alistair23-linux/arch/arm64/include/asm/pgtable-hwdef.h

/*
 * Copyright (C) 2012 ARM Ltd.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef __ASM_PGTABLE_HWDEF_H
#define __ASM_PGTABLE_HWDEF_H

/*
 * Number of page-table levels required to address 'va_bits' wide
 * address, without section mapping. We resolve the top (va_bits - PAGE_SHIFT)
 * bits with (PAGE_SHIFT - 3) bits at each page table level. Hence:
 *
 *  levels = DIV_ROUND_UP((va_bits - PAGE_SHIFT), (PAGE_SHIFT - 3))
 *
 * where DIV_ROUND_UP(n, d) => (((n) + (d) - 1) / (d))
 *
 * We cannot include linux/kernel.h which defines DIV_ROUND_UP here
 * due to build issues. So we open code DIV_ROUND_UP here:
 *
 *	((((va_bits) - PAGE_SHIFT) + (PAGE_SHIFT - 3) - 1) / (PAGE_SHIFT - 3))
 *
 * which gets simplified as :
 */
#define ARM64_HW_PGTABLE_LEVELS(va_bits) (((va_bits) - 4) / (PAGE_SHIFT - 3))

/*
 * Size mapped by an entry at level n ( 0 <= n <= 3)
 * We map (PAGE_SHIFT - 3) at all translation levels and PAGE_SHIFT bits
 * in the final page. The maximum number of translation levels supported by
 * the architecture is 4. Hence, starting at at level n, we have further
 * ((4 - n) - 1) levels of translation excluding the offset within the page.
 * So, the total number of bits mapped by an entry at level n is :
 *
 *  ((4 - n) - 1) * (PAGE_SHIFT - 3) + PAGE_SHIFT
 *
 * Rearranging it a bit we get :
 *   (4 - n) * (PAGE_SHIFT - 3) + 3
 */
#define ARM64_HW_PGTABLE_LEVEL_SHIFT(n)	((PAGE_SHIFT - 3) * (4 - (n)) + 3)

#define PTRS_PER_PTE		(1 << (PAGE_SHIFT - 3))

/*
 * PMD_SHIFT determines the size a level 2 page table entry can map.
 */
#if CONFIG_PGTABLE_LEVELS > 2
#define PMD_SHIFT		ARM64_HW_PGTABLE_LEVEL_SHIFT(2)
#define PMD_SIZE		(_AC(1, UL) << PMD_SHIFT)
#define PMD_MASK		(~(PMD_SIZE-1))
#define PTRS_PER_PMD		PTRS_PER_PTE
#endif

/*
 * PUD_SHIFT determines the size a level 1 page table entry can map.
 */
#if CONFIG_PGTABLE_LEVELS > 3
#define PUD_SHIFT		ARM64_HW_PGTABLE_LEVEL_SHIFT(1)
#define PUD_SIZE		(_AC(1, UL) << PUD_SHIFT)
#define PUD_MASK		(~(PUD_SIZE-1))
#define PTRS_PER_PUD		PTRS_PER_PTE
#endif

/*
 * PGDIR_SHIFT determines the size a top-level page table entry can map
 * (depending on the configuration, this level can be 0, 1 or 2).
 */
#define PGDIR_SHIFT		ARM64_HW_PGTABLE_LEVEL_SHIFT(4 - CONFIG_PGTABLE_LEVELS)
#define PGDIR_SIZE		(_AC(1, UL) << PGDIR_SHIFT)
#define PGDIR_MASK		(~(PGDIR_SIZE-1))
#define PTRS_PER_PGD		(1 << (VA_BITS - PGDIR_SHIFT))

/*
 * Section address mask and size definitions.
 */
#define SECTION_SHIFT		PMD_SHIFT
#define SECTION_SIZE		(_AC(1, UL) << SECTION_SHIFT)
#define SECTION_MASK		(~(SECTION_SIZE-1))

