scsi: mpt3sas: Add an I/O barrier

thenzl · martinkpetersen · commit 10ee1f2206a3 · 2018-06-05T21:24:34.000-04:00
A barrier should be added to ensure proper ordering of memory mapped
writes.

Signed-off-by: Tomas Henzl &lt;thenzl@redhat.com&gt;
Acked-by: Chaitra P B &lt;chaitra.basappa@broadcom.com&gt;
Signed-off-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -3344,6 +3344,7 @@ _base_mpi_ep_writeq(__u64 b, volatile void __iomem *addr,
 	spin_lock_irqsave(writeq_lock, flags);
 	writel((u32)(data_out), addr);
 	writel((u32)(data_out >> 32), (addr + 4));
+	mmiowb();
 	spin_unlock_irqrestore(writeq_lock, flags);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -3344,6 +3344,7 @@ _base_mpi_ep_writeq(__u64 b, volatile void __iomem *addr,`
`3344`	`3344`	`spin_lock_irqsave(writeq_lock, flags);`
`3345`	`3345`	`writel((u32)(data_out), addr);`
`3346`	`3346`	`writel((u32)(data_out >> 32), (addr + 4));`
	`3347`	`+ mmiowb();`
`3347`	`3348`	`spin_unlock_irqrestore(writeq_lock, flags);`
`3348`	`3349`	`}`
`3349`	`3350`