xtensa: add MMU v3 support

MMUv3 comes out of reset with identity vaddr -> paddr mapping in the TLB
way 6:

Way 6 (512 MB)
        Vaddr       Paddr       ASID  Attr RWX Cache
        ----------  ----------  ----  ---- --- -------
        0x00000000  0x00000000  0x01  0x03 RWX Bypass
        0x20000000  0x20000000  0x01  0x03 RWX Bypass
        0x40000000  0x40000000  0x01  0x03 RWX Bypass
        0x60000000  0x60000000  0x01  0x03 RWX Bypass
        0x80000000  0x80000000  0x01  0x03 RWX Bypass
        0xa0000000  0xa0000000  0x01  0x03 RWX Bypass
        0xc0000000  0xc0000000  0x01  0x03 RWX Bypass
        0xe0000000  0xe0000000  0x01  0x03 RWX Bypass

This patch adds remapping code at the reset vector or at the kernel
_start (depending on CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX) that
reconfigures MMUv3 as MMUv2:

Way 5 (128 MB)
        Vaddr       Paddr       ASID  Attr RWX Cache
        ----------  ----------  ----  ---- --- -------
        0xd0000000  0x00000000  0x01  0x07 RWX WB
        0xd8000000  0x00000000  0x01  0x03 RWX Bypass
Way 6 (256 MB)
        Vaddr       Paddr       ASID  Attr RWX Cache
        ----------  ----------  ----  ---- --- -------
        0xe0000000  0xf0000000  0x01  0x07 RWX WB
        0xf0000000  0xf0000000  0x01  0x03 RWX Bypass
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>

arch/xtensa/Kconfig

@@ -103,6 +103,35 @@ config MATH_EMULATION
 	help
 	Can we use information of configuration file?
 
+config INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
+	bool "Initialize Xtensa MMU inside the Linux kernel code"
+	default y
+	help
+	  Earlier version initialized the MMU in the exception vector
+	  before jumping to _startup in head.S and had an advantage that
+	  it was possible to place a software breakpoint at 'reset' and
+	  then enter your normal kernel breakpoints once the MMU was mapped
+	  to the kernel mappings (0XC0000000).
+
+	  This unfortunately doesn't work for U-Boot and likley also wont
+	  work for using KEXEC to have a hot kernel ready for doing a
+	  KDUMP.
+
+	  So now the MMU is initialized in head.S but it's necessary to
+	  use hardware breakpoints (gdb 'hbreak' cmd) to break at _startup.
+	  xt-gdb can't place a Software Breakpoint in the  0XD region prior
+	  to mapping the MMU and after mapping even if the area of low memory
+	  was mapped gdb wouldn't remove the breakpoint on hitting it as the
+	  PC wouldn't match. Since Hardware Breakpoints are recommended for
+	  Linux configurations it seems reasonable to just assume they exist
+	  and leave this older mechanism for unfortunate souls that choose
+	  not to follow Tensilica's recommendation.
+
+	  Selecting this will cause U-Boot to set the KERNEL Load and Entry
+	  address at 0x00003000 instead of the mapped std of 0xD0003000.
+
+	  If in doubt, say Y.
+
 endmenu
 
 config XTENSA_CALIBRATE_CCOUNT

arch/xtensa/boot/boot-elf/Makefile

@@ -12,6 +12,7 @@ endif
 
 export OBJCOPY_ARGS
 export CPPFLAGS_boot.lds += -P -C
+export KBUILD_AFLAGS += -mtext-section-literals
 
 boot-y		:= bootstrap.o
 

arch/xtensa/boot/boot-elf/boot.lds.S

-#include <variant/core.h>
+/*
+ *  linux/arch/xtensa/boot/boot-elf/boot.lds.S
+ *
+ *  Copyright (C) 2008 - 2013 by Tensilica Inc.
+ *
+ *  Chris Zankel <chris@zankel.net>
+ *  Marc Gauthier <marc@tensilica.com
+ *  Pete Delaney <piet@tensilica.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.
+ */
+
+#include <asm/vectors.h>
 OUTPUT_ARCH(xtensa)
 ENTRY(_ResetVector)
 
