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/*
* Copyright (c) 2007 Pavel Jancik, Michal Kebrt
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup arm32mm
* @{
*/
/** @file
* @brief Paging related declarations.
*/
#ifndef KERN_arm32_PAGE_H_
#define KERN_arm32_PAGE_H_
#include <arch/mm/frame.h>
#include <mm/mm.h>
#include <arch/exception.h>
#define PAGE_WIDTH FRAME_WIDTH
#define PAGE_SIZE FRAME_SIZE
#ifndef __ASM__
# define KA2PA(x) (((uintptr_t) (x)) - 0x80000000)
# define PA2KA(x) (((uintptr_t) (x)) + 0x80000000)
#else
# define KA2PA(x) ((x) - 0x80000000)
# define PA2KA(x) ((x) + 0x80000000)
#endif
#ifdef KERNEL
/* Number of entries in each level. */
#define PTL0_ENTRIES_ARCH (2 << 12) /* 4096 */
#define PTL1_ENTRIES_ARCH 0
#define PTL2_ENTRIES_ARCH 0
/* coarse page tables used (256 * 4 = 1KB per page) */
#define PTL3_ENTRIES_ARCH (2 << 8) /* 256 */
/* Page table sizes for each level. */
#define PTL0_SIZE_ARCH FOUR_FRAMES
#define PTL1_SIZE_ARCH 0
#define PTL2_SIZE_ARCH 0
#define PTL3_SIZE_ARCH ONE_FRAME
/* Macros calculating indices into page tables for each level. */
#define PTL0_INDEX_ARCH(vaddr) (((vaddr) >> 20) & 0xfff)
#define PTL1_INDEX_ARCH(vaddr) 0
#define PTL2_INDEX_ARCH(vaddr) 0
#define PTL3_INDEX_ARCH(vaddr) (((vaddr) >> 12) & 0x0ff)
/* Get PTE address accessors for each level. */
#define GET_PTL1_ADDRESS_ARCH(ptl0, i) \
((pte_t *) ((((pte_level0_t *)(ptl0))[(i)]).coarse_table_addr << 10))
#define GET_PTL2_ADDRESS_ARCH(ptl1, i) \
(ptl1)
#define GET_PTL3_ADDRESS_ARCH(ptl2, i) \
(ptl2)
#define GET_FRAME_ADDRESS_ARCH(ptl3, i) \
((uintptr_t) ((((pte_level1_t *)(ptl3))[(i)]).frame_base_addr << 12))
/* Set PTE address accessors for each level. */
#define SET_PTL0_ADDRESS_ARCH(ptl0) \
(set_ptl0_addr((pte_level0_t *) (ptl0)))
#define SET_PTL1_ADDRESS_ARCH(ptl0, i, a) \
(((pte_level0_t *) (ptl0))[(i)].coarse_table_addr = (a) >> 10)
#define SET_PTL2_ADDRESS_ARCH(ptl1, i, a)
#define SET_PTL3_ADDRESS_ARCH(ptl2, i, a)
#define SET_FRAME_ADDRESS_ARCH(ptl3, i, a) \
(((pte_level1_t *) (ptl3))[(i)].frame_base_addr = (a) >> 12)
/* Get PTE flags accessors for each level. */
#define GET_PTL1_FLAGS_ARCH(ptl0, i) \
get_pt_level0_flags((pte_level0_t *) (ptl0), (size_t) (i))
#define GET_PTL2_FLAGS_ARCH(ptl1, i) \
PAGE_PRESENT
#define GET_PTL3_FLAGS_ARCH(ptl2, i) \
PAGE_PRESENT
#define GET_FRAME_FLAGS_ARCH(ptl3, i) \
get_pt_level1_flags((pte_level1_t *) (ptl3), (size_t) (i))
/* Set PTE flags accessors for each level. */
#define SET_PTL1_FLAGS_ARCH(ptl0, i, x) \
set_pt_level0_flags((pte_level0_t *) (ptl0), (size_t) (i), (x))
#define SET_PTL2_FLAGS_ARCH(ptl1, i, x)
#define SET_PTL3_FLAGS_ARCH(ptl2, i, x)
#define SET_FRAME_FLAGS_ARCH(ptl3, i, x) \
