From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Shawn Landden <shawn@git.icu>
Cc: Paul Mackerras <paulus@samba.org>, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 1/2] [PowerPC] Add simd.h implementation
Date: Tue, 14 May 2019 15:43:23 +1000 [thread overview]
Message-ID: <a9f1e109e0b6de8abfabc62375403754ab22dcfc.camel@kernel.crashing.org> (raw)
In-Reply-To: <20190514014412.25373-1-shawn@git.icu>
On Mon, 2019-05-13 at 22:44 -0300, Shawn Landden wrote:
> +
> +/*
> + * Were we in user mode when we were
> + * interrupted?
> + *
> + * Doing kernel_altivec/vsx_begin/end() is ok if we are running
> + * in an interrupt context from user mode - we'll just
> + * save the FPU state as required.
> + */
> +static bool interrupted_user_mode(void)
> +{
> + struct pt_regs *regs = get_irq_regs();
> +
> + return regs && user_mode(regs);
> +}
> +
That's interesting .... it *could* work but we'll have to careful audit
the code to make sure thats ok.
We probably also want to handle the case where the CPU is in the idle
loop.
Do we always save the user state when switching out these days ? If
yes, then there's no "live" state to worry about...
Cheers,
Ben.
next prev parent reply other threads:[~2019-05-14 5:45 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-12 16:50 [PATCH] powerpc: add simd.h implementation specific to PowerPC Shawn Landden
2019-05-13 0:51 ` [PATCH RESEND] " Shawn Landden
2019-05-13 11:53 ` Michael Ellerman
2019-05-14 1:44 ` [PATCH 1/2] [PowerPC] Add simd.h implementation Shawn Landden
2019-05-14 1:44 ` [PATCH 2/2] [PowerPC] Allow use of SIMD in interrupts from kernel code Shawn Landden
2019-05-14 5:43 ` Benjamin Herrenschmidt [this message]
2019-05-14 15:44 ` [PATCH 1/2] [PowerPC] Add simd.h implementation Shawn Landden
2019-05-14 15:46 ` [v3 " Shawn Landden
2019-05-14 15:46 ` [v3 2/2] [PowerPC] Allow use of SIMD in interrupts from kernel code Shawn Landden
2019-05-15 1:03 ` kbuild test robot
2019-05-14 2:23 ` [v2 1/2] [PowerPC] Add simd.h implementation Shawn Landden
2019-05-14 2:23 ` [v2 2/2] [PowerPC] Allow use of SIMD in interrupts from kernel code Shawn Landden
2019-05-14 7:22 ` Russell Currey
2019-05-14 15:35 ` Shawn Landden
2019-05-14 12:49 ` [PATCH] powerpc: Allow may_use_simd() to function as feature detection Shawn Landden
2019-05-14 18:06 ` Segher Boessenkool
2019-05-14 19:00 ` Shawn Landden
2019-05-15 1:36 ` [PATCH 1/2] [PowerPC] Add simd.h implementation Shawn Landden
2019-05-15 1:37 ` [v4 PATCH " Shawn Landden
2019-05-15 1:37 ` [v4 PATCH 2/2] [PowerPC] Allow use of SIMD in interrupts from kernel code Shawn Landden
2019-05-15 6:27 ` [v4 PATCH 1/2] [PowerPC] Add simd.h implementation Christophe Leroy
2019-05-16 1:12 ` Shawn Landden
2019-05-18 16:04 ` [RESEND v4 " Shawn Landden
2019-05-18 16:04 ` [RESEND v4 PATCH 2/2] [PowerPC] Allow use of SIMD in interrupts from kernel code Shawn Landden
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