From: Philipp Tomsich <philipp.tomsich@vrull.eu>
To: Christoph Hellwig <hch@lst.de>
Cc: Heiko Stuebner <heiko@sntech.de>,
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,
arnd@arndb.de, wens@csie.org, maxime@cerno.tech,
gfavor@ventanamicro.com, andrea.mondelli@huawei.com,
behrensj@mit.edu, xinhaoqu@huawei.com, mick@ics.forth.gr,
allen.baum@esperantotech.com, jscheid@ventanamicro.com,
rtrauben@gmail.com, samuel@sholland.org, cmuellner@linux.com,
Wei Wu <lazyparser@gmail.com>, Daniel Lustig <dlustig@nvidia.com>,
Bill Huffman <huffman@cadence.com>
Subject: Re: [PATCH 09/12] riscv: add RISC-V Svpbmt extension support
Date: Mon, 16 May 2022 11:09:12 +0200 [thread overview]
Message-ID: <CAAeLtUA1FWQRot6=zHXWBa3YnfxuhL2TW-a-TNomDeUFPrrz1A@mail.gmail.com> (raw)
In-Reply-To: <20220516061057.GL12339@lst.de>
On Mon, 16 May 2022 at 08:11, Christoph Hellwig <hch@lst.de> wrote:
>
> > +config RISCV_ISA_SVPBMT
> > + bool "SVPBMT extension support"
>
> I don't think this prompt is very useful as it doesn't describe
> what it does. But do we even want people to disable it as it is
> really essentially for a fully functioning kernel and a pity that
> it took RISC-V so long to get there?
Given that RISC-V is (in some ways) an ISA construction set, there
will be valid use cases for embedded users to disable this (e.g. if
they have their own non-standard way to configure these). So while
kernels for binary distributions (and desktop, server, or
general-purpose embedded) will always enable these, I would fully
expect some users to want to turn these off.
@Heiko: I would request that we have a longer help text on this, which
explains what it is and ends with the usual "When in doubt, say Y."
> > + depends on 64BIT && MMU
> > + select RISCV_ALTERNATIVE
> > + default y
> > + help
> > + Adds support to dynamically detect the presence of the SVPBMT extension
>
> overly long line here.
>
> > index 5f1046e82d9f..dbfcd9b72bd8 100644
> > --- a/arch/riscv/include/asm/errata_list.h
> > +++ b/arch/riscv/include/asm/errata_list.h
> > @@ -14,6 +14,9 @@
> > #define ERRATA_SIFIVE_NUMBER 2
> > #endif
> >
> > +#define CPUFEATURE_SVPBMT 0
> > +#define CPUFEATURE_NUMBER 1
>
> is errata_list.h really the right place for architectural features?
>
> Otherwise looks good:
>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
next prev parent reply other threads:[~2022-05-16 9:09 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-11 19:29 [PATCH v10 00/12] riscv: support for Svpbmt and D1 memory types Heiko Stuebner
2022-05-11 19:29 ` [PATCH 01/12] riscv: integrate alternatives better into the main architecture Heiko Stuebner
2022-05-16 6:01 ` Christoph Hellwig
2022-05-16 6:45 ` Guo Ren
2022-05-11 19:29 ` [PATCH 02/12] riscv: allow different stages with alternatives Heiko Stuebner
2022-05-16 6:01 ` Christoph Hellwig
2022-05-16 6:51 ` Guo Ren
2022-05-11 19:29 ` [PATCH 03/12] riscv: implement module alternatives Heiko Stuebner
2022-05-16 6:02 ` Christoph Hellwig
2022-05-16 6:54 ` Guo Ren
2022-05-11 19:29 ` [PATCH 04/12] riscv: implement ALTERNATIVE_2 macro Heiko Stuebner
2022-05-16 6:03 ` Christoph Hellwig
2022-05-16 6:54 ` Guo Ren
2022-05-11 19:29 ` [PATCH 05/12] riscv: extend concatenated alternatives-lines to the same length Heiko Stuebner
2022-05-16 6:03 ` Christoph Hellwig
2022-05-16 6:55 ` Guo Ren
2022-05-11 19:29 ` [PATCH 06/12] riscv: prevent compressed instructions in alternatives Heiko Stuebner
2022-05-16 6:04 ` Christoph Hellwig
2022-05-16 6:55 ` Guo Ren
2022-05-11 19:29 ` [PATCH 07/12] riscv: move boot alternatives to after fill_hwcap Heiko Stuebner
2022-05-11 19:29 ` [PATCH 08/12] riscv: Fix accessing pfn bits in PTEs for non-32bit variants Heiko Stuebner
2022-05-16 6:04 ` Christoph Hellwig
2022-05-16 6:55 ` Guo Ren
2022-05-23 14:03 ` Alexandre Ghiti
2022-05-25 15:22 ` Heiko Stübner
2022-05-28 8:15 ` Alexandre Ghiti
2022-05-11 19:29 ` [PATCH 09/12] riscv: add RISC-V Svpbmt extension support Heiko Stuebner
2022-05-16 6:10 ` Christoph Hellwig
2022-05-16 9:09 ` Philipp Tomsich [this message]
2022-05-16 10:30 ` Heiko Stübner
2022-05-11 19:29 ` [PATCH 10/12] riscv: remove FIXMAP_PAGE_IO and fall back to its default value Heiko Stuebner
2022-05-11 19:29 ` [PATCH 11/12] riscv: don't use global static vars to store alternative data Heiko Stuebner
2022-05-16 6:15 ` Christoph Hellwig
2022-05-11 19:29 ` [PATCH 12/12] riscv: add memory-type errata for T-Head Heiko Stuebner
2022-05-13 13:37 ` Guo Ren
2022-05-13 3:32 ` [PATCH v10 00/12] riscv: support for Svpbmt and D1 memory types Palmer Dabbelt
2022-05-13 21:41 ` Heiko Stuebner
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