From cf17a1e3aa1ad33d375d71a1c30356b86b2683ef Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 22 Nov 2019 13:01:17 +0100 Subject: [PATCH] ARM: 8942/1: Revert "8857/1: efi: enable CP15 DMB instructions before cleaning the cache" This reverts commit e17b1af96b2afc38e684aa2f1033387e2ed10029, which is no longer necessary now that the v7 specific routines take care not to issue CP15 barrier instructions before they are enabled in SCTLR. Signed-off-by: Ard Biesheuvel Signed-off-by: Russell King --- arch/arm/boot/compressed/head.S | 16 +--------------- 1 file changed, 1 insertion(+), 15 deletions(-) diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 469a2b3b60c0..088b0a060876 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -1460,21 +1460,7 @@ ENTRY(efi_stub_entry) @ Preserve return value of efi_entry() in r4 mov r4, r0 - - @ our cache maintenance code relies on CP15 barrier instructions - @ but since we arrived here with the MMU and caches configured - @ by UEFI, we must check that the CP15BEN bit is set in SCTLR. - @ Note that this bit is RAO/WI on v6 and earlier, so the ISB in - @ the enable path will be executed on v7+ only. - mrc p15, 0, r1, c1, c0, 0 @ read SCTLR - tst r1, #(1 << 5) @ CP15BEN bit set? - bne 0f - orr r1, r1, #(1 << 5) @ CP15 barrier instructions - mcr p15, 0, r1, c1, c0, 0 @ write SCTLR - ARM( .inst 0xf57ff06f @ v7+ isb ) - THUMB( isb ) - -0: bl cache_clean_flush + bl cache_clean_flush bl cache_off @ Set parameters for booting zImage according to boot protocol