1/*
  2 * Hexagon VM page table entry definitions
  3 *
  4 * Copyright (c) 2010-2011,2013 The Linux Foundation. All rights reserved.
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 and
  8 * only version 2 as published by the Free Software Foundation.
  9 *
 10 * This program is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 * GNU General Public License for more details.
 14 *
 15 * You should have received a copy of the GNU General Public License
 16 * along with this program; if not, write to the Free Software
 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 18 * 02110-1301, USA.
 19 */
 20
 21#ifndef _ASM_VM_MMU_H
 22#define _ASM_VM_MMU_H
 23
 24/*
 25 * Shift, mask, and other constants for the Hexagon Virtual Machine
 26 * page tables.
 27 *
 28 * Virtual machine MMU allows first-level entries to either be
 29 * single-level lookup PTEs for very large pages, or PDEs pointing
 30 * to second-level PTEs for smaller pages. If PTE is single-level,
 31 * the least significant bits cannot be used as software bits to encode
 32 * virtual memory subsystem information about the page, and that state
 33 * must be maintained in some parallel data structure.
 34 */
 35
 36/* S or Page Size field in PDE */
 37#define	__HVM_PDE_S		(0x7 << 0)
 38#define __HVM_PDE_S_4KB		0
 39#define __HVM_PDE_S_16KB	1
 40#define __HVM_PDE_S_64KB	2
 41#define __HVM_PDE_S_256KB	3
 42#define __HVM_PDE_S_1MB		4
 43#define __HVM_PDE_S_4MB		5
 44#define __HVM_PDE_S_16MB	6
 45#define __HVM_PDE_S_INVALID	7
 46
 47/* Masks for L2 page table pointer, as function of page size */
 48#define __HVM_PDE_PTMASK_4KB	0xfffff000
 49#define __HVM_PDE_PTMASK_16KB	0xfffffc00
 50#define __HVM_PDE_PTMASK_64KB	0xffffff00
 51#define __HVM_PDE_PTMASK_256KB	0xffffffc0
 52#define __HVM_PDE_PTMASK_1MB	0xfffffff0
 53
 54/*
 55 * Virtual Machine PTE Bits/Fields
 56 */
 57#define __HVM_PTE_T		(1<<4)
 58#define __HVM_PTE_U		(1<<5)
 59#define	__HVM_PTE_C		(0x7<<6)
 60#define __HVM_PTE_CVAL(pte)	(((pte) & __HVM_PTE_C) >> 6)
 61#define __HVM_PTE_R		(1<<9)
 62#define __HVM_PTE_W		(1<<10)
 63#define __HVM_PTE_X		(1<<11)
 64
 65/*
 66 * Cache Attributes, to be shifted as necessary for virtual/physical PTEs
 67 */
 68
 69#define __HEXAGON_C_WB		0x0	/* Write-back, no L2 */
 70#define	__HEXAGON_C_WT		0x1	/* Write-through, no L2 */
 71#define	__HEXAGON_C_UNC		0x6	/* Uncached memory */
 72#if CONFIG_HEXAGON_ARCH_VERSION >= 2
 73#define	__HEXAGON_C_DEV		0x4	/* Device register space */
 74#else
 75#define __HEXAGON_C_DEV		__HEXAGON_C_UNC
 76#endif
 77#define	__HEXAGON_C_WT_L2	0x5	/* Write-through, with L2 */
 78#define	__HEXAGON_C_WB_L2	0x7	/* Write-back, with L2 */
 79
 80/*
 81 * This can be overriden, but we're defaulting to the most aggressive
 82 * cache policy, the better to find bugs sooner.
 83 */
 84
 85#define	CACHE_DEFAULT	__HEXAGON_C_WB_L2
 86
 87/* Masks for physical page address, as a function of page size */
 88
 89#define __HVM_PTE_PGMASK_4KB	0xfffff000
 90#define __HVM_PTE_PGMASK_16KB	0xffffc000
 91#define __HVM_PTE_PGMASK_64KB	0xffff0000
 92#define __HVM_PTE_PGMASK_256KB	0xfffc0000
 93#define __HVM_PTE_PGMASK_1MB	0xfff00000
 94
 95/* Masks for single-level large page lookups */
 96
 97#define __HVM_PTE_PGMASK_4MB	0xffc00000
 98#define __HVM_PTE_PGMASK_16MB	0xff000000
 99
100/*
101 * "Big kernel page mappings" (see vm_init_segtable.S)
102 * are currently 16MB
103 */
104
105#define BIG_KERNEL_PAGE_SHIFT 24
106#define BIG_KERNEL_PAGE_SIZE (1 << BIG_KERNEL_PAGE_SHIFT)
107
108
109
110#endif /* _ASM_VM_MMU_H */