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hugetlbpage.c

/*
 * PPC64 (POWER4) Huge TLB Page Support for Kernel.
 *
 * Copyright (C) 2003 David Gibson, IBM Corporation.
 *
 * Based on the IA-32 version:
 * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
 */

#include <linux/init.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/sysctl.h>
#include <asm/mman.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
#include <asm/machdep.h>
#include <asm/cputable.h>
#include <asm/spu.h>

#define PAGE_SHIFT_64K  16
#define PAGE_SHIFT_16M  24
#define PAGE_SHIFT_16G  34

#define NUM_LOW_AREAS   (0x100000000UL >> SID_SHIFT)
#define NUM_HIGH_AREAS  (PGTABLE_RANGE >> HTLB_AREA_SHIFT)
#define MAX_NUMBER_GPAGES     1024

/* Tracks the 16G pages after the device tree is scanned and before the
 * huge_boot_pages list is ready.  */
static unsigned long gpage_freearray[MAX_NUMBER_GPAGES];
static unsigned nr_gpages;

/* Array of valid huge page sizes - non-zero value(hugepte_shift) is
 * stored for the huge page sizes that are valid.
 */
unsigned int mmu_huge_psizes[MMU_PAGE_COUNT] = { }; /* initialize all to 0 */

#define hugepte_shift               mmu_huge_psizes
#define PTRS_PER_HUGEPTE(psize)           (1 << hugepte_shift[psize])
#define HUGEPTE_TABLE_SIZE(psize)   (sizeof(pte_t) << hugepte_shift[psize])

#define HUGEPD_SHIFT(psize)         (mmu_psize_to_shift(psize) \
                                    + hugepte_shift[psize])
#define HUGEPD_SIZE(psize)          (1UL << HUGEPD_SHIFT(psize))
#define HUGEPD_MASK(psize)          (~(HUGEPD_SIZE(psize)-1))

/* Subtract one from array size because we don't need a cache for 4K since
 * is not a huge page size */
#define huge_pgtable_cache(psize)   (pgtable_cache[HUGEPTE_CACHE_NUM \
                                          + psize-1])
#define HUGEPTE_CACHE_NAME(psize)   (huge_pgtable_cache_name[psize])

static const char *huge_pgtable_cache_name[MMU_PAGE_COUNT] = {
      "unused_4K", "hugepte_cache_64K", "unused_64K_AP",
      "hugepte_cache_1M", "hugepte_cache_16M", "hugepte_cache_16G"
};

/* Flag to mark huge PD pointers.  This means pmd_bad() and pud_bad()
 * will choke on pointers to hugepte tables, which is handy for
 * catching screwups early. */
#define HUGEPD_OK 0x1

typedef struct { unsigned long pd; } hugepd_t;

#define hugepd_none(hpd)      ((hpd).pd == 0)

static inline int shift_to_mmu_psize(unsigned int shift)
{
      switch (shift) {
#ifndef CONFIG_PPC_64K_PAGES
      case PAGE_SHIFT_64K:
          return MMU_PAGE_64K;
#endif
      case PAGE_SHIFT_16M:
          return MMU_PAGE_16M;
      case PAGE_SHIFT_16G:
          return MMU_PAGE_16G;
      }
      return -1;
}

static inline unsigned int mmu_psize_to_shift(unsigned int mmu_psize)
{
      if (mmu_psize_defs[mmu_psize].shift)
            return mmu_psize_defs[mmu_psize].shift;
      BUG();
}

static inline pte_t *hugepd_page(hugepd_t hpd)
{
      BUG_ON(!(hpd.pd & HUGEPD_OK));
      return (pte_t *)(hpd.pd & ~HUGEPD_OK);
}

static inline pte_t *hugepte_offset(hugepd_t *hpdp, unsigned long addr,
                            struct hstate *hstate)
{
      unsigned int shift = huge_page_shift(hstate);
      int psize = shift_to_mmu_psize(shift);
      unsigned long idx = ((addr >> shift) & (PTRS_PER_HUGEPTE(psize)-1));
      pte_t *dir = hugepd_page(*hpdp);

      return dir + idx;
}

static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
                     unsigned long address, unsigned int psize)
{
      pte_t *new = kmem_cache_zalloc(huge_pgtable_cache(psize),
                              GFP_KERNEL|__GFP_REPEAT);

