text: /* SPDX-License-Identifier: GPL-2.0 */
  #ifndef _PARISC_PAGE_H
  #define _PARISC_PAGE_H
  
  #include <linux/const.h>
  
  #if defined(CONFIG_PARISC_PAGE_SIZE_4KB)
  # define PAGE_SHIFT	12
  #elif defined(CONFIG_PARISC_PAGE_SIZE_16KB)
  # define PAGE_SHIFT	14
  #elif defined(CONFIG_PARISC_PAGE_SIZE_64KB)
  # define PAGE_SHIFT	16
  #else
  # error "unknown default kernel page size"
  #endif
  #define PAGE_SIZE	(_AC(1,UL) << PAGE_SHIFT)
  #define PAGE_MASK	(~(PAGE_SIZE-1))
  
  
  #ifndef __ASSEMBLY__
  
  #include <asm/types.h>
  #include <asm/cache.h>
  
  #define clear_page(page)	clear_page_asm((void *)(page))
  #define copy_page(to, from)	copy_page_asm((void *)(to), (void *)(from))
  
  struct page;
  
  void clear_page_asm(void *page);
  void copy_page_asm(void *to, void *from);
  #define clear_user_page(vto, vaddr, page) clear_page_asm(vto)
  void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
  			struct page *pg);
  
  /*
   * These are used to make use of C type-checking..
   */
  #define STRICT_MM_TYPECHECKS
  #ifdef STRICT_MM_TYPECHECKS
  typedef struct { unsigned long pte; } pte_t; /* either 32 or 64bit */
  
  /* NOTE: even on 64 bits, these entries are __u32 because we allocate
   * the pmd and pgd in ZONE_DMA (i.e. under 4GB) */
  typedef struct { __u32 pmd; } pmd_t;
  typedef struct { __u32 pgd; } pgd_t;
  typedef struct { unsigned long pgprot; } pgprot_t;
  
  #define pte_val(x)	((x).pte)
  /* These do not work lvalues, so make sure we don't use them as such. */
  #define pmd_val(x)	((x).pmd + 0)
  #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 __pgd(x)	((pgd_t) { (x) } )
  #define __pgprot(x)	((pgprot_t) { (x) } )
  
  #define __pmd_val_set(x,n) (x).pmd = (n)
  #define __pgd_val_set(x,n) (x).pgd = (n)
  
  #else
  /*
   * .. while these make it easier on the compiler
   */
  typedef unsigned long pte_t;
  typedef         __u32 pmd_t;
  typedef         __u32 pgd_t;
  typedef unsigned long pgprot_t;
  
  #define pte_val(x)      (x)
  #define pmd_val(x)      (x)
  #define pgd_val(x)      (x)
  #define pgprot_val(x)   (x)
  
  #define __pte(x)        (x)
  #define __pmd(x)	(x)
  #define __pgd(x)        (x)
  #define __pgprot(x)     (x)
  
  #define __pmd_val_set(x,n) (x) = (n)
  #define __pgd_val_set(x,n) (x) = (n)
  
  #endif /* STRICT_MM_TYPECHECKS */
  
  typedef struct page *pgtable_t;
  
  typedef struct __physmem_range {
  	unsigned long start_pfn;
  	unsigned long pages;       /* PAGE_SIZE pages */
  } physmem_range_t;
  
  extern physmem_range_t pmem_ranges[];
  extern int npmem_ranges;
  
  #endif /* !__ASSEMBLY__ */
  
  /* WARNING: The definitions below must match exactly to sizeof(pte_t)
   * etc
   */
  #ifdef CONFIG_64BIT
  #define BITS_PER_PTE_ENTRY	3
  #define BITS_PER_PMD_ENTRY	2
  #define BITS_PER_PGD_ENTRY	2
  #else
  #define BITS_PER_PTE_ENTRY	2
  #define BITS_PER_PMD_ENTRY	2
  #define BITS_PER_PGD_ENTRY	BITS_PER_PMD_ENTRY
  #endif
  #define PGD_ENTRY_SIZE	(1UL << BITS_PER_PGD_ENTRY)
  #define PMD_ENTRY_SIZE	(1UL << BITS_PER_PMD_ENTRY)
  #define PTE_ENTRY_SIZE	(1UL << BITS_PER_PTE_ENTRY)
  
