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linux-stable/arch/mips/include/asm/pgtable-32.h

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/*
* 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) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle
* Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
*/
#ifndef _ASM_PGTABLE_32_H
#define _ASM_PGTABLE_32_H
#include <asm/addrspace.h>
#include <asm/page.h>
#include <linux/linkage.h>
#include <asm/cachectl.h>
#include <asm/fixmap.h>
#include <asm-generic/pgtable-nopmd.h>
#ifdef CONFIG_HIGHMEM
#include <asm/highmem.h>
#endif
/*
* Regarding 32-bit MIPS huge page support (and the tradeoff it entails):
*
* We use the same huge page sizes as 64-bit MIPS. Assuming a 4KB page size,
* our 2-level table layout would normally have a PGD entry cover a contiguous
* 4MB virtual address region (pointing to a 4KB PTE page of 1,024 32-bit pte_t
* pointers, each pointing to a 4KB physical page). The problem is that 4MB,
* spanning both halves of a TLB EntryLo0,1 pair, requires 2MB hardware page
* support, not one of the standard supported sizes (1MB,4MB,16MB,...).
* To correct for this, when huge pages are enabled, we halve the number of
* pointers a PTE page holds, making its last half go to waste. Correspondingly,
* we double the number of PGD pages. Overall, page table memory overhead
* increases to match 64-bit MIPS, but PTE lookups remain CPU cache-friendly.
*
* NOTE: We don't yet support huge pages if extended-addressing is enabled
* (i.e. EVA, XPA, 36-bit Alchemy/Netlogic).
*/
extern int temp_tlb_entry;
/*
* - add_temporary_entry() add a temporary TLB entry. We use TLB entries
* starting at the top and working down. This is for populating the
* TLB before trap_init() puts the TLB miss handler in place. It
* should be used only for entries matching the actual page tables,
* to prevent inconsistencies.
*/
extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
unsigned long entryhi, unsigned long pagemask);
/*
* Basically we have the same two-level (which is the logical three level
* Linux page table layout folded) page tables as the i386. Some day
* when we have proper page coloring support we can have a 1% quicker
* tlb refill handling mechanism, but for now it is a bit slower but
* works even with the cache aliasing problem the R4k and above have.
*/
/* PGDIR_SHIFT determines what a third-level page table entry can map */
#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
# define PGDIR_SHIFT (2 * PAGE_SHIFT - PTE_T_LOG2 - 1)
#else
# define PGDIR_SHIFT (2 * PAGE_SHIFT - PTE_T_LOG2)
#endif
#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
/*
* Entries per page directory level: we use two-level, so
* we don't really have any PUD/PMD directory physically.
*/
#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
# define __PGD_TABLE_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2 + 1)
#else
# define __PGD_TABLE_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2)
#endif
#define PGD_TABLE_ORDER (__PGD_TABLE_ORDER >= 0 ? __PGD_TABLE_ORDER : 0)
#define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud
#define PMD_TABLE_ORDER aieeee_attempt_to_allocate_pmd
#define PTRS_PER_PGD (USER_PTRS_PER_PGD * 2)
#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
# define PTRS_PER_PTE (PAGE_SIZE / sizeof(pte_t) / 2)
#else
# define PTRS_PER_PTE (PAGE_SIZE / sizeof(pte_t))
#endif
#define USER_PTRS_PER_PGD (0x80000000UL/PGDIR_SIZE)
#define VMALLOC_START MAP_BASE
#define PKMAP_END ((FIXADDR_START) & ~((LAST_PKMAP << PAGE_SHIFT)-1))
#define PKMAP_BASE (PKMAP_END - PAGE_SIZE * LAST_PKMAP)
#ifdef CONFIG_HIGHMEM
# define VMALLOC_END (PKMAP_BASE-2*PAGE_SIZE)
#else
# define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE)
#endif
#ifdef CONFIG_PHYS_ADDR_T_64BIT
#define pte_ERROR(e) \
printk("%s:%d: bad pte %016Lx.\n", __FILE__, __LINE__, pte_val(e))
#else
#define pte_ERROR(e) \
printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
#endif
#define pgd_ERROR(e) \
printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
extern void load_pgd(unsigned long pg_dir);
extern pte_t invalid_pte_table[PTRS_PER_PTE];
/*
* Empty pgd/pmd entries point to the invalid_pte_table.
