3 files changed, 20 insertions, 23 deletions

diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index 60406ec62eb8..ea00c8a17f07 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -165,7 +165,6 @@ END(EV_Extension)
 tracesys:
 	; save EFA in case tracer wants the PC of traced task
 	; using ERET won't work since next-PC has already committed
-	lr  r12, [efa]
 	GET_CURR_TASK_FIELD_PTR   TASK_THREAD, r11
 	st  r12, [r11, THREAD_FAULT_ADDR]	; thread.fault_address
 
@@ -208,15 +207,9 @@ tracesys_exit:
 ; Breakpoint TRAP
 ; ---------------------------------------------
 trap_with_param:
-
-	; stop_pc info by gdb needs this info
-	lr  r0, [efa]
+	mov r0, r12	; EFA in case ptracer/gdb wants stop_pc
 	mov r1, sp
 
-	; Now that we have read EFA, it is safe to do "fake" rtie
-	;   and get out of CPU exception mode
-	FAKE_RET_FROM_EXCPN
-
 	; Save callee regs in case gdb wants to have a look
 	; SP will grow up by size of CALLEE Reg-File
 	; NOTE: clobbers r12
@@ -243,6 +236,10 @@ ENTRY(EV_Trap)
 
 	EXCEPTION_PROLOGUE
 
+	lr  r12, [efa]
+
+	FAKE_RET_FROM_EXCPN
+
 	;============ TRAP 1   :breakpoints
 	; Check ECR for trap with arg (PROLOGUE ensures r10 has ECR)
 	bmsk.f 0, r10, 7
@@ -250,9 +247,6 @@ ENTRY(EV_Trap)
 
 	;============ TRAP  (no param): syscall top level
 
-	; First return from Exception to pure K mode (Exception/IRQs renabled)
-	FAKE_RET_FROM_EXCPN
-
 	; If syscall tracing ongoing, invoke pre-post-hooks
 	GET_CURR_THR_INFO_FLAGS   r10
 	btst r10, TIF_SYSCALL_TRACE
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
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index dad8a656a2f1..41f07b3e594e 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -58,10 +58,12 @@ static const struct id_to_str arc_legacy_rel[] = {
 	{ 0x00,		NULL   }
 };
 
-static const struct id_to_str arc_cpu_rel[] = {
+static const struct id_to_str arc_hs_ver54_rel[] = {
 	/* UARCH.MAJOR,	Release */
 	{  0,		"R3.10a"},
 	{  1,		"R3.50a"},
+	{  2,		"R3.60a"},
+	{  3,		"R4.00a"},
 	{  0xFF,	NULL   }
 };
 
@@ -117,12 +119,6 @@ static void decode_arc_core(struct cpuinfo_arc *cpu)
 	struct bcr_uarch_build_arcv2 uarch;
 	const struct id_to_str *tbl;
 
-	/*
-	 * Up until (including) the first core4 release (0x54) things were
-	 * simple: AUX IDENTITY.ARCVER was sufficient to identify arc family
-	 * and release: 0x50 to 0x53 was HS38, 0x54 was HS48 (dual issue)
-	 */
-
 	if (cpu->core.family < 0x54) { /* includes arc700 */
 
 		for (tbl = &arc_legacy_rel[0]; tbl->id != 0; tbl++) {
@@ -143,11 +139,10 @@ static void decode_arc_core(struct cpuinfo_arc *cpu)
 	}
 
 	/*
-	 * However the subsequent HS release (same 0x54) allow HS38 or HS48
-	 * configurations and encode this info in a different BCR.
-	 * The BCR was introduced in 0x54 so can't be read unconditionally.
+	 * Initial HS cores bumped AUX IDENTITY.ARCVER for each release until
+	 * ARCVER 0x54 which introduced AUX MICRO_ARCH_BUILD and subsequent
+	 * releases only update it.
 	 */
-
 	READ_BCR(ARC_REG_MICRO_ARCH_BCR, uarch);
 
 	if (uarch.prod == 4) {
@@ -158,7 +153,7 @@ static void decode_arc_core(struct cpuinfo_arc *cpu)
 		cpu->name = "HS38";
 	}
 
-	for (tbl = &arc_cpu_rel[0]; tbl->id != 0xFF; tbl++) {
+	for (tbl = &arc_hs_ver54_rel[0]; tbl->id != 0xFF; tbl++) {
 		if (uarch.maj == tbl->id) {
 			cpu->release = tbl->str;
 			break;