diff options
Diffstat (limited to 'arch/powerpc/mm/book3s64/hugetlbpage.c')
| -rw-r--r-- | arch/powerpc/mm/book3s64/hugetlbpage.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/arch/powerpc/mm/book3s64/hugetlbpage.c b/arch/powerpc/mm/book3s64/hugetlbpage.c new file mode 100644 index 000000000000..ea8f83afb0ae --- /dev/null +++ b/arch/powerpc/mm/book3s64/hugetlbpage.c @@ -0,0 +1,164 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PPC64 Huge TLB Page Support for hash based MMUs (POWER4 and later) + * + * Copyright (C) 2003 David Gibson, IBM Corporation. + * + * Based on the IA-32 version: + * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com> + */ + +#include <linux/mm.h> +#include <linux/hugetlb.h> +#include <asm/cacheflush.h> +#include <asm/machdep.h> + +unsigned int hpage_shift; +EXPORT_SYMBOL(hpage_shift); + +#ifdef CONFIG_PPC_64S_HASH_MMU +int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid, + pte_t *ptep, unsigned long trap, unsigned long flags, + int ssize, unsigned int shift, unsigned int mmu_psize) +{ + real_pte_t rpte; + unsigned long vpn; + unsigned long old_pte, new_pte; + unsigned long rflags, pa; + long slot, offset; + + BUG_ON(shift != mmu_psize_defs[mmu_psize].shift); + + /* Search the Linux page table for a match with va */ + vpn = hpt_vpn(ea, vsid, ssize); + + /* + * At this point, we have a pte (old_pte) which can be used to build + * or update an HPTE. There are 2 cases: + * + * 1. There is a valid (present) pte with no associated HPTE (this is + * the most common case) + * 2. There is a valid (present) pte with an associated HPTE. The + * current values of the pp bits in the HPTE prevent access + * because we are doing software DIRTY bit management and the + * page is currently not DIRTY. + */ + + + do { + old_pte = pte_val(*ptep); + /* If PTE busy, retry the access */ + if (unlikely(old_pte & H_PAGE_BUSY)) + return 0; + /* If PTE permissions don't match, take page fault */ + if (unlikely(!check_pte_access(access, old_pte))) + return 1; + + /* + * Try to lock the PTE, add ACCESSED and DIRTY if it was + * a write access + */ + new_pte = old_pte | H_PAGE_BUSY | _PAGE_ACCESSED; + if (access & _PAGE_WRITE) + new_pte |= _PAGE_DIRTY; + } while(!pte_xchg(ptep, __pte(old_pte), __pte(new_pte))); + + /* Make sure this is a hugetlb entry */ + if (old_pte & (H_PAGE_THP_HUGE | _PAGE_DEVMAP)) + return 0; + + rflags = htab_convert_pte_flags(new_pte, flags); + if (unlikely(mmu_psize == MMU_PAGE_16G)) + offset = PTRS_PER_PUD; + else + offset = PTRS_PER_PMD; + rpte = __real_pte(__pte(old_pte), ptep, offset); + + if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) + /* + * No CPU has hugepages but lacks no execute, so we + * don't need to worry about that case + */ + rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap); + + /* Check if pte already has an hpte (case 2) */ + if (unlikely(old_pte & H_PAGE_HASHPTE)) { + /* There MIGHT be an HPTE for this pte */ + unsigned long gslot; + + gslot = pte_get_hash_gslot(vpn, shift, ssize, rpte, 0); + if (mmu_hash_ops.hpte_updatepp(gslot, rflags, vpn, mmu_psize, + mmu_psize, ssize, flags) == -1) + old_pte &= ~_PAGE_HPTEFLAGS; + } + + if (likely(!(old_pte & H_PAGE_HASHPTE))) { + unsigned long hash = hpt_hash(vpn, shift, ssize); + + pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT; + + /* clear HPTE slot informations in new PTE */ + new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | H_PAGE_HASHPTE; + + slot = hpte_insert_repeating(hash, vpn, pa, rflags, 0, + mmu_psize, ssize); + + /* + * Hypervisor failure. Restore old pte and return -1 + * similar to __hash_page_* + */ + if (unlikely(slot == -2)) { + *ptep = __pte(old_pte); + hash_failure_debug(ea, access, vsid, trap, ssize, + mmu_psize, mmu_psize, old_pte); + return -1; + } + + new_pte |= pte_set_hidx(ptep, rpte, 0, slot, offset); + } + + /* + * No need to use ldarx/stdcx here + */ + *ptep = __pte(new_pte & ~H_PAGE_BUSY); + return 0; +} +#endif + +pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) +{ + unsigned long pte_val; + /* + * Clear the _PAGE_PRESENT so that no hardware parallel update is + * possible. Also keep the pte_present true so that we don't take + * wrong fault. + */ + pte_val = pte_update(vma->vm_mm, addr, ptep, + _PAGE_PRESENT, _PAGE_INVALID, 1); + + return __pte(pte_val); +} + +void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, + pte_t *ptep, pte_t old_pte, pte_t pte) +{ + + if (radix_enabled()) + return radix__huge_ptep_modify_prot_commit(vma, addr, ptep, + old_pte, pte); + set_huge_pte_at(vma->vm_mm, addr, ptep, pte); +} + +void __init hugetlbpage_init_default(void) +{ + /* 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; +} |