*/
static inline int pmd_none(pmd_t pmd)
{
return pmd_val(pmd) == (unsigned long) invalid_pte_table;
}
static inline int pmd_bad(pmd_t pmd)
{
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
/* pmd_huge(pmd) but inline */
if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
return 0;
#endif
if (unlikely(pmd_val(pmd) & ~PAGE_MASK))
return 1;
return 0;
}
static inline int pmd_present(pmd_t pmd)
{
return pmd_val(pmd) != (unsigned long) invalid_pte_table;
}
static inline void pmd_clear(pmd_t *pmdp)
{
pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
}
#if defined(CONFIG_XPA)
#define MAX_POSSIBLE_PHYSMEM_BITS 40
#define pte_pfn(x) (((unsigned long)((x).pte_high >> _PFN_SHIFT)) | (unsigned long)((x).pte_low << _PAGE_PRESENT_SHIFT))
static inline pte_t
pfn_pte(unsigned long pfn, pgprot_t prot)
{
pte_t pte;
pte.pte_low = (pfn >> _PAGE_PRESENT_SHIFT) |
(pgprot_val(prot) & ~_PFNX_MASK);
pte.pte_high = (pfn << _PFN_SHIFT) |
(pgprot_val(prot) & ~_PFN_MASK);
return pte;
}
#elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
#define MAX_POSSIBLE_PHYSMEM_BITS 36
#define pte_pfn(x) ((unsigned long)((x).pte_high >> 6))
static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
{
pte_t pte;
pte.pte_high = (pfn << 6) | (pgprot_val(prot) & 0x3f);
pte.pte_low = pgprot_val(prot);
return pte;
}
#else
#define MAX_POSSIBLE_PHYSMEM_BITS 32
#define pte_pfn(x) ((unsigned long)((x).pte >> _PFN_SHIFT))
#define pfn_pte(pfn, prot) __pte(((unsigned long long)(pfn) << _PFN_SHIFT) | pgprot_val(prot))
#define pfn_pmd(pfn, prot) __pmd(((unsigned long long)(pfn) << _PFN_SHIFT) | pgprot_val(prot))
#endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */
#define pte_page(x) pfn_to_page(pte_pfn(x))
/*
* Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
* are !pte_none() && !pte_present().
*/
#if defined(CONFIG_CPU_R3K_TLB)
/*
* Format of swap PTEs:
*
* 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
* 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
* <----------- offset ------------> < type -> V G E 0 0 0 0 0 0 P
*
* E is the exclusive marker that is not stored in swap entries.
* _PAGE_PRESENT (P), _PAGE_VALID (V) and_PAGE_GLOBAL (G) have to remain
* unused.
*/
#define __swp_type(x) (((x).val >> 10) & 0x1f)
#define __swp_offset(x) ((x).val >> 15)
#define __swp_entry(type, offset) ((swp_entry_t) { (((type) & 0x1f) << 10) | ((offset) << 15) })
#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
/* We borrow bit 7 to store the exclusive marker in swap PTEs. */
#define _PAGE_SWP_EXCLUSIVE (1 << 7)
#else
#if defined(CONFIG_XPA)
/*
* Format of swap PTEs:
*
* 6 6 6 6 5 5 5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3 3 3
* 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2
* 0 0 0 0 0 0 E P <------------------ zeroes ------------------->
*
* 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
* 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
* <----------------- offset ------------------> < type -> V G 0 0
*
* E is the exclusive marker that is not stored in swap entries.
* _PAGE_PRESENT (P), _PAGE_VALID (V) and_PAGE_GLOBAL (G) have to remain
* unused.
*/
#define __swp_type(x) (((x).val >> 4) & 0x1f)
#define __swp_offset(x) ((x).val >> 9)
#define __swp_entry(type, offset) ((swp_entry_t) { (((type) & 0x1f) << 4) | ((offset) << 9) })
#define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_high })
#define __swp_entry_to_pte(x) ((pte_t) { 0, (x).val })
/*
* We borrow bit 57 (bit 25 in the low PTE) to store the exclusive marker in
* swap PTEs.
*/
#define _PAGE_SWP_EXCLUSIVE (1 << 25)
#elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
/*
* Format of swap PTEs:
*
* 6 6 6 6 5 5 5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3 3 3
* 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2
* <------------------ zeroes -------------------> E P 0 0 0 0 0 0
*
* 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
* 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
* <------------------- offset --------------------> < type -> V G
*
* E is the exclusive marker that is not stored in swap entries.
* _PAGE_PRESENT (P), _PAGE_VALID (V) and_PAGE_GLOBAL (G) have to remain
* unused.
*/
#define __swp_type(x) (((x).val >> 2) & 0x1f)
#define __swp_offset(x) ((x).val >> 7)
#define __swp_entry(type, offset) ((swp_entry_t) { (((type) & 0x1f) << 2) | ((offset) << 7) })
#define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_high })
#define __swp_entry_to_pte(x) ((pte_t) { 0, (x).val })
/*
* We borrow bit 39 (bit 7 in the low PTE) to store the exclusive marker in swap
* PTEs.
*/
#define _PAGE_SWP_EXCLUSIVE (1 << 7)
#else
/*
* Format of swap PTEs:
*
* 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
* 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
* <------------- offset --------------> < type -> 0 0 0 0 0 0 E P
*
* E is the exclusive marker that is not stored in swap entries.
* _PAGE_PRESENT (P), _PAGE_VALID (V) and_PAGE_GLOBAL (G) have to remain
* unused. The location of V and G varies.
*/
#define __swp_type(x) (((x).val >> 8) & 0x1f)
#define __swp_offset(x) ((x).val >> 13)
#define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 8) | ((offset) << 13) })
#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
/* We borrow bit 1 to store the exclusive marker in swap PTEs. */
#define _PAGE_SWP_EXCLUSIVE (1 << 1)
#endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */
#endif /* defined(CONFIG_CPU_R3K_TLB) */
#endif /* _ASM_PGTABLE_32_H */
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