/*
 * Contiguous page definitions.
 */
#ifdef CONFIG_ARM64_64K_PAGES
#define CONT_PTE_SHIFT		5
#define CONT_PMD_SHIFT		5
#elif defined(CONFIG_ARM64_16K_PAGES)
#define CONT_PTE_SHIFT		7
#define CONT_PMD_SHIFT		5
#else
#define CONT_PTE_SHIFT		4
#define CONT_PMD_SHIFT		4
#endif

#define CONT_PTES		(1 << CONT_PTE_SHIFT)
#define CONT_PTE_SIZE		(CONT_PTES * PAGE_SIZE)
#define CONT_PTE_MASK		(~(CONT_PTE_SIZE - 1))
#define CONT_PMDS		(1 << CONT_PMD_SHIFT)
#define CONT_PMD_SIZE		(CONT_PMDS * PMD_SIZE)
#define CONT_PMD_MASK		(~(CONT_PMD_SIZE - 1))
/* the the numerical offset of the PTE within a range of CONT_PTES */
#define CONT_RANGE_OFFSET(addr) (((addr)>>PAGE_SHIFT)&(CONT_PTES-1))

/*
 * Hardware page table definitions.
 *
 * Level 1 descriptor (PUD).
 */
#define PUD_TYPE_TABLE		(_AT(pudval_t, 3) << 0)
#define PUD_TABLE_BIT		(_AT(pgdval_t, 1) << 1)
#define PUD_TYPE_MASK		(_AT(pgdval_t, 3) << 0)
#define PUD_TYPE_SECT		(_AT(pgdval_t, 1) << 0)

/*
 * Level 2 descriptor (PMD).
 */
#define PMD_TYPE_MASK		(_AT(pmdval_t, 3) << 0)
#define PMD_TYPE_FAULT		(_AT(pmdval_t, 0) << 0)
#define PMD_TYPE_TABLE		(_AT(pmdval_t, 3) << 0)
#define PMD_TYPE_SECT		(_AT(pmdval_t, 1) << 0)
#define PMD_TABLE_BIT		(_AT(pmdval_t, 1) << 1)

/*
 * Section
 */
#define PMD_SECT_VALID		(_AT(pmdval_t, 1) << 0)
#define PMD_SECT_PROT_NONE	(_AT(pmdval_t, 1) << 58)
#define PMD_SECT_USER		(_AT(pmdval_t, 1) << 6)		/* AP[1] */
#define PMD_SECT_RDONLY		(_AT(pmdval_t, 1) << 7)		/* AP[2] */
#define PMD_SECT_S		(_AT(pmdval_t, 3) << 8)
#define PMD_SECT_AF		(_AT(pmdval_t, 1) << 10)
#define PMD_SECT_NG		(_AT(pmdval_t, 1) << 11)
#define PMD_SECT_CONT		(_AT(pmdval_t, 1) << 52)
#define PMD_SECT_PXN		(_AT(pmdval_t, 1) << 53)
#define PMD_SECT_UXN		(_AT(pmdval_t, 1) << 54)

/*
 * AttrIndx[2:0] encoding (mapping attributes defined in the MAIR* registers).
 */
#define PMD_ATTRINDX(t)		(_AT(pmdval_t, (t)) << 2)
#define PMD_ATTRINDX_MASK	(_AT(pmdval_t, 7) << 2)

/*
 * Level 3 descriptor (PTE).
 */
#define PTE_TYPE_MASK		(_AT(pteval_t, 3) << 0)
#define PTE_TYPE_FAULT		(_AT(pteval_t, 0) << 0)
#define PTE_TYPE_PAGE		(_AT(pteval_t, 3) << 0)
#define PTE_TABLE_BIT		(_AT(pteval_t, 1) << 1)
#define PTE_USER		(_AT(pteval_t, 1) << 6)		/* AP[1] */
#define PTE_RDONLY		(_AT(pteval_t, 1) << 7)		/* AP[2] */
#define PTE_SHARED		(_AT(pteval_t, 3) << 8)		/* SH[1:0], inner shareable */
#define PTE_AF			(_AT(pteval_t, 1) << 10)	/* Access Flag */
#define PTE_NG			(_AT(pteval_t, 1) << 11)	/* nG */
#define PTE_DBM			(_AT(pteval_t, 1) << 51)	/* Dirty Bit Management */
#define PTE_CONT		(_AT(pteval_t, 1) << 52)	/* Contiguous range */
#define PTE_PXN			(_AT(pteval_t, 1) << 53)	/* Privileged XN */
#define PTE_UXN			(_AT(pteval_t, 1) << 54)	/* User XN */

