582 lines
13 KiB
C
582 lines
13 KiB
C
/*
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* PPC64 (POWER4) 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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*
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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 <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/tlb.h>
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#define PAGE_SHIFT_64K 16
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#define PAGE_SHIFT_16M 24
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#define PAGE_SHIFT_16G 34
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#define MAX_NUMBER_GPAGES 1024
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/* Tracks the 16G pages after the device tree is scanned and before the
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* huge_boot_pages list is ready. */
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static unsigned long gpage_freearray[MAX_NUMBER_GPAGES];
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static unsigned nr_gpages;
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/* Flag to mark huge PD pointers. This means pmd_bad() and pud_bad()
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* will choke on pointers to hugepte tables, which is handy for
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* catching screwups early. */
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static inline int shift_to_mmu_psize(unsigned int shift)
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{
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int psize;
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for (psize = 0; psize < MMU_PAGE_COUNT; ++psize)
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if (mmu_psize_defs[psize].shift == shift)
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return psize;
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return -1;
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}
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static inline unsigned int mmu_psize_to_shift(unsigned int mmu_psize)
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{
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if (mmu_psize_defs[mmu_psize].shift)
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return mmu_psize_defs[mmu_psize].shift;
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BUG();
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}
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#define hugepd_none(hpd) ((hpd).pd == 0)
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static inline pte_t *hugepd_page(hugepd_t hpd)
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{
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BUG_ON(!hugepd_ok(hpd));
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return (pte_t *)((hpd.pd & ~HUGEPD_SHIFT_MASK) | 0xc000000000000000);
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}
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static inline unsigned int hugepd_shift(hugepd_t hpd)
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{
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return hpd.pd & HUGEPD_SHIFT_MASK;
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}
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static inline pte_t *hugepte_offset(hugepd_t *hpdp, unsigned long addr, unsigned pdshift)
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{
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unsigned long idx = (addr & ((1UL << pdshift) - 1)) >> hugepd_shift(*hpdp);
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pte_t *dir = hugepd_page(*hpdp);
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return dir + idx;
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}
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pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift)
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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 pdshift = PGDIR_SHIFT;
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if (shift)
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*shift = 0;
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pg = pgdir + pgd_index(ea);
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if (is_hugepd(pg)) {
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hpdp = (hugepd_t *)pg;
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} else if (!pgd_none(*pg)) {
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pdshift = PUD_SHIFT;
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pu = pud_offset(pg, ea);
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if (is_hugepd(pu))
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hpdp = (hugepd_t *)pu;
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else if (!pud_none(*pu)) {
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pdshift = PMD_SHIFT;
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pm = pmd_offset(pu, ea);
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if (is_hugepd(pm))
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hpdp = (hugepd_t *)pm;
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else if (!pmd_none(*pm)) {
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return pte_offset_map(pm, ea);
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}
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}
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}
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if (!hpdp)
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return NULL;
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if (shift)
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*shift = hugepd_shift(*hpdp);
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return hugepte_offset(hpdp, ea, pdshift);
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}
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pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
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{
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return find_linux_pte_or_hugepte(mm->pgd, addr, 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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pte_t *new = kmem_cache_zalloc(PGT_CACHE(pdshift - pshift),
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GFP_KERNEL|__GFP_REPEAT);
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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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spin_lock(&mm->page_table_lock);
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if (!hugepd_none(*hpdp))
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kmem_cache_free(PGT_CACHE(pdshift - pshift), new);
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else
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hpdp->pd = ((unsigned long)new & ~0x8000000000000000) | pshift;
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spin_unlock(&mm->page_table_lock);
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return 0;
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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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if (pshift >= PUD_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 >= 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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hpdp = (hugepd_t *)pm;
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}
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}
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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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/* Build list of addresses of gigantic pages. This function is used in early
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* boot before the buddy or bootmem allocator is setup.
