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Message-ID: <b0b824bebb9ef13ce746f9914de83126b0386e23.camel@suse.de>
Subject: Re: [PATCH v5 3/4] arm64: use both ZONE_DMA and ZONE_DMA32
From:   Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
To:     catalin.marinas@arm.com, hch@lst.de, wahrenst@gmx.net,
        marc.zyngier@arm.com, robh+dt@kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
        linux-riscv@lists.infradead.org, Will Deacon <will@kernel.org>
Cc:     f.fainelli@gmail.com, robin.murphy@arm.com,
        linux-kernel@vger.kernel.org, mbrugger@suse.com,
        linux-rpi-kernel@lists.infradead.org, phill@raspberrypi.org,
        m.szyprowski@samsung.com
Date:   Wed, 11 Sep 2019 12:54:38 +0200
In-Reply-To: <20190909095807.18709-4-nsaenzjulienne@suse.de>
References: <20190909095807.18709-1-nsaenzjulienne@suse.de>
         <20190909095807.18709-4-nsaenzjulienne@suse.de>
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On Mon, 2019-09-09 at 11:58 +0200, Nicolas Saenz Julienne wrote:
> +
>  /*
> - * Return the maximum physical address for ZONE_DMA32 (DMA_BIT_MASK(32))=
. It
> - * currently assumes that for memory starting above 4G, 32-bit devices w=
ill
> - * use a DMA offset.
> + * Return the maximum physical address for a zone with a given address s=
ize
> + * limit. It currently assumes that for memory starting above 4G, 32-bit
> + * devices will use a DMA offset.
>   */
> -static phys_addr_t __init max_zone_dma32_phys(void)
> +static phys_addr_t __init max_zone_phys(unsigned int zone_bits)
>  {
>         phys_addr_t offset =3D memblock_start_of_DRAM() & GENMASK_ULL(63,=
 32);
> -       return min(offset + (1ULL << 32), memblock_end_of_DRAM());
> +       return min(offset + (1ULL << zone_bits), memblock_end_of_DRAM());
>  }

Hi all,
while testing other code on top of this series on odd arm64 machines I foun=
d an
issue: when memblock_start_of_DRAM() !=3D 0, max_zone_phys() isn't taking i=
nto
account the offset to the beginning of memory. This doesn't matter with
zone_bits =3D=3D 32 but it does when zone_bits =3D=3D 30.

I'll send a follow-up series.

Regards,
Nicolas


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