[PATCH 5.15 599/917] iommu/mediatek: Fix out-of-range warning with clang

Greg Kroah-Hartman
2021-11-15T23:57:50Z

From: Arnd Bergmann <arnd@arndb.de>

[ Upstream commit f13efafc1a2cf30d4a74c00f40210d6de36db2d0 ]

clang-14 notices that a comparison is never true when
CONFIG_PHYS_ADDR_T_64BIT is disabled:

drivers/iommu/mtk_iommu.c:553:34: error: result of comparison of constant 5368709120 with expression of type 'phys_addr_t' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
if (dom->data->enable_4GB && pa >= MTK_IOMMU_4GB_MODE_REMAP_BASE)
~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Add an explicit check for the type of the variable to skip the check
and the warning in that case.

Fixes: b4dad40e4f35 ("iommu/mediatek: Adjust the PA for the 4GB Mode")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Yong Wu <yong.wu@mediatek.com>
Link: https://lore.kernel.org/r/20210927121857.941160-1-arnd@kernel.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/iommu/mtk_iommu.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index d837adfd1da55..25b834104790c 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -550,7 +550,9 @@ static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
phys_addr_t pa;

pa = dom->iop->iova_to_phys(dom->iop, iova);
- if (dom->data->enable_4GB && pa >= MTK_IOMMU_4GB_MODE_REMAP_BASE)
+ if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT) &&
+ dom->data->enable_4GB &&
+ pa >= MTK_IOMMU_4GB_MODE_REMAP_BASE)
pa &= ~BIT_ULL(32);

return pa;
--
2.33.0