RE: [PATCH v2 1/6] ia64, processor: fix -Wincompatible-pointer-types in ia64_get_irr()

[David Laight]

From: Alexander Lobakin
> Sent: 10 June 2022 12:34
> 
> test_bit(), as any other bitmap op, takes `unsigned long *` as a
> second argument (pointer to the actual bitmap), as any bitmap
> itself is an array of unsigned longs. However, the ia64_get_irr()
> code passes a ref to `u64` as a second argument.
> This works with the ia64 bitops implementation due to that they
> have `void *` as the second argument and then cast it later on.
> This works with the bitmap API itself due to that `unsigned long`
> has the same size on ia64 as `u64` (`unsigned long long`), but
> from the compiler PoV those two are different.
> Define @irr as `unsigned long` to fix that. That implies no
> functional changes. Has been hidden for 16 years!

Wouldn't it be better to just test the bit?
As in:
	return irr & (1ull << bit);

    David

> 
> Fixes: a58786917ce2 ("[IA64] avoid broken SAL_CACHE_FLUSH implementations")
> Cc: stable@xxxxxxxxxxxxxxx # 2.6.16+
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Signed-off-by: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx>
> ---
>  arch/ia64/include/asm/processor.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/ia64/include/asm/processor.h b/arch/ia64/include/asm/processor.h
> index 7cbce290f4e5..757c2f6d8d4b 100644
> --- a/arch/ia64/include/asm/processor.h
> +++ b/arch/ia64/include/asm/processor.h
> @@ -538,7 +538,7 @@ ia64_get_irr(unsigned int vector)
>  {
>  	unsigned int reg = vector / 64;
>  	unsigned int bit = vector % 64;
> -	u64 irr;
> +	unsigned long irr;
> 
>  	switch (reg) {
>  	case 0: irr = ia64_getreg(_IA64_REG_CR_IRR0); break;
> --
> 2.36.1

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)