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yaml
---
r: 264611
b: refs/heads/master
c: 17f5721
h: refs/heads/master
i:
  264609: 7f30417
  264607: a2881c2
v: v3
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Catalin Marinas authored and Russell King committed Oct 6, 2011
1 parent da04433 commit 3201d55
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Showing 7 changed files with 303 additions and 251 deletions.
2 changes: 1 addition & 1 deletion [refs]
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@@ -1,2 +1,2 @@
---
refs/heads/master: e73fc88e19d74fd4dd664cff45b88caab8cde45c
refs/heads/master: 17f57211969bddca2e922299a2530b1c65ccabfa
42 changes: 1 addition & 41 deletions trunk/arch/arm/include/asm/page.h
Original file line number Diff line number Diff line change
Expand Up @@ -151,47 +151,7 @@ extern void __cpu_copy_user_highpage(struct page *to, struct page *from,
#define clear_page(page) memset((void *)(page), 0, PAGE_SIZE)
extern void copy_page(void *to, const void *from);

typedef unsigned long pteval_t;

#undef STRICT_MM_TYPECHECKS

#ifdef STRICT_MM_TYPECHECKS
/*
* These are used to make use of C type-checking..
*/
typedef struct { pteval_t pte; } pte_t;
typedef struct { unsigned long pmd; } pmd_t;
typedef struct { unsigned long pgd[2]; } pgd_t;
typedef struct { unsigned long pgprot; } pgprot_t;

#define pte_val(x) ((x).pte)
#define pmd_val(x) ((x).pmd)
#define pgd_val(x) ((x).pgd[0])
#define pgprot_val(x) ((x).pgprot)

#define __pte(x) ((pte_t) { (x) } )
#define __pmd(x) ((pmd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )

#else
/*
* .. while these make it easier on the compiler
*/
typedef pteval_t pte_t;
typedef unsigned long pmd_t;
typedef unsigned long pgd_t[2];
typedef unsigned long pgprot_t;

#define pte_val(x) (x)
#define pmd_val(x) (x)
#define pgd_val(x) ((x)[0])
#define pgprot_val(x) (x)

#define __pte(x) (x)
#define __pmd(x) (x)
#define __pgprot(x) (x)

#endif /* STRICT_MM_TYPECHECKS */
#include <asm/pgtable-2level-types.h>

#endif /* CONFIG_MMU */

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91 changes: 91 additions & 0 deletions trunk/arch/arm/include/asm/pgtable-2level-hwdef.h
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@@ -0,0 +1,91 @@
/*
* arch/arm/include/asm/pgtable-2level-hwdef.h
*
* Copyright (C) 1995-2002 Russell King
*
* 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.
*/
#ifndef _ASM_PGTABLE_2LEVEL_HWDEF_H
#define _ASM_PGTABLE_2LEVEL_HWDEF_H

/*
* Hardware page table definitions.
*
* + Level 1 descriptor (PMD)
* - common
*/
#define PMD_TYPE_MASK (3 << 0)
#define PMD_TYPE_FAULT (0 << 0)
#define PMD_TYPE_TABLE (1 << 0)
#define PMD_TYPE_SECT (2 << 0)
#define PMD_BIT4 (1 << 4)
#define PMD_DOMAIN(x) ((x) << 5)
#define PMD_PROTECTION (1 << 9) /* v5 */
/*
* - section
*/
#define PMD_SECT_BUFFERABLE (1 << 2)
#define PMD_SECT_CACHEABLE (1 << 3)
#define PMD_SECT_XN (1 << 4) /* v6 */
#define PMD_SECT_AP_WRITE (1 << 10)
#define PMD_SECT_AP_READ (1 << 11)
#define PMD_SECT_TEX(x) ((x) << 12) /* v5 */
#define PMD_SECT_APX (1 << 15) /* v6 */
#define PMD_SECT_S (1 << 16) /* v6 */
#define PMD_SECT_nG (1 << 17) /* v6 */
#define PMD_SECT_SUPER (1 << 18) /* v6 */
#define PMD_SECT_AF (0)

#define PMD_SECT_UNCACHED (0)
#define PMD_SECT_BUFFERED (PMD_SECT_BUFFERABLE)
#define PMD_SECT_WT (PMD_SECT_CACHEABLE)
#define PMD_SECT_WB (PMD_SECT_CACHEABLE | PMD_SECT_BUFFERABLE)
#define PMD_SECT_MINICACHE (PMD_SECT_TEX(1) | PMD_SECT_CACHEABLE)
#define PMD_SECT_WBWA (PMD_SECT_TEX(1) | PMD_SECT_CACHEABLE | PMD_SECT_BUFFERABLE)
#define PMD_SECT_NONSHARED_DEV (PMD_SECT_TEX(2))

/*
* - coarse table (not used)
*/

/*
* + Level 2 descriptor (PTE)
* - common
*/
#define PTE_TYPE_MASK (3 << 0)
#define PTE_TYPE_FAULT (0 << 0)
#define PTE_TYPE_LARGE (1 << 0)
#define PTE_TYPE_SMALL (2 << 0)
#define PTE_TYPE_EXT (3 << 0) /* v5 */
#define PTE_BUFFERABLE (1 << 2)
#define PTE_CACHEABLE (1 << 3)

