Re: [PATCH v2 4/6] qemu/bitops.h: Add MAKE_32BIT_MASK macro

[LIU Zhiwei]

On 2023/10/11 22:45, Rob Bradford wrote:
> Add 32-bit version of mask generating macro and use it in the RISC-V PMU
> code.
CC Richard
> Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
> ---
>   include/qemu/bitops.h | 3 +++
>   target/riscv/pmu.c    | 2 --
>   2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h
> index cb3526d1f4..9b25b2d5e4 100644
> --- a/include/qemu/bitops.h
> +++ b/include/qemu/bitops.h
> @@ -25,6 +25,9 @@
>   #define BIT_WORD(nr)            ((nr) / BITS_PER_LONG)
>   #define BITS_TO_LONGS(nr)       DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
>   
> +#define MAKE_32BIT_MASK(shift, length) \
> +    (((uint32_t)(~0UL) >> (32 - (length))) << (shift))
> +
>   #define MAKE_64BIT_MASK(shift, length) \
>       (((~0ULL) >> (64 - (length))) << (shift))
>   
> diff --git a/target/riscv/pmu.c b/target/riscv/pmu.c
> index 7ddf4977b1..360c76f63e 100644
> --- a/target/riscv/pmu.c
> +++ b/target/riscv/pmu.c
> @@ -24,8 +24,6 @@
>   #include "sysemu/device_tree.h"
>   
>   #define RISCV_TIMEBASE_FREQ 1000000000 /* 1Ghz */
> -#define MAKE_32BIT_MASK(shift, length) \
> -        (((uint32_t)(~0UL) >> (32 - (length))) << (shift))
>   

We can always use the MAKE_64BIT_MASK instead of MAKE_32BIT_MASK.  And 
MAKE_32BIT_MASK only used in target/riscv. I am not sure  whether this 
patch will be accepted.

Acked-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>

Zhiwei

>   /*
>    * To keep it simple, any event can be mapped to any programmable counters in