From: Dave Martin <Dave.Martin@arm.com>
To: Julien Grall <julien.grall@arm.com>
Cc: julien.thierry@arm.com, marc.zyngier@arm.com,
catalin.marinas@arm.com, ard.biesheuvel@linaro.org,
will.deacon@arm.com, linux-kernel@vger.kernel.org,
christoffer.dall@arm.com, james.morse@arm.com,
suzuki.poulose@arm.com, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 2/3] arch/arm64: fpsimd: Introduce fpsimd_save_and_flush_cpu_state() and use it
Date: Thu, 25 Apr 2019 15:12:31 +0100 [thread overview]
Message-ID: <20190425141230.GE3567@e103592.cambridge.arm.com> (raw)
In-Reply-To: <97a49fad-380b-4494-9722-03857441ffe5@arm.com>
On Thu, Apr 25, 2019 at 01:37:40PM +0100, Julien Grall wrote:
> Hi Dave,
>
> On 24/04/2019 14:17, Dave Martin wrote:
> >On Tue, Apr 23, 2019 at 02:57:18PM +0100, Julien Grall wrote:
> >>tent-Length: 4295
> >>Lines: 128
> >>
> >>The only external user of fpsimd_save() and fpsimd_flush_cpu_state() is
> >>the KVM FPSIMD code.
> >>
> >>A following patch will introduce a mechanism to acquire owernship of the
> >>FPSIMD/SVE context for performing context management operations. Rather
> >>than having to export the new helpers to get/put the context, we can just
> >>introduce a new function to combine fpsimd_save() and
> >>fpsimd_flush_cpu_state().
> >>
> >>This has also the advantage to remove any external call of fpsimd_save()
> >>and fpsimd_flush_cpu_state(), so they can be turned static.
> >>
> >>Lastly, the new function can also be used in the PM notifier.
> >>
> >>Signed-off-by: Julien Grall <julien.grall@arm.com>
> >>
> >>---
> >> kernel_neon_begin() does not use fpsimd_save_and_flush_cpu_state()
> >> because the next patch will modify the function to also grab the
> >> FPSIMD/SVE context.
> >>
> >> Changes in v3:
> >> - Rework the commit message
> >> - Move the prototype of fpsimd_save_and_flush_cpu_state()
> >> further down in the header
> >> - Remove comment in kvm_arch_vcpu_put_fp()
> >>
> >> Changes in v2:
> >> - Patch added
> >>---
> >> arch/arm64/include/asm/fpsimd.h | 5 ++---
> >> arch/arm64/kernel/fpsimd.c | 17 +++++++++++++----
> >> arch/arm64/kvm/fpsimd.c | 4 +---
> >> 3 files changed, 16 insertions(+), 10 deletions(-)
> >>
> >>diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h
> >>index b73d12fcc7f9..c311d36ecffe 100644
> >>--- a/arch/arm64/include/asm/fpsimd.h
> >>+++ b/arch/arm64/include/asm/fpsimd.h
> >>@@ -48,8 +48,6 @@ struct task_struct;
> >> extern void fpsimd_save_state(struct user_fpsimd_state *state);
> >> extern void fpsimd_load_state(struct user_fpsimd_state *state);
> >>-extern void fpsimd_save(void);
> >>-
> >> extern void fpsimd_thread_switch(struct task_struct *next);
> >> extern void fpsimd_flush_thread(void);
> >>@@ -63,7 +61,8 @@ extern void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *state,
> >> void *sve_state, unsigned int sve_vl);
> >> extern void fpsimd_flush_task_state(struct task_struct *target);
> >>-extern void fpsimd_flush_cpu_state(void);
> >>+
> >>+extern void fpsimd_save_and_flush_cpu_state(void);
> >
> >Nit: You could drop this blank line: these are all "state maintenance"
> >operations, roughly speaking.
> >
> >But don't bother unless you respin for some other reason.
>
> It looks like I will need to make some changes in patch #3. So I will remove
> the line at the same time.
OK, fair enough.
Cheers
---Dave
next prev parent reply other threads:[~2019-04-25 14:12 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-23 13:57 [PATCH v3 0/3] arm64/fpsimd: Don't disable softirq when touching FPSIMD/SVE state Julien Grall
2019-04-23 13:57 ` [PATCH v3 1/3] arm64/fpsimd: Remove the prototype for sve_flush_cpu_state() Julien Grall
2019-04-23 13:57 ` [PATCH v3 2/3] arch/arm64: fpsimd: Introduce fpsimd_save_and_flush_cpu_state() and use it Julien Grall
2019-04-24 13:17 ` Dave Martin
2019-04-25 12:37 ` Julien Grall
2019-04-25 14:12 ` Dave Martin [this message]
2019-04-23 13:57 ` [PATCH v3 3/3] arm64/fpsimd: Don't disable softirq when touching FPSIMD/SVE state Julien Grall
2019-04-24 13:17 ` Dave Martin
2019-04-25 15:57 ` Julien Grall
2019-04-25 16:39 ` Dave Martin
2019-04-25 17:12 ` Julien Grall
2019-04-26 10:48 ` Dave Martin
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