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-rw-r--r--arch/tile/mm/hugetlbpage.c346
1 files changed, 346 insertions, 0 deletions
diff --git a/arch/tile/mm/hugetlbpage.c b/arch/tile/mm/hugetlbpage.c
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+++ b/arch/tile/mm/hugetlbpage.c
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+/*
+ * 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/slab.h>
+#include <linux/err.h>
+#include <linux/sysctl.h>
+#include <linux/mman.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/setup.h>
+
+#ifdef CONFIG_HUGETLB_SUPER_PAGES
+
+/*
+ * Provide an additional huge page size (in addition to the regular default
+ * huge page size) if no "hugepagesz" arguments are specified.
+ * Note that it must be smaller than the default huge page size so
+ * that it's possible to allocate them on demand from the buddy allocator.
+ * You can change this to 64K (on a 16K build), 256K, 1M, or 4M,
+ * or not define it at all.
+ */
+#define ADDITIONAL_HUGE_SIZE (1024 * 1024UL)
+
+/* "Extra" page-size multipliers, one per level of the page table. */
+int huge_shift[HUGE_SHIFT_ENTRIES] = {
+#ifdef ADDITIONAL_HUGE_SIZE
+#define ADDITIONAL_HUGE_SHIFT __builtin_ctzl(ADDITIONAL_HUGE_SIZE / PAGE_SIZE)
+ [HUGE_SHIFT_PAGE] = ADDITIONAL_HUGE_SHIFT
+#endif
+};
+
+#endif
+
+pte_t *huge_pte_alloc(struct mm_struct *mm,
+ unsigned long addr, unsigned long sz)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+
+ addr &= -sz; /* Mask off any low bits in the address. */
+
+ pgd = pgd_offset(mm, addr);
+ pud = pud_alloc(mm, pgd, addr);
+
+#ifdef CONFIG_HUGETLB_SUPER_PAGES
+ if (sz >= PGDIR_SIZE) {
+ BUG_ON(sz != PGDIR_SIZE &&
+ sz != PGDIR_SIZE << huge_shift[HUGE_SHIFT_PGDIR]);
+ return (pte_t *)pud;
+ } else {
+ pmd_t *pmd = pmd_alloc(mm, pud, addr);
+ if (sz >= PMD_SIZE) {
+ BUG_ON(sz != PMD_SIZE &&
+ sz != (PMD_SIZE << huge_shift[HUGE_SHIFT_PMD]));
+ return (pte_t *)pmd;
+ }
+ else {
+ if (sz != PAGE_SIZE << huge_shift[HUGE_SHIFT_PAGE])
+ panic("Unexpected page size %#lx\n", sz);
+ return pte_alloc_map(mm, NULL, pmd, addr);
+ }
+ }
+#else
+ BUG_ON(sz != PMD_SIZE);
+ return (pte_t *) pmd_alloc(mm, pud, addr);
+#endif
+}
+
+static pte_t *get_pte(pte_t *base, int index, int level)
+{
+ pte_t *ptep = base + index;
+#ifdef CONFIG_HUGETLB_SUPER_PAGES
+ if (!pte_present(*ptep) && huge_shift[level] != 0) {
+ unsigned long mask = -1UL << huge_shift[level];
+ pte_t *super_ptep = base + (index & mask);
+ pte_t pte = *super_ptep;
+ if (pte_present(pte) && pte_super(pte))
+ ptep = super_ptep;
+ }
+#endif
+ return ptep;
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+#ifdef CONFIG_HUGETLB_SUPER_PAGES
+ pte_t *pte;
+#endif
+
+ /* Get the top-level page table entry. */
+ pgd = (pgd_t *)get_pte((pte_t *)mm->pgd, pgd_index(addr), 0);
+
+ /* We don't have four levels. */
+ pud = pud_offset(pgd, addr);
+#ifndef __PAGETABLE_PUD_FOLDED
+# error support fourth page table level
+#endif
+ if (!pud_present(*pud))
+ return NULL;
+
+ /* Check for an L0 huge PTE, if we have three levels. */
+#ifndef __PAGETABLE_PMD_FOLDED
+ if (pud_huge(*pud))
+ return (pte_t *)pud;
+
+ pmd = (pmd_t *)get_pte((pte_t *)pud_page_vaddr(*pud),
+ pmd_index(addr), 1);
+ if (!pmd_present(*pmd))
+ return NULL;
+#else
+ pmd = pmd_offset(pud, addr);
+#endif
+
+ /* Check for an L1 huge PTE. */
+ if (pmd_huge(*pmd))
+ return (pte_t *)pmd;
+
+#ifdef CONFIG_HUGETLB_SUPER_PAGES
+ /* Check for an L2 huge PTE. */
+ pte = get_pte((pte_t *)pmd_page_vaddr(*pmd), pte_index(addr), 2);
+ if (!pte_present(*pte))
+ return NULL;
+ if (pte_super(*pte))
+ return pte;
+#endif
+
+ return NULL;
+}
+
+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);
+}
+
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
+{
+ return 0;
+}
+
+#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 vm_unmapped_area_info info;
+
+ info.flags = 0;
+ info.length = len;
+ info.low_limit = TASK_UNMAPPED_BASE;
+ info.high_limit = TASK_SIZE;
+ info.align_mask = PAGE_MASK & ~huge_page_mask(h);
+ info.align_offset = 0;
+ return vm_unmapped_area(&info);
+}
+
+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 vm_unmapped_area_info info;
+ unsigned long addr;
+
+ info.flags = VM_UNMAPPED_AREA_TOPDOWN;
+ info.length = len;
+ info.low_limit = PAGE_SIZE;
+ info.high_limit = current->mm->mmap_base;
+ info.align_mask = PAGE_MASK & ~huge_page_mask(h);
+ info.align_offset = 0;
+ addr = vm_unmapped_area(&info);
+
+ /*
+ * 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.
