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>

1 files changed, 125 insertions, 0 deletions

diff --git a/arch/xtensa/include/asm/vectors.h b/arch/xtensa/include/asm/vectors.h
new file mode 100644
index 000000000000..c52b656d0310
--- /dev/null
+++ b/arch/xtensa/include/asm/vectors.h
@@ -0,0 +1,125 @@
+/*
+ * 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 */