From: Joshua Kinard <kumba@gentoo.org>
To: "Maciej W. Rozycki" <macro@linux-mips.org>,
Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Subject: Re: [PATCH] MIPS: Avoid an FPE exception in FCSR mask probing
Date: Tue, 02 Jun 2015 16:36:11 -0400 [thread overview]
Message-ID: <556E13BB.3070708@gentoo.org> (raw)
In-Reply-To: <alpine.LFD.2.11.1506021739230.6751@eddie.linux-mips.org>
On 06/02/2015 12:50, Maciej W. Rozycki wrote:
> Use the default FCSR value in mask probing, avoiding an FPE exception
> where reset has left any exception enable and their corresponding cause
> bits set and the register is then rewritten with these bits active.
>
> Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
> ---
> linux-mips-fcsr-mask-fix.diff
> Index: linux-org-test/arch/mips/kernel/cpu-probe.c
> ===================================================================
> --- linux-org-test.orig/arch/mips/kernel/cpu-probe.c 2015-06-01 00:43:32.000000000 +0100
> +++ linux-org-test/arch/mips/kernel/cpu-probe.c 2015-06-02 12:14:10.088786000 +0100
> @@ -74,13 +74,12 @@ static inline void cpu_set_fpu_fcsr_mask
> {
> unsigned long sr, mask, fcsr, fcsr0, fcsr1;
>
> + fcsr = c->fpu_csr31;
> mask = FPU_CSR_ALL_X | FPU_CSR_ALL_E | FPU_CSR_ALL_S | FPU_CSR_RM;
>
> sr = read_c0_status();
> __enable_fpu(FPU_AS_IS);
>
> - fcsr = read_32bit_cp1_register(CP1_STATUS);
> -
> fcsr0 = fcsr & mask;
> write_32bit_cp1_register(CP1_STATUS, fcsr0);
> fcsr0 = read_32bit_cp1_register(CP1_STATUS);
>
Tested-by: Joshua Kinard <kumba@gentoo.org>
next prev parent reply other threads:[~2015-06-02 20:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-02 16:50 [PATCH] MIPS: Avoid an FPE exception in FCSR mask probing Maciej W. Rozycki
2015-06-02 20:36 ` Joshua Kinard [this message]
2015-06-03 7:50 ` Ralf Baechle
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