linux-kernel - Re: [RESEND][PATCH v8 4/5] dma-buf: heaps: Add CMA heap to dmabuf heaps

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Message-ID: <CALAqxLUPjtfOmK7Dc9y+vZ6iw9dbUzu5pbRKes7i5jaysz4yXA@mail.gmail.com>
Date:   Wed, 2 Oct 2019 09:15:35 -0700
From:   John Stultz <john.stultz@...aro.org>
To:     Hillf Danton <hdanton@...a.com>
Cc:     lkml <linux-kernel@...r.kernel.org>,
        Laura Abbott <labbott@...hat.com>,
        Benjamin Gaignard <benjamin.gaignard@...aro.org>,
        Sumit Semwal <sumit.semwal@...aro.org>,
        Liam Mark <lmark@...eaurora.org>,
        Pratik Patel <pratikp@...eaurora.org>,
        Brian Starkey <Brian.Starkey@....com>,
        Vincent Donnefort <Vincent.Donnefort@....com>,
        Sudipto Paul <Sudipto.Paul@....com>,
        "Andrew F . Davis" <afd@...com>,
        Christoph Hellwig <hch@...radead.org>,
        Chenbo Feng <fengc@...gle.com>,
        Alistair Strachan <astrachan@...gle.com>,
        Hridya Valsaraju <hridya@...gle.com>,
        dri-devel <dri-devel@...ts.freedesktop.org>
Subject: Re: [RESEND][PATCH v8 4/5] dma-buf: heaps: Add CMA heap to dmabuf heaps

On Mon, Sep 30, 2019 at 1:14 AM Hillf Danton <hdanton@...a.com> wrote:
> On Fri,  6 Sep 2019 18:47:09 +0000 John Stultz wrote:
> >
> > +     cma_pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
> > +     if (!cma_pages)
> > +             goto free_buf;
> > +
> > +     if (PageHighMem(cma_pages)) {
> > +             unsigned long nr_clear_pages = nr_pages;
> > +             struct page *page = cma_pages;
> > +
> > +             while (nr_clear_pages > 0) {
> > +                     void *vaddr = kmap_atomic(page);
> > +
> > +                     memset(vaddr, 0, PAGE_SIZE);
> > +                     kunmap_atomic(vaddr);
> > +                     page++;
> > +                     nr_clear_pages--;
> > +             }
> > +     } else {
> > +             memset(page_address(cma_pages), 0, size);
> > +     }
>
> Take a breath after zeroing a page, and a peep at pending signal.

Ok. Took a swing at this. It will be in the next revision.

Thanks again for the review!
-john