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From:   Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
To:     linux-snps-arc@lists.infradead.org,
        Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc:     linux-kernel@vger.kernel.org,
        Alexey Brodkin <Alexey.Brodkin@synopsys.com>,
        Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Subject: [PATCH] ARC: guard dsp early init against non ARCv2
Date:   Tue, 28 Apr 2020 21:50:24 +0300
Message-Id: <20200428185024.5168-1-Eugeniy.Paltsev@synopsys.com>
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

As of today we guard early DSP init code with
ARC_AUX_DSP_BUILD (0x7A) BCR check to verify that we have
CPU with DSP configured. However that's not enough as in
ARCv1 CPU the same BCR (0x7A) is used for checking MUL/MAC
instructions presence.

So, let's guard DSP early init against non ARCv2.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
---
 arch/arc/include/asm/dsp-impl.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arc/include/asm/dsp-impl.h b/arch/arc/include/asm/dsp-impl.h
index e1aa212ca6eb..e64d945ae7df 100644
--- a/arch/arc/include/asm/dsp-impl.h
+++ b/arch/arc/include/asm/dsp-impl.h
@@ -15,12 +15,14 @@
 
 /* clobbers r5 register */
 .macro DSP_EARLY_INIT
+#if defined(CONFIG_ISA_ARCV2)
 	lr	r5, [ARC_AUX_DSP_BUILD]
 	bmsk	r5, r5, 7
 	breq    r5, 0, 1f
 	mov	r5, DSP_CTRL_DISABLED_ALL
 	sr	r5, [ARC_AUX_DSP_CTRL]
 1:
+#endif
 .endm
 
 /* clobbers r10, r11 registers pair */
-- 
2.21.1