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References: <20220413030307.133807-1-heiko@sntech.de> <20220413030307.133807-9-heiko@sntech.de>
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From:   Philipp Tomsich <philipp.tomsich@vrull.eu>
Date:   Wed, 13 Apr 2022 11:09:31 +0200
Message-ID: <CAAeLtUDdRTuehHFi576tpzEo0QV9=qQtU8BOarAb4OF-Bizdow@mail.gmail.com>
Subject: Re: [PATCH v9 08/12] riscv: Fix accessing pfn bits in PTEs for
 non-32bit variants
To:     Heiko Stuebner <heiko@sntech.de>
Cc:     palmer@dabbelt.com, paul.walmsley@sifive.com,
        aou@eecs.berkeley.edu, linux-riscv@lists.infradead.org,
        linux-kernel@vger.kernel.org, wefu@redhat.com,
        liush@allwinnertech.com, guoren@kernel.org, atishp@atishpatra.org,
        anup@brainfault.org, drew@beagleboard.org, hch@lst.de,
        arnd@arndb.de, wens@csie.org, maxime@cerno.tech,
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On Wed, 13 Apr 2022 at 05:04, Heiko Stuebner <heiko@sntech.de> wrote:
>
> On rv32 the PFN part of PTEs is defined to use bits [xlen-1:10]
> while on rv64 it is defined to use bits [53:10], leaving [63:54]
> as reserved.
>
> With upcoming optional extensions like svpbmt these previously
> reserved bits will get used so simply right-shifting the PTE
> to get the PFN won't be enough.
>
> So introduce a _PAGE_PFN_MASK constant to mask the correct bits
> for both rv32 and rv64 before shifting.
>
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>