[PATCH net-next 2/4] io: add function to flush the write combine buffer to device immediately

[Catalin Marinas]

On Fri, Jul 30, 2021 at 11:14:22AM +0800, Guangbin Huang wrote:
> From: Xiongfeng Wang <wangxiongfeng2 at huawei.com>
> 
> Device registers can be mapped as write-combine type. In this case, data
> are not written into the device immediately. They are temporarily stored
> in the write combine buffer and written into the device when the buffer
> is full. But in some situation, we need to flush the write combine
> buffer to device immediately for better performance. So we add a general
> function called 'flush_wc_write()'. We use DGH instruction to implement
> this function for ARM64.

Isn't this slightly misleading? IIUC DGH does not guarantee flushing, it
just prevents writes merging (maybe this was already discussed on the
previous RFC).

-- 
Catalin