set_pt_level1_flags((pte_level1_t *) (ptl3), (size_t) (i), (x))
/* Macros for querying the last-level PTE entries. */
#define PTE_VALID_ARCH(pte) \
(*((uint32_t *) (pte)) != 0)
#define PTE_PRESENT_ARCH(pte) \
(((pte_level0_t *) (pte))->descriptor_type != 0)
#define PTE_GET_FRAME_ARCH(pte) \
(((pte_level1_t *) (pte))->frame_base_addr << FRAME_WIDTH)
#define PTE_WRITABLE_ARCH(pte) \
(((pte_level1_t *) (pte))->access_permission_0 == \
PTE_AP_USER_RW_KERNEL_RW)
#define PTE_EXECUTABLE_ARCH(pte) \
1
#ifndef __ASM__
/** Level 0 page table entry. */
typedef struct {
/* 0b01 for coarse tables, see below for details */
unsigned descriptor_type : 2;
unsigned impl_specific : 3;
unsigned domain : 4;
unsigned should_be_zero : 1;
/* Pointer to the coarse 2nd level page table (holding entries for small
* (4KB) or large (64KB) pages. ARM also supports fine 2nd level page
* tables that may hold even tiny pages (1KB) but they are bigger (4KB
* per table in comparison with 1KB per the coarse table)
*/
unsigned coarse_table_addr : 22;
} ATTRIBUTE_PACKED pte_level0_t;
/** Level 1 page table entry (small (4KB) pages used). */
typedef struct {
/* 0b10 for small pages */
unsigned descriptor_type : 2;
unsigned bufferable : 1;
unsigned cacheable : 1;
/* access permissions for each of 4 subparts of a page
* (for each 1KB when small pages used */
unsigned access_permission_0 : 2;
unsigned access_permission_1 : 2;
unsigned access_permission_2 : 2;
unsigned access_permission_3 : 2;
unsigned frame_base_addr : 20;
} ATTRIBUTE_PACKED pte_level1_t;
/* Level 1 page tables access permissions */
/** User mode: no access, privileged mode: no access. */
#define PTE_AP_USER_NO_KERNEL_NO 0
/** User mode: no access, privileged mode: read/write. */
#define PTE_AP_USER_NO_KERNEL_RW 1
/** User mode: read only, privileged mode: read/write. */
#define PTE_AP_USER_RO_KERNEL_RW 2
/** User mode: read/write, privileged mode: read/write. */
#define PTE_AP_USER_RW_KERNEL_RW 3
/* pte_level0_t and pte_level1_t descriptor_type flags */
/** pte_level0_t and pte_level1_t "not present" flag (used in descriptor_type). */
#define PTE_DESCRIPTOR_NOT_PRESENT 0
/** pte_level0_t coarse page table flag (used in descriptor_type). */
#define PTE_DESCRIPTOR_COARSE_TABLE 1
/** pte_level1_t small page table flag (used in descriptor type). */
#define PTE_DESCRIPTOR_SMALL_PAGE 2
/** Sets the address of level 0 page table.
*
* @param pt Pointer to the page table to set.
*/
static inline void set_ptl0_addr(pte_level0_t *pt)
{
asm volatile (
"mcr p15, 0, %[pt], c2, c0, 0\n"
:: [pt] "r" (pt)
);
}
/** Returns level 0 page table entry flags.
*
* @param pt Level 0 page table.
* @param i Index of the entry to return.
