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![Aneesh Kumar K.V](/assets/img/avatar_default.png)
Without this if firmware reports 1MB page size support we will crash trying to use 1MB as hugetlb page size. echo 300 > /sys/kernel/mm/hugepages/hugepages-1024kB/nr_hugepages kernel BUG at ./arch/powerpc/include/asm/hugetlb.h:19! ..... .... [c0000000e2c27b30] c00000000029dae8 .hugetlb_fault+0x638/0xda0 [c0000000e2c27c30] c00000000026fb64 .handle_mm_fault+0x844/0x1d70 [c0000000e2c27d70] c00000000004805c .do_page_fault+0x3dc/0x7c0 [c0000000e2c27e30] c00000000000ac98 handle_page_fault+0x10/0x30 With fix, we don't enable 1MB as hugepage size. bash-4.2# cd /sys/kernel/mm/hugepages/ bash-4.2# ls hugepages-16384kB hugepages-16777216kB Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
1051 lines
26 KiB
C
1051 lines
26 KiB
C
/*
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* PPC Huge TLB Page Support for Kernel.
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*
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* Copyright (C) 2003 David Gibson, IBM Corporation.
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* Copyright (C) 2011 Becky Bruce, Freescale Semiconductor
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*
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* Based on the IA-32 version:
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* Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
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*/
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#include <linux/mm.h>
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#include <linux/io.h>
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#include <linux/slab.h>
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#include <linux/hugetlb.h>
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#include <linux/export.h>
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#include <linux/of_fdt.h>
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#include <linux/memblock.h>
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#include <linux/bootmem.h>
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#include <linux/moduleparam.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/tlb.h>
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#include <asm/setup.h>
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#include <asm/hugetlb.h>
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#ifdef CONFIG_HUGETLB_PAGE
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#define PAGE_SHIFT_64K 16
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#define PAGE_SHIFT_512K 19
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#define PAGE_SHIFT_8M 23
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#define PAGE_SHIFT_16M 24
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#define PAGE_SHIFT_16G 34
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unsigned int HPAGE_SHIFT;
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/*
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* Tracks gpages after the device tree is scanned and before the
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* huge_boot_pages list is ready. On non-Freescale implementations, this is
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* just used to track 16G pages and so is a single array. FSL-based
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* implementations may have more than one gpage size, so we need multiple
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* arrays
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*/
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#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
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#define MAX_NUMBER_GPAGES 128
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struct psize_gpages {
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u64 gpage_list[MAX_NUMBER_GPAGES];
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unsigned int nr_gpages;
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};
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static struct psize_gpages gpage_freearray[MMU_PAGE_COUNT];
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#else
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#define MAX_NUMBER_GPAGES 1024
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static u64 gpage_freearray[MAX_NUMBER_GPAGES];
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static unsigned nr_gpages;
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#endif
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#define hugepd_none(hpd) (hpd_val(hpd) == 0)
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pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
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{
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/* Only called for hugetlbfs pages, hence can ignore THP */
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return __find_linux_pte_or_hugepte(mm->pgd, addr, NULL, NULL);
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}
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static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
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unsigned long address, unsigned pdshift, unsigned pshift)
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{
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struct kmem_cache *cachep;
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pte_t *new;
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int i;
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int num_hugepd;
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if (pshift >= pdshift) {
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cachep = hugepte_cache;
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num_hugepd = 1 << (pshift - pdshift);
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} else {
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cachep = PGT_CACHE(pdshift - pshift);
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num_hugepd = 1;
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}
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new = kmem_cache_zalloc(cachep, GFP_KERNEL);
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BUG_ON(pshift > HUGEPD_SHIFT_MASK);
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BUG_ON((unsigned long)new & HUGEPD_SHIFT_MASK);
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if (! new)
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return -ENOMEM;
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/*
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* Make sure other cpus find the hugepd set only after a
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* properly initialized page table is visible to them.
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* For more details look for comment in __pte_alloc().
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*/
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smp_wmb();
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spin_lock(&mm->page_table_lock);
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/*
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* We have multiple higher-level entries that point to the same
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* actual pte location. Fill in each as we go and backtrack on error.
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* We need all of these so the DTLB pgtable walk code can find the
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* right higher-level entry without knowing if it's a hugepage or not.