 SECTIONS
 {
-	.start 0xD0000000 : { *(.start) }
-
-	.text 0xD0000000:
-	{
-		__reloc_start = . ;
-		_text_start = . ;
-		*(.literal .text.literal .text)
-		_text_end = . ;
-	}
-
-	.rodata ALIGN(0x04):
-	{
-		*(.rodata)
-		*(.rodata1)
-	}
-
-	.data ALIGN(0x04):
+	.ResetVector.text XCHAL_RESET_VECTOR_VADDR :
 	{
-		*(.data)
-		*(.data1)
-		*(.sdata)
-		*(.sdata2)
-		*(.got.plt)
-		*(.got)
-		*(.dynamic)
+		*(.ResetVector.text)
 	}
 
-	__reloc_end = . ;
-
-	. = ALIGN(0x10);
-	__image_load = . ;
-	.image 0xd0001000:
+	.image KERNELOFFSET: AT (LOAD_MEMORY_ADDRESS)
 	{
 		_image_start = .;
 		*(image)
@@ -43,7 +31,6 @@ SECTIONS
 		_image_end = .	;
 	}
 
-
 	.bss ((LOADADDR(.image) + SIZEOF(.image) + 3) & ~ 3):
 	{
 		__bss_start = .;
@@ -53,14 +40,15 @@ SECTIONS
 		*(.bss)
 		__bss_end = .;
 	}
-	_end = .;
-	_param_start = .;
 
-	.ResetVector.text XCHAL_RESET_VECTOR_VADDR :
+	/*
+	 * This is a remapped copy of the Reset Vector Code.
+	 * It keeps gdb in sync with the PC after switching
+	 * to the temporary mapping used while setting up
+	 * the V2 MMU mappings for Linux.
+	 */
+	.ResetVector.remapped_text 0x46000000 (INFO):
 	{
-		*(.ResetVector.text)
+		*(.ResetVector.remapped_text)
 	}
-
-
-	PROVIDE (end = .);
 }

arch/xtensa/boot/boot-elf/bootstrap.S

+/*
+ * arch/xtensa/boot/boot-elf/bootstrap.S
+ *
+ * Low-level exception handling
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2004 - 2013 by Tensilica Inc.
+ *
+ * Chris Zankel <chris@zankel.net>
+ * Marc Gauthier <marc@tensilica.com>
+ * Piet Delaney <piet@tensilica.com>
+ */
 
 #include <asm/bootparam.h>
+#include <asm/processor.h>
+#include <asm/pgtable.h>
+#include <asm/page.h>
+#include <asm/cacheasm.h>
+#include <asm/initialize_mmu.h>
+#include <linux/linkage.h>
 
-
-/* ResetVector
- */
-	.section        .ResetVector.text, "ax"
+	.section	.ResetVector.text, "ax"
 	.global         _ResetVector
+	.global         reset
+
 _ResetVector:
-	_j reset
+	_j _SetupMMU
+
+	.begin  no-absolute-literals
+	.literal_position
+
 	.align 4
 RomInitAddr:
-	.word 0xd0001000
+#if defined(CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX) && \
+	XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY
+	.word 0x00003000
+#else
+	.word 0xd0003000
+#endif
 RomBootParam:
 	.word _bootparam
+_bootparam:
+	.short	BP_TAG_FIRST
+	.short	4
+	.long	BP_VERSION
+	.short	BP_TAG_LAST
+	.short	0
+	.long	0
+
+	.align  4
+_SetupMMU:
+	movi	a0, 0
+	wsr	a0, windowbase
+	rsync
+	movi	a0, 1
+	wsr	a0, windowstart
+	rsync
+	movi	a0, 0x1F
+	wsr	a0, ps
+	rsync
+
+	Offset = _SetupMMU - _ResetVector
+
+#ifndef CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
+	initialize_mmu
+#endif
+
+	.end    no-absolute-literals
+
+	rsil    a0, XCHAL_DEBUGLEVEL-1
+	rsync
 reset:
 	l32r    a0, RomInitAddr
 	l32r	a2, RomBootParam
@@ -21,13 +80,25 @@ reset:
 	jx      a0
 
