Re: [PATCH bpf-next v6 2/4] arm64: Add LDR (literal) instruction

[Xu Kuohai <xukuohai@huawei.com>]

On 7/6/2022 12:39 AM, Will Deacon wrote:
> On Sat, Jun 25, 2022 at 12:12:53PM -0400, Xu Kuohai wrote:
>> Add LDR (literal) instruction to load data from address relative to PC.
>> This instruction will be used to implement long jump from bpf prog to
>> bpf rampoline in the follow-up patch.
> 
> typo: trampoline
>

will fix

>>
>> The instruction encoding:
>>
>>     3       2   2     2                                     0        0
>>     0       7   6     4                                     5        0
>> +-----+-------+---+-----+-------------------------------------+--------+
>> | 0 x | 0 1 1 | 0 | 0 0 |                imm19                |   Rt   |
>> +-----+-------+---+-----+-------------------------------------+--------+
>>
>> for 32-bit, variant x == 0; for 64-bit, x == 1.
>>
>> branch_imm_common() is used to check the distance between pc and target
>> address, since it's reused by this patch and LDR (literal) is not a branch
>> instruction, rename it to aarch64_imm_common().
> 
> nit, but I think "label_imm_common()" would be a better name.
> 

will rename

> Anyway, I checked the encodings and the code looks good, so:
> 
> Acked-by: Will Deacon <will@kernel.org>
> 
> Will
> .