelog: v2 - Add related upstream commit
Signed-off-by: Alastair D'Silva alastair@d-silva.org --- 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 1ad4089dd110..d4d096f80f4b 100644 --- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -130,7 +130,7 @@ _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 @@ -148,7 +148,7 @@ _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