| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318 | #ifndef _ALPHA_PGTABLE_H#define _ALPHA_PGTABLE_H#include <asm-generic/4level-fixup.h>/* * This file contains the functions and defines necessary to modify and use * the Alpha page table tree. * * This hopefully works with any standard Alpha page-size, as defined * in <asm/page.h> (currently 8192). */#include <linux/mmzone.h>#include <asm/page.h>#include <asm/processor.h>	/* For TASK_SIZE */#include <asm/machvec.h>#include <asm/setup.h>struct mm_struct;struct vm_area_struct;/* Certain architectures need to do special things when PTEs * within a page table are directly modified.  Thus, the following * hook is made available. */#define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval))#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)/* PMD_SHIFT determines the size of the area a second-level page table can map */#define PMD_SHIFT	(PAGE_SHIFT + (PAGE_SHIFT-3))#define PMD_SIZE	(1UL << PMD_SHIFT)#define PMD_MASK	(~(PMD_SIZE-1))/* PGDIR_SHIFT determines what a third-level page table entry can map */#define PGDIR_SHIFT	(PAGE_SHIFT + 2*(PAGE_SHIFT-3))#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)#define PGDIR_MASK	(~(PGDIR_SIZE-1))/* * Entries per page directory level:  the Alpha is three-level, with * all levels having a one-page page table. */#define PTRS_PER_PTE	(1UL << (PAGE_SHIFT-3))#define PTRS_PER_PMD	(1UL << (PAGE_SHIFT-3))#define PTRS_PER_PGD	(1UL << (PAGE_SHIFT-3))#define USER_PTRS_PER_PGD	(TASK_SIZE / PGDIR_SIZE)#define FIRST_USER_ADDRESS	0/* Number of pointers that fit on a page:  this will go away. */#define PTRS_PER_PAGE	(1UL << (PAGE_SHIFT-3))#ifdef CONFIG_ALPHA_LARGE_VMALLOC#define VMALLOC_START		0xfffffe0000000000#else#define VMALLOC_START		(-2*PGDIR_SIZE)#endif#define VMALLOC_END		(-PGDIR_SIZE)/* * OSF/1 PAL-code-imposed page table bits */#define _PAGE_VALID	0x0001#define _PAGE_FOR	0x0002	/* used for page protection (fault on read) */#define _PAGE_FOW	0x0004	/* used for page protection (fault on write) */#define _PAGE_FOE	0x0008	/* used for page protection (fault on exec) */#define _PAGE_ASM	0x0010#define _PAGE_KRE	0x0100	/* xxx - see below on the "accessed" bit */#define _PAGE_URE	0x0200	/* xxx */#define _PAGE_KWE	0x1000	/* used to do the dirty bit in software */#define _PAGE_UWE	0x2000	/* used to do the dirty bit in software *//* .. and these are ours ... */#define _PAGE_DIRTY	0x20000#define _PAGE_ACCESSED	0x40000#define _PAGE_FILE	0x80000	/* set:pagecache, unset:swap *//* * NOTE! The "accessed" bit isn't necessarily exact:  it can be kept exactly * by software (use the KRE/URE/KWE/UWE bits appropriately), but I'll fake it. * Under Linux/AXP, the "accessed" bit just means "read", and I'll just use * the KRE/URE bits to watch for it. That way we don't need to overload the * KWE/UWE bits with both handling dirty and accessed. * * Note that the kernel uses the accessed bit just to check whether to page * out a page or not, so it doesn't have to be exact anyway. */#define __DIRTY_BITS	(_PAGE_DIRTY | _PAGE_KWE | _PAGE_UWE)#define __ACCESS_BITS	(_PAGE_ACCESSED | _PAGE_KRE | _PAGE_URE)#define _PFN_MASK	0xFFFFFFFF00000000UL#define _PAGE_TABLE	(_PAGE_VALID | __DIRTY_BITS | __ACCESS_BITS)#define _PAGE_CHG_MASK	(_PFN_MASK | __DIRTY_BITS | __ACCESS_BITS)/* * All the normal masks have the "page accessed" bits on, as any time they are used, * the page is accessed. They are cleared only by the page-out routines */#define PAGE_NONE	__pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOR | _PAGE_FOW | _PAGE_FOE)#define PAGE_SHARED	__pgprot(_PAGE_VALID | __ACCESS_BITS)#define PAGE_COPY	__pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOW)#define PAGE_READONLY	__pgprot(_PAGE_VALID | __ACCESS_BITS | _PAGE_FOW)#define PAGE_KERNEL	__pgprot(_PAGE_VALID | _PAGE_ASM | _PAGE_KRE | _PAGE_KWE)#define _PAGE_NORMAL(x) __pgprot(_PAGE_VALID | __ACCESS_BITS | (x))#define _PAGE_P(x) _PAGE_NORMAL((x) | (((x) & _PAGE_FOW)?0:_PAGE_FOW))#define _PAGE_S(x) _PAGE_NORMAL(x)/* * The hardware can handle write-only mappings, but as the Alpha * architecture does byte-wide writes with a read-modify-write * sequence, it's not practical to have write-without-read privs. * Thus the "-w- -> rw-" and "-wx -> rwx" mapping here (and in * arch/alpha/mm/fault.c) */	/* xwr */#define __P000	_PAGE_P(_PAGE_FOE | _PAGE_FOW | _PAGE_FOR)#define __P001	_PAGE_P(_PAGE_FOE | _PAGE_FOW)#define __P010	_PAGE_P(_PAGE_FOE)#define __P011	_PAGE_P(_PAGE_FOE)#define __P100	_PAGE_P(_PAGE_FOW | _PAGE_FOR)#define __P101	_PAGE_P(_PAGE_FOW)#define __P110	_PAGE_P(0)#define __P111	_PAGE_P(0)#define __S000	_PAGE_S(_PAGE_FOE | _PAGE_FOW | _PAGE_FOR)#define __S001	_PAGE_S(_PAGE_FOE | _PAGE_FOW)#define __S010	_PAGE_S(_PAGE_FOE)#define __S011	_PAGE_S(_PAGE_FOE)#define __S100	_PAGE_S(_PAGE_FOW | _PAGE_FOR)#define __S101	_PAGE_S(_PAGE_FOW)#define __S110	_PAGE_S(0)#define __S111	_PAGE_S(0)/* * pgprot_noncached() is only for infiniband pci support, and a real * implementation for RAM would be more complicated. */#define pgprot_noncached(prot)	(prot)/* * BAD_PAGETABLE is used when we need a bogus page-table, while * BAD_PAGE is used for a bogus page. * * ZERO_PAGE is a global shared page that is always zero:  used * for zero-mapped memory areas etc.. */extern pte_t __bad_page(void);extern pmd_t * __bad_pagetable(void);extern unsigned long __zero_page(void);#define BAD_PAGETABLE	__bad_pagetable()#define BAD_PAGE	__bad_page()#define ZERO_PAGE(vaddr)	(virt_to_page(ZERO_PGE))/* number of bits that fit into a memory pointer */#define BITS_PER_PTR			(8*sizeof(unsigned long))/* to align the pointer to a pointer address */#define PTR_MASK			(~(sizeof(void*)-1))/* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */#define SIZEOF_PTR_LOG2			3/* to find an entry in a page-table */#define PAGE_PTR(address)		\  ((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK)/* * On certain platforms whose physical address space can overlap KSEG, * namely EV6 and above, we must re-twiddle the physaddr to restore the * correct high-order bits. * * This is extremely confusing until you realize that this is actually * just working around a userspace bug.  The X server was intending to * provide the physical address but instead provided the KSEG address. * Or tried to, except it's not representable. *  * On Tsunami there's nothing meaningful at 0x40000000000, so this is * a safe thing to do.  Come the first core logic that does put something * in this area -- memory or whathaveyou -- then this hack will have * to go away.  So be prepared! */#if defined(CONFIG_ALPHA_GENERIC) && defined(USE_48_BIT_KSEG)#error "EV6-only feature in a generic kernel"#endif#if defined(CONFIG_ALPHA_GENERIC) || \    (defined(CONFIG_ALPHA_EV6) && !defined(USE_48_BIT_KSEG))#define KSEG_PFN	(0xc0000000000UL >> PAGE_SHIFT)#define PHYS_TWIDDLE(pfn) \  ((((pfn) & KSEG_PFN) == (0x40000000000UL >> PAGE_SHIFT)) \  ? ((pfn) ^= KSEG_PFN) : (pfn))#else#define PHYS_TWIDDLE(pfn) (pfn)#endif/* * Conversion functions:  convert a page and protection to a page entry, * and a page entry and page directory to the page they refer to. */#ifndef CONFIG_DISCONTIGMEM#define page_to_pa(page)	(((page) - mem_map) << PAGE_SHIFT)#define pte_pfn(pte)	(pte_val(pte) >> 32)#define pte_page(pte)	pfn_to_page(pte_pfn(pte))#define mk_pte(page, pgprot)						\({									\	pte_t pte;							\									\	pte_val(pte) = (page_to_pfn(page) << 32) | pgprot_val(pgprot);	\	pte;								\})#endifextern inline pte_t pfn_pte(unsigned long physpfn, pgprot_t pgprot){ pte_t pte; pte_val(pte) = (PHYS_TWIDDLE(physpfn) << 32) | pgprot_val(pgprot); return pte; }extern inline pte_t pte_modify(pte_t pte, pgprot_t newprot){ pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; }extern inline void pmd_set(pmd_t * pmdp, pte_t * ptep){ pmd_val(*pmdp) = _PAGE_TABLE | ((((unsigned long) ptep) - PAGE_OFFSET) << (32-PAGE_SHIFT)); }extern