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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: Alexey Brodkin <Alexey.Brodkin@synopsys.com>,
	Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2 2/4] ARC: ARCv2: support loop buffer (LPB) disabling
Date: Thu,  4 Jun 2020 20:39:25 +0300	[thread overview]
Message-ID: <20200604173927.23127-3-Eugeniy.Paltsev@synopsys.com> (raw)
In-Reply-To: <20200604173927.23127-1-Eugeniy.Paltsev@synopsys.com>

On HS cores, loop buffer (LPB) is programmable in runtime and can
be optionally disabled.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
---
 arch/arc/Kconfig       | 6 ++++++
 arch/arc/kernel/head.S | 8 ++++++++
 2 files changed, 14 insertions(+)

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 7034c217708f..2dc142c8e1f5 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -473,6 +473,12 @@ config ARC_IRQ_NO_AUTOSAVE
 	  This is programmable and can be optionally disabled in which case
 	  software INTERRUPT_PROLOGUE/EPILGUE do the needed work
 
+config ARC_LPB_DISABLE
+	bool "Disable loop buffer (LPB)"
+	help
+	  On HS cores, loop buffer (LPB) is programmable in runtime and can
+	  be optionally disabled.
+
 endif # ISA_ARCV2
 
 endmenu   # "ARC CPU Configuration"
diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
index 6eb23f1545ee..17fd1ed700cc 100644
--- a/arch/arc/kernel/head.S
+++ b/arch/arc/kernel/head.S
@@ -59,6 +59,14 @@
 	bclr	r5, r5, STATUS_AD_BIT
 #endif
 	kflag	r5
+
+#ifdef CONFIG_ARC_LPB_DISABLE
+	lr	r5, [ARC_REG_LPB_BUILD]
+	breq    r5, 0, 1f		; LPB doesn't exist
+	mov	r5, 1
+	sr	r5, [ARC_REG_LPB_CTRL]
+1:
+#endif /* CONFIG_ARC_LPB_DISABLE */
 #endif
 	; Config DSP_CTRL properly, so kernel may use integer multiply,
 	; multiply-accumulate, and divide operations
-- 
2.21.3


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  parent reply	other threads:[~2020-06-04 17:39 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-04 17:39 [PATCH v2 0/4] ARC: [plat-hsdk-4xd] initial port for HSDK-4xD board Eugeniy Paltsev
2020-06-04 17:39 ` [PATCH v2 1/4] ARC: allow to override default mcpu compiler flag Eugeniy Paltsev
2020-06-04 18:27   ` Vineet Gupta
2020-06-05 10:47   ` Alexey Brodkin
2020-06-16 22:12     ` Vineet Gupta
2020-06-04 17:39 ` Eugeniy Paltsev [this message]
2020-06-18 19:50   ` [PATCH v2 2/4] ARC: ARCv2: support loop buffer (LPB) disabling Eugeniy Paltsev
2020-06-18 20:00     ` Vineet Gupta
2020-06-04 17:39 ` [PATCH v2 3/4] ARC: [plat-hsdk-4xd] initial port for HSDK-4xD board Eugeniy Paltsev
2020-06-04 22:02   ` Rob Herring
2020-06-04 17:39 ` [PATCH v2 4/4] ARC: [plat-hsdk*] document HSDK-4xD board/SoC bindings Eugeniy Paltsev
2020-06-04 20:00 ` [PATCH v2 0/4] ARC: [plat-hsdk-4xd] initial port for HSDK-4xD board Vineet Gupta

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