  #define LINUX_GATEWAY_SPACE     0
  
  /* This governs the relationship between virtual and physical addresses.
   * If you alter it, make sure to take care of our various fixed mapping
   * segments in fixmap.h */
  #ifdef CONFIG_64BIT
  #define __PAGE_OFFSET_DEFAULT	(0x40000000)	/* 1GB */
  #else
  #define __PAGE_OFFSET_DEFAULT	(0x10000000)	/* 256MB */
  #endif
  
  #if defined(BOOTLOADER)
  #define __PAGE_OFFSET	(0)	/* bootloader uses physical addresses */
  #else
  #define __PAGE_OFFSET	__PAGE_OFFSET_DEFAULT
  #endif /* BOOTLOADER */
  
  #define PAGE_OFFSET		((unsigned long)__PAGE_OFFSET)
  
  /* The size of the gateway page (we leave lots of room for expansion) */
  #define GATEWAY_PAGE_SIZE	0x4000
  
  /* The start of the actual kernel binary---used in vmlinux.lds.S
   * Leave some space after __PAGE_OFFSET for detecting kernel null
   * ptr derefs */
  #define KERNEL_BINARY_TEXT_START	(__PAGE_OFFSET + 0x100000)
  
  /* These macros don't work for 64-bit C code -- don't allow in C at all */
  #ifdef __ASSEMBLY__
  #   define PA(x)	((x)-__PAGE_OFFSET)
  #   define VA(x)	((x)+__PAGE_OFFSET)
  #endif
  #define __pa(x)			((unsigned long)(x)-PAGE_OFFSET)
  #define __va(x)			((void *)((unsigned long)(x)+PAGE_OFFSET))
  
  #ifndef CONFIG_DISCONTIGMEM
  #define pfn_valid(pfn)		((pfn) < max_mapnr)
  #endif /* CONFIG_DISCONTIGMEM */
  
  #ifdef CONFIG_HUGETLB_PAGE
  #define HPAGE_SHIFT		PMD_SHIFT /* fixed for transparent huge pages */
  #define HPAGE_SIZE      	((1UL) << HPAGE_SHIFT)
  #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
  #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
  
  #if defined(CONFIG_64BIT) && defined(CONFIG_PARISC_PAGE_SIZE_4KB)
  # define REAL_HPAGE_SHIFT	20 /* 20 = 1MB */
  # define _HUGE_PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_1M
  #elif !defined(CONFIG_64BIT) && defined(CONFIG_PARISC_PAGE_SIZE_4KB)
  # define REAL_HPAGE_SHIFT	22 /* 22 = 4MB */
  # define _HUGE_PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_4M
  #else
  # define REAL_HPAGE_SHIFT	24 /* 24 = 16MB */
  # define _HUGE_PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_16M
  #endif
  #endif /* CONFIG_HUGETLB_PAGE */
  
  #define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
  
  #define page_to_phys(page)	(page_to_pfn(page) << PAGE_SHIFT)
  #define virt_to_page(kaddr)     pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
  
  #define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
  				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
  
  #include <asm-generic/memory_model.h>
  #include <asm-generic/getorder.h>
  #include <asm/pdc.h>
  
  #define PAGE0   ((struct zeropage *)__PAGE_OFFSET)
  
  /* DEFINITION OF THE ZERO-PAGE (PAG0) */
  /* based on work by Jason Eckhardt (jason@equator.com) */
  
  #endif /* _PARISC_PAGE_H */
  