[PATCH 4/8] iommu/io-pgtable-arm: Ensure ARM_64_LPAE_S2_TCR_RES1 is unsigned

Will Deacon
2020-01-10T15:29:08Z

ARM_64_LPAE_S2_TCR_RES1 is intended to map to bit 31 of the VTCR register,
which is required to be set to 1 by the architecture. Unfortunately, we
accidentally treat this as a signed quantity which means we also set the
upper 32 bits of the VTCR to one, and they are required to be zero.

Treat ARM_64_LPAE_S2_TCR_RES1 as unsigned to avoid the unwanted
sign-extension up to 64 bits.

Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
drivers/iommu/io-pgtable-arm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 4b437ead2300..89216bf37282 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -101,7 +101,7 @@

/* Register bits */
#define ARM_32_LPAE_TCR_EAE (1 << 31)
-#define ARM_64_LPAE_S2_TCR_RES1 (1 << 31)
+#define ARM_64_LPAE_S2_TCR_RES1 (1U << 31)

#define ARM_LPAE_TCR_EPD1 (1 << 23)