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*/
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void add_gpage(unsigned long addr, unsigned long page_size,
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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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int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
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{
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return 0;
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}
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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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unsigned shift = hugepd_shift(*hpdp);
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unsigned long pdmask = ~((1UL << pdshift) - 1);
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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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hpdp->pd = 0;
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tlb->need_flush = 1;
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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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pmd = pmd_offset(pud, addr);
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do {
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next = pmd_addr_end(addr, end);
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if (pmd_none(*pmd))
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continue;
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free_hugepd_range(tlb, (hugepd_t *)pmd, PMD_SHIFT,
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addr, next, floor, ceiling);
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} while (pmd++, addr = next, addr != end);
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start &= PUD_MASK;
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if (start < floor)
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return;
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if (ceiling) {
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ceiling &= PUD_MASK;
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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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pmd = pmd_offset(pud, start);
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pud_clear(pud);
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pmd_free_tlb(tlb, pmd, start);
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}
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static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
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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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pud_t *pud;
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unsigned long next;
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unsigned long start;
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start = addr;
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pud = pud_offset(pgd, addr);
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do {
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next = pud_addr_end(addr, end);
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if (!is_hugepd(pud)) {
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if (pud_none_or_clear_bad(pud))
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continue;
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hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
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ceiling);
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} else {
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free_hugepd_range(tlb, (hugepd_t *)pud, PUD_SHIFT,
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addr, next, floor, ceiling);
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}
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} while (pud++, addr = next, addr != end);
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start &= PGDIR_MASK;
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if (start < floor)
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return;
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if (ceiling) {
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ceiling &= PGDIR_MASK;
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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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pud = pud_offset(pgd, start);
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pgd_clear(pgd);
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pud_free_tlb(tlb, pud, start);
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}
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/*
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* This function frees user-level page tables of a process.
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*
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* Must be called with pagetable lock held.
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*/
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void hugetlb_free_pgd_range(struct mmu_gather *tlb,
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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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pgd_t *pgd;
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unsigned long next;
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/*
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* Because there are a number of different possible pagetable
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* layouts for hugepage ranges, we limit knowledge of how
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* things should be laid out to the allocation path
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* (huge_pte_alloc(), above). Everything else works out the
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* structure as it goes from information in the hugepd
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* pointers. That means that we can't here use the
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* optimization used in the normal page free_pgd_range(), of
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* checking whether we're actually covering a large enough
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* range to have to do anything at the top level of the walk
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* instead of at the bottom.
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*
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* To make sense of this, you should probably go read the big
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* block comment at the top of the normal free_pgd_range(),
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* too.
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*/
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pgd = pgd_offset(tlb->mm, addr);
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do {
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next = pgd_addr_end(addr, end);
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if (!is_hugepd(pgd)) {
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if (pgd_none_or_clear_bad(pgd))
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continue;
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hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling);
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} else {
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free_hugepd_range(tlb, (hugepd_t *)pgd, PGDIR_SHIFT,
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addr, next, floor, ceiling);
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}
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} while (pgd++, addr = next, addr != end);
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}
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struct page *
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follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
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{
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pte_t *ptep;
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struct page *page;
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unsigned shift;
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unsigned long mask;
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ptep = find_linux_pte_or_hugepte(mm->pgd, address, &shift);
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/* Verify it is a huge page else bail. */
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if (!ptep || !shift)
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return ERR_PTR(-EINVAL);
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mask = (1UL << shift) - 1;
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page = pte_page(*ptep);
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if (page)
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page += (address & mask) / PAGE_SIZE;
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return page;
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}
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int pmd_huge(pmd_t pmd)
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{
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return 0;
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}
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int pud_huge(pud_t pud)
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{
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return 0;
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}
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struct page *
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follow_huge_pmd(struct mm_struct *mm, unsigned long address,
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pmd_t *pmd, int write)
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{
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BUG();
