cregit-Linux how code gets into the kernel

Release 4.14 arch/unicore32/include/asm/pgtable.h

/*
 * linux/arch/unicore32/include/asm/pgtable.h
 *
 * Code specific to PKUnity SoC and UniCore ISA
 *
 * Copyright (C) 2001-2010 GUAN Xue-tao
 *
 * 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 __UNICORE_PGTABLE_H__

#define __UNICORE_PGTABLE_H__


#define __ARCH_USE_5LEVEL_HACK
#include <asm-generic/pgtable-nopmd.h>
#include <asm/cpu-single.h>

#include <asm/memory.h>
#include <asm/pgtable-hwdef.h>

/*
 * Just any arbitrary offset to the start of the vmalloc VM area: the
 * current 8MB value just means that there will be a 8MB "hole" after the
 * physical memory until the kernel virtual memory starts.  That means that
 * any out-of-bounds memory accesses will hopefully be caught.
 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
 * area for the same reason. ;)
 *
 * Note that platforms may override VMALLOC_START, but they must provide
 * VMALLOC_END.  VMALLOC_END defines the (exclusive) limit of this space,
 * which may not overlap IO space.
 */
#ifndef VMALLOC_START

#define VMALLOC_OFFSET		SZ_8M

#define VMALLOC_START		(((unsigned long)high_memory + VMALLOC_OFFSET) \
                                        & ~(VMALLOC_OFFSET-1))

#define VMALLOC_END		(0xff000000UL)
#endif


#define PTRS_PER_PTE		1024

#define PTRS_PER_PGD		1024

/*
 * PGDIR_SHIFT determines what a third-level page table entry can map
 */

#define PGDIR_SHIFT		22

#ifndef __ASSEMBLY__
extern void __pte_error(const char *file, int line, unsigned long val);
extern void __pgd_error(const char *file, int line, unsigned long val);


#define pte_ERROR(pte)		__pte_error(__FILE__, __LINE__, pte_val(pte))

#define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
#endif /* !__ASSEMBLY__ */


#define PGDIR_SIZE		(1UL << PGDIR_SHIFT)

#define PGDIR_MASK		(~(PGDIR_SIZE-1))

/*
 * This is the lowest virtual address we can permit any user space
 * mapping to be mapped at.  This is particularly important for
 * non-high vector CPUs.
 */

#define FIRST_USER_ADDRESS	PAGE_SIZE


#define FIRST_USER_PGD_NR	1

#define USER_PTRS_PER_PGD	((TASK_SIZE/PGDIR_SIZE) - FIRST_USER_PGD_NR)

/*
 * section address mask and size definitions.
 */

#define SECTION_SHIFT		22

#define SECTION_SIZE		(1UL << SECTION_SHIFT)

#define SECTION_MASK		(~(SECTION_SIZE-1))

#ifndef __ASSEMBLY__

/*
 * The pgprot_* and protection_map entries will be fixed up in runtime
 * to include the cachable bits based on memory policy, as well as any
 * architecture dependent bits.
 */

#define _PTE_DEFAULT		(PTE_PRESENT | PTE_YOUNG | PTE_CACHEABLE)

extern pgprot_t pgprot_user;
extern pgprot_t pgprot_kernel;


#define PAGE_NONE		pgprot_user

#define PAGE_SHARED		__pgprot(pgprot_val(pgprot_user | PTE_READ \
                                                                | PTE_WRITE))

#define PAGE_SHARED_EXEC	__pgprot(pgprot_val(pgprot_user | PTE_READ \
                                                                | PTE_WRITE \
                                                                | PTE_EXEC))

#define PAGE_COPY		__pgprot(pgprot_val(pgprot_user | PTE_READ)

#define PAGE_COPY_EXEC		__pgprot(pgprot_val(pgprot_user | PTE_READ \
                                                                | PTE_EXEC))

#define PAGE_READONLY		__pgprot(pgprot_val(pgprot_user | PTE_READ))

#define PAGE_READONLY_EXEC	__pgprot(pgprot_val(pgprot_user | PTE_READ \
                                                                | PTE_EXEC))

#define PAGE_KERNEL		pgprot_kernel

#define PAGE_KERNEL_EXEC	__pgprot(pgprot_val(pgprot_kernel | PTE_EXEC))


#define __PAGE_NONE		__pgprot(_PTE_DEFAULT)

#define __PAGE_SHARED		__pgprot(_PTE_DEFAULT | PTE_READ \
                                                        | PTE_WRITE)

#define __PAGE_SHARED_EXEC	__pgprot(_PTE_DEFAULT | PTE_READ \
                                                        | PTE_WRITE \
                                                        | PTE_EXEC)

#define __PAGE_COPY		__pgprot(_PTE_DEFAULT | PTE_READ)

#define __PAGE_COPY_EXEC	__pgprot(_PTE_DEFAULT | PTE_READ \
                                                        | PTE_EXEC)

#define __PAGE_READONLY		__pgprot(_PTE_DEFAULT | PTE_READ)

#define __PAGE_READONLY_EXEC	__pgprot(_PTE_DEFAULT | PTE_READ \
                                                        | PTE_EXEC)

#endif /* __ASSEMBLY__ */

/*
 * The table below defines the page protection levels that we insert into our
 * Linux page table version.  These get translated into the best that the
 * architecture can perform.  Note that on UniCore hardware:
 *  1) We cannot do execute protection
 *  2) If we could do execute protection, then read is implied
 *  3) write implies read permissions
 */

