Re: [PATCH v6 2/9] xen/riscv: use {read,write}{b,w,l,q}_cpu() to define {read,write}_atomic()

[Andrew Cooper]

On 02/09/2024 6:01 pm, Oleksii Kurochko wrote:
> diff --git a/xen/arch/riscv/include/asm/atomic.h 
> b/xen/arch/riscv/include/asm/atomic.h
> index 31b91a79c8..3c6bd86406 100644
> --- a/xen/arch/riscv/include/asm/atomic.h
> +++ b/xen/arch/riscv/include/asm/atomic.h
> @@ -31,21 +31,17 @@
>  
>  void __bad_atomic_size(void);
>  
> -/*
> - * Legacy from Linux kernel. For some reason they wanted to have ordered
> - * read/write access. Thereby read* is used instead of read*_cpu()
> - */
>  static always_inline void read_atomic_size(const volatile void *p,
>                                             void *res,
>                                             unsigned int size)
>  {
>      switch ( size )
>      {
> -    case 1: *(uint8_t *)res = readb(p); break;
> -    case 2: *(uint16_t *)res = readw(p); break;
> -    case 4: *(uint32_t *)res = readl(p); break;
> +    case 1: *(uint8_t *)res = readb_cpu(p); break;
> +    case 2: *(uint16_t *)res = readw_cpu(p); break;
> +    case 4: *(uint32_t *)res = readl_cpu(p); break;
>  #ifndef CONFIG_RISCV_32
> -    case 8: *(uint32_t *)res = readq(p); break;
> +    case 8: *(uint32_t *)res = readq_cpu(p); break;

This cast looks suspiciously like it's wrong already in staging...

~Andrew