1 files changed, 343 insertions, 0 deletions

diff --git a/arch/tile/mm/hugetlbpage.c b/arch/tile/mm/hugetlbpage.c
new file mode 100644
index 000000000000..24688b697a8d
--- /dev/null
+++ b/arch/tile/mm/hugetlbpage.c
@@ -0,0 +1,343 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ *
+ * TILE Huge TLB Page Support for Kernel.
+ * Taken from i386 hugetlb implementation:
+ * 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/smp_lock.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/sysctl.h>
+#include <linux/mman.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+
+pte_t *huge_pte_alloc(struct mm_struct *mm,
+                      unsigned long addr, unsigned long sz)
+{
+        pgd_t *pgd;
+        pud_t *pud;
+        pte_t *pte = NULL;
+
+        /* We do not yet support multiple huge page sizes. */
+        BUG_ON(sz != PMD_SIZE);
+
+        pgd = pgd_offset(mm, addr);
+        pud = pud_alloc(mm, pgd, addr);
+        if (pud)
+                pte = (pte_t *) pmd_alloc(mm, pud, addr);
+        BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte));
+
+        return pte;
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
+{
+        pgd_t *pgd;
+        pud_t *pud;
+        pmd_t *pmd = NULL;
+
+        pgd = pgd_offset(mm, addr);
+        if (pgd_present(*pgd)) {
+                pud = pud_offset(pgd, addr);
+                if (pud_present(*pud))
+                        pmd = pmd_offset(pud, addr);
+        }
+        return (pte_t *) pmd;
+}
+
+#ifdef HUGETLB_TEST
+struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
+                              int write)
+{
+        unsigned long start = address;
+        int length = 1;
+        int nr;
+        struct page *page;
+        struct vm_area_struct *vma;
+
+        vma = find_vma(mm, addr);
+        if (!vma || !is_vm_hugetlb_page(vma))
+                return ERR_PTR(-EINVAL);
+
+        pte = huge_pte_offset(mm, address);
+
+        /* hugetlb should be locked, and hence, prefaulted */
+        WARN_ON(!pte || pte_none(*pte));
+
+        page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)];
+
+        WARN_ON(!PageHead(page));
+
+        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)
+{
+        return NULL;
+}
+
+#else
+
+struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
+                              int write)
+{
+        return ERR_PTR(-EINVAL);
+}
+
+int pmd_huge(pmd_t pmd)
+{
+        return !!(pmd_val(pmd) & _PAGE_HUGE_PAGE);
+}
+
+int pud_huge(pud_t pud)
+{
+        return !!(pud_val(pud) & _PAGE_HUGE_PAGE);
+}
+
+struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
+                             pmd_t *pmd, int write)
+{
+        struct page *page;
+
+        page = pte_page(*(pte_t *)pmd);
+        if (page)
+                page += ((address & ~PMD_MASK) >> PAGE_SHIFT);
+        return page;
+}
+
+struct page *follow_huge_pud(struct mm_struct *mm, unsigned long address,
+                             pud_t *pud, int write)
+{
+        struct page *page;
+
+        page = pte_page(*(pte_t *)pud);
+        if (page)
+                page += ((address & ~PUD_MASK) >> PAGE_SHIFT);
+        return page;
+}
+
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
+{
+        return 0;
+}
+
+#endif
+
+#ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
+static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
+                unsigned long addr, unsigned long len,
+                unsigned long pgoff, unsigned long flags)
+{
+        struct hstate *h = hstate_file(file);
+        struct mm_struct *mm = current->mm;
+        struct vm_area_struct *vma;
+        unsigned long start_addr;
+
+        if (len > mm->cached_hole_size) {
+                start_addr = mm->free_area_cache;
+        } else {
+                start_addr = TASK_UNMAPPED_BASE;
+                mm->cached_hole_size = 0;
+        }
+
+full_search:
+        addr = ALIGN(start_addr, huge_page_size(h));
+
+        for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
+                /* At this point:  (!vma || addr < vma->vm_end). */
+                if (TASK_SIZE - len < addr) {
+                        /*
+                         * Start a new search - just in case we missed
+                         * some holes.
