LXR linux-bk/include/asm-parisc/pgalloc.h

   1#ifndef _ASM_PGALLOC_H
   2#define _ASM_PGALLOC_H
   3
   4#include <linux/gfp.h>
   5#include <linux/mm.h>
   6#include <linux/threads.h>
   7#include <asm/processor.h>
   8#include <asm/fixmap.h>
   9
  10#include <asm/pgtable.h>
  11#include <asm/cache.h>
  12
  13/* Allocate the top level pgd (page directory)
  14 *
  15 * Here (for 64 bit kernels) we implement a Hybrid L2/L3 scheme: we
  16 * allocate the first pmd adjacent to the pgd.  This means that we can
  17 * subtract a constant offset to get to it.  The pmd and pgd sizes are
  18 * arranged so that a single pmd covers 4GB (giving a full LP64
  19 * process access to 8TB) so our lookups are effectively L2 for the
  20 * first 4GB of the kernel (i.e. for all ILP32 processes and all the
  21 * kernel for machines with under 4GB of memory) */
  22static inline pgd_t *pgd_alloc(struct mm_struct *mm)
  23{
  24        pgd_t *pgd = (pgd_t *)__get_free_pages(GFP_KERNEL,
  25                                               PGD_ALLOC_ORDER);
  26        pgd_t *actual_pgd = pgd;
  27
  28        if (likely(pgd != NULL)) {
  29                memset(pgd, 0, PAGE_SIZE<<PGD_ALLOC_ORDER);
  30#ifdef __LP64__
  31                actual_pgd += PTRS_PER_PGD;
  32                /* Populate first pmd with allocated memory.  We mark it
  33                 * with PxD_FLAG_ATTACHED as a signal to the system that this
  34                 * pmd entry may not be cleared. */
  35                __pgd_val_set(*actual_pgd, (PxD_FLAG_PRESENT | 
  36                                        PxD_FLAG_VALID | 
  37                                        PxD_FLAG_ATTACHED) 
  38                        + (__u32)(__pa((unsigned long)pgd) >> PxD_VALUE_SHIFT));
  39                /* The first pmd entry also is marked with _PAGE_GATEWAY as
  40                 * a signal that this pmd may not be freed */
  41                __pgd_val_set(*pgd, PxD_FLAG_ATTACHED);
  42#endif
  43        }
  44        return actual_pgd;
  45}
  46
  47static inline void pgd_free(pgd_t *pgd)
  48{
  49#ifdef __LP64__
  50        pgd -= PTRS_PER_PGD;
  51#endif
  52        free_pages((unsigned long)pgd, PGD_ALLOC_ORDER);
  53}
  54
  55#if PT_NLEVELS == 3
  56
  57/* Three Level Page Table Support for pmd's */
  58
  59static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmd)
  60{
  61        __pgd_val_set(*pgd, (PxD_FLAG_PRESENT | PxD_FLAG_VALID) +
  62                        (__u32)(__pa((unsigned long)pmd) >> PxD_VALUE_SHIFT));
  63}
  64
  65static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
  66{
  67        pmd_t *pmd = (pmd_t *)__get_free_pages(GFP_KERNEL|__GFP_REPEAT,
  68                                               PMD_ORDER);
  69        if (pmd)
  70                memset(pmd, 0, PAGE_SIZE<<PMD_ORDER);
  71        return pmd;
  72}
  73
  74static inline void pmd_free(pmd_t *pmd)
  75{
  76#ifdef __LP64__
  77        if(pmd_flag(*pmd) & PxD_FLAG_ATTACHED)
  78                /* This is the permanent pmd attached to the pgd;
  79                 * cannot free it */
  80                return;
  81#endif
  82        free_pages((unsigned long)pmd, PMD_ORDER);
  83}
  84
  85#else
  86
  87/* Two Level Page Table Support for pmd's */
  88
  89/*
  90 * allocating and freeing a pmd is trivial: the 1-entry pmd is
  91 * inside the pgd, so has no extra memory associated with it.
  92 */
  93
  94#define pmd_alloc_one(mm, addr)         ({ BUG(); ((pmd_t *)2); })
  95#define pmd_free(x)                     do { } while (0)
  96#define pgd_populate(mm, pmd, pte)      BUG()
  97
  98#endif
  99
 100static inline void
 101pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
 102{
 103#ifdef __LP64__
 104        /* preserve the gateway marker if this is the beginning of
 105         * the permanent pmd */
 106        if(pmd_flag(*pmd) & PxD_FLAG_ATTACHED)
 107                __pmd_val_set(*pmd, (PxD_FLAG_PRESENT |
 108                                 PxD_FLAG_VALID |
 109                                 PxD_FLAG_ATTACHED) 
 110                        + (__u32)(__pa((unsigned long)pte) >> PxD_VALUE_SHIFT));
 111        else
 112#endif
 113                __pmd_val_set(*pmd, (PxD_FLAG_PRESENT | PxD_FLAG_VALID) 
 114                        + (__u32)(__pa((unsigned long)pte) >> PxD_VALUE_SHIFT));
 115}
 116
 117#define pmd_populate(mm, pmd, pte_page) \
 118        pmd_populate_kernel(mm, pmd, page_address(pte_page))
 119
 120static inline struct page *
 121pte_alloc_one(struct mm_struct *mm, unsigned long address)
 122{
 123        struct page *page = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 124        return page;
 125}
 126
 127static inline pte_t *
 128pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr)
 129{
 130        pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 131        return pte;
 132}
 133
 134static inline void pte_free_kernel(pte_t *pte)
 135{
 136        free_page((unsigned long)pte);
 137}
 138
 139#define pte_free(page)  pte_free_kernel(page_address(page))
 140
 141extern int do_check_pgt_cache(int, int);
 142#define check_pgt_cache()       do { } while (0)
 143
 144#endif
 145