From cea394772d3c41d04cb71a032f6ed878392bd134 Mon Sep 17 00:00:00 2001 From: Vladimir Murzin Date: Mon, 18 Jun 2018 14:33:03 +0100 Subject: ARM: 8775/1: NOMMU: Use instr_sync instead of plain isb in common code Greg reported that commit 3c24121039c9d ("ARM: 8756/1: NOMMU: Postpone MPU activation till __after_proc_init") is causing breakage for the old Versatile platform in no-MMU mode (with out-of-tree patches): AS arch/arm/kernel/head-nommu.o arch/arm/kernel/head-nommu.S: Assembler messages: arch/arm/kernel/head-nommu.S:180: Error: selected processor does not support `isb' in ARM mode scripts/Makefile.build:417: recipe for target 'arch/arm/kernel/head-nommu.o' failed make[2]: *** [arch/arm/kernel/head-nommu.o] Error 1 Makefile:1034: recipe for target 'arch/arm/kernel' failed make[1]: *** [arch/arm/kernel] Error 2 Since the code is common for all NOMMU builds usage of the isb was a bad idea (please, note that isb also used in MPU related code which is fine because MPU has dependency on CPU_V7/CPU_V7M), instead use more robust instr_sync assembler macro. Fixes: 3c24121039c9 ("ARM: 8756/1: NOMMU: Postpone MPU activation till __after_proc_init") Reported-by: Greg Ungerer Tested-by: Greg Ungerer Signed-off-by: Vladimir Murzin Signed-off-by: Russell King --- arch/arm/kernel/head-nommu.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm') diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S index dd546d65a383..7a9b86978ee1 100644 --- a/arch/arm/kernel/head-nommu.S +++ b/arch/arm/kernel/head-nommu.S @@ -177,7 +177,7 @@ M_CLASS(streq r3, [r12, #PMSAv8_MAIR1]) bic r0, r0, #CR_I #endif mcr p15, 0, r0, c1, c0, 0 @ write control reg - isb + instr_sync #elif defined (CONFIG_CPU_V7M) #ifdef CONFIG_ARM_MPU ldreq r3, [r12, MPU_CTRL] -- cgit v1.2.3