 	.align 4
-	.section .bootstrap.data, "aw"
 
-	.globl _bootparam
-_bootparam:
-	.short	BP_TAG_FIRST
-	.short	4
-	.long	BP_VERSION
-	.short	BP_TAG_LAST
-	.short	0
-	.long	0
+	.section	.ResetVector.remapped_text, "x"
+	.global         _RemappedResetVector
+
+	/* Do org before literals */
+	.org 0
+
+_RemappedResetVector:
+	.begin  no-absolute-literals
+	.literal_position
+
+	_j	_RemappedSetupMMU
+
+	/* Position Remapped code at the same location as the original code */
+	. = _RemappedResetVector + Offset
+
+_RemappedSetupMMU:
+#ifndef CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
+	initialize_mmu
+#endif
+
+	.end    no-absolute-literals

arch/xtensa/boot/boot-uboot/Makefile

@@ -4,7 +4,11 @@
 # for more details.
 #
 
-UIMAGE_LOADADDR = 0xd0001000
+ifdef CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
+UIMAGE_LOADADDR = 0x00003000
+else
+UIMAGE_LOADADDR = 0xd0003000
+endif
 UIMAGE_COMPRESSION = gzip
 
 $(obj)/../uImage: vmlinux.bin.gz FORCE

arch/xtensa/include/asm/initialize_mmu.h

@@ -23,6 +23,9 @@
 #ifndef _XTENSA_INITIALIZE_MMU_H
 #define _XTENSA_INITIALIZE_MMU_H
 
+#include <asm/pgtable.h>
+#include <asm/vectors.h>
+
 #ifdef __ASSEMBLY__
 
 #define XTENSA_HWVERSION_RC_2009_0 230000
@@ -48,6 +51,110 @@
 	 * (XCHAL_HW_MIN_VERSION >= XTENSA_HWVERSION_RC_2009_0)
 	 */
 
+#if defined(CONFIG_MMU) && XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY
+/*
+ * Have MMU v3
+ */
+
+#if !XCHAL_HAVE_VECBASE
+# error "MMU v3 requires reloc vectors"
+#endif
+
+	movi	a1, 0
+	_call0	1f
+	_j	2f
+
+	.align	4
+1:	movi	a2, 0x10000000
+	movi	a3, 0x18000000
+	add	a2, a2, a0
+9:	bgeu	a2, a3, 9b	/* PC is out of the expected range */
+
+	/* Step 1: invalidate mapping at 0x40000000..0x5FFFFFFF. */
+
+	movi	a2, 0x40000006
+	idtlb	a2
+	iitlb	a2
+	isync
+
+	/* Step 2: map 0x40000000..0x47FFFFFF to paddr containing this code
+	 * and jump to the new mapping.
+	 */
+#define CA_BYPASS	(_PAGE_CA_BYPASS | _PAGE_HW_WRITE | _PAGE_HW_EXEC)
+#define CA_WRITEBACK	(_PAGE_CA_WB     | _PAGE_HW_WRITE | _PAGE_HW_EXEC)
+
+	srli	a3, a0, 27
+	slli	a3, a3, 27
+	addi	a3, a3, CA_BYPASS
+	addi	a7, a2, -1
+	wdtlb	a3, a7
+	witlb	a3, a7
+	isync
+
+	slli	a4, a0, 5
+	srli	a4, a4, 5
+	addi	a5, a2, -6
+	add	a4, a4, a5
+	jx	a4
+
+	/* Step 3: unmap everything other than current area.
+	 *	   Start at 0x60000000, wrap around, and end with 0x20000000
+	 */
+2:	movi	a4, 0x20000000
+	add	a5, a2, a4
+3:	idtlb	a5
+	iitlb	a5
+	add	a5, a5, a4
+	bne	a5, a2, 3b
+
+	/* Step 4: Setup MMU with the old V2 mappings. */
+	movi	a6, 0x01000000
+	wsr	a6, ITLBCFG
+	wsr	a6, DTLBCFG
+	isync
+
+	movi	a5, 0xd0000005
+	movi	a4, CA_WRITEBACK
+	wdtlb	a4, a5
+	witlb	a4, a5
+
+	movi	a5, 0xd8000005
+	movi	a4, CA_BYPASS
+	wdtlb	a4, a5
+	witlb	a4, a5
+
+	movi	a5, 0xe0000006
+	movi	a4, 0xf0000000 + CA_WRITEBACK
+	wdtlb	a4, a5
+	witlb	a4, a5
+
+	movi	a5, 0xf0000006
+	movi	a4, 0xf0000000 + CA_BYPASS
+	wdtlb	a4, a5
+	witlb	a4, a5
+
+	isync
+
+	/* Jump to self, using MMU v2 mappings. */
+	movi	a4, 1f
+	jx	a4
+
+1:
+	movi    a2, VECBASE_RESET_VADDR
+	wsr	a2, vecbase
+
+	/* Step 5: remove temporary mapping. */
+	idtlb	a7
+	iitlb	a7
+	isync
+
+	movi	a0, 0
+	wsr	a0, ptevaddr
+	rsync
+
+#endif /* defined(CONFIG_MMU) && XCHAL_HAVE_PTP_MMU &&
+	  XCHAL_HAVE_SPANNING_WAY */
+
 	.endm
 
