Re: [PATCH v1 7/8] xen/arm: vgic: Introduce helpers to read/write/clear/set vGIC register ...

[Julien Grall <julien.grall@citrix.com>]

On 29/09/15 14:23, Ian Campbell wrote:
> On Fri, 2015-09-25 at 15:51 +0100, Julien Grall wrote:
>> and use them in the vGIC emulation.
>>
>> The GIC registers may support different access sizes. Rather than open
>> coding the access for every registers, provide a set of helpers to access
>> them.
>>
>> The caller will have to call vgic_regN_* where N is the size of the
>> emulated registers.
> 
> These helpers end up as e.g. vgic_regN_read/write, but they don't really
> read or write anything, they just extract the required bits into a register
> or update the bits into a variable.
> 
> Can we think of a better name? encode/decode?

Encode/decode would be the best. I will replace read by decode and write
by encode.

> 
> This might be more apparent (maybe without the need to rename) if the
> helpers took info->dabt.size instead of info.

We also need info to get the MMIO adddress. I would prefer to keep info
and avoid having another parameter here.

>> [...]
>> +static inline void vgic_reg_clearbit(unsigned long *reg, register_t bits,
> 
> Please call these ones clearbits/setbits to avoid giving the impression
> that they take a bit offset and just set/clear that one.

Will do.


-- 
Julien Grall