#define __P000  __PAGE_NONE

#define __P001  __PAGE_READONLY

#define __P010  __PAGE_COPY

#define __P011  __PAGE_COPY

#define __P100  __PAGE_READONLY_EXEC

#define __P101  __PAGE_READONLY_EXEC

#define __P110  __PAGE_COPY_EXEC

#define __P111  __PAGE_COPY_EXEC


#define __S000  __PAGE_NONE

#define __S001  __PAGE_READONLY

#define __S010  __PAGE_SHARED

#define __S011  __PAGE_SHARED

#define __S100  __PAGE_READONLY_EXEC

#define __S101  __PAGE_READONLY_EXEC

#define __S110  __PAGE_SHARED_EXEC

#define __S111  __PAGE_SHARED_EXEC

#ifndef __ASSEMBLY__
/*
 * ZERO_PAGE is a global shared page that is always zero: used
 * for zero-mapped memory areas etc..
 */
extern struct page *empty_zero_page;

#define ZERO_PAGE(vaddr)		(empty_zero_page)


#define pte_pfn(pte)			(pte_val(pte) >> PAGE_SHIFT)

#define pfn_pte(pfn, prot)		(__pte(((pfn) << PAGE_SHIFT) \
                                                | pgprot_val(prot)))


#define pte_none(pte)			(!pte_val(pte))

#define pte_clear(mm, addr, ptep)	set_pte(ptep, __pte(0))

#define pte_page(pte)			(pfn_to_page(pte_pfn(pte)))

#define pte_offset_kernel(dir, addr)	(pmd_page_vaddr(*(dir)) \
                                                + __pte_index(addr))


#define pte_offset_map(dir, addr)	(pmd_page_vaddr(*(dir)) \
                                                + __pte_index(addr))

#define pte_unmap(pte)			do { } while (0)


#define set_pte(ptep, pte)	cpu_set_pte(ptep, pte)


#define set_pte_at(mm, addr, ptep, pteval)	\
	do {                                    \
                set_pte(ptep, pteval);          \
        } while (0)

/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */

#define pte_present(pte)	(pte_val(pte) & PTE_PRESENT)

#define pte_write(pte)		(pte_val(pte) & PTE_WRITE)

#define pte_dirty(pte)		(pte_val(pte) & PTE_DIRTY)

#define pte_young(pte)		(pte_val(pte) & PTE_YOUNG)

#define pte_exec(pte)		(pte_val(pte) & PTE_EXEC)

#define pte_special(pte)	(0)


#define PTE_BIT_FUNC(fn, op) \
static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }

PTE_BIT_FUNC(wrprotect, &= ~PTE_WRITE);
PTE_BIT_FUNC(mkwrite,   |= PTE_WRITE);
PTE_BIT_FUNC(mkclean,   &= ~PTE_DIRTY);
PTE_BIT_FUNC(mkdirty,   |= PTE_DIRTY);
PTE_BIT_FUNC(mkold,     &= ~PTE_YOUNG);
PTE_BIT_FUNC(mkyoung,   |= PTE_YOUNG);


static inline pte_t pte_mkspecial(pte_t pte) { return pte; }

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/* * Mark the prot value as uncacheable. */ #define pgprot_noncached(prot) \ __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE) #define pgprot_writecombine(prot) \ __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE) #define pgprot_dmacoherent(prot) \ __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE) #define pmd_none(pmd) (!pmd_val(pmd)) #define pmd_present(pmd) (pmd_val(pmd) & PMD_PRESENT) #define pmd_bad(pmd) (((pmd_val(pmd) & \ (PMD_PRESENT | PMD_TYPE_MASK)) \ != (PMD_PRESENT | PMD_TYPE_TABLE))) #define set_pmd(pmdpd, pmdval) \ do { \ *(pmdpd) = pmdval; \ } while (0) #define pmd_clear(pmdp) \ do { \ set_pmd(pmdp, __pmd(0));\ clean_pmd_entry(pmdp); \ } while (0) #define pmd_page_vaddr(pmd) ((pte_t *)__va(pmd_val(pmd) & PAGE_MASK)) #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd))) /* * Conversion functions: convert a page and protection to a page entry, * and a page entry and page directory to the page they refer to. */ #define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot) /* to find an entry in a page-table-directory */ #define pgd_index(addr) ((addr) >> PGDIR_SHIFT) #define pgd_offset(mm, addr) ((mm)->pgd+pgd_index(addr)) /* to find an entry in a kernel page-table-directory */ #define pgd_offset_k(addr) pgd_offset(&init_mm, addr) /* Find an entry in the third-level page table.. */ #define __pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { const unsigned long mask = PTE_EXEC | PTE_WRITE | PTE_READ; pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask); return pte; }

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extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* * Encode and decode a swap entry. Swap entries are stored in the Linux * page tables as follows: * * 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 * * This gives us up to 127 swap files and 32GB per swap file. Note that * the offset field is always non-zero. */ #define __SWP_TYPE_SHIFT 5 #define __SWP_TYPE_BITS 7 #define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1) #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT) #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) \ & __SWP_TYPE_MASK) #define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT) #define __swp_entry(type, offset) ((swp_entry_t) { \ ((type) << __SWP_TYPE_SHIFT) | \ ((offset) << __SWP_OFFSET_SHIFT) }) #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val }) /* * It is an error for the kernel to have more swap files than we can * encode in the PTEs. This ensures that we know when MAX_SWAPFILES * is increased beyond what we presently support. */ #define MAX_SWAPFILES_CHECK() \ BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */ /* FIXME: this is not correct */ #define kern_addr_valid(addr) (1) #include <asm-generic/pgtable.h> #define pgtable_cache_init() do { } while (0) #endif /* !__ASSEMBLY__ */ #endif /* __UNICORE_PGTABLE_H__ */

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Guan Xuetao76798.97%133.33%
Chen Gang S50.65%133.33%
Kirill A. Shutemov30.39%133.33%
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