 #endif /*__ASSEMBLY__*/

arch/xtensa/include/asm/vectors.h

+/*
+ * arch/xtensa/include/asm/xchal_vaddr_remap.h
+ *
+ * Xtensa macros for MMU V3 Support. Deals with re-mapping the Virtual
+ * Memory Addresses from "Virtual == Physical" to their prevvious V2 MMU
+ * mappings (KSEG at 0xD0000000 and KIO at 0XF0000000).
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2008 - 2012 Tensilica Inc.
+ *
+ * Pete Delaney <piet@tensilica.com>
+ * Marc Gauthier <marc@tensilica.com
+ */
+
+#ifndef _XTENSA_VECTORS_H
+#define _XTENSA_VECTORS_H
+
+#include <variant/core.h>
+
+#if defined(CONFIG_MMU)
+
+/* Will Become VECBASE */
+#define VIRTUAL_MEMORY_ADDRESS		0xD0000000
+
+/* Image Virtual Start Address */
+#define KERNELOFFSET			0xD0003000
+
+#if defined(XCHAL_HAVE_PTP_MMU) && XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY
+  /* MMU v3  - XCHAL_HAVE_PTP_MMU  == 1 */
+  #define PHYSICAL_MEMORY_ADDRESS	0x00000000
+  #define LOAD_MEMORY_ADDRESS		0x00003000
+#else
+  /* MMU V2 -  XCHAL_HAVE_PTP_MMU  == 0 */
+  #define PHYSICAL_MEMORY_ADDRESS	0xD0000000
+  #define LOAD_MEMORY_ADDRESS		0xD0003000
+#endif
+
+#else /* !defined(CONFIG_MMU) */
+  /* MMU Not being used - Virtual == Physical */
+
+  /* VECBASE */
+  #define VIRTUAL_MEMORY_ADDRESS	0x00002000
+
+  /* Location of the start of the kernel text, _start */
+  #define KERNELOFFSET			0x00003000
+  #define PHYSICAL_MEMORY_ADDRESS	0x00000000
+
+  /* Loaded just above possibly live vectors */
+  #define LOAD_MEMORY_ADDRESS		0x00003000
+
+#endif /* CONFIG_MMU */
+
+#define XC_VADDR(offset)		(VIRTUAL_MEMORY_ADDRESS  + offset)
+#define XC_PADDR(offset)		(PHYSICAL_MEMORY_ADDRESS + offset)
+
+/* Used to set VECBASE register */
+#define VECBASE_RESET_VADDR		VIRTUAL_MEMORY_ADDRESS
+
+#define RESET_VECTOR_VECOFS		(XCHAL_RESET_VECTOR_VADDR - \
+						VECBASE_RESET_VADDR)
+#define RESET_VECTOR_VADDR		XC_VADDR(RESET_VECTOR_VECOFS)
+
+#define RESET_VECTOR1_VECOFS		(XCHAL_RESET_VECTOR1_VADDR - \
+						VECBASE_RESET_VADDR)
+#define RESET_VECTOR1_VADDR		XC_VADDR(RESET_VECTOR1_VECOFS)
+
+#if XCHAL_HAVE_VECBASE
+
+#define USER_VECTOR_VADDR		XC_VADDR(XCHAL_USER_VECOFS)
