From: Conor Dooley <conor@kernel.org>
To: "Rémi Denis-Courmont" <remi@remlab.net>
Cc: linux-riscv@lists.infradead.org
Subject: Re: [PATCH -next v21 20/27] riscv: hwcap: change ELF_HWCAP to a function
Date: Mon, 12 Jun 2023 16:30:54 +0100 [thread overview]
Message-ID: <20230612-walrus-trickster-c49072f0d3e5@spud> (raw)
In-Reply-To: <2311672.PxeS7tEIvr@basile.remlab.net>
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On Mon, Jun 12, 2023 at 05:36:32PM +0300, Rémi Denis-Courmont wrote:
> Le maanantaina 5. kesäkuuta 2023, 19.24.53 EEST Conor Dooley a écrit :
> > On Mon, Jun 05, 2023 at 11:07:17AM +0000, Andy Chiu wrote:
> > > Using a function is flexible to represent ELF_HWCAP. So the kernel may
> > > encode hwcap reflecting supported hardware features just at the moment of
> > > the start of each program.
> > >
> > > This will be helpful when we introduce prctl/sysctl interface to control
> > > per-process availability of Vector extension in following patches.
> > > Programs started with V disabled should see V masked off in theirs
> > > ELF_HWCAP.
> >
> > For the uninformed, like myself, this needs to be a function, rather
> > than open coding the masking of the V bit at the one user of ELF_HWCAP
> > this series adds, because the binfmt stuff needs to get the value in
> > create_elf_fdpic_tables() & co?
>
> No, this is to deal with existing userspace that expects vectors to "just
> work" when the V bit is set (e.g. FFmpeg 6.0).
Is that not what create_elf_fdpic_tables() & its ilk do? Inform
userspace of whether the V bit is set?
Cheers,
Conor.
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next prev parent reply other threads:[~2023-06-12 15:31 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-05 11:06 [PATCH -next v21 00/27] riscv: Add vector ISA support Andy Chiu
2023-06-05 11:06 ` [PATCH -next v21 01/27] riscv: Rename __switch_to_aux() -> fpu Andy Chiu
2023-06-05 11:06 ` [PATCH -next v21 02/27] riscv: Extending cpufeature.c to detect V-extension Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 03/27] riscv: hwprobe: Add support for probing V in RISCV_HWPROBE_KEY_IMA_EXT_0 Andy Chiu
2023-06-08 12:36 ` Heiko Stübner
2023-06-28 0:30 ` Stefan O'Rear
2023-06-28 1:56 ` Palmer Dabbelt
2023-06-28 4:53 ` Stefan O'Rear
2023-06-05 11:07 ` [PATCH -next v21 04/27] riscv: Add new csr defines related to vector extension Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 05/27] riscv: Clear vector regfile on bootup Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 06/27] riscv: Disable Vector Instructions for kernel itself Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 07/27] riscv: Introduce Vector enable/disable helpers Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 08/27] riscv: Introduce riscv_v_vsize to record size of Vector context Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 09/27] riscv: Introduce struct/helpers to save/restore per-task Vector state Andy Chiu
2023-06-12 14:32 ` Rémi Denis-Courmont
2023-06-13 14:19 ` Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 10/27] riscv: Add task switch support for vector Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 11/27] riscv: Allocate user's vector context in the first-use trap Andy Chiu
2023-06-05 16:04 ` Conor Dooley
2023-06-08 13:58 ` Heiko Stübner
2023-06-05 11:07 ` [PATCH -next v21 12/27] riscv: Add ptrace vector support Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 13/27] riscv: signal: check fp-reserved words unconditionally Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 14/27] riscv: signal: Add sigcontext save/restore for vector Andy Chiu
2023-10-08 9:19 ` Aurelien Jarno
2023-10-08 16:23 ` Andy Chiu
2023-10-09 17:08 ` Aurelien Jarno
2023-06-05 11:07 ` [PATCH -next v21 15/27] riscv: signal: Report signal frame size to userspace via auxv Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 16/27] riscv: signal: validate altstack to reflect Vector Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 17/27] riscv: prevent stack corruption by reserving task_pt_regs(p) early Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 18/27] riscv: kvm: Add V extension to KVM ISA Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 19/27] riscv: KVM: Add vector lazy save/restore support Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 20/27] riscv: hwcap: change ELF_HWCAP to a function Andy Chiu
2023-06-05 16:24 ` Conor Dooley
2023-06-12 14:36 ` Rémi Denis-Courmont
2023-06-12 15:30 ` Conor Dooley [this message]
2023-06-05 11:07 ` [PATCH -next v21 21/27] riscv: Add prctl controls for userspace vector management Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 22/27] riscv: Add sysctl to set the default vector rule for new processes Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 23/27] riscv: detect assembler support for .option arch Andy Chiu
2023-06-05 15:48 ` Nathan Chancellor
2023-06-05 16:25 ` Conor Dooley
2024-01-21 1:13 ` Eric Biggers
2024-01-21 2:55 ` Palmer Dabbelt
2024-01-21 14:32 ` Andy Chiu
2024-01-21 18:10 ` Eric Biggers
2024-01-22 22:29 ` Nathan Chancellor
2024-01-24 21:58 ` Eric Biggers
2023-06-05 11:07 ` [PATCH -next v21 24/27] riscv: Enable Vector code to be built Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 25/27] riscv: Add documentation for Vector Andy Chiu
2023-06-12 14:40 ` Rémi Denis-Courmont
2023-06-05 11:07 ` [PATCH -next v21 26/27] selftests: Test RISC-V Vector prctl interface Andy Chiu
2023-06-05 11:07 ` [PATCH -next v21 27/27] selftests: add .gitignore file for RISC-V hwprobe Andy Chiu
2023-06-09 14:00 ` [PATCH -next v21 00/27] riscv: Add vector ISA support Palmer Dabbelt
2023-06-09 14:50 ` patchwork-bot+linux-riscv
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