[PATCH 3.16 077/148] powerpc: Allow flush_icache_range to work across ranges >4GB

[Ben Hutchings]

3.16.82-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Alastair D'Silva <alastair@xxxxxxxxxxx>

commit 29430fae82073d39b1b881a3cd507416a56a363f upstream.

When calling flush_icache_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 <alastair@xxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20191104023305.9581-2-alastair@xxxxxxxxxxx
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 arch/powerpc/kernel/misc_64.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -84,7 +84,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_I
 	subf	r8,r6,r4		/* compute length */
 	add	r8,r8,r5		/* ensure we get enough */
 	lwz	r9,DCACHEL1LOGLINESIZE(r10)	/* Get log-2 of cache line size */
-	srw.	r8,r8,r9		/* compute line count */
+	srd.	r8,r8,r9		/* compute line count */
 	beqlr				/* nothing to do? */
 	mtctr	r8
 1:	dcbst	0,r6
@@ -100,7 +100,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_I
 	subf	r8,r6,r4		/* compute length */
 	add	r8,r8,r5
 	lwz	r9,ICACHEL1LOGLINESIZE(r10)	/* Get log-2 of Icache line size */
-	srw.	r8,r8,r9		/* compute line count */
+	srd.	r8,r8,r9		/* compute line count */
 	beqlr				/* nothing to do? */
 	mtctr	r8
 2:	icbi	0,r6