+#define KERNEL_VECTOR_VADDR		XC_VADDR(XCHAL_KERNEL_VECOFS)
+#define DOUBLEEXC_VECTOR_VADDR		XC_VADDR(XCHAL_DOUBLEEXC_VECOFS)
+#define WINDOW_VECTORS_VADDR		XC_VADDR(XCHAL_WINDOW_OF4_VECOFS)
+#define INTLEVEL2_VECTOR_VADDR		XC_VADDR(XCHAL_INTLEVEL2_VECOFS)
+#define INTLEVEL3_VECTOR_VADDR		XC_VADDR(XCHAL_INTLEVEL3_VECOFS)
+#define INTLEVEL4_VECTOR_VADDR		XC_VADDR(XCHAL_INTLEVEL4_VECOFS)
+#define INTLEVEL5_VECTOR_VADDR		XC_VADDR(XCHAL_INTLEVEL5_VECOFS)
+#define INTLEVEL6_VECTOR_VADDR		XC_VADDR(XCHAL_INTLEVEL6_VECOFS)
+
+#define DEBUG_VECTOR_VADDR		XC_VADDR(XCHAL_DEBUG_VECOFS)
+
+#undef  XCHAL_NMI_VECTOR_VADDR
+#define XCHAL_NMI_VECTOR_VADDR		XC_VADDR(XCHAL_NMI_VECOFS)
+
+#undef  XCHAL_INTLEVEL7_VECTOR_VADDR
+#define XCHAL_INTLEVEL7_VECTOR_VADDR	XC_VADDR(XCHAL_INTLEVEL7_VECOFS)
+
+/*
+ * These XCHAL_* #defines from varian/core.h
+ * are not valid to use with V3 MMU. Non-XCHAL
+ * constants are defined above and should be used.
+ */
+#undef  XCHAL_VECBASE_RESET_VADDR
+#undef  XCHAL_RESET_VECTOR0_VADDR
+#undef  XCHAL_USER_VECTOR_VADDR
+#undef  XCHAL_KERNEL_VECTOR_VADDR
+#undef  XCHAL_DOUBLEEXC_VECTOR_VADDR
+#undef  XCHAL_WINDOW_VECTORS_VADDR
+#undef  XCHAL_INTLEVEL2_VECTOR_VADDR
+#undef  XCHAL_INTLEVEL3_VECTOR_VADDR
+#undef  XCHAL_INTLEVEL4_VECTOR_VADDR
+#undef  XCHAL_INTLEVEL5_VECTOR_VADDR
+#undef  XCHAL_INTLEVEL6_VECTOR_VADDR
+#undef  XCHAL_DEBUG_VECTOR_VADDR
+#undef  XCHAL_NMI_VECTOR_VADDR
+#undef  XCHAL_INTLEVEL7_VECTOR_VADDR
+
+#else
+
+#define USER_VECTOR_VADDR		XCHAL_USER_VECTOR_VADDR
+#define KERNEL_VECTOR_VADDR		XCHAL_KERNEL_VECTOR_VADDR
+#define DOUBLEEXC_VECTOR_VADDR		XCHAL_DOUBLEEXC_VECTOR_VADDR
+#define WINDOW_VECTORS_VADDR		XCHAL_WINDOW_VECTORS_VADDR
+#define INTLEVEL2_VECTOR_VADDR		XCHAL_INTLEVEL2_VECTOR_VADDR
+#define INTLEVEL3_VECTOR_VADDR		XCHAL_INTLEVEL3_VECTOR_VADDR
+#define INTLEVEL4_VECTOR_VADDR		XCHAL_INTLEVEL4_VECTOR_VADDR
+#define INTLEVEL5_VECTOR_VADDR		XCHAL_INTLEVEL5_VECTOR_VADDR
+#define INTLEVEL6_VECTOR_VADDR		XCHAL_INTLEVEL6_VECTOR_VADDR
+#define DEBUG_VECTOR_VADDR		XCHAL_DEBUG_VECTOR_VADDR
+
+#endif
+
+#endif /* _XTENSA_VECTORS_H */

