On 2/11/21 1:34 PM, Christoph Hellwig wrote:
> On Thu, Feb 11, 2021 at 11:52:11AM +0530, Anshuman Khandual wrote:
>> Type cast MAX_ORDER as unsigned int to fix the following build warning.
>>
>> In file included from ./include/linux/kernel.h:14,
>> from ./include/asm-generic/bug.h:20,
>> from ./arch/arm64/include/asm/bug.h:26,
>> from ./include/linux/bug.h:5,
>> from ./include/linux/mmdebug.h:5,
>> from ./arch/arm64/include/asm/memory.h:166,
>> from ./arch/arm64/include/asm/page.h:42,
>> from kernel/dma/contiguous.c:46:
>> kernel/dma/contiguous.c: In function ‘rmem_cma_setup’:
>> ./include/linux/minmax.h:18:28: warning: comparison of distinct pointer
>> types lacks a cast
>> (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
>> ^~
>> ./include/linux/minmax.h:32:4: note: in expansion of macro ‘__typecheck’
>> (__typecheck(x, y) && __no_side_effects(x, y))
>> ^~~~~~~~~~~
>> ./include/linux/minmax.h:42:24: note: in expansion of macro ‘__safe_cmp’
>> __builtin_choose_expr(__safe_cmp(x, y), \
>> ^~~~~~~~~~
>> ./include/linux/minmax.h:58:19: note: in expansion of macro
>> ‘__careful_cmp’
>> #define max(x, y) __careful_cmp(x, y, >)
>> ^~~~~~~~~~~~~
>> kernel/dma/contiguous.c:402:35: note: in expansion of macro ‘max’
>> phys_addr_t align = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
>>
>> Cc: Christoph Hellwig <hch@xxxxxx>
>> Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
>> Cc: Robin Murphy <robin.murphy@xxxxxxx>
>> Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
>> Cc: linux-kernel@xxxxxxxxxxxxxxx
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
>> ---
>> kernel/dma/contiguous.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
>> index 3d63d91cba5c..1c2782349d71 100644
>> --- a/kernel/dma/contiguous.c
>> +++ b/kernel/dma/contiguous.c
>> @@ -399,7 +399,7 @@ static const struct reserved_mem_ops rmem_cma_ops = {
>>
>> static int __init rmem_cma_setup(struct reserved_mem *rmem)
>> {
>> - phys_addr_t align = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
>> + phys_addr_t align = PAGE_SIZE << max((unsigned int)MAX_ORDER - 1, pageblock_order);
>
> MAX_ORDER and pageblock_order should be the same type. So either fix
Right.
> MAX_ORDER to be an unsigned constant, which would be fundamentally
> the right thing to do but might cause some fallout, or turn
> pageblock_order into an int, which is probably much either as the stub
> define of it already has an integer type derived from MAX_ORDER as well.
Right, will change pageblock_order as 'int' which would be easier.
