Re: [PATCH v4 1/2] target/arm: allow DC CVA[D]P in user mode emulation

[Philippe Mathieu-Daudé]

On 2/6/23 00:11, Zhuojia Shen wrote:
> DC CVAP and DC CVADP instructions can be executed in EL0 on Linux,
> either directly when SCTLR_EL1.UCI == 1 or emulated by the kernel (see
> user_cache_maint_handler() in arch/arm64/kernel/traps.c).
>
> This patch enables execution of the two instructions in user mode
> emulation.
>
> Signed-off-by: Zhuojia Shen <chaosdefinition@hotmail.com>
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   target/arm/helper.c | 6 ++----
>   1 file changed, 2 insertions(+), 4 deletions(-)


> -#ifndef CONFIG_USER_ONLY
>   static void dccvap_writefn(CPUARMState *env, const ARMCPRegInfo *opaque,
>                             uint64_t value)
>   {
> @@ -7420,6 +7419,7 @@ static void dccvap_writefn(CPUARMState *env, const 
> ARMCPRegInfo *opaque,
>       /* This won't be crossing page boundaries */
>       haddr = probe_read(env, vaddr, dline_size, mem_idx, GETPC());
>       if (haddr) {
> +#ifndef CONFIG_USER_ONLY

This ifdef'ry placement is odd. Is it to silent a
unused-but-set-variable warning?

>           ram_addr_t offset;
>           MemoryRegion *mr;
> @@ -7430,6 +7430,7 @@ static void dccvap_writefn(CPUARMState *env, const 
> ARMCPRegInfo *opaque,
>           if (mr) {
>               memory_region_writeback(mr, offset, dline_size);
>           }
> +#endif /*CONFIG_USER_ONLY*/
>       }
>   }
>   
> @@ -7448,7 +7449,6 @@ static const ARMCPRegInfo dcpodp_reg[] = {
>         .fgt = FGT_DCCVADP,
>         .accessfn = aa64_cacheop_poc_access, .writefn = dccvap_writefn },
>   };
> -#endif /*CONFIG_USER_ONLY*/