/*
* - extended small page/tiny page
*/
#define PTE_EXT_XN (1 << 0) /* v6 */
#define PTE_EXT_AP_MASK (3 << 4)
#define PTE_EXT_AP0 (1 << 4)
#define PTE_EXT_AP1 (2 << 4)
#define PTE_EXT_AP_UNO_SRO (0 << 4)
#define PTE_EXT_AP_UNO_SRW (PTE_EXT_AP0)
#define PTE_EXT_AP_URO_SRW (PTE_EXT_AP1)
#define PTE_EXT_AP_URW_SRW (PTE_EXT_AP1|PTE_EXT_AP0)
#define PTE_EXT_TEX(x) ((x) << 6) /* v5 */
#define PTE_EXT_APX (1 << 9) /* v6 */
#define PTE_EXT_COHERENT (1 << 9) /* XScale3 */
#define PTE_EXT_SHARED (1 << 10) /* v6 */
#define PTE_EXT_NG (1 << 11) /* v6 */

/*
* - small page
*/
#define PTE_SMALL_AP_MASK (0xff << 4)
#define PTE_SMALL_AP_UNO_SRO (0x00 << 4)
#define PTE_SMALL_AP_UNO_SRW (0x55 << 4)
#define PTE_SMALL_AP_URO_SRW (0xaa << 4)
#define PTE_SMALL_AP_URW_SRW (0xff << 4)

#endif
64 changes: 64 additions & 0 deletions trunk/arch/arm/include/asm/pgtable-2level-types.h
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@@ -0,0 +1,64 @@
/*
* arch/arm/include/asm/pgtable-2level-types.h
*
* Copyright (C) 1995-2003 Russell King
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _ASM_PGTABLE_2LEVEL_TYPES_H
#define _ASM_PGTABLE_2LEVEL_TYPES_H

typedef unsigned long pteval_t;

#undef STRICT_MM_TYPECHECKS

#ifdef STRICT_MM_TYPECHECKS
/*
* These are used to make use of C type-checking..
*/
typedef struct { pteval_t pte; } pte_t;
typedef struct { unsigned long pmd; } pmd_t;
typedef struct { unsigned long pgd[2]; } pgd_t;
typedef struct { unsigned long pgprot; } pgprot_t;

#define pte_val(x) ((x).pte)
#define pmd_val(x) ((x).pmd)
#define pgd_val(x) ((x).pgd[0])
#define pgprot_val(x) ((x).pgprot)

#define __pte(x) ((pte_t) { (x) } )
#define __pmd(x) ((pmd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )

#else
/*
* .. while these make it easier on the compiler
*/
typedef pteval_t pte_t;
typedef unsigned long pmd_t;
typedef unsigned long pgd_t[2];
typedef unsigned long pgprot_t;

#define pte_val(x) (x)
#define pmd_val(x) (x)
#define pgd_val(x) ((x)[0])
#define pgprot_val(x) (x)

#define __pte(x) (x)
#define __pmd(x) (x)
#define __pgprot(x) (x)

#endif /* STRICT_MM_TYPECHECKS */

#endif /* _ASM_PGTABLE_2LEVEL_TYPES_H */
143 changes: 143 additions & 0 deletions trunk/arch/arm/include/asm/pgtable-2level.h
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@@ -0,0 +1,143 @@
/*
* arch/arm/include/asm/pgtable-2level.h
*
* Copyright (C) 1995-2002 Russell King
*
* 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.
*/
#ifndef _ASM_PGTABLE_2LEVEL_H
#define _ASM_PGTABLE_2LEVEL_H

