Re: [RFC 2/4] ptimer: Rename ptimer_init() to ptimer_init_with_bh()

[Richard Henderson <richard.henderson@linaro.org>]

On 10/4/19 4:48 AM, Peter Maydell wrote:
> Currently the ptimer design uses a QEMU bottom-half as its
> mechanism for calling back into the device model using the
> ptimer when the timer has expired. Unfortunately this design
> is fatally flawed, because it means that there is a lag
> between the ptimer updating its own state and the device
> callback function updating device state, and guest accesses
> to device registers between the two can return inconsistent
> device state.
> 
> We want to replace the bottom-half design with one where
> the guest device's callback is called either immediately
> (when the ptimer triggers by timeout) or when the device
> model code closes a transaction-begin/end section (when the
> ptimer triggers because the device model changed the
> ptimer's count value or other state). As the first step,
> rename ptimer_init() to ptimer_init_with_bh(), to free up
> the ptimer_init() name for the new API. We can then convert
> all the ptimer users away from ptimer_init_with_bh() before
> removing it entirely.
> 
> (Commit created with
>  git grep -l ptimer_init | xargs sed -i -e 's/ptimer_init/ptimer_init_with_bh/'
> and three overlong lines folded by hand.)
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


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