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*/
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for (i = 0; i < num_hugepd; i++, hpdp++) {
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if (unlikely(!hugepd_none(*hpdp)))
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break;
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else {
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#ifdef CONFIG_PPC_BOOK3S_64
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*hpdp = __hugepd(__pa(new) |
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(shift_to_mmu_psize(pshift) << 2));
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#elif defined(CONFIG_PPC_8xx)
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*hpdp = __hugepd(__pa(new) |
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(pshift == PAGE_SHIFT_8M ? _PMD_PAGE_8M :
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_PMD_PAGE_512K) | _PMD_PRESENT);
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#else
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/* We use the old format for PPC_FSL_BOOK3E */
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*hpdp = __hugepd(((unsigned long)new & ~PD_HUGE) | pshift);
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#endif
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}
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}
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/* If we bailed from the for loop early, an error occurred, clean up */
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if (i < num_hugepd) {
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for (i = i - 1 ; i >= 0; i--, hpdp--)
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*hpdp = __hugepd(0);
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kmem_cache_free(cachep, new);
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}
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spin_unlock(&mm->page_table_lock);
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return 0;
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}
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/*
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* These macros define how to determine which level of the page table holds
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* the hpdp.
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*/
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#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
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#define HUGEPD_PGD_SHIFT PGDIR_SHIFT
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#define HUGEPD_PUD_SHIFT PUD_SHIFT
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#else
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#define HUGEPD_PGD_SHIFT PUD_SHIFT
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#define HUGEPD_PUD_SHIFT PMD_SHIFT
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#endif
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/*
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* At this point we do the placement change only for BOOK3S 64. This would
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* possibly work on other subarchs.
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*/
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pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
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{
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pgd_t *pg;
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pud_t *pu;
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pmd_t *pm;
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hugepd_t *hpdp = NULL;
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unsigned pshift = __ffs(sz);
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unsigned pdshift = PGDIR_SHIFT;
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addr &= ~(sz-1);
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pg = pgd_offset(mm, addr);
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#ifdef CONFIG_PPC_BOOK3S_64
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if (pshift == PGDIR_SHIFT)
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/* 16GB huge page */
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return (pte_t *) pg;
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else if (pshift > PUD_SHIFT)
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/*
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* We need to use hugepd table
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*/
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hpdp = (hugepd_t *)pg;
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else {
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pdshift = PUD_SHIFT;
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pu = pud_alloc(mm, pg, addr);
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if (pshift == PUD_SHIFT)
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return (pte_t *)pu;
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else if (pshift > PMD_SHIFT)
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hpdp = (hugepd_t *)pu;
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else {
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pdshift = PMD_SHIFT;
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pm = pmd_alloc(mm, pu, addr);
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if (pshift == PMD_SHIFT)
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/* 16MB hugepage */
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return (pte_t *)pm;
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else
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hpdp = (hugepd_t *)pm;
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}
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}
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#else
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if (pshift >= HUGEPD_PGD_SHIFT) {
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hpdp = (hugepd_t *)pg;
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} else {
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pdshift = PUD_SHIFT;
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pu = pud_alloc(mm, pg, addr);
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if (pshift >= HUGEPD_PUD_SHIFT) {
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hpdp = (hugepd_t *)pu;
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} else {
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pdshift = PMD_SHIFT;
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pm = pmd_alloc(mm, pu, addr);
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hpdp = (hugepd_t *)pm;
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}
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}
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#endif
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if (!hpdp)
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return NULL;
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BUG_ON(!hugepd_none(*hpdp) && !hugepd_ok(*hpdp));
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if (hugepd_none(*hpdp) && __hugepte_alloc(mm, hpdp, addr, pdshift, pshift))
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return NULL;
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return hugepte_offset(*hpdp, addr, pdshift);
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}
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#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
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/* Build list of addresses of gigantic pages. This function is used in early
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* boot before the buddy allocator is setup.
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*/
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void add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages)
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{
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unsigned int idx = shift_to_mmu_psize(__ffs(page_size));
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int i;
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if (addr == 0)
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return;
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gpage_freearray[idx].nr_gpages = number_of_pages;
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for (i = 0; i < number_of_pages; i++) {
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gpage_freearray[idx].gpage_list[i] = addr;
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addr += page_size;
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}
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}
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/*
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* Moves the gigantic page addresses from the temporary list to the
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* huge_boot_pages list.
