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From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
To: Paul Burton <paul.burton@imgtec.com>, linux-mips@linux-mips.org
Subject: Re: [PATCH 05/11] MIPS: clear MSACSR cause bits when handling MSA FP exception
Date: Wed, 24 Sep 2014 15:10:14 +0400	[thread overview]
Message-ID: <5422A696.7080408@cogentembedded.com> (raw)
In-Reply-To: <1411551942-11153-6-git-send-email-paul.burton@imgtec.com>

Hello.

On 9/24/2014 1:45 PM, Paul Burton wrote:

> Much like for traditional scalar FP exceptions, the cause bits in the
> MSACSR register need to be cleared following an MSA FP exception.
> Without doing so the exception will simply be raised again whenever
> the kernel restores MSACSR from a tasks saved context, leading to
> undesirable spurious exceptions. Clear the cause bits from the
> handle_msa_fpe function, mirroring the way handle_fpe clears the
> cause bits in FCSR.

> Signed-off-by: Paul Burton <paul.burton@imgtec.com>
> ---
>   arch/mips/kernel/genex.S | 11 ++++++++++-
>   1 file changed, 10 insertions(+), 1 deletion(-)

> diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S
> index ac35e12..ae84496 100644
> --- a/arch/mips/kernel/genex.S
> +++ b/arch/mips/kernel/genex.S
> @@ -367,6 +367,15 @@ NESTED(nmi_handler, PT_SIZE, sp)
>   	STI
>   	.endm
>
> +	.macro	__build_clear_msa_fpe
> +	_cfcmsa	a1, MSA_CSR
> +	li	a2, ~(0x3f << 12)
> +	and	a2, a1
> +	_ctcmsa	MSA_CSR, a1

    Not a2?

> +	TRACE_IRQS_ON
> +	STI
> +	.endm
> +
>   	.macro	__build_clear_ade
>   	MFC0	t0, CP0_BADVADDR
>   	PTR_S	t0, PT_BVADDR(sp)

WBR, Sergei

  parent reply	other threads:[~2014-09-24 11:10 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-24  9:45 [PATCH 00/11] FP/MSA fixes Paul Burton
2014-09-24  9:45 ` Paul Burton
2014-09-24  9:45 ` [PATCH 01/11] MIPS: push .set arch=r4000 into the functions needing it Paul Burton
2014-09-24  9:45   ` Paul Burton
2014-11-11 14:19   ` Ralf Baechle
2014-09-24  9:45 ` [PATCH 02/11] MIPS: assume at as source/dest of MSA copy/insert instructions Paul Burton
2014-09-24  9:45   ` Paul Burton
2014-09-24  9:45 ` [PATCH 03/11] MIPS: remove MSA macro recursion Paul Burton
2014-09-24  9:45   ` Paul Burton
2014-09-24  9:45 ` [PATCH 04/11] MIPS: wrap cfcmsa & ctcmsa accesses for toolchains with MSA support Paul Burton
2014-09-24  9:45   ` Paul Burton
2014-09-24 12:08   ` James Hogan
2014-09-24 12:08     ` James Hogan
2014-09-25  9:23     ` Paul Burton
2014-09-25  9:23       ` Paul Burton
2014-09-25 10:24       ` James Hogan
2014-09-25 10:24         ` James Hogan
2014-09-24  9:45 ` [PATCH 05/11] MIPS: clear MSACSR cause bits when handling MSA FP exception Paul Burton
2014-09-24  9:45   ` Paul Burton
2014-09-24 11:10   ` Sergei Shtylyov [this message]
2014-09-25  9:20     ` [PATCH v2 " Paul Burton
2014-09-25  9:20       ` Paul Burton
2014-09-24  9:45 ` [PATCH 06/11] MIPS: fix mfc1 & mfhc1 emulation for mips64 systems Paul Burton
2014-09-24  9:45   ` Paul Burton
2014-09-24  9:45 ` [PATCH 07/11] MIPS: ensure FCSR cause bits are clear after invoking FPU emulator Paul Burton
2014-09-24  9:45   ` Paul Burton
2014-09-24  9:45 ` [PATCH 08/11] MIPS: prevent FP context set via ptrace being discarded Paul Burton
2014-09-24  9:45   ` Paul Burton
2014-09-24  9:45 ` [PATCH 09/11] MIPS: disable FPU if the mode is unsupported Paul Burton
2014-09-24  9:45   ` Paul Burton
2014-09-24  9:45 ` [PATCH 10/11] Revert "MIPS: Don't assume 64-bit FP registers for context switch" Paul Burton
2014-09-24  9:45   ` Paul Burton
2014-09-24  9:45 ` [PATCH 11/11] MIPS: MSA: Fix big-endian FPR_IDX implementation Paul Burton
2014-09-24  9:45   ` Paul Burton
2014-09-24 13:00 ` [PATCH 00/11] FP/MSA fixes James Hogan
2014-09-24 13:00   ` James Hogan

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