+ */
+ if (addr & ~PAGE_MASK) {
+ VM_BUG_ON(addr != -ENOMEM);
+ info.flags = 0;
+ info.low_limit = TASK_UNMAPPED_BASE;
+ info.high_limit = TASK_SIZE;
+ addr = vm_unmapped_area(&info);
+ }
+
+ 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);
+}
+#endif /* HAVE_ARCH_HUGETLB_UNMAPPED_AREA */
+
+#ifdef CONFIG_HUGETLB_SUPER_PAGES
+static __init int __setup_hugepagesz(unsigned long ps)
+{
+ int log_ps = __builtin_ctzl(ps);
+ int level, base_shift;
+
+ if ((1UL << log_ps) != ps || (log_ps & 1) != 0) {
+ pr_warn("Not enabling %ld byte huge pages; must be a power of four\n",
+ ps);
+ return -EINVAL;
+ }
+
+ if (ps > 64*1024*1024*1024UL) {
+ pr_warn("Not enabling %ld MB huge pages; largest legal value is 64 GB\n",
+ ps >> 20);
+ return -EINVAL;
+ } else if (ps >= PUD_SIZE) {
+ static long hv_jpage_size;
+ if (hv_jpage_size == 0)
+ hv_jpage_size = hv_sysconf(HV_SYSCONF_PAGE_SIZE_JUMBO);
+ if (hv_jpage_size != PUD_SIZE) {
+ pr_warn("Not enabling >= %ld MB huge pages: hypervisor reports size %ld\n",
+ PUD_SIZE >> 20, hv_jpage_size);
+ return -EINVAL;
+ }
+ level = 0;
+ base_shift = PUD_SHIFT;
+ } else if (ps >= PMD_SIZE) {
+ level = 1;
+ base_shift = PMD_SHIFT;
+ } else if (ps > PAGE_SIZE) {
+ level = 2;
+ base_shift = PAGE_SHIFT;
+ } else {
+ pr_err("hugepagesz: huge page size %ld too small\n", ps);
+ return -EINVAL;
+ }
+
+ if (log_ps != base_shift) {
+ int shift_val = log_ps - base_shift;
+ if (huge_shift[level] != 0) {
+ int old_shift = base_shift + huge_shift[level];
+ pr_warn("Not enabling %ld MB huge pages; already have size %ld MB\n",
+ ps >> 20, (1UL << old_shift) >> 20);
+ return -EINVAL;
+ }
+ if (hv_set_pte_super_shift(level, shift_val) != 0) {
+ pr_warn("Not enabling %ld MB huge pages; no hypervisor support\n",
+ ps >> 20);
+ return -EINVAL;
+ }
+ printk(KERN_DEBUG "Enabled %ld MB huge pages\n", ps >> 20);
+ huge_shift[level] = shift_val;
+ }
+
+ hugetlb_add_hstate(log_ps - PAGE_SHIFT);
+
+ return 0;
+}
+
+static bool saw_hugepagesz;
+
+static __init int setup_hugepagesz(char *opt)
+{
+ if (!saw_hugepagesz) {
+ saw_hugepagesz = true;
+ memset(huge_shift, 0, sizeof(huge_shift));
+ }
+ return __setup_hugepagesz(memparse(opt, NULL));
+}
+__setup("hugepagesz=", setup_hugepagesz);
+
+#ifdef ADDITIONAL_HUGE_SIZE
+/*
+ * Provide an additional huge page size if no "hugepagesz" args are given.
+ * In that case, all the cores have properly set up their hv super_shift
+ * already, but we need to notify the hugetlb code to enable the
+ * new huge page size from the Linux point of view.
+ */
+static __init int add_default_hugepagesz(void)
+{
+ if (!saw_hugepagesz) {
+ BUILD_BUG_ON(ADDITIONAL_HUGE_SIZE >= PMD_SIZE ||
+ ADDITIONAL_HUGE_SIZE <= PAGE_SIZE);
+ BUILD_BUG_ON((PAGE_SIZE << ADDITIONAL_HUGE_SHIFT) !=
+ ADDITIONAL_HUGE_SIZE);
+ BUILD_BUG_ON(ADDITIONAL_HUGE_SHIFT & 1);
+ hugetlb_add_hstate(ADDITIONAL_HUGE_SHIFT);
+ }
+ return 0;
+}
+arch_initcall(add_default_hugepagesz);
+#endif
+
+#endif /* CONFIG_HUGETLB_SUPER_PAGES */