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*/
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int alloc_bootmem_huge_page(struct hstate *hstate)
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{
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struct huge_bootmem_page *m;
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int idx = shift_to_mmu_psize(huge_page_shift(hstate));
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int nr_gpages = gpage_freearray[idx].nr_gpages;
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if (nr_gpages == 0)
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return 0;
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#ifdef CONFIG_HIGHMEM
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/*
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* If gpages can be in highmem we can't use the trick of storing the
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* data structure in the page; allocate space for this
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*/
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m = memblock_virt_alloc(sizeof(struct huge_bootmem_page), 0);
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m->phys = gpage_freearray[idx].gpage_list[--nr_gpages];
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#else
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m = phys_to_virt(gpage_freearray[idx].gpage_list[--nr_gpages]);
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#endif
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list_add(&m->list, &huge_boot_pages);
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gpage_freearray[idx].nr_gpages = nr_gpages;
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gpage_freearray[idx].gpage_list[nr_gpages] = 0;
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m->hstate = hstate;
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return 1;
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}
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/*
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* Scan the command line hugepagesz= options for gigantic pages; store those in
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* a list that we use to allocate the memory once all options are parsed.
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*/
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unsigned long gpage_npages[MMU_PAGE_COUNT];
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static int __init do_gpage_early_setup(char *param, char *val,
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const char *unused, void *arg)
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{
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static phys_addr_t size;
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unsigned long npages;
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/*
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* The hugepagesz and hugepages cmdline options are interleaved. We
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* use the size variable to keep track of whether or not this was done
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* properly and skip over instances where it is incorrect. Other
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* command-line parsing code will issue warnings, so we don't need to.
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*
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*/
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if ((strcmp(param, "default_hugepagesz") == 0) ||
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(strcmp(param, "hugepagesz") == 0)) {
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size = memparse(val, NULL);
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} else if (strcmp(param, "hugepages") == 0) {
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if (size != 0) {
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if (sscanf(val, "%lu", &npages) <= 0)
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npages = 0;
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if (npages > MAX_NUMBER_GPAGES) {
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pr_warn("MMU: %lu pages requested for page "
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#ifdef CONFIG_PHYS_ADDR_T_64BIT
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"size %llu KB, limiting to "
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#else
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"size %u KB, limiting to "
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#endif
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__stringify(MAX_NUMBER_GPAGES) "\n",
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npages, size / 1024);
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npages = MAX_NUMBER_GPAGES;
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}
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gpage_npages[shift_to_mmu_psize(__ffs(size))] = npages;
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size = 0;
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}
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}
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return 0;
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}
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/*
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* This function allocates physical space for pages that are larger than the
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* buddy allocator can handle. We want to allocate these in highmem because
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* the amount of lowmem is limited. This means that this function MUST be
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* called before lowmem_end_addr is set up in MMU_init() in order for the lmb
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* allocate to grab highmem.
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*/
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void __init reserve_hugetlb_gpages(void)
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{
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static __initdata char cmdline[COMMAND_LINE_SIZE];
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phys_addr_t size, base;
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int i;
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strlcpy(cmdline, boot_command_line, COMMAND_LINE_SIZE);
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parse_args("hugetlb gpages", cmdline, NULL, 0, 0, 0,
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NULL, &do_gpage_early_setup);
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/*
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* Walk gpage list in reverse, allocating larger page sizes first.
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* Skip over unsupported sizes, or sizes that have 0 gpages allocated.
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* When we reach the point in the list where pages are no longer
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* considered gpages, we're done.
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*/
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for (i = MMU_PAGE_COUNT-1; i >= 0; i--) {
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if (mmu_psize_defs[i].shift == 0 || gpage_npages[i] == 0)
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continue;
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else if (mmu_psize_to_shift(i) < (MAX_ORDER + PAGE_SHIFT))
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break;
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size = (phys_addr_t)(1ULL << mmu_psize_to_shift(i));
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base = memblock_alloc_base(size * gpage_npages[i], size,
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MEMBLOCK_ALLOC_ANYWHERE);
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add_gpage(base, size, gpage_npages[i]);
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}
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}
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#else /* !PPC_FSL_BOOK3E */
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/* Build list of addresses of gigantic pages. This function is used in early
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* boot before the buddy allocator is setup.
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*/
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void add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages)
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{
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if (!addr)
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return;
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while (number_of_pages > 0) {
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gpage_freearray[nr_gpages] = addr;
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nr_gpages++;
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number_of_pages--;
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addr += page_size;
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}
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}
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/* Moves the gigantic page addresses from the temporary list to the
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* huge_boot_pages list.