arch/xtensa/kernel/Makefile

@@ -12,6 +12,8 @@ obj-$(CONFIG_KGDB) += xtensa-stub.o
 obj-$(CONFIG_PCI) += pci.o
 obj-$(CONFIG_MODULES) += xtensa_ksyms.o module.o
 
+AFLAGS_head.o += -mtext-section-literals
+
 # In the Xtensa architecture, assembly generates literals which must always
 # precede the L32R instruction with a relative offset less than 256 kB.
 # Therefore, the .text and .literal section must be combined in parenthesis

arch/xtensa/kernel/head.S

@@ -48,17 +48,36 @@
 	 */
 
 	__HEAD
+	.begin	no-absolute-literals
+
 ENTRY(_start)
 
-	_j	2f
+	/* Preserve the pointer to the boot parameter list in EXCSAVE_1 */
+	wsr     a2, excsave1
+	_j	_SetupMMU
+
+	.align	4
+	.literal_position
+.Lstartup:
+	.word	_startup
+
 	.align	4
-1:	.word	_startup
-2:	l32r	a0, 1b
+	.global _SetupMMU
+_SetupMMU:
+	Offset = _SetupMMU - _start
+
+#ifdef CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
+	initialize_mmu
+#endif
+	.end	no-absolute-literals
+
+	l32r	a0, .Lstartup
 	jx	a0
 
 ENDPROC(_start)
 
-	.section .init.text, "ax"
+	__INIT
+	.literal_position
 
 ENTRY(_startup)
 
@@ -67,10 +86,6 @@ ENTRY(_startup)
 	movi	a0, LOCKLEVEL
 	wsr	a0, ps
 
-	/* Preserve the pointer to the boot parameter list in EXCSAVE_1 */
-
-	wsr	a2, excsave1
-
 	/* Start with a fresh windowbase and windowstart.  */
 
 	movi	a1, 1
@@ -158,8 +173,6 @@ ENTRY(_startup)
 
 	isync
 
-	initialize_mmu
-
 	/* Unpack data sections
 	 *
 	 * The linker script used to build the Linux kernel image
@@ -207,6 +220,10 @@ ENTRY(_startup)
 
 	___flush_dcache_all a2 a3
 #endif
+	memw
+	isync
+	___invalidate_icache_all a2 a3
+	isync
 
 	/* Setup stack and enable window exceptions (keep irqs disabled) */
 

arch/xtensa/kernel/vectors.S

@@ -50,6 +50,7 @@
 #include <asm/processor.h>
 #include <asm/page.h>
 #include <asm/thread_info.h>
+#include <asm/vectors.h>
 
 #define WINDOW_VECTORS_SIZE   0x180
 
@@ -220,7 +221,7 @@ ENTRY(_DoubleExceptionVector)
 
 	xsr	a0, depc		# get DEPC, save a0
 
-	movi	a3, XCHAL_WINDOW_VECTORS_VADDR
+	movi	a3, WINDOW_VECTORS_VADDR
 	_bltu	a0, a3, .Lfixup
 	addi	a3, a3, WINDOW_VECTORS_SIZE
 	_bgeu	a0, a3, .Lfixup

arch/xtensa/kernel/vmlinux.lds.S

@@ -18,6 +18,7 @@
 #include <asm/page.h>
 #include <asm/thread_info.h>
 
+#include <asm/vectors.h>
 #include <variant/core.h>
 #include <platform/hardware.h>
 OUTPUT_ARCH(xtensa)
@@ -30,7 +31,7 @@ jiffies = jiffies_64;
 #endif
 
