Re: [PATCH] target/ppc/translate: Add dummy implementation for dcblc instruction

[Bernhard Beschow]

Am 30. Januar 2023 22:23:59 UTC schrieb Richard Henderson 
<richard.henderson@linaro.org>:
>On 1/30/23 08:49, Bernhard Beschow wrote:
>> The dcblc instruction is used by u-boot in mpc85xx/start.S. Without it,
>> an illegal istruction exception is generated very early in the boot
>> process where the processor is not yet able to handle exceptions. See:
>> 
>> https://github.com/u-boot/u-boot/blob/v2023.01/arch/powerpc/cpu/mpc85xx/start.S#L1840
>> 
>> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
>> ---
>>   target/ppc/translate.c | 9 +++++++++
>>   1 file changed, 9 insertions(+)
>> 
>> diff --git a/target/ppc/translate.c b/target/ppc/translate.c
>> index edb3daa9b5..8c32e697d9 100644
>> --- a/target/ppc/translate.c
>> +++ b/target/ppc/translate.c
>> @@ -5261,6 +5261,14 @@ static void gen_dcbtls(DisasContext *ctx)
>>       tcg_temp_free(t0);
>>   }
>>   +/* dcblc */
>> +static void gen_dcblc(DisasContext *ctx)
>> +{
>> +    /*
>> +     * interpreted as no-op
>> +     */
>
>Missing
>
>If MSR[UCLE] (user-mode cache lock enable) is set, dcblc[e] may be performed 
>while in
>user mode (MSR[PR] = 1). If MSR[UCLE] is clear, an attempt to perform this 
>instructions
>in user mode causes a DSI. ESR[DLK] is set for this DSI.
>
>but that's also true for the current implementation of dcbtls.  So,
>
>Acked-by: Richard Henderson <richard.henderson@linaro.org>

Ping

Does that mean it's ready to be queued or do we need a Reviewed-by as well?
>
>
>r~