From f5236225a3858b505221a59233af1f1158be9139 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 1 Dec 2006 19:31:42 +0100 Subject: [PATCH] [ARM] 3967/1: xsc3: make branch predication configurable on xsc3 Remove BTB_ENABLE from proc-xsc3.S On some early revisions of xsc3 enabling the branch target buffer can cause crashes, see erratum #42. Cc: Lennert Buytenhek Signed-off-by: Dan Williams Signed-off-by: Russell King --- arch/arm/mm/Kconfig | 2 +- arch/arm/mm/proc-xsc3.S | 7 ------- 2 files changed, 1 insertion(+), 8 deletions(-) diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index c0bfb8212b77..efebd6050285 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -580,7 +580,7 @@ config CPU_CACHE_ROUND_ROBIN config CPU_BPREDICT_DISABLE bool "Disable branch prediction" - depends on CPU_ARM1020 || CPU_V6 + depends on CPU_ARM1020 || CPU_V6 || CPU_XSC3 help Say Y here to disable branch prediction. If unsure, say N. diff --git a/arch/arm/mm/proc-xsc3.S b/arch/arm/mm/proc-xsc3.S index 85c3523d0a95..1ef564d0957f 100644 --- a/arch/arm/mm/proc-xsc3.S +++ b/arch/arm/mm/proc-xsc3.S @@ -56,11 +56,6 @@ */ #define L2_CACHE_ENABLE 1 -/* - * Enable the Branch Target Buffer (can cause crashes, see erratum #42.) - */ -#define BTB_ENABLE 0 - /* * This macro is used to wait for a CP15 write and is needed * when we have to ensure that the last operation to the co-pro @@ -434,9 +429,7 @@ __xsc3_setup: mrc p15, 0, r0, c1, c0, 0 @ get control register bic r0, r0, r5 @ .... .... .... ..A. orr r0, r0, r6 @ .... .... .... .C.M -#if BTB_ENABLE orr r0, r0, #0x00000800 @ ..VI Z..S .... .... -#endif #if L2_CACHE_ENABLE orr r0, r0, #0x04000000 @ L2 enable #endif -- GitLab