/*
* arch/xtensa/include/asm/initialize_mmu.h
*
* Initializes MMU:
*
* For the new V3 MMU we remap the TLB from virtual == physical
* to the standard Linux mapping used in earlier MMU's.
*
* The the MMU we also support a new configuration register that
* specifies how the S32C1I instruction operates with the cache
* controller.
*
* 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.
*
* Marc Gauthier <[email protected]>
* Pete Delaney <[email protected]>
*/

#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

.macro initialize_mmu

#if XCHAL_HAVE_S32C1I && (XCHAL_HW_MIN_VERSION >= XTENSA_HWVERSION_RC_2009_0)
/*
* We Have Atomic Operation Control (ATOMCTL) Register; Initialize it.
* For details see Documentation/xtensa/atomctl.txt
*/
#if XCHAL_DCACHE_IS_COHERENT
movi a3, 0x25 /* For SMP/MX -- internal for writeback,
* RCW otherwise
*/
#else
movi a3, 0x29 /* non-MX -- Most cores use Std Memory
* Controlers which usually can't use RCW
*/
#endif
wsr a3, atomctl
#endif /* XCHAL_HAVE_S32C1I &&
* (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__*/

#endif /* _XTENSA_INITIALIZE_MMU_H */