 #ifndef KERNELOFFSET
-#define KERNELOFFSET 0xd0001000
+#define KERNELOFFSET 0xd0003000
 #endif
 
 /* Note: In the following macros, it would be nice to specify only the
@@ -185,16 +186,16 @@ SECTIONS
 
   SECTION_VECTOR (_WindowVectors_text,
 		  .WindowVectors.text,
-		  XCHAL_WINDOW_VECTORS_VADDR, 4,
+		  WINDOW_VECTORS_VADDR, 4,
 		  .dummy)
   SECTION_VECTOR (_DebugInterruptVector_literal,
 		  .DebugInterruptVector.literal,
-		  XCHAL_DEBUG_VECTOR_VADDR - 4,
+		  DEBUG_VECTOR_VADDR - 4,
 		  SIZEOF(.WindowVectors.text),
 		  .WindowVectors.text)
   SECTION_VECTOR (_DebugInterruptVector_text,
 		  .DebugInterruptVector.text,
-		  XCHAL_DEBUG_VECTOR_VADDR,
+		  DEBUG_VECTOR_VADDR,
 		  4,
 		  .DebugInterruptVector.literal)
 #undef LAST
@@ -202,7 +203,7 @@ SECTIONS
 #if XCHAL_EXCM_LEVEL >= 2
   SECTION_VECTOR (_Level2InterruptVector_text,
 		  .Level2InterruptVector.text,
-		  XCHAL_INTLEVEL2_VECTOR_VADDR,
+		  INTLEVEL2_VECTOR_VADDR,
 		  SIZEOF(LAST), LAST)
 # undef LAST
 # define LAST	.Level2InterruptVector.text
@@ -210,7 +211,7 @@ SECTIONS
 #if XCHAL_EXCM_LEVEL >= 3
   SECTION_VECTOR (_Level3InterruptVector_text,
 		  .Level3InterruptVector.text,
-		  XCHAL_INTLEVEL3_VECTOR_VADDR,
+		  INTLEVEL3_VECTOR_VADDR,
 		  SIZEOF(LAST), LAST)
 # undef LAST
 # define LAST	.Level3InterruptVector.text
@@ -218,7 +219,7 @@ SECTIONS
 #if XCHAL_EXCM_LEVEL >= 4
   SECTION_VECTOR (_Level4InterruptVector_text,
 		  .Level4InterruptVector.text,
-		  XCHAL_INTLEVEL4_VECTOR_VADDR,
+		  INTLEVEL4_VECTOR_VADDR,
 		  SIZEOF(LAST), LAST)
 # undef LAST
 # define LAST	.Level4InterruptVector.text
@@ -226,7 +227,7 @@ SECTIONS
 #if XCHAL_EXCM_LEVEL >= 5
   SECTION_VECTOR (_Level5InterruptVector_text,
 		  .Level5InterruptVector.text,
-		  XCHAL_INTLEVEL5_VECTOR_VADDR,
+		  INTLEVEL5_VECTOR_VADDR,
 		  SIZEOF(LAST), LAST)
 # undef LAST
 # define LAST	.Level5InterruptVector.text
@@ -234,39 +235,39 @@ SECTIONS
 #if XCHAL_EXCM_LEVEL >= 6
   SECTION_VECTOR (_Level6InterruptVector_text,
 		  .Level6InterruptVector.text,
-		  XCHAL_INTLEVEL6_VECTOR_VADDR,
+		  INTLEVEL6_VECTOR_VADDR,
 		  SIZEOF(LAST), LAST)
 # undef LAST
 # define LAST	.Level6InterruptVector.text
 #endif
   SECTION_VECTOR (_KernelExceptionVector_literal,
 		  .KernelExceptionVector.literal,
-		  XCHAL_KERNEL_VECTOR_VADDR - 4,
+		  KERNEL_VECTOR_VADDR - 4,
 		  SIZEOF(LAST), LAST)
 #undef LAST
   SECTION_VECTOR (_KernelExceptionVector_text,
 		  .KernelExceptionVector.text,
-		  XCHAL_KERNEL_VECTOR_VADDR,
+		  KERNEL_VECTOR_VADDR,
 		  4,
 		  .KernelExceptionVector.literal)
   SECTION_VECTOR (_UserExceptionVector_literal,
 		  .UserExceptionVector.literal,
-		  XCHAL_USER_VECTOR_VADDR - 4,
+		  USER_VECTOR_VADDR - 4,
 		  SIZEOF(.KernelExceptionVector.text),
 		  .KernelExceptionVector.text)
   SECTION_VECTOR (_UserExceptionVector_text,
 		  .UserExceptionVector.text,
-		  XCHAL_USER_VECTOR_VADDR,
+		  USER_VECTOR_VADDR,
 		  4,
 		  .UserExceptionVector.literal)
   SECTION_VECTOR (_DoubleExceptionVector_literal,
 		  .DoubleExceptionVector.literal,
-		  XCHAL_DOUBLEEXC_VECTOR_VADDR - 16,
+		  DOUBLEEXC_VECTOR_VADDR - 16,
 		  SIZEOF(.UserExceptionVector.text),
 		  .UserExceptionVector.text)
   SECTION_VECTOR (_DoubleExceptionVector_text,
 		  .DoubleExceptionVector.text,
-		  XCHAL_DOUBLEEXC_VECTOR_VADDR,
+		  DOUBLEEXC_VECTOR_VADDR,
 		  32,
 		  .DoubleExceptionVector.literal)
 
