Clang 12.0.1 cannot understand that value 64 is excluded from the shift at compile time (for use in global context) resulting in build error: drivers/hv/vmbus_drv.c:2082:29: error: shift count >= width of type [-Werror,-Wshift-count-overflow] static u64 vmbus_dma_mask = DMA_BIT_MASK(64); ^~~~~~~~~~~~~~~~ ./include/linux/dma-mapping.h:76:54: note: expanded from macro 'DMA_BIT_MASK' #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1)) ^ ~~~ Avoid using DMA_BIT_MASK macro for that corner case. Cc: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx> Cc: Michael Kelley <mikelley@xxxxxxxxxxxxx> Cc: Long Li <longli@xxxxxxxxxxxxx> Cc: Wei Liu <wei.liu@xxxxxxxxxx> Signed-off-by: Vitaly Chikunov <vt@xxxxxxxxxxxx> --- drivers/hv/vmbus_drv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 17bf55fe3169..a1306ca15d3f 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -2079,7 +2079,8 @@ struct hv_device *vmbus_device_create(const guid_t *type, return child_device_obj; } -static u64 vmbus_dma_mask = DMA_BIT_MASK(64); +/* Use ~0ULL instead of DMA_BIT_MASK(64) to work around a bug in Clang. */ +static u64 vmbus_dma_mask = ~0ULL; /* * vmbus_device_register - Register the child device */ -- 2.33.0