inline void pgd_set(pgd_t * pgdp, pmd_t * pmdp){ pgd_val(*pgdp) = _PAGE_TABLE | ((((unsigned long) pmdp) - PAGE_OFFSET) << (32-PAGE_SHIFT)); }extern inline unsigned longpmd_page_vaddr(pmd_t pmd){	return ((pmd_val(pmd) & _PFN_MASK) >> (32-PAGE_SHIFT)) + PAGE_OFFSET;}#ifndef CONFIG_DISCONTIGMEM#define pmd_page(pmd)	(mem_map + ((pmd_val(pmd) & _PFN_MASK) >> 32))#define pgd_page(pgd)	(mem_map + ((pgd_val(pgd) & _PFN_MASK) >> 32))#endifextern inline unsigned long pgd_page_vaddr(pgd_t pgd){ return PAGE_OFFSET + ((pgd_val(pgd) & _PFN_MASK) >> (32-PAGE_SHIFT)); }extern inline int pte_none(pte_t pte)		{ return !pte_val(pte); }extern inline int pte_present(pte_t pte)	{ return pte_val(pte) & _PAGE_VALID; }extern inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep){	pte_val(*ptep) = 0;}extern inline int pmd_none(pmd_t pmd)		{ return !pmd_val(pmd); }extern inline int pmd_bad(pmd_t pmd)		{ return (pmd_val(pmd) & ~_PFN_MASK) != _PAGE_TABLE; }extern inline int pmd_present(pmd_t pmd)	{ return pmd_val(pmd) & _PAGE_VALID; }extern inline void pmd_clear(pmd_t * pmdp)	{ pmd_val(*pmdp) = 0; }extern inline int pgd_none(pgd_t pgd)		{ return !pgd_val(pgd); }extern inline int pgd_bad(pgd_t pgd)		{ return (pgd_val(pgd) & ~_PFN_MASK) != _PAGE_TABLE; }extern inline int pgd_present(pgd_t pgd)	{ return pgd_val(pgd) & _PAGE_VALID; }extern inline void pgd_clear(pgd_t * pgdp)	{ pgd_val(*pgdp) = 0; }/* * The following only work if pte_present() is true. * Undefined behaviour if not.. */extern inline int pte_write(pte_t pte)		{ return !(pte_val(pte) & _PAGE_FOW); }extern inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }extern inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }extern inline int pte_file(pte_t pte)		{ return pte_val(pte) & _PAGE_FILE; }extern inline int pte_special(pte_t pte)	{ return 0; }extern inline pte_t pte_wrprotect(pte_t pte)	{ pte_val(pte) |= _PAGE_FOW; return pte; }extern inline pte_t pte_mkclean(pte_t pte)	{ pte_val(pte) &= ~(__DIRTY_BITS); return pte; }extern inline pte_t pte_mkold(pte_t pte)	{ pte_val(pte) &= ~(__ACCESS_BITS); return pte; }extern inline pte_t pte_mkwrite(pte_t pte)	{ pte_val(pte) &= ~_PAGE_FOW; return pte; }extern inline pte_t pte_mkdirty(pte_t pte)	{ pte_val(pte) |= __DIRTY_BITS; return pte; }extern inline pte_t pte_mkyoung(pte_t pte)	{ pte_val(pte) |= __ACCESS_BITS; return pte; }extern inline pte_t pte_mkspecial(pte_t pte)	{ return pte; }#define PAGE_DIR_OFFSET(tsk,address) pgd_offset((tsk),(address))/* to find an entry in a kernel page-table-directory */#define pgd_offset_k(address) pgd_offset(&init_mm, (address))/* to find an entry in a page-table-directory. */#define pgd_index(address)	(((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))#define pgd_offset(mm, address)	((mm)->pgd+pgd_index(address))/* * The smp_read_barrier_depends() in the following functions are required to * order the load of *dir (the pointer in the top level page table) with any * subsequent load of the returned pmd_t *ret (ret is data dependent on *dir). * * If this ordering is not enforced, the CPU might load an older value of * *ret, which may be uninitialized data. See mm/memory.c:__pte_alloc for * more details. * * Note that we never change the mm->pgd pointer after the task is running, so * pgd_offset does not require such a barrier. *//* Find an entry in the second-level page table.. */extern inline pmd_t * pmd_offset(pgd_t * dir, unsigned long address){	pmd_t *ret = (pmd_t *) pgd_page_vaddr(*dir) + ((address >> PMD_SHIFT) & (PTRS_PER_PAGE - 1));	smp_read_barrier_depends(); /* see above */	return ret;}/* Find an entry in the third-level page table.. */extern inline pte_t * pte_offset_kernel(pmd_t * dir, unsigned long address){	pte_t *ret = (pte_t *) pmd_page_vaddr(*dir)		+ ((address >> PAGE_SHIFT) & (PTRS_PER_PAGE - 1));	smp_read_barrier_depends(); /* see above */	return ret;
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