Hi Julien,
On Mon, Sep 21, 2015 at 10:47:23AM +0100, Julien Grall wrote:
>Hi Peng,
>
>On 21/09/15 08:07, Peng Fan wrote:
>> To ARM64, "if ( hsr.ec >= 0x10 ) return 1;" is ok for unconditional
>> check, but to ARM32, we need to use 'hsr.ec >> 30' to check.
>
>hsr.ec is encoded on 5 bits, therefore the shift you suggest is wrong.
>Maybe you wanted to use (hsr.ec >> 4)?
Thanks for correcting me. 0x10 can handle hsr.ec >> 4.
My bad, this patch is wrong.
Regards,
Peng.
>
>Although, can you explain why you need a different check for ARM32?
>
>Regards,
>
>> Signed-off-by: Peng Fan
>> Cc: Ian Campbell
>> Cc: Stefano Stabellini
>> Cc: Julien Grall
>> ---
>> xen/arch/arm/traps.c | 5 +
>> 1 file changed, 5 insertions(+)
>>
>> diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
>> index 9d2bd6a..2e2b1f2 100644
>> --- a/xen/arch/arm/traps.c
>> +++ b/xen/arch/arm/traps.c
>> @@ -1531,8 +1531,13 @@ static int check_conditional_instr(struct
>> cpu_user_regs *regs,
>> int cond;
>>
>> /* Unconditional Exception classes */
>> +#ifdef CONFIG_ARM_64
>> if ( hsr.ec >= 0x10 )
>> return 1;
>> +#else
>> +if ( hsr.ec >> 30 )
>> +return 1;
>> +#endif
>>
>> /* Check for valid condition in hsr */
>> cond = hsr.cond.ccvalid ? hsr.cond.cc : -1;
>>
>
>
>--
>Julien Grall
--
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