On Tue, Jan 17, 2023 at 10:34:07PM +0100, Thomas Gleixner wrote: > On Mon, Jan 16 2023 at 14:50, Johan Hovold wrote: > > Avoid looking for an existing mapping twice when creating a new mapping > > using irq_create_fwspec_mapping() by factoring out the actual allocation > > which is shared with irq_create_mapping_affinity(). > > This changelog is incomplete and it took me a while to figure out why > this is before the race fix. > > The point is that you need __irq_create_mapping_affinity() later to fix > the shared mapping race. The double check avoidance is just a nice side > effect. > > So please spell it out and make it clear that this needs to be > backported too, e.g. by adding: > > The split out internal function will be used to fix a shared interrupt > mapping race. This change is therefore tagged with the same fixes tag. > > Fixes: .... Sure. It was originally part of the fix of the race, but I was told to clean up the code first (and not worry about backporting). I'll see what I can do about reordering these again with the aim of making things easier to backport. > > +static unsigned int __irq_create_mapping_affinity(struct irq_domain *domain, > > + irq_hw_number_t hwirq, > > + const struct irq_affinity_desc *affinity) > > Please rename to irq_create_mapping_affinity_locked() so it's clear what > this is about and what the calling convention is. A lockdep assert to > that effect would be nice too. Will do. Johan