      if (! new)
            return -ENOMEM;

      spin_lock(&mm->page_table_lock);
      if (!hugepd_none(*hpdp))
            kmem_cache_free(huge_pgtable_cache(psize), new);
      else
            hpdp->pd = (unsigned long)new | HUGEPD_OK;
      spin_unlock(&mm->page_table_lock);
      return 0;
}


static pud_t *hpud_offset(pgd_t *pgd, unsigned long addr, struct hstate *hstate)
{
      if (huge_page_shift(hstate) < PUD_SHIFT)
            return pud_offset(pgd, addr);
      else
            return (pud_t *) pgd;
}
static pud_t *hpud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long addr,
                   struct hstate *hstate)
{
      if (huge_page_shift(hstate) < PUD_SHIFT)
            return pud_alloc(mm, pgd, addr);
      else
            return (pud_t *) pgd;
}
static pmd_t *hpmd_offset(pud_t *pud, unsigned long addr, struct hstate *hstate)
{
      if (huge_page_shift(hstate) < PMD_SHIFT)
            return pmd_offset(pud, addr);
      else
            return (pmd_t *) pud;
}
static pmd_t *hpmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long addr,
                   struct hstate *hstate)
{
      if (huge_page_shift(hstate) < PMD_SHIFT)
            return pmd_alloc(mm, pud, addr);
      else
            return (pmd_t *) pud;
}

/* Build list of addresses of gigantic pages.  This function is used in early
 * boot before the buddy or bootmem allocator is setup.
 */
void add_gpage(unsigned long addr, unsigned long page_size,
      unsigned long number_of_pages)
{
      if (!addr)
            return;
      while (number_of_pages > 0) {
            gpage_freearray[nr_gpages] = addr;
            nr_gpages++;
            number_of_pages--;
            addr += page_size;
      }
}

/* Moves the gigantic page addresses from the temporary list to the
 * huge_boot_pages list.
 */
int alloc_bootmem_huge_page(struct hstate *hstate)
{
      struct huge_bootmem_page *m;
      if (nr_gpages == 0)
            return 0;
      m = phys_to_virt(gpage_freearray[--nr_gpages]);
      gpage_freearray[nr_gpages] = 0;
      list_add(&m->list, &huge_boot_pages);
      m->hstate = hstate;
      return 1;
}


/* Modelled after find_linux_pte() */
pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
      pgd_t *pg;
      pud_t *pu;
      pmd_t *pm;

      unsigned int psize;
      unsigned int shift;
      unsigned long sz;
      struct hstate *hstate;
      psize = get_slice_psize(mm, addr);
      shift = mmu_psize_to_shift(psize);
      sz = ((1UL) << shift);
      hstate = size_to_hstate(sz);

      addr &= hstate->mask;

      pg = pgd_offset(mm, addr);
      if (!pgd_none(*pg)) {
            pu = hpud_offset(pg, addr, hstate);
            if (!pud_none(*pu)) {
                  pm = hpmd_offset(pu, addr, hstate);
                  if (!pmd_none(*pm))
                        return hugepte_offset((hugepd_t *)pm, addr,
                                          hstate);
            }
      }

      return NULL;
}

pte_t *huge_pte_alloc(struct mm_struct *mm,
                  unsigned long addr, unsigned long sz)
{
      pgd_t *pg;
      pud_t *pu;
      pmd_t *pm;
      hugepd_t *hpdp = NULL;
      struct hstate *hstate;
      unsigned int psize;
      hstate = size_to_hstate(sz);

      psize = get_slice_psize(mm, addr);
      BUG_ON(!mmu_huge_psizes[psize]);

      addr &= hstate->mask;

      pg = pgd_offset(mm, addr);
      pu = hpud_alloc(mm, pg, addr, hstate);

      if (pu) {
            pm = hpmd_alloc(mm, pu, addr, hstate);
            if (pm)
                  hpdp = (hugepd_t *)pm;
      }

      if (! hpdp)
            return NULL;

      if (hugepd_none(*hpdp) && __hugepte_alloc(mm, hpdp, addr, psize))
            return NULL;