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return NULL;
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}
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static noinline int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
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unsigned long end, int write, struct page **pages, int *nr)
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{
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unsigned long mask;
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unsigned long pte_end;
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struct page *head, *page;
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pte_t pte;
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int refs;
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pte_end = (addr + sz) & ~(sz-1);
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if (pte_end < end)
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end = pte_end;
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pte = *ptep;
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mask = _PAGE_PRESENT | _PAGE_USER;
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if (write)
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mask |= _PAGE_RW;
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if ((pte_val(pte) & mask) != mask)
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return 0;
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/* hugepages are never "special" */
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VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
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refs = 0;
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head = pte_page(pte);
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page = head + ((addr & (sz-1)) >> PAGE_SHIFT);
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do {
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VM_BUG_ON(compound_head(page) != head);
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pages[*nr] = page;
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(*nr)++;
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page++;
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refs++;
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} while (addr += PAGE_SIZE, addr != end);
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if (!page_cache_add_speculative(head, refs)) {
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*nr -= refs;
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return 0;
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}
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if (unlikely(pte_val(pte) != pte_val(*ptep))) {
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/* Could be optimized better */
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while (*nr) {
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put_page(page);
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(*nr)--;
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}
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}
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return 1;
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}
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static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end,
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unsigned long sz)
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{
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unsigned long __boundary = (addr + sz) & ~(sz-1);
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return (__boundary - 1 < end - 1) ? __boundary : end;
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}
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int gup_hugepd(hugepd_t *hugepd, unsigned pdshift,
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unsigned long addr, unsigned long end,
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int write, struct page **pages, int *nr)
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{
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pte_t *ptep;
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unsigned long sz = 1UL << hugepd_shift(*hugepd);
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unsigned long next;
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ptep = hugepte_offset(hugepd, addr, pdshift);
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do {
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next = hugepte_addr_end(addr, end, sz);
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if (!gup_hugepte(ptep, sz, addr, end, write, pages, nr))
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return 0;
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} while (ptep++, addr = next, addr != end);
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return 1;
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}
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unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
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unsigned long len, unsigned long pgoff,
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unsigned long flags)
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{
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struct hstate *hstate = hstate_file(file);
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int mmu_psize = shift_to_mmu_psize(huge_page_shift(hstate));
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return slice_get_unmapped_area(addr, len, flags, mmu_psize, 1, 0);
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}
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unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
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{
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unsigned int psize = get_slice_psize(vma->vm_mm, vma->vm_start);
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return 1UL << mmu_psize_to_shift(psize);
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}
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static int __init add_huge_page_size(unsigned long long size)
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{
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int shift = __ffs(size);
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int mmu_psize;
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/* Check that it is a page size supported by the hardware and
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* that it fits within pagetable and slice limits. */
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if (!is_power_of_2(size)
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|| (shift > SLICE_HIGH_SHIFT) || (shift <= PAGE_SHIFT))
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return -EINVAL;
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if ((mmu_psize = shift_to_mmu_psize(shift)) < 0)
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return -EINVAL;
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#ifdef CONFIG_SPU_FS_64K_LS
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/* Disable support for 64K huge pages when 64K SPU local store
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* support is enabled as the current implementation conflicts.
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*/
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if (shift == PAGE_SHIFT_64K)
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return -EINVAL;
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#endif /* CONFIG_SPU_FS_64K_LS */
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BUG_ON(mmu_psize_defs[mmu_psize].shift != shift);
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/* Return if huge page size has already been setup */
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if (size_to_hstate(size))
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return 0;
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hugetlb_add_hstate(shift - PAGE_SHIFT);
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return 0;
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}
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static int __init hugepage_setup_sz(char *str)
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{
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unsigned long long size;
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size = memparse(str, &str);
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if (add_huge_page_size(size) != 0)
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printk(KERN_WARNING "Invalid huge page size specified(%llu)\n", size);
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return 1;
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}
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__setup("hugepagesz=", hugepage_setup_sz);
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|
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static int __init hugetlbpage_init(void)
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{
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int psize;
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|
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if (!cpu_has_feature(CPU_FTR_16M_PAGE))
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return -ENODEV;
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|
|
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 < PMD_SHIFT)
|
|
pdshift = PMD_SHIFT;
|
|
else if (shift < PUD_SHIFT)
|
|
pdshift = PUD_SHIFT;
|
|
else
|
|
pdshift = PGDIR_SHIFT;
|
|
|
|
pgtable_cache_add(pdshift - shift, NULL);
|
|
if (!PGT_CACHE(pdshift - shift))
|
|
panic("hugetlbpage_init(): could not create "
|
|
"pgtable cache for %d bit pagesize\n", shift);
|
|
}
|
|
|
|
/* 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;
|
|
|
|
return 0;
|
|
}
|
|
|
|
module_init(hugetlbpage_init);
|
|
|
|
void flush_dcache_icache_hugepage(struct page *page)
|
|
{
|
|
int i;
|
|
|
|
BUG_ON(!PageCompound(page));
|
|
|
|
for (i = 0; i < (1UL << compound_order(page)); i++)
|
|
__flush_dcache_icache(page_address(page+i));
|
|
}
|