From 10011f7d95dea311c0f2a3ea6725b5a2e97015a8 Mon Sep 17 00:00:00 2001 From: Eugeniy Paltsev Date: Thu, 4 Jun 2020 20:39:25 +0300 Subject: [PATCH] ARCv2: support loop buffer (LPB) disabling On HS cores, loop buffer (LPB) is programmable in runtime and can be optionally disabled. Signed-off-by: Eugeniy Paltsev Signed-off-by: Vineet Gupta --- 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 323014149e485..197896cfbd23e 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -474,6 +474,12 @@ 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 6eb23f1545eec..17fd1ed700cca 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