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*/
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int alloc_bootmem_huge_page(struct hstate *hstate)
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{
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struct huge_bootmem_page *m;
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if (nr_gpages == 0)
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return 0;
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m = phys_to_virt(gpage_freearray[--nr_gpages]);
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gpage_freearray[nr_gpages] = 0;
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list_add(&m->list, &huge_boot_pages);
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m->hstate = hstate;
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return 1;
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}
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#endif
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#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
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#define HUGEPD_FREELIST_SIZE \
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((PAGE_SIZE - sizeof(struct hugepd_freelist)) / sizeof(pte_t))
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struct hugepd_freelist {
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struct rcu_head rcu;
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unsigned int index;
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void *ptes[0];
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};
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static DEFINE_PER_CPU(struct hugepd_freelist *, hugepd_freelist_cur);
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static void hugepd_free_rcu_callback(struct rcu_head *head)
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{
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struct hugepd_freelist *batch =
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container_of(head, struct hugepd_freelist, rcu);
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unsigned int i;
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for (i = 0; i < batch->index; i++)
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kmem_cache_free(hugepte_cache, batch->ptes[i]);
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free_page((unsigned long)batch);
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}
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static void hugepd_free(struct mmu_gather *tlb, void *hugepte)
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{
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struct hugepd_freelist **batchp;
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batchp = &get_cpu_var(hugepd_freelist_cur);
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if (atomic_read(&tlb->mm->mm_users) < 2 ||
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cpumask_equal(mm_cpumask(tlb->mm),
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cpumask_of(smp_processor_id()))) {
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kmem_cache_free(hugepte_cache, hugepte);
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put_cpu_var(hugepd_freelist_cur);
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return;
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}
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if (*batchp == NULL) {
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*batchp = (struct hugepd_freelist *)__get_free_page(GFP_ATOMIC);
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(*batchp)->index = 0;
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}
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(*batchp)->ptes[(*batchp)->index++] = hugepte;
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if ((*batchp)->index == HUGEPD_FREELIST_SIZE) {
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call_rcu_sched(&(*batchp)->rcu, hugepd_free_rcu_callback);
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*batchp = NULL;
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}
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put_cpu_var(hugepd_freelist_cur);
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}
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#else
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static inline void hugepd_free(struct mmu_gather *tlb, void *hugepte) {}
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#endif
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static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshift,
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unsigned long start, unsigned long end,
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unsigned long floor, unsigned long ceiling)
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{
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pte_t *hugepte = hugepd_page(*hpdp);
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int i;
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unsigned long pdmask = ~((1UL << pdshift) - 1);
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unsigned int num_hugepd = 1;
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unsigned int shift = hugepd_shift(*hpdp);
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/* Note: On fsl the hpdp may be the first of several */
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if (shift > pdshift)
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num_hugepd = 1 << (shift - pdshift);
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start &= pdmask;
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if (start < floor)
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return;
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if (ceiling) {
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ceiling &= pdmask;
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if (! ceiling)
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return;
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}
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if (end - 1 > ceiling - 1)
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return;
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for (i = 0; i < num_hugepd; i++, hpdp++)
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*hpdp = __hugepd(0);
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if (shift >= pdshift)
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hugepd_free(tlb, hugepte);
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else
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pgtable_free_tlb(tlb, hugepte, pdshift - shift);
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}
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static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
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unsigned long addr, unsigned long end,
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unsigned long floor, unsigned long ceiling)
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{
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pmd_t *pmd;
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unsigned long next;
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unsigned long start;
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start = addr;
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do {
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unsigned long more;
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pmd = pmd_offset(pud, addr);
|
|
next = pmd_addr_end(addr, end);
|
|
if (!is_hugepd(__hugepd(pmd_val(*pmd)))) {
|
|
/*
|
|
* if it is not hugepd pointer, we should already find
|
|
* it cleared.
|
|
*/
|
|
WARN_ON(!pmd_none_or_clear_bad(pmd));
|
|
continue;
|
|
}
|
|
/*
|
|
* Increment next by the size of the huge mapping since
|
|
* there may be more than one entry at this level for a
|
|
* single hugepage, but all of them point to
|
|
* the same kmem cache that holds the hugepte.
|
|
*/
|
|
more = addr + (1 << hugepd_shift(*(hugepd_t *)pmd));
|
|
if (more > next)
|
|
next = more;
|
|
|
|
free_hugepd_range(tlb, (hugepd_t *)pmd, PMD_SHIFT,
|
|
addr, next, floor, ceiling);
|
|
} while (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, start);
|
|
mm_dec_nr_pmds(tlb->mm);
|
|
}
|
|
|
|
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;
|
|
|
|
start = addr;
|
|
do {
|
|
pud = pud_offset(pgd, addr);
|
|
next = pud_addr_end(addr, end);
|
|
if (!is_hugepd(__hugepd(pud_val(*pud)))) {
|
|
if (pud_none_or_clear_bad(pud))
|
|
continue;
|
|
hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
|
|
ceiling);
|
|
} else {
|
|
unsigned long more;
|
|
/*
|
|
* Increment next by the size of the huge mapping since
|
|
* there may be more than one entry at this level for a
|
|
* single hugepage, but all of them point to
|
|
* the same kmem cache that holds the hugepte.
