2021-09-27 12:20:45

by Arnd Bergmann

Subject: [PATCH] iommu/mediatek: fix out-of-range warning with clang

From: Arnd Bergmann <[email protected]>

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 <[email protected]>
---
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 d837adfd1da5..25b834104790 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;
--
2.29.2

2021-09-28 01:23:09

by Yong Wu (吴勇)

Subject: Re: [PATCH] iommu/mediatek: fix out-of-range warning with clang

On Mon, 2021-09-27 at 14:18 +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <[email protected]>
>
> 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 <[email protected]>

Reviewed-by: Yong Wu <[email protected]>

Thanks.

2021-09-28 10:01:34

by Joerg Roedel

Subject: Re: [PATCH] iommu/mediatek: fix out-of-range warning with clang

On Mon, Sep 27, 2021 at 02:18:44PM +0200, Arnd Bergmann wrote:
> drivers/iommu/mtk_iommu.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)

Applied, thanks.