      return hugepte_offset(hpdp, addr, hstate);
}

int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
{
      return 0;
}

static void free_hugepte_range(struct mmu_gather *tlb, hugepd_t *hpdp,
                         unsigned int psize)
{
      pte_t *hugepte = hugepd_page(*hpdp);

      hpdp->pd = 0;
      tlb->need_flush = 1;
      pgtable_free_tlb(tlb, pgtable_free_cache(hugepte,
                                     HUGEPTE_CACHE_NUM+psize-1,
                                     PGF_CACHENUM_MASK));
}

static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
                           unsigned long addr, unsigned long end,
                           unsigned long floor, unsigned long ceiling,
                           unsigned int psize)
{
      pmd_t *pmd;
      unsigned long next;
      unsigned long start;

      start = addr;
      pmd = pmd_offset(pud, addr);
      do {
            next = pmd_addr_end(addr, end);
            if (pmd_none(*pmd))
                  continue;
            free_hugepte_range(tlb, (hugepd_t *)pmd, psize);
      } while (pmd++, addr = next, addr != end);

      start &= PUD_MASK;
      if (start < floor)
            return;
      if (ceiling) {
            ceiling &= PUD_MASK;
            if (!ceiling)
                  return;
      }
      if (end - 1 > ceiling - 1)
            return;

      pmd = pmd_offset(pud, start);
      pud_clear(pud);
      pmd_free_tlb(tlb, pmd);
}

static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
                           unsigned long addr, unsigned long end,
                           unsigned long floor, unsigned long ceiling)
{
      pud_t *pud;
      unsigned long next;
      unsigned long start;
      unsigned int shift;
      unsigned int psize = get_slice_psize(tlb->mm, addr);
      shift = mmu_psize_to_shift(psize);

      start = addr;
      pud = pud_offset(pgd, addr);
      do {
            next = pud_addr_end(addr, end);
            if (shift < PMD_SHIFT) {
                  if (pud_none_or_clear_bad(pud))
                        continue;
                  hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
                                     ceiling, psize);
            } else {
                  if (pud_none(*pud))
                        continue;
                  free_hugepte_range(tlb, (hugepd_t *)pud, psize);
            }
      } while (pud++, addr = next, addr != end);

      start &= PGDIR_MASK;
      if (start < floor)
            return;
      if (ceiling) {
            ceiling &= PGDIR_MASK;
            if (!ceiling)
                  return;
      }
      if (end - 1 > ceiling - 1)
            return;

      pud = pud_offset(pgd, start);
      pgd_clear(pgd);
      pud_free_tlb(tlb, pud);
}

/*
 * This function frees user-level page tables of a process.
 *
 * Must be called with pagetable lock held.
 */
void hugetlb_free_pgd_range(struct mmu_gather *tlb,
                      unsigned long addr, unsigned long end,
                      unsigned long floor, unsigned long ceiling)
{
      pgd_t *pgd;
      unsigned long next;
      unsigned long start;

      /*
       * Comments below take from the normal free_pgd_range().  They
       * apply here too.  The tests against HUGEPD_MASK below are
       * essential, because we *don't* test for this at the bottom
       * level.  Without them we'll attempt to free a hugepte table
       * when we unmap just part of it, even if there are other
       * active mappings using it.
       *
       * The next few lines have given us lots of grief...
       *
       * Why are we testing HUGEPD* at this top level?  Because
       * often there will be no work to do at all, and we'd prefer
       * not to go all the way down to the bottom just to discover
       * that.
       *
       * Why all these "- 1"s?  Because 0 represents both the bottom
       * of the address space and the top of it (using -1 for the
       * top wouldn't help much: the masks would do the wrong thing).
       * The rule is that addr 0 and floor 0 refer to the bottom of
       * the address space, but end 0 and ceiling 0 refer to the top
       * Comparisons need to use "end - 1" and "ceiling - 1" (though
       * that end 0 case should be mythical).
       *
       * Wherever addr is brought up or ceiling brought down, we
       * must be careful to reject "the opposite 0" before it
       * confuses the subsequent tests.  But what about where end is
       * brought down by HUGEPD_SIZE below? no, end can't go down to
       * 0 there.
       *
       * Whereas we round start (addr) and ceiling down, by different
       * masks at different levels, in order to test whether a table
       * now has no other vmas using it, so can be freed, we don't
       * bother to round floor or end up - the tests don't need that.
       */
      unsigned int psize = get_slice_psize(tlb->mm, addr);

