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-rw-r--r--arch/arc/kernel/head.S56
1 files changed, 47 insertions, 9 deletions
diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
index 8b90d25a15cc..8d541f53fae3 100644
--- a/arch/arc/kernel/head.S
+++ b/arch/arc/kernel/head.S
@@ -1,12 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
/*
* ARC CPU startup Code
*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
* Vineetg: Dec 2007
* -Check if we are running on Simulator or on real hardware
* to skip certain things during boot on simulator
@@ -17,6 +14,8 @@
#include <asm/entry.h>
#include <asm/arcregs.h>
#include <asm/cache.h>
+#include <asm/dsp-impl.h>
+#include <asm/irqflags.h>
.macro CPU_EARLY_SETUP
@@ -47,6 +46,46 @@
sr r5, [ARC_REG_DC_CTRL]
1:
+
+#ifdef CONFIG_ISA_ARCV2
+ ; Unaligned access is disabled at reset, so re-enable early as
+ ; gcc 7.3.1 (ARC GNU 2018.03) onwards generates unaligned access
+ ; by default
+ lr r5, [status32]
+#ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS
+ bset r5, r5, STATUS_AD_BIT
+#else
+ ; Although disabled at reset, bootloader might have enabled it
+ 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 */
+
+ /* On HSDK, CCMs need to remapped super early */
+#ifdef CONFIG_ARC_SOC_HSDK
+ mov r6, 0x60000000
+ lr r5, [ARC_REG_ICCM_BUILD]
+ breq r5, 0, 1f
+ sr r6, [ARC_REG_AUX_ICCM]
+1:
+ lr r5, [ARC_REG_DCCM_BUILD]
+ breq r5, 0, 2f
+ sr r6, [ARC_REG_AUX_DCCM]
+2:
+#endif /* CONFIG_ARC_SOC_HSDK */
+
+#endif /* CONFIG_ISA_ARCV2 */
+
+ ; Config DSP_CTRL properly, so kernel may use integer multiply,
+ ; multiply-accumulate, and divide operations
+ DSP_EARLY_INIT
.endm
.section .init.text, "ax",@progbits
@@ -90,15 +129,14 @@ ENTRY(stext)
st.ab 0, [r5, 4]
1:
-#ifdef CONFIG_ARC_UBOOT_SUPPORT
; Uboot - kernel ABI
; r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2
- ; r1 = magic number (board identity, unused as of now
+ ; r1 = magic number (always zero as of now)
; r2 = pointer to uboot provided cmdline or external DTB in mem
- ; These are handled later in setup_arch()
+ ; These are handled later in handle_uboot_args()
st r0, [@uboot_tag]
+ st r1, [@uboot_magic]
st r2, [@uboot_arg]
-#endif
; setup "current" tsk and optionally cache it in dedicated r25
mov r9, @init_task
@@ -127,7 +165,7 @@ ENTRY(first_lines_of_secondary)
; setup stack (fp, sp)
mov fp, 0
- ; set it's stack base to tsk->thread_info bottom
+ ; set its stack base to tsk->thread_info bottom
GET_TSK_STACK_BASE r0, sp
j start_kernel_secondary