[PATCH] drm/amdkfd: Cast atomic64_read return value

[Felix Kuehling]

Am 2021-09-13 um 10:19 a.m. schrieb Michel Dänzer:
> From: Michel Dänzer <mdaenzer at redhat.com>
>
> Avoids warning with -Wformat:
>
>   CC [M]  drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_smi_events.o
> ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_smi_events.c: In function ‘kfd_smi_event_update_thermal_throttling’:
> ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_smi_events.c:224:60: warning: format ‘%llx’ expects argument of type
>  ‘long long unsigned int’, but argument 6 has type ‘long int’ [-Wformat=]
>   224 |         len = snprintf(fifo_in, sizeof(fifo_in), "%x %x:%llx\n",
>       |                                                         ~~~^
>       |                                                            |
>       |                                                            long long unsigned int
>       |                                                         %lx
>   225 |                        KFD_SMI_EVENT_THERMAL_THROTTLE, throttle_bitmask,
>   226 |                        atomic64_read(&adev->smu.throttle_int_counter));
>       |                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>       |                        |
>       |                        long int

That's weird. As far as I can see, atomic64_read is defined to return
s64, which should be the same as long long. Which architecture are you
on? For the record, these are the definition for x86 and x86_64 on Linux
5.13:

./arch/x86/include/asm/atomic64_32.h:static inline s64
arch_atomic64_read(const atomic64_t *v)
./arch/x86/include/asm/atomic64_64.h:static inline s64
arch_atomic64_read(const atomic64_t *v)

Looks like x86 uses int-ll64.h (64-bit types are long-long). Some other
architectures use int-l64.h (64-bit types are long). On architectures
that use int-l64.h, this patch just casts s64 (long) to u64 (unsigned
long), which doesn't fix the problem.

Regards,
  Felix


>
> Signed-off-by: Michel Dänzer <mdaenzer at redhat.com>
> ---
>  drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c b/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c
> index ed4bc5f844ce..46e1c0cda94c 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c
> @@ -223,7 +223,7 @@ void kfd_smi_event_update_thermal_throttling(struct kfd_dev *dev,
>  
>  	len = snprintf(fifo_in, sizeof(fifo_in), "%x %llx:%llx\n",
>  		       KFD_SMI_EVENT_THERMAL_THROTTLE, throttle_bitmask,
> -		       atomic64_read(&adev->smu.throttle_int_counter));
> +		       (u64)atomic64_read(&adev->smu.throttle_int_counter));
>  
>  	add_event_to_kfifo(dev, KFD_SMI_EVENT_THERMAL_THROTTLE,	fifo_in, len);
>  }