      addr &= HUGEPD_MASK(psize);
      if (addr < floor) {
            addr += HUGEPD_SIZE(psize);
            if (!addr)
                  return;
      }
      if (ceiling) {
            ceiling &= HUGEPD_MASK(psize);
            if (!ceiling)
                  return;
      }
      if (end - 1 > ceiling - 1)
            end -= HUGEPD_SIZE(psize);
      if (addr > end - 1)
            return;

      start = addr;
      pgd = pgd_offset(tlb->mm, addr);
      do {
            psize = get_slice_psize(tlb->mm, addr);
            BUG_ON(!mmu_huge_psizes[psize]);
            next = pgd_addr_end(addr, end);
            if (mmu_psize_to_shift(psize) < PUD_SHIFT) {
                  if (pgd_none_or_clear_bad(pgd))
                        continue;
                  hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling);
            } else {
                  if (pgd_none(*pgd))
                        continue;
                  free_hugepte_range(tlb, (hugepd_t *)pgd, psize);
            }
      } while (pgd++, addr = next, addr != end);
}

void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
                 pte_t *ptep, pte_t pte)
{
      if (pte_present(*ptep)) {
            /* We open-code pte_clear because we need to pass the right
             * argument to hpte_need_flush (huge / !huge). Might not be
             * necessary anymore if we make hpte_need_flush() get the
             * page size from the slices
             */
            unsigned int psize = get_slice_psize(mm, addr);
            unsigned int shift = mmu_psize_to_shift(psize);
            unsigned long sz = ((1UL) << shift);
            struct hstate *hstate = size_to_hstate(sz);
            pte_update(mm, addr & hstate->mask, ptep, ~0UL, 1);
      }
      *ptep = __pte(pte_val(pte) & ~_PAGE_HPTEFLAGS);
}

pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
                        pte_t *ptep)
{
      unsigned long old = pte_update(mm, addr, ptep, ~0UL, 1);
      return __pte(old);
}

struct page *
follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
{
      pte_t *ptep;
      struct page *page;
      unsigned int mmu_psize = get_slice_psize(mm, address);

      /* Verify it is a huge page else bail. */
      if (!mmu_huge_psizes[mmu_psize])
            return ERR_PTR(-EINVAL);

      ptep = huge_pte_offset(mm, address);
      page = pte_page(*ptep);
      if (page) {
            unsigned int shift = mmu_psize_to_shift(mmu_psize);
            unsigned long sz = ((1UL) << shift);
            page += (address % sz) / PAGE_SIZE;
      }

      return page;
}

int pmd_huge(pmd_t pmd)
{
      return 0;
}

int pud_huge(pud_t pud)
{
      return 0;
}

struct page *
follow_huge_pmd(struct mm_struct *mm, unsigned long address,
            pmd_t *pmd, int write)
{
      BUG();
      return NULL;
}


unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
                              unsigned long len, unsigned long pgoff,
                              unsigned long flags)
{
      struct hstate *hstate = hstate_file(file);
      int mmu_psize = shift_to_mmu_psize(huge_page_shift(hstate));

      if (!mmu_huge_psizes[mmu_psize])
            return -EINVAL;
      return slice_get_unmapped_area(addr, len, flags, mmu_psize, 1, 0);
}

/*
 * Called by asm hashtable.S for doing lazy icache flush
 */
static unsigned int hash_huge_page_do_lazy_icache(unsigned long rflags,
                              pte_t pte, int trap, unsigned long sz)
{
      struct page *page;
      int i;

      if (!pfn_valid(pte_pfn(pte)))
            return rflags;

      page = pte_page(pte);

