[PATCH v2 2/2] iommu/mediatek: Fix a build warning of BIT(32) in ARM

From: Yong Wu
Date: Thu Aug 24 2017 - 03:42:37 EST


The commit ("iommu/mediatek: Enlarge the validate PA range
for 4GB mode") introduce the following build warning while ARCH=arm:

drivers/iommu/mtk_iommu.c: In function 'mtk_iommu_iova_to_phys':
include/linux/bitops.h:6:24: warning: left shift count >= width
of type [-Wshift-count-overflow]
#define BIT(nr) (1UL << (nr))
^
>> drivers/iommu/mtk_iommu.c:407:9: note: in expansion of macro 'BIT'
pa |= BIT(32);

drivers/iommu/mtk_iommu.c: In function 'mtk_iommu_probe':
include/linux/bitops.h:6:24: warning: left shift count >= width
of type [-Wshift-count-overflow]
#define BIT(nr) (1UL << (nr))
^
drivers/iommu/mtk_iommu.c:589:35: note: in expansion of macro 'BIT'
data->enable_4GB = !!(max_pfn > (BIT(32) >> PAGE_SHIFT));

Use BIT_ULL instead of BIT.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
---
drivers/iommu/mtk_iommu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index bc00e40..bd515be 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -404,7 +404,7 @@ static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
spin_unlock_irqrestore(&dom->pgtlock, flags);

if (data->enable_4GB)
- pa |= BIT(32);
+ pa |= BIT_ULL(32);

return pa;
}
@@ -586,7 +586,7 @@ static int mtk_iommu_probe(struct platform_device *pdev)
data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);

/* Whether the current dram is over 4GB */
- data->enable_4GB = !!(max_pfn > (BIT(32) >> PAGE_SHIFT));
+ data->enable_4GB = !!(max_pfn > (BIT_ULL(32) >> PAGE_SHIFT));

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
data->base = devm_ioremap_resource(dev, res);
--
1.9.1