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Diffstat (limited to 'kernel/arch/tile/mm/hugetlbpage.c')
| -rw-r--r-- | kernel/arch/tile/mm/hugetlbpage.c | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/kernel/arch/tile/mm/hugetlbpage.c b/kernel/arch/tile/mm/hugetlbpage.c new file mode 100644 index 000000000..8416240c3 --- /dev/null +++ b/kernel/arch/tile/mm/hugetlbpage.c @@ -0,0 +1,346 @@ +/* + * 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 */ |