/*
* Hardware-wise, we have a two level page table structure, where the first
* level has 4096 entries, and the second level has 256 entries. Each entry
* is one 32-bit word. Most of the bits in the second level entry are used
* by hardware, and there aren't any "accessed" and "dirty" bits.
*
* Linux on the other hand has a three level page table structure, which can
* be wrapped to fit a two level page table structure easily - using the PGD
* and PTE only. However, Linux also expects one "PTE" table per page, and
* at least a "dirty" bit.
*
* Therefore, we tweak the implementation slightly - we tell Linux that we
* have 2048 entries in the first level, each of which is 8 bytes (iow, two
* hardware pointers to the second level.) The second level contains two
* hardware PTE tables arranged contiguously, preceded by Linux versions
* which contain the state information Linux needs. We, therefore, end up
* with 512 entries in the "PTE" level.
*
* This leads to the page tables having the following layout:
*
* pgd pte
* | |
* +--------+
* | | +------------+ +0
* +- - - - + | Linux pt 0 |
* | | +------------+ +1024
* +--------+ +0 | Linux pt 1 |
* | |-----> +------------+ +2048
* +- - - - + +4 | h/w pt 0 |
* | |-----> +------------+ +3072
* +--------+ +8 | h/w pt 1 |
* | | +------------+ +4096
*
* See L_PTE_xxx below for definitions of bits in the "Linux pt", and
* PTE_xxx for definitions of bits appearing in the "h/w pt".
*
* PMD_xxx definitions refer to bits in the first level page table.
*
* The "dirty" bit is emulated by only granting hardware write permission
* iff the page is marked "writable" and "dirty" in the Linux PTE. This
* means that a write to a clean page will cause a permission fault, and
* the Linux MM layer will mark the page dirty via handle_pte_fault().
* For the hardware to notice the permission change, the TLB entry must
* be flushed, and ptep_set_access_flags() does that for us.
*
* The "accessed" or "young" bit is emulated by a similar method; we only
* allow accesses to the page if the "young" bit is set. Accesses to the
* page will cause a fault, and handle_pte_fault() will set the young bit
* for us as long as the page is marked present in the corresponding Linux
* PTE entry. Again, ptep_set_access_flags() will ensure that the TLB is
* up to date.
*
* However, when the "young" bit is cleared, we deny access to the page
* by clearing the hardware PTE. Currently Linux does not flush the TLB
* for us in this case, which means the TLB will retain the transation
* until either the TLB entry is evicted under pressure, or a context
* switch which changes the user space mapping occurs.
*/
#define PTRS_PER_PTE 512
#define PTRS_PER_PMD 1
#define PTRS_PER_PGD 2048

#define PTE_HWTABLE_PTRS (PTRS_PER_PTE)
#define PTE_HWTABLE_OFF (PTE_HWTABLE_PTRS * sizeof(pte_t))
#define PTE_HWTABLE_SIZE (PTRS_PER_PTE * sizeof(u32))

/*
* PMD_SHIFT determines the size of the area a second-level page table can map
* PGDIR_SHIFT determines what a third-level page table entry can map
*/
#define PMD_SHIFT 21
#define PGDIR_SHIFT 21

#define PMD_SIZE (1UL << PMD_SHIFT)
#define PMD_MASK (~(PMD_SIZE-1))
#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))

/*
* section address mask and size definitions.
*/
#define SECTION_SHIFT 20
#define SECTION_SIZE (1UL << SECTION_SHIFT)
#define SECTION_MASK (~(SECTION_SIZE-1))

/*
* ARMv6 supersection address mask and size definitions.
*/
#define SUPERSECTION_SHIFT 24
#define SUPERSECTION_SIZE (1UL << SUPERSECTION_SHIFT)
#define SUPERSECTION_MASK (~(SUPERSECTION_SIZE-1))

#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)

/*
* "Linux" PTE definitions.
*
* We keep two sets of PTEs - the hardware and the linux version.
* This allows greater flexibility in the way we map the Linux bits
* onto the hardware tables, and allows us to have YOUNG and DIRTY
* bits.
*
* The PTE table pointer refers to the hardware entries; the "Linux"
* entries are stored 1024 bytes below.
*/
#define L_PTE_PRESENT (_AT(pteval_t, 1) << 0)
#define L_PTE_YOUNG (_AT(pteval_t, 1) << 1)
#define L_PTE_FILE (_AT(pteval_t, 1) << 2) /* only when !PRESENT */
#define L_PTE_DIRTY (_AT(pteval_t, 1) << 6)
#define L_PTE_RDONLY (_AT(pteval_t, 1) << 7)
#define L_PTE_USER (_AT(pteval_t, 1) << 8)
#define L_PTE_XN (_AT(pteval_t, 1) << 9)
#define L_PTE_SHARED (_AT(pteval_t, 1) << 10) /* shared(v6), coherent(xsc3) */

/*
* These are the memory types, defined to be compatible with
* pre-ARMv6 CPUs cacheable and bufferable bits: XXCB
*/
#define L_PTE_MT_UNCACHED (_AT(pteval_t, 0x00) << 2) /* 0000 */
#define L_PTE_MT_BUFFERABLE (_AT(pteval_t, 0x01) << 2) /* 0001 */
#define L_PTE_MT_WRITETHROUGH (_AT(pteval_t, 0x02) << 2) /* 0010 */
#define L_PTE_MT_WRITEBACK (_AT(pteval_t, 0x03) << 2) /* 0011 */
#define L_PTE_MT_MINICACHE (_AT(pteval_t, 0x06) << 2) /* 0110 (sa1100, xscale) */
#define L_PTE_MT_WRITEALLOC (_AT(pteval_t, 0x07) << 2) /* 0111 */
#define L_PTE_MT_DEV_SHARED (_AT(pteval_t, 0x04) << 2) /* 0100 */
#define L_PTE_MT_DEV_NONSHARED (_AT(pteval_t, 0x0c) << 2) /* 1100 */
#define L_PTE_MT_DEV_WC (_AT(pteval_t, 0x09) << 2) /* 1001 */
#define L_PTE_MT_DEV_CACHED (_AT(pteval_t, 0x0b) << 2) /* 1011 */
#define L_PTE_MT_MASK (_AT(pteval_t, 0x0f) << 2)

#endif /* _ASM_PGTABLE_2LEVEL_H */
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