@@ -284,11 +285,26 @@ SECTIONS
   . = ALIGN(0x10);
   .bootstrap : { *(.bootstrap.literal .bootstrap.text .bootstrap.data) }
 
-  .ResetVector.text XCHAL_RESET_VECTOR_VADDR :
+  .ResetVector.text RESET_VECTOR_VADDR :
   {
     *(.ResetVector.text)
   }
 
+
+  /*
+   * This is a remapped copy of the Secondary Reset Vector Code.
+   * It keeps gdb in sync with the PC after switching
+   * to the temporary mapping used while setting up
+   * the V2 MMU mappings for Linux.
+   *
+   * Only debug information about this section is put in the kernel image.
+   */
+  .SecondaryResetVector.remapped_text 0x46000000 (INFO):
+  {
+	*(.SecondaryResetVector.remapped_text)
+  }
+
+
   .xt.lit : { *(.xt.lit) }
   .xt.prop : { *(.xt.prop) }
 

arch/xtensa/mm/mmu.c

@@ -24,15 +24,19 @@ void __init paging_init(void)
  */
 void __init init_mmu(void)
 {
-	/* Writing zeros to the <t>TLBCFG special registers ensure
-	 * that valid values exist in the register.  For existing
-	 * PGSZID<w> fields, zero selects the first element of the
-	 * page-size array.  For nonexistent PGSZID<w> fields, zero is
-	 * the best value to write.  Also, when changing PGSZID<w>
+#if !(XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY)
+	/*
+	 * Writing zeros to the instruction and data TLBCFG special
+	 * registers ensure that valid values exist in the register.
+	 *
+	 * For existing PGSZID<w> fields, zero selects the first element
+	 * of the page-size array.  For nonexistent PGSZID<w> fields,
+	 * zero is the best value to write.  Also, when changing PGSZID<w>
 	 * fields, the corresponding TLB must be flushed.
 	 */
 	set_itlbcfg_register(0);
 	set_dtlbcfg_register(0);
+#endif
 	flush_tlb_all();
 
 	/* Set rasid register to a known value. */