+                         */
+                        if (start_addr != TASK_UNMAPPED_BASE) {
+                                start_addr = TASK_UNMAPPED_BASE;
+                                mm->cached_hole_size = 0;
+                                goto full_search;
+                        }
+                        return -ENOMEM;
+                }
+                if (!vma || addr + len <= vma->vm_start) {
+                        mm->free_area_cache = addr + len;
+                        return addr;
+                }
+                if (addr + mm->cached_hole_size < vma->vm_start)
+                        mm->cached_hole_size = vma->vm_start - addr;
+                addr = ALIGN(vma->vm_end, huge_page_size(h));
+        }
+}
+
+static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
+                unsigned long addr0, unsigned long len,
+                unsigned long pgoff, unsigned long flags)
+{
+        struct hstate *h = hstate_file(file);
+        struct mm_struct *mm = current->mm;
+        struct vm_area_struct *vma, *prev_vma;
+        unsigned long base = mm->mmap_base, addr = addr0;
+        unsigned long largest_hole = mm->cached_hole_size;
+        int first_time = 1;
+
+        /* don't allow allocations above current base */
+        if (mm->free_area_cache > base)
+                mm->free_area_cache = base;
+
+        if (len <= largest_hole) {
+                largest_hole = 0;
+                mm->free_area_cache  = base;
+        }
+try_again:
+        /* make sure it can fit in the remaining address space */
+        if (mm->free_area_cache < len)
+                goto fail;
+
+        /* either no address requested or cant fit in requested address hole */
+        addr = (mm->free_area_cache - len) & huge_page_mask(h);
+        do {
+                /*
+                 * Lookup failure means no vma is above this address,
+                 * i.e. return with success:
+                 */
+                vma = find_vma_prev(mm, addr, &prev_vma);
+                if (!vma) {
+                        return addr;
+                        break;
+                }
+
+                /*
+                 * new region fits between prev_vma->vm_end and
+                 * vma->vm_start, use it:
+                 */
+                if (addr + len <= vma->vm_start &&
+                            (!prev_vma || (addr >= prev_vma->vm_end))) {
+                        /* remember the address as a hint for next time */
+                        mm->cached_hole_size = largest_hole;
+                        mm->free_area_cache = addr;
+                        return addr;
+                } else {
+                        /* pull free_area_cache down to the first hole */
+                        if (mm->free_area_cache == vma->vm_end) {
+                                mm->free_area_cache = vma->vm_start;
+                                mm->cached_hole_size = largest_hole;
+                        }
+                }
+
+                /* remember the largest hole we saw so far */
+                if (addr + largest_hole < vma->vm_start)
+                        largest_hole = vma->vm_start - addr;
+
+                /* try just below the current vma->vm_start */
+                addr = (vma->vm_start - len) & huge_page_mask(h);
+
+        } while (len <= vma->vm_start);
+
+fail:
+        /*
+         * if hint left us with no space for the requested
+         * mapping then try again:
+         */
+        if (first_time) {
+                mm->free_area_cache = base;
+                largest_hole = 0;
+                first_time = 0;
+                goto try_again;
+        }
+        /*
+         * A failed mmap() very likely causes application failure,
+         * so fall back to the bottom-up function here. This scenario
+         * can happen with large stack limits and large mmap()
+         * allocations.
+         */
+        mm->free_area_cache = TASK_UNMAPPED_BASE;
+        mm->cached_hole_size = ~0UL;
+        addr = hugetlb_get_unmapped_area_bottomup(file, addr0,
+                        len, pgoff, flags);
+
+        /*
+         * Restore the topdown base:
+         */
+        mm->free_area_cache = base;
+        mm->cached_hole_size = ~0UL;
+
+        return addr;
+}
+
+unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
+                unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+        struct hstate *h = hstate_file(file);
+        struct mm_struct *mm = current->mm;
+        struct vm_area_struct *vma;
+
+        if (len & ~huge_page_mask(h))
+                return -EINVAL;
+        if (len > TASK_SIZE)
+                return -ENOMEM;
+
+        if (flags & MAP_FIXED) {
+                if (prepare_hugepage_range(file, addr, len))
+                        return -EINVAL;
+                return addr;
+        }
+
+        if (addr) {
+                addr = ALIGN(addr, huge_page_size(h));
+                vma = find_vma(mm, addr);
+                if (TASK_SIZE - len >= addr &&
+                    (!vma || addr + len <= vma->vm_start))
+                        return addr;
+        }
+        if (current->mm->get_unmapped_area == arch_get_unmapped_area)
+                return hugetlb_get_unmapped_area_bottomup(file, addr, len,
+                                pgoff, flags);
+        else
+                return hugetlb_get_unmapped_area_topdown(file, addr, len,
+                                pgoff, flags);
+}
+
+static __init int setup_hugepagesz(char *opt)
+{
+        unsigned long ps = memparse(opt, &opt);
+        if (ps == PMD_SIZE) {
+                hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
+        } else if (ps == PUD_SIZE) {
+                hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
+        } else {
+                pr_err("hugepagesz: Unsupported page size %lu M\n",
+                        ps >> 20);
+                return 0;
+        }
+        return 1;
+}
+__setup("hugepagesz=", setup_hugepagesz);
+
+#endif /*HAVE_ARCH_HUGETLB_UNMAPPED_AREA*/