*/
static inline int get_pt_level0_flags(pte_level0_t *pt, size_t i)
{
pte_level0_t *p = &pt[i];
int np = (p->descriptor_type == PTE_DESCRIPTOR_NOT_PRESENT);
return (np << PAGE_PRESENT_SHIFT) | (1 << PAGE_USER_SHIFT) |
(1 << PAGE_READ_SHIFT) | (1 << PAGE_WRITE_SHIFT) |
(1 << PAGE_EXEC_SHIFT) | (1 << PAGE_CACHEABLE_SHIFT);
}
/** Returns level 1 page table entry flags.
*
* @param pt Level 1 page table.
* @param i Index of the entry to return.
*/
static inline int get_pt_level1_flags(pte_level1_t *pt, size_t i)
{
pte_level1_t *p = &pt[i];
int dt = p->descriptor_type;
int ap = p->access_permission_0;
return ((dt == PTE_DESCRIPTOR_NOT_PRESENT) << PAGE_PRESENT_SHIFT) |
((ap == PTE_AP_USER_RO_KERNEL_RW) << PAGE_READ_SHIFT) |
((ap == PTE_AP_USER_RW_KERNEL_RW) << PAGE_READ_SHIFT) |
((ap == PTE_AP_USER_RW_KERNEL_RW) << PAGE_WRITE_SHIFT) |
((ap != PTE_AP_USER_NO_KERNEL_RW) << PAGE_USER_SHIFT) |
((ap == PTE_AP_USER_NO_KERNEL_RW) << PAGE_READ_SHIFT) |
((ap == PTE_AP_USER_NO_KERNEL_RW) << PAGE_WRITE_SHIFT) |
(1 << PAGE_EXEC_SHIFT) |
(p->bufferable << PAGE_CACHEABLE);
}
/** Sets flags of level 0 page table entry.
*
* @param pt level 0 page table
* @param i index of the entry to be changed
* @param flags new flags
*/
static inline void set_pt_level0_flags(pte_level0_t *pt, size_t i, int flags)
{
pte_level0_t *p = &pt[i];
if (flags & PAGE_NOT_PRESENT) {
p->descriptor_type = PTE_DESCRIPTOR_NOT_PRESENT;
/*
* Ensures that the entry will be recognized as valid when
* PTE_VALID_ARCH applied.
*/
p->should_be_zero = 1;
} else {
p->descriptor_type = PTE_DESCRIPTOR_COARSE_TABLE;
p->should_be_zero = 0;
}
}
/** Sets flags of level 1 page table entry.
*
* We use same access rights for the whole page. When page is not preset we
* store 1 in acess_rigts_3 so that at least one bit is 1 (to mark correct
* page entry, see #PAGE_VALID_ARCH).
*
* @param pt Level 1 page table.
* @param i Index of the entry to be changed.
* @param flags New flags.
*/
static inline void set_pt_level1_flags(pte_level1_t *pt, size_t i, int flags)
{
pte_level1_t *p = &pt[i];
if (flags & PAGE_NOT_PRESENT) {
p->descriptor_type = PTE_DESCRIPTOR_NOT_PRESENT;
p->access_permission_3 = 1;
} else {
p->descriptor_type = PTE_DESCRIPTOR_SMALL_PAGE;
p->access_permission_3 = p->access_permission_0;
}
p->cacheable = p->bufferable = (flags & PAGE_CACHEABLE) != 0;
/* default access permission */
p->access_permission_0 = p->access_permission_1 =
p->access_permission_2 = p->access_permission_3 =
PTE_AP_USER_NO_KERNEL_RW;
if (flags & PAGE_USER) {
if (flags & PAGE_READ) {
p->access_permission_0 = p->access_permission_1 =
p->access_permission_2 = p->access_permission_3 =
PTE_AP_USER_RO_KERNEL_RW;
}
if (flags & PAGE_WRITE) {
p->access_permission_0 = p->access_permission_1 =
p->access_permission_2 = p->access_permission_3 =
PTE_AP_USER_RW_KERNEL_RW;
}
}
}
extern void page_arch_init(void);
#endif /* __ASM__ */
#endif /* KERNEL */
#endif
/** @}
*/