|
|
*/
|
|
more = addr + (1 << hugepd_shift(*(hugepd_t *)pud));
|
|
if (more > next)
|
|
next = more;
|
|
|
|
free_hugepd_range(tlb, (hugepd_t *)pud, PUD_SHIFT,
|
|
addr, next, floor, ceiling);
|
|
}
|
|
} while (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, start);
|
|
}
|
|
|
|
/*
|
|
* This function frees user-level page tables of a process.
|
|
*/
|
|
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;
|
|
|
|
/*
|
|
* Because there are a number of different possible pagetable
|
|
* layouts for hugepage ranges, we limit knowledge of how
|
|
* things should be laid out to the allocation path
|
|
* (huge_pte_alloc(), above). Everything else works out the
|
|
* structure as it goes from information in the hugepd
|
|
* pointers. That means that we can't here use the
|
|
* optimization used in the normal page free_pgd_range(), of
|
|
* checking whether we're actually covering a large enough
|
|
* range to have to do anything at the top level of the walk
|
|
* instead of at the bottom.
|
|
*
|
|
* To make sense of this, you should probably go read the big
|
|
* block comment at the top of the normal free_pgd_range(),
|
|
* too.
|
|
*/
|
|
|
|
do {
|
|
next = pgd_addr_end(addr, end);
|
|
pgd = pgd_offset(tlb->mm, addr);
|
|
if (!is_hugepd(__hugepd(pgd_val(*pgd)))) {
|
|
if (pgd_none_or_clear_bad(pgd))
|
|
continue;
|
|
hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling);
|
|
} else {
|
|
unsigned long more;
|
|
/*
|
|
* Increment next by the size of the huge mapping since
|
|
* there may be more than one entry at the pgd level
|
|
* for a single hugepage, but all of them point to the
|
|
* same kmem cache that holds the hugepte.
|
|
*/
|
|
more = addr + (1 << hugepd_shift(*(hugepd_t *)pgd));
|
|
if (more > next)
|
|
next = more;
|
|
|
|
free_hugepd_range(tlb, (hugepd_t *)pgd, PGDIR_SHIFT,
|
|
addr, next, floor, ceiling);
|
|
}
|
|
} while (addr = next, addr != end);
|
|
}
|
|
|
|
/*
|
|
* We are holding mmap_sem, so a parallel huge page collapse cannot run.
|
|
* To prevent hugepage split, disable irq.
|
|
*/
|
|
struct page *
|
|
follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
|
|
{
|
|
bool is_thp;
|
|
pte_t *ptep, pte;
|
|
unsigned shift;
|
|
unsigned long mask, flags;
|
|
struct page *page = ERR_PTR(-EINVAL);
|
|
|
|
local_irq_save(flags);
|
|
ptep = find_linux_pte_or_hugepte(mm->pgd, address, &is_thp, &shift);
|
|
if (!ptep)
|
|
goto no_page;
|
|
pte = READ_ONCE(*ptep);
|
|
/*
|
|
* Verify it is a huge page else bail.
|
|
* Transparent hugepages are handled by generic code. We can skip them
|
|
* here.
