diff options
Diffstat (limited to 'arch/powerpc/mm/hugetlbpage-hash64.c')
| -rw-r--r-- | arch/powerpc/mm/hugetlbpage-hash64.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c new file mode 100644 index 00000000000..199539882f9 --- /dev/null +++ b/arch/powerpc/mm/hugetlbpage-hash64.c @@ -0,0 +1,139 @@ +/* + * 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/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/cacheflush.h> +#include <asm/machdep.h> + +int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid, + pte_t *ptep, unsigned long trap, int local, int ssize, + unsigned int shift, unsigned int mmu_psize) +{ + unsigned long old_pte, new_pte; + unsigned long va, rflags, pa, sz; + long slot; + int err = 1; + + BUG_ON(shift != mmu_psize_defs[mmu_psize].shift); + + /* Search the Linux page table for a match with va */ + va = hpt_va(ea, vsid, ssize); + + /* + * Check the user's access rights to the page. If access should be + * prevented then send the problem up to do_page_fault. + */ + if (unlikely(access & ~pte_val(*ptep))) + goto out; + /* + * 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 (old_pte & _PAGE_BUSY) + goto out; + new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED; + } while(old_pte != __cmpxchg_u64((unsigned long *)ptep, + old_pte, new_pte)); + + rflags = 0x2 | (!(new_pte & _PAGE_RW)); + /* _PAGE_EXEC -> HW_NO_EXEC since it's inverted */ + rflags |= ((new_pte & _PAGE_EXEC) ? 0 : HPTE_R_N); + sz = ((1UL) << shift); + 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 & _PAGE_HASHPTE)) { + /* There MIGHT be an HPTE for this pte */ + unsigned long hash, slot; + + hash = hpt_hash(va, shift, ssize); + if (old_pte & _PAGE_F_SECOND) + hash = ~hash; + slot = (hash & htab_hash_mask) * HPTES_PER_GROUP; + slot += (old_pte & _PAGE_F_GIX) >> 12; + + if (ppc_md.hpte_updatepp(slot, rflags, va, mmu_psize, + ssize, local) == -1) + old_pte &= ~_PAGE_HPTEFLAGS; + } + + if (likely(!(old_pte & _PAGE_HASHPTE))) { + unsigned long hash = hpt_hash(va, shift, ssize); + unsigned long hpte_group; + + pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT; + +repeat: + hpte_group = ((hash & htab_hash_mask) * + HPTES_PER_GROUP) & ~0x7UL; + + /* clear HPTE slot informations in new PTE */ +#ifdef CONFIG_PPC_64K_PAGES + new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | _PAGE_HPTE_SUB0; +#else + new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | _PAGE_HASHPTE; +#endif + /* Add in WIMG bits */ + rflags |= (new_pte & (_PAGE_WRITETHRU | _PAGE_NO_CACHE | + _PAGE_COHERENT | _PAGE_GUARDED)); + + /* Insert into the hash table, primary slot */ + slot = ppc_md.hpte_insert(hpte_group, va, pa, rflags, 0, + mmu_psize, ssize); + + /* Primary is full, try the secondary */ + if (unlikely(slot == -1)) { + hpte_group = ((~hash & htab_hash_mask) * + HPTES_PER_GROUP) & ~0x7UL; + slot = ppc_md.hpte_insert(hpte_group, va, pa, rflags, + HPTE_V_SECONDARY, + mmu_psize, ssize); + if (slot == -1) { + if (mftb() & 0x1) + hpte_group = ((hash & htab_hash_mask) * + HPTES_PER_GROUP)&~0x7UL; + + ppc_md.hpte_remove(hpte_group); + goto repeat; + } + } + + if (unlikely(slot == -2)) + panic("hash_huge_page: pte_insert failed\n"); + + new_pte |= (slot << 12) & (_PAGE_F_SECOND | _PAGE_F_GIX); + } + + /* + * No need to use ldarx/stdcx here + */ + *ptep = __pte(new_pte & ~_PAGE_BUSY); + + err = 0; + + out: + return err; +} |