[PATCH 5.4 251/270] parisc: mask out enable and reserved bits from sba imask

From: Greg Kroah-Hartman
Date: Mon Aug 17 2020 - 13:58:48 EST


From: Sven Schnelle <svens@xxxxxxxxxxxxxx>

commit 5b24993c21cbf2de11aff077a48c5cb0505a0450 upstream.

When using kexec the SBA IOMMU IBASE might still have the RE
bit set. This triggers a WARN_ON when trying to write back the
IBASE register later, and it also makes some mask calculations fail.

Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Sven Schnelle <svens@xxxxxxxxxxxxxx>
Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/parisc/sba_iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/parisc/sba_iommu.c
+++ b/drivers/parisc/sba_iommu.c
@@ -1270,7 +1270,7 @@ sba_ioc_init_pluto(struct parisc_device
** (one that doesn't overlap memory or LMMIO space) in the
** IBASE and IMASK registers.
*/
- ioc->ibase = READ_REG(ioc->ioc_hpa + IOC_IBASE);
+ ioc->ibase = READ_REG(ioc->ioc_hpa + IOC_IBASE) & ~0x1fffffULL;
iova_space_size = ~(READ_REG(ioc->ioc_hpa + IOC_IMASK) & 0xFFFFFFFFUL) + 1;

if ((ioc->ibase < 0xfed00000UL) && ((ioc->ibase + iova_space_size) > 0xfee00000UL)) {