[PATCH v2] powerpc/powernv/memtrace: Fix dcache flushing

[Sandipan Das <sandipan@linux.ibm.com>]

Trace memory is cleared and the corresponding dcache lines
are flushed after allocation. However, this should not be
done using the PFN. This adds the missing conversion to
virtual address.

Fixes: 2ac02e5ecec0 ("powerpc/mm: Remove dcache flush from memory remove.")
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
Previous versions can be found at:
v1: https://lore.kernel.org/linuxppc-dev/20210430075557.893819-1-sandipan@linux.ibm.com/

Changes in v2:
- Added review tag from Aneesh.
- Used pfn_to_kaddr() based on Christophe's suggestion.

---
 arch/powerpc/platforms/powernv/memtrace.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c
index 71c1262589fe..537a4daed614 100644
--- a/arch/powerpc/platforms/powernv/memtrace.c
+++ b/arch/powerpc/platforms/powernv/memtrace.c
@@ -104,8 +104,8 @@ static void memtrace_clear_range(unsigned long start_pfn,
 	 * Before we go ahead and use this range as cache inhibited range
 	 * flush the cache.
 	 */
-	flush_dcache_range_chunked(PFN_PHYS(start_pfn),
-				   PFN_PHYS(start_pfn + nr_pages),
+	flush_dcache_range_chunked((unsigned long)pfn_to_kaddr(start_pfn),
+				   (unsigned long)pfn_to_kaddr(start_pfn + nr_pages),
 				   FLUSH_CHUNK_SIZE);
 }
 
-- 
2.25.1