|
|
*/
|
|
if (!shift || is_thp)
|
|
goto no_page;
|
|
|
|
if (!pte_present(pte)) {
|
|
page = NULL;
|
|
goto no_page;
|
|
}
|
|
mask = (1UL << shift) - 1;
|
|
page = pte_page(pte);
|
|
if (page)
|
|
page += (address & mask) / PAGE_SIZE;
|
|
|
|
no_page:
|
|
local_irq_restore(flags);
|
|
return page;
|
|
}
|
|
|
|
struct page *
|
|
follow_huge_pmd(struct mm_struct *mm, unsigned long address,
|
|
pmd_t *pmd, int write)
|
|
{
|
|
BUG();
|
|
return NULL;
|
|
}
|
|
|
|
struct page *
|
|
follow_huge_pud(struct mm_struct *mm, unsigned long address,
|
|
pud_t *pud, int write)
|
|
{
|
|
BUG();
|
|
return NULL;
|
|
}
|
|
|
|
static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end,
|
|
unsigned long sz)
|
|
{
|
|
unsigned long __boundary = (addr + sz) & ~(sz-1);
|
|
return (__boundary - 1 < end - 1) ? __boundary : end;
|
|
}
|
|
|
|
int gup_huge_pd(hugepd_t hugepd, unsigned long addr, unsigned pdshift,
|
|
unsigned long end, int write, struct page **pages, int *nr)
|
|
{
|
|
pte_t *ptep;
|
|
unsigned long sz = 1UL << hugepd_shift(hugepd);
|
|
unsigned long next;
|
|
|
|
ptep = hugepte_offset(hugepd, addr, pdshift);
|
|
do {
|
|
next = hugepte_addr_end(addr, end, sz);
|
|
if (!gup_hugepte(ptep, sz, addr, end, write, pages, nr))
|
|
return 0;
|
|
} while (ptep++, addr = next, addr != end);
|
|
|
|
return 1;
|
|
}
|
|
|
|
#ifdef CONFIG_PPC_MM_SLICES
|
|
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 (radix_enabled())
|
|
return radix__hugetlb_get_unmapped_area(file, addr, len,
|
|
pgoff, flags);
|
|
return slice_get_unmapped_area(addr, len, flags, mmu_psize, 1);
|
|
}
|
|
#endif
|
|
|
|
unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
|
|
{
|
|
#ifdef CONFIG_PPC_MM_SLICES
|
|
unsigned int psize = get_slice_psize(vma->vm_mm, vma->vm_start);
|
|
/* With radix we don't use slice, so derive it from vma*/
|
|
if (!radix_enabled())
|
|
return 1UL << mmu_psize_to_shift(psize);
|
|
#endif
|
|
if (!is_vm_hugetlb_page(vma))
|
|
return PAGE_SIZE;
|
|
|
|
return huge_page_size(hstate_vma(vma));
|
|
}
|
|
|
|
static inline bool is_power_of_4(unsigned long x)
|
|
{
|
|
if (is_power_of_2(x))
|
|
return (__ilog2(x) % 2) ? false : true;
|
|
return false;
|
|
}
|
|
|
|
static int __init add_huge_page_size(unsigned long long size)
|
|
{
|
|
int shift = __ffs(size);
|
|
int mmu_psize;
|
|
|
|
/* Check that it is a page size supported by the hardware and
|
|
* that it fits within pagetable and slice limits. */
|
|
if (size <= PAGE_SIZE)
|
|
return -EINVAL;
|
|
#if defined(CONFIG_PPC_FSL_BOOK3E)
|
|
if (!is_power_of_4(size))
|
|
return -EINVAL;
|
|
#elif !defined(CONFIG_PPC_8xx)
|
|
if (!is_power_of_2(size) || (shift > SLICE_HIGH_SHIFT))
|
|
return -EINVAL;
|
|
#endif
|
|
|
|
if ((mmu_psize = shift_to_mmu_psize(shift)) < 0)
|
|
return -EINVAL;
|
|
|
|
#ifdef CONFIG_PPC_BOOK3S_64
|
|
/*
|
|
* We need to make sure that for different page sizes reported by
|
|
* firmware we only add hugetlb support for page sizes that can be
|
|
* supported by linux page table layout.
|
|
* For now we have
|
|
* Radix: 2M
|
|
* Hash: 16M and 16G
|
|
*/
|
|
if (radix_enabled()) {
|
|
if (mmu_psize != MMU_PAGE_2M)
|
|
return -EINVAL;
|
|
} else {
|
|
if (mmu_psize != MMU_PAGE_16M && mmu_psize != MMU_PAGE_16G)
|
|
return -EINVAL;
|
|
}
|
|
#endif
|
|
|
|
BUG_ON(mmu_psize_defs[mmu_psize].shift != shift);
|
|
|
|
/* Return if huge page size has already been setup */
|
|
if (size_to_hstate(size))
|
|
return 0;
|
|
|
|
hugetlb_add_hstate(shift - PAGE_SHIFT);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __init hugepage_setup_sz(char *str)
|
|
{
|
|
unsigned long long size;
|
|
|
|
size = memparse(str, &str);
|
|
|
|
if (add_huge_page_size(size) != 0) {
|
|
hugetlb_bad_size();
|
|
pr_err("Invalid huge page size specified(%llu)\n", size);
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
__setup("hugepagesz=", hugepage_setup_sz);
|
|
|
|
struct kmem_cache *hugepte_cache;
|
|
static int __init hugetlbpage_init(void)
|
|
{
|
|
int psize;
|
|
|
|
#if !defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_PPC_8xx)
|
|
if (!radix_enabled() && !mmu_has_feature(MMU_FTR_16M_PAGE))
|
|
return -ENODEV;
|
|
#endif
|
|
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
|
|
unsigned shift;
|
|
unsigned pdshift;
|
|
|
|
if (!mmu_psize_defs[psize].shift)
|
|
continue;
|
|
|
|
shift = mmu_psize_to_shift(psize);
|
|
|
|
if (add_huge_page_size(1ULL << shift) < 0)
|
|
continue;
|
|
|
|
if (shift < HUGEPD_PUD_SHIFT)
|
|
pdshift = PMD_SHIFT;
|
|
else if (shift < HUGEPD_PGD_SHIFT)
|
|
pdshift = PUD_SHIFT;
|
|
else
|
|
pdshift = PGDIR_SHIFT;
|
|
/*
|
|
* if we have pdshift and shift value same, we don't
|
|
* use pgt cache for hugepd.