/*
 * AttrIndx[2:0] encoding (mapping attributes defined in the MAIR* registers).
 */
#define PTE_ATTRINDX(t)		(_AT(pteval_t, (t)) << 2)
#define PTE_ATTRINDX_MASK	(_AT(pteval_t, 7) << 2)

/*
 * 2nd stage PTE definitions
 */
#define PTE_S2_RDONLY		(_AT(pteval_t, 1) << 6)   /* HAP[2:1] */
#define PTE_S2_RDWR		(_AT(pteval_t, 3) << 6)   /* HAP[2:1] */

#define PMD_S2_RDONLY		(_AT(pmdval_t, 1) << 6)   /* HAP[2:1] */
#define PMD_S2_RDWR		(_AT(pmdval_t, 3) << 6)   /* HAP[2:1] */

/*
 * Memory Attribute override for Stage-2 (MemAttr[3:0])
 */
#define PTE_S2_MEMATTR(t)	(_AT(pteval_t, (t)) << 2)
#define PTE_S2_MEMATTR_MASK	(_AT(pteval_t, 0xf) << 2)

/*
 * EL2/HYP PTE/PMD definitions
 */
#define PMD_HYP			PMD_SECT_USER
#define PTE_HYP			PTE_USER

/*
 * Highest possible physical address supported.
 */
#define PHYS_MASK_SHIFT		(48)
#define PHYS_MASK		((UL(1) << PHYS_MASK_SHIFT) - 1)

/*
 * TCR flags.
 */
#define TCR_T0SZ_OFFSET		0
#define TCR_T1SZ_OFFSET		16
#define TCR_T0SZ(x)		((UL(64) - (x)) << TCR_T0SZ_OFFSET)
#define TCR_T1SZ(x)		((UL(64) - (x)) << TCR_T1SZ_OFFSET)
#define TCR_TxSZ(x)		(TCR_T0SZ(x) | TCR_T1SZ(x))
#define TCR_TxSZ_WIDTH		6
#define TCR_IRGN_NC		((UL(0) << 8) | (UL(0) << 24))
#define TCR_IRGN_WBWA		((UL(1) << 8) | (UL(1) << 24))
#define TCR_IRGN_WT		((UL(2) << 8) | (UL(2) << 24))
#define TCR_IRGN_WBnWA		((UL(3) << 8) | (UL(3) << 24))
#define TCR_IRGN_MASK		((UL(3) << 8) | (UL(3) << 24))
#define TCR_ORGN_NC		((UL(0) << 10) | (UL(0) << 26))
#define TCR_ORGN_WBWA		((UL(1) << 10) | (UL(1) << 26))
#define TCR_ORGN_WT		((UL(2) << 10) | (UL(2) << 26))
#define TCR_ORGN_WBnWA		((UL(3) << 10) | (UL(3) << 26))
#define TCR_ORGN_MASK		((UL(3) << 10) | (UL(3) << 26))
#define TCR_SHARED		((UL(3) << 12) | (UL(3) << 28))
#define TCR_TG0_4K		(UL(0) << 14)
#define TCR_TG0_64K		(UL(1) << 14)
#define TCR_TG0_16K		(UL(2) << 14)
#define TCR_TG1_16K		(UL(1) << 30)
#define TCR_TG1_4K		(UL(2) << 30)
#define TCR_TG1_64K		(UL(3) << 30)
#define TCR_ASID16		(UL(1) << 36)
#define TCR_TBI0		(UL(1) << 37)
#define TCR_HA			(UL(1) << 39)
#define TCR_HD			(UL(1) << 40)

#endif