Re: [PATCH 9/9] iommu: Move flush queue data into iommu_dma_cookie

[Robin Murphy]

On 2021-11-24 17:25, John Garry wrote:
> On 23/11/2021 14:10, Robin Murphy wrote:
> > ruct iommu_dma_msi_page {
> >       struct list_head    list;
> > @@ -41,7 +43,19 @@ struct iommu_dma_cookie {
> >       enum iommu_dma_cookie_type    type;
> >       union {
> >           /* Full allocator for IOMMU_DMA_IOVA_COOKIE */
> > -        struct iova_domain    iovad;
> > +        struct {
> > +            struct iova_domain    iovad;
> > +
> > +            struct iova_fq __percpu *fq;    /* Flush queue */
> > +            /* Number of TLB flushes that have been started */
> > +            atomic64_t        fq_flush_start_cnt;
> > +            /* Number of TLB flushes that have been finished */
> > +            atomic64_t        fq_flush_finish_cnt;
> > +            /* Timer to regularily empty the flush queues */
> > +            struct timer_list    fq_timer;
> > +            /* 1 when timer is active, 0 when not */
> > +            atomic_t        fq_timer_on;
>
> I thought that putting all the FQ stuff in its own structure would be 
> neater, but that's just personal preference.

But look, it is! ;)

The iova_domain is still a fundamental part of the flush queue built 
around it; the rest of the machinery can't stand in isolation. It's just 
an anonymous structure because I don't feel like needlessly cluttering 
up the code with "cookie->fq.fq" silliness.

Cheers,
Robin.