|
|
*/
|
|
if (pdshift > shift)
|
|
pgtable_cache_add(pdshift - shift, NULL);
|
|
#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
|
|
else if (!hugepte_cache) {
|
|
/*
|
|
* Create a kmem cache for hugeptes. The bottom bits in
|
|
* the pte have size information encoded in them, so
|
|
* align them to allow this
|
|
*/
|
|
hugepte_cache = kmem_cache_create("hugepte-cache",
|
|
sizeof(pte_t),
|
|
HUGEPD_SHIFT_MASK + 1,
|
|
0, NULL);
|
|
if (hugepte_cache == NULL)
|
|
panic("%s: Unable to create kmem cache "
|
|
"for hugeptes\n", __func__);
|
|
|
|
}
|
|
#endif
|
|
}
|
|
|
|
#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
|
|
/* Default hpage size = 4M on FSL_BOOK3E and 512k on 8xx */
|
|
if (mmu_psize_defs[MMU_PAGE_4M].shift)
|
|
HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_4M].shift;
|
|
else if (mmu_psize_defs[MMU_PAGE_512K].shift)
|
|
HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_512K].shift;
|
|
#else
|
|
/* Set default large page size. Currently, we pick 16M or 1M
|
|
* depending on what is available
|
|
*/
|
|
if (mmu_psize_defs[MMU_PAGE_16M].shift)
|
|
HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_16M].shift;
|
|
else if (mmu_psize_defs[MMU_PAGE_1M].shift)
|
|
HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_1M].shift;
|
|
else if (mmu_psize_defs[MMU_PAGE_2M].shift)
|
|
HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_2M].shift;
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
arch_initcall(hugetlbpage_init);
|
|
|
|
void flush_dcache_icache_hugepage(struct page *page)
|
|
{
|
|
int i;
|
|
void *start;
|
|
|
|
BUG_ON(!PageCompound(page));
|
|
|
|
for (i = 0; i < (1UL << compound_order(page)); i++) {
|
|
if (!PageHighMem(page)) {
|
|
__flush_dcache_icache(page_address(page+i));
|
|
} else {
|
|
start = kmap_atomic(page+i);
|
|
__flush_dcache_icache(start);
|
|
kunmap_atomic(start);
|
|
}
|
|
}
|
|
}
|
|
|
|
#endif /* CONFIG_HUGETLB_PAGE */
|
|
|
|
/*
|
|
* We have 4 cases for pgds and pmds:
|
|
* (1) invalid (all zeroes)
|
|
* (2) pointer to next table, as normal; bottom 6 bits == 0
|
|
* (3) leaf pte for huge page _PAGE_PTE set
|
|
* (4) hugepd pointer, _PAGE_PTE = 0 and bits [2..6] indicate size of table
|
|
*
|
|
* So long as we atomically load page table pointers we are safe against teardown,
|
|
* we can follow the address down to the the page and take a ref on it.
|
|
* This function need to be called with interrupts disabled. We use this variant
|
|
* when we have MSR[EE] = 0 but the paca->soft_enabled = 1
|
|
*/
|
|
|
|
pte_t *__find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
|
|
bool *is_thp, unsigned *shift)
|
|
{
|
|
pgd_t pgd, *pgdp;
|
|
pud_t pud, *pudp;
|
|
pmd_t pmd, *pmdp;
|
|
pte_t *ret_pte;
|
|
hugepd_t *hpdp = NULL;
|
|
unsigned pdshift = PGDIR_SHIFT;
|
|
|
|
if (shift)
|
|
*shift = 0;
|
|
|
|
if (is_thp)
|
|
*is_thp = false;
|
|
|
|
pgdp = pgdir + pgd_index(ea);
|
|
pgd = READ_ONCE(*pgdp);
|
|
/*
|
|
* Always operate on the local stack value. This make sure the
|
|
* value don't get updated by a parallel THP split/collapse,
|
|
* page fault or a page unmap. The return pte_t * is still not
|
|
* stable. So should be checked there for above conditions.