      /* page is dirty */
      if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) {
            if (trap == 0x400) {
                  for (i = 0; i < (sz / PAGE_SIZE); i++)
                        __flush_dcache_icache(page_address(page+i));
                  set_bit(PG_arch_1, &page->flags);
            } else {
                  rflags |= HPTE_R_N;
            }
      }
      return rflags;
}

int hash_huge_page(struct mm_struct *mm, unsigned long access,
               unsigned long ea, unsigned long vsid, int local,
               unsigned long trap)
{
      pte_t *ptep;
      unsigned long old_pte, new_pte;
      unsigned long va, rflags, pa, sz;
      long slot;
      int err = 1;
      int ssize = user_segment_size(ea);
      unsigned int mmu_psize;
      int shift;
      mmu_psize = get_slice_psize(mm, ea);

      if (!mmu_huge_psizes[mmu_psize])
            goto out;
      ptep = huge_pte_offset(mm, ea);

      /* Search the Linux page table for a match with va */
      va = hpt_va(ea, vsid, ssize);

      /*
       * If no pte found or not present, send the problem up to
       * do_page_fault
       */
      if (unlikely(!ptep || pte_none(*ptep)))
            goto out;

      /* 
       * Check the user's access rights to the page.  If access should be
       * prevented then send the problem up to do_page_fault.
       */
      if (unlikely(access & ~pte_val(*ptep)))
            goto out;
      /*
       * At this point, we have a pte (old_pte) which can be used to build
       * or update an HPTE. There are 2 cases:
       *
       * 1. There is a valid (present) pte with no associated HPTE (this is 
       *    the most common case)
       * 2. There is a valid (present) pte with an associated HPTE. The
       *    current values of the pp bits in the HPTE prevent access
       *    because we are doing software DIRTY bit management and the
       *    page is currently not DIRTY. 
       */


      do {
            old_pte = pte_val(*ptep);
            if (old_pte & _PAGE_BUSY)
                  goto out;
            new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED;
      } while(old_pte != __cmpxchg_u64((unsigned long *)ptep,
                               old_pte, new_pte));

      rflags = 0x2 | (!(new_pte & _PAGE_RW));
      /* _PAGE_EXEC -> HW_NO_EXEC since it's inverted */
      rflags |= ((new_pte & _PAGE_EXEC) ? 0 : HPTE_R_N);
      shift = mmu_psize_to_shift(mmu_psize);
      sz = ((1UL) << shift);
      if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
            /* No CPU has hugepages but lacks no execute, so we
             * don't need to worry about that case */
            rflags = hash_huge_page_do_lazy_icache(rflags, __pte(old_pte),
                                           trap, sz);

      /* Check if pte already has an hpte (case 2) */
      if (unlikely(old_pte & _PAGE_HASHPTE)) {
            /* There MIGHT be an HPTE for this pte */
            unsigned long hash, slot;

            hash = hpt_hash(va, shift, ssize);
            if (old_pte & _PAGE_F_SECOND)
                  hash = ~hash;
            slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
            slot += (old_pte & _PAGE_F_GIX) >> 12;

            if (ppc_md.hpte_updatepp(slot, rflags, va, mmu_psize,
                               ssize, local) == -1)
                  old_pte &= ~_PAGE_HPTEFLAGS;
      }

      if (likely(!(old_pte & _PAGE_HASHPTE))) {
            unsigned long hash = hpt_hash(va, shift, ssize);
            unsigned long hpte_group;

            pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT;

repeat:
            hpte_group = ((hash & htab_hash_mask) *
                        HPTES_PER_GROUP) & ~0x7UL;

            /* clear HPTE slot informations in new PTE */
#ifdef CONFIG_PPC_64K_PAGES
            new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | _PAGE_HPTE_SUB0;
#else
            new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | _PAGE_HASHPTE;
#endif
            /* Add in WIMG bits */
            rflags |= (new_pte & (_PAGE_WRITETHRU | _PAGE_NO_CACHE |
                              _PAGE_COHERENT | _PAGE_GUARDED));

            /* Insert into the hash table, primary slot */
            slot = ppc_md.hpte_insert(hpte_group, va, pa, rflags, 0,
                                mmu_psize, ssize);

            /* Primary is full, try the secondary */
            if (unlikely(slot == -1)) {
                  hpte_group = ((~hash & htab_hash_mask) *
                              HPTES_PER_GROUP) & ~0x7UL; 
                  slot = ppc_md.hpte_insert(hpte_group, va, pa, rflags,
                                      HPTE_V_SECONDARY,
                                      mmu_psize, ssize);
                  if (slot == -1) {
                        if (mftb() & 0x1)
                              hpte_group = ((hash & htab_hash_mask) *
                                          HPTES_PER_GROUP)&~0x7UL;

