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>
2012-12-03 15:01:43 +04:00
parent d83ff0bb82
commit e85e335f8f
12 changed files with 451 additions and 86 deletions
--- a/arch/xtensa/boot/boot-elf/Makefile
+++ b/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

--- a/arch/xtensa/boot/boot-elf/boot.lds.S
+++ b/arch/xtensa/boot/boot-elf/boot.lds.S
@@ -1,41 +1,29 @@
-#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:
+	.ResetVector.text XCHAL_RESET_VECTOR_VADDR :
 	{
-		__reloc_start = . ;
-		_text_start = . ;
-		*(.literal .text.literal .text)
-		_text_end = . ;
+		*(.ResetVector.text)
 	}

-	.rodata ALIGN(0x04):
-	{
-		*(.rodata)
-		*(.rodata1)
-	}
-
-	.data ALIGN(0x04):
-	{
-		*(.data)
-		*(.data1)
-		*(.sdata)
-		*(.sdata2)
-		*(.got.plt)
-		*(.got)
-		*(.dynamic)
-	}
-
-	__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 = .);
 }
--- a/arch/xtensa/boot/boot-elf/bootstrap.S
+++ b/arch/xtensa/boot/boot-elf/bootstrap.S
@@ -1,18 +1,77 @@
+/*
+ * 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