[PATCH 11/33] scsi: qla2xxx: Use memset_io() to clear QLAFX00 request ring slot

For QLAFX00 the request ring is ioremapped device I/O memory
(ha->iobase + req_que_off), not DMA-coherent RAM, which is why the rest
of the FX00 path accesses it through memcpy_toio() and the wrt_reg_*
helpers. __qla2x00_alloc_iocbs() however zeroed the producer slot with a
plain memset(). On architectures such as ARM64 a regular memset() may
emit unaligned or block-zeroing instructions (e.g. DC ZVA) that are
invalid on Device memory, leading to a synchronous external abort.

Use memset_io() to clear the slot for QLAFX00, matching the I/O
accessors used elsewhere on this ring. Other adapters keep the plain
memset() on their DMA-coherent rings. The zero-fill is retained for FX00
because its IOCB builders (e.g. qlafx00_fxdisc_iocb()) copy only part of
the entry and rely on the unused tail being pre-zeroed.

Fixes: 8ae6d9c7eb10 ("[SCSI] qla2xxx: Enhancements to support ISPFx00.")
Cc: [email protected]
Reported-by: Sashiko <[email protected]>
Signed-off-by: Nilesh Javali <[email protected]>
---
 drivers/scsi/qla2xxx/qla_iocb.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/qla2xxx/qla_iocb.c b/drivers/scsi/qla2xxx/qla_iocb.c
index c4595626c16b..88bae1166a24 100644
--- a/drivers/scsi/qla2xxx/qla_iocb.c
+++ b/drivers/scsi/qla2xxx/qla_iocb.c
@@ -2530,11 +2530,13 @@ __qla2x00_alloc_iocbs(struct qla_qpair *qpair, srb_t *sp)
 	 */
 	req->cnt -= req_cnt;
 	pkt = qla_req_ring_slot(ha, req);
-	memset(pkt, 0, qla_req_entry_size(ha));
 	if (IS_QLAFX00(ha)) {
+		memset_io((void __iomem __force *)pkt, 0,
+			  qla_req_entry_size(ha));
 		wrt_reg_byte((u8 __force __iomem *)&pkt->entry_count, req_cnt);
 		wrt_reg_dword((__le32 __force __iomem *)&pkt->handle, handle);
 	} else {
+		memset(pkt, 0, qla_req_entry_size(ha));
 		pkt->entry_count = req_cnt;
 		pkt->handle = handle;
 	}
-- 
2.47.3