                        ppc_md.hpte_remove(hpte_group);
                        goto repeat;
                        }
            }

            if (unlikely(slot == -2))
                  panic("hash_huge_page: pte_insert failed\n");

            new_pte |= (slot << 12) & (_PAGE_F_SECOND | _PAGE_F_GIX);
      }

      /*
       * No need to use ldarx/stdcx here
       */
      *ptep = __pte(new_pte & ~_PAGE_BUSY);

      err = 0;

 out:
      return err;
}

static void __init set_huge_psize(int psize)
{
      /* Check that it is a page size supported by the hardware and
       * that it fits within pagetable limits. */
      if (mmu_psize_defs[psize].shift &&
            mmu_psize_defs[psize].shift < SID_SHIFT_1T &&
            (mmu_psize_defs[psize].shift > MIN_HUGEPTE_SHIFT ||
             mmu_psize_defs[psize].shift == PAGE_SHIFT_64K ||
             mmu_psize_defs[psize].shift == PAGE_SHIFT_16G)) {
            /* Return if huge page size has already been setup or is the
             * same as the base page size. */
            if (mmu_huge_psizes[psize] ||
               mmu_psize_defs[psize].shift == PAGE_SHIFT)
                  return;
            hugetlb_add_hstate(mmu_psize_defs[psize].shift - PAGE_SHIFT);

            switch (mmu_psize_defs[psize].shift) {
            case PAGE_SHIFT_64K:
                /* We only allow 64k hpages with 4k base page,
                 * which was checked above, and always put them
                 * at the PMD */
                hugepte_shift[psize] = PMD_SHIFT;
                break;
            case PAGE_SHIFT_16M:
                /* 16M pages can be at two different levels
                 * of pagestables based on base page size */
                if (PAGE_SHIFT == PAGE_SHIFT_64K)
                      hugepte_shift[psize] = PMD_SHIFT;
                else /* 4k base page */
                      hugepte_shift[psize] = PUD_SHIFT;
                break;
            case PAGE_SHIFT_16G:
                /* 16G pages are always at PGD level */
                hugepte_shift[psize] = PGDIR_SHIFT;
                break;
            }
            hugepte_shift[psize] -= mmu_psize_defs[psize].shift;
      } else
            hugepte_shift[psize] = 0;
}

static int __init hugepage_setup_sz(char *str)
{
      unsigned long long size;
      int mmu_psize;
      int shift;

      size = memparse(str, &str);

      shift = __ffs(size);
      mmu_psize = shift_to_mmu_psize(shift);
      if (mmu_psize >= 0 && mmu_psize_defs[mmu_psize].shift)
            set_huge_psize(mmu_psize);
      else
            printk(KERN_WARNING "Invalid huge page size specified(%llu)\n", size);

      return 1;
}
__setup("hugepagesz=", hugepage_setup_sz);

static int __init hugetlbpage_init(void)
{
      unsigned int psize;

      if (!cpu_has_feature(CPU_FTR_16M_PAGE))
            return -ENODEV;

      /* Add supported huge page sizes.  Need to change HUGE_MAX_HSTATE
       * and adjust PTE_NONCACHE_NUM if the number of supported huge page
       * sizes changes.
       */
      set_huge_psize(MMU_PAGE_16M);
      set_huge_psize(MMU_PAGE_16G);

      /* Temporarily disable support for 64K huge pages when 64K SPU local
       * store support is enabled as the current implementation conflicts.
       */
#ifndef CONFIG_SPU_FS_64K_LS
      set_huge_psize(MMU_PAGE_64K);
#endif

      for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
            if (mmu_huge_psizes[psize]) {
                  huge_pgtable_cache(psize) = kmem_cache_create(
                                    HUGEPTE_CACHE_NAME(psize),
                                    HUGEPTE_TABLE_SIZE(psize),
                                    HUGEPTE_TABLE_SIZE(psize),
                                    0,
                                    NULL);
                  if (!huge_pgtable_cache(psize))
                        panic("hugetlbpage_init(): could not create %s"\
                              "\n", HUGEPTE_CACHE_NAME(psize));
            }
      }

      return 0;
}

module_init(hugetlbpage_init);

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