|
|
*/
|
|
if (pgd_none(pgd))
|
|
return NULL;
|
|
else if (pgd_huge(pgd)) {
|
|
ret_pte = (pte_t *) pgdp;
|
|
goto out;
|
|
} else if (is_hugepd(__hugepd(pgd_val(pgd))))
|
|
hpdp = (hugepd_t *)&pgd;
|
|
else {
|
|
/*
|
|
* Even if we end up with an unmap, the pgtable will not
|
|
* be freed, because we do an rcu free and here we are
|
|
* irq disabled
|
|
*/
|
|
pdshift = PUD_SHIFT;
|
|
pudp = pud_offset(&pgd, ea);
|
|
pud = READ_ONCE(*pudp);
|
|
|
|
if (pud_none(pud))
|
|
return NULL;
|
|
else if (pud_huge(pud)) {
|
|
ret_pte = (pte_t *) pudp;
|
|
goto out;
|
|
} else if (is_hugepd(__hugepd(pud_val(pud))))
|
|
hpdp = (hugepd_t *)&pud;
|
|
else {
|
|
pdshift = PMD_SHIFT;
|
|
pmdp = pmd_offset(&pud, ea);
|
|
pmd = READ_ONCE(*pmdp);
|
|
/*
|
|
* A hugepage collapse is captured by pmd_none, because
|
|
* it mark the pmd none and do a hpte invalidate.
|
|
*/
|
|
if (pmd_none(pmd))
|
|
return NULL;
|
|
|
|
if (pmd_trans_huge(pmd)) {
|
|
if (is_thp)
|
|
*is_thp = true;
|
|
ret_pte = (pte_t *) pmdp;
|
|
goto out;
|
|
}
|
|
|
|
if (pmd_huge(pmd)) {
|
|
ret_pte = (pte_t *) pmdp;
|
|
goto out;
|
|
} else if (is_hugepd(__hugepd(pmd_val(pmd))))
|
|
hpdp = (hugepd_t *)&pmd;
|
|
else
|
|
return pte_offset_kernel(&pmd, ea);
|
|
}
|
|
}
|
|
if (!hpdp)
|
|
return NULL;
|
|
|
|
ret_pte = hugepte_offset(*hpdp, ea, pdshift);
|
|
pdshift = hugepd_shift(*hpdp);
|
|
out:
|
|
if (shift)
|
|
*shift = pdshift;
|
|
return ret_pte;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__find_linux_pte_or_hugepte);
|
|
|
|
int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
|
|
unsigned long end, int write, struct page **pages, int *nr)
|
|
{
|
|
unsigned long mask;
|
|
unsigned long pte_end;
|
|
struct page *head, *page;
|
|
pte_t pte;
|
|
int refs;
|
|
|
|
pte_end = (addr + sz) & ~(sz-1);
|
|
if (pte_end < end)
|
|
end = pte_end;
|
|
|
|
pte = READ_ONCE(*ptep);
|
|
mask = _PAGE_PRESENT | _PAGE_READ;
|
|
|
|
/*
|
|
* On some CPUs like the 8xx, _PAGE_RW hence _PAGE_WRITE is defined
|
|
* as 0 and _PAGE_RO has to be set when a page is not writable
|
|
*/
|
|
if (write)
|
|
mask |= _PAGE_WRITE;
|
|
else
|
|
mask |= _PAGE_RO;
|
|
|
|
if ((pte_val(pte) & mask) != mask)
|
|
return 0;
|
|
|
|
/* hugepages are never "special" */
|
|
VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
|
|
|
|
refs = 0;
|
|
head = pte_page(pte);
|
|
|
|
page = head + ((addr & (sz-1)) >> PAGE_SHIFT);
|
|
do {
|
|
VM_BUG_ON(compound_head(page) != head);
|
|
pages[*nr] = page;
|
|
(*nr)++;
|
|
page++;
|
|
refs++;
|
|
} while (addr += PAGE_SIZE, addr != end);
|
|
|
|
if (!page_cache_add_speculative(head, refs)) {
|
|
*nr -= refs;
|
|
return 0;
|
|
}
|
|
|
|
if (unlikely(pte_val(pte) != pte_val(*ptep))) {
|
|
/* Could be optimized better */
|
|
*nr -= refs;
|
|
while (refs--)
|
|
put_page(head);
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|