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945537df7a
This helps to make following hash only pte bits easier. We have kept _PAGE_CHG_MASK, _HPAGE_CHG_MASK and _PAGE_PROT_BITS as it is in this patch eventhough they use hash specific bits. Using them in radix as it is should be ok, because with radix we expect those bit positions to be zero. Only renames in this patch, no change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
327 lines
9.0 KiB
C
327 lines
9.0 KiB
C
/*
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* Copyright IBM Corporation, 2015
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* Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of version 2 of the GNU Lesser General Public License
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it would be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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*
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*/
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#include <linux/mm.h>
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#include <asm/machdep.h>
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#include <asm/mmu.h>
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/*
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* index from 0 - 15
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*/
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bool __rpte_sub_valid(real_pte_t rpte, unsigned long index)
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{
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unsigned long g_idx;
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unsigned long ptev = pte_val(rpte.pte);
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g_idx = (ptev & H_PAGE_COMBO_VALID) >> H_PAGE_F_GIX_SHIFT;
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index = index >> 2;
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if (g_idx & (0x1 << index))
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return true;
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else
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return false;
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}
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/*
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* index from 0 - 15
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*/
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static unsigned long mark_subptegroup_valid(unsigned long ptev, unsigned long index)
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{
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unsigned long g_idx;
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if (!(ptev & H_PAGE_COMBO))
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return ptev;
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index = index >> 2;
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g_idx = 0x1 << index;
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return ptev | (g_idx << H_PAGE_F_GIX_SHIFT);
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}
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int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
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pte_t *ptep, unsigned long trap, unsigned long flags,
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int ssize, int subpg_prot)
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{
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real_pte_t rpte;
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unsigned long *hidxp;
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unsigned long hpte_group;
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unsigned int subpg_index;
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unsigned long rflags, pa, hidx;
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unsigned long old_pte, new_pte, subpg_pte;
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unsigned long vpn, hash, slot;
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unsigned long shift = mmu_psize_defs[MMU_PAGE_4K].shift;
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/*
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* atomically mark the linux large page PTE busy and dirty
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*/
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do {
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pte_t pte = READ_ONCE(*ptep);
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old_pte = pte_val(pte);
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/* If PTE busy, retry the access */
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if (unlikely(old_pte & H_PAGE_BUSY))
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return 0;
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/* If PTE permissions don't match, take page fault */
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if (unlikely(!check_pte_access(access, old_pte)))
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return 1;
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/*
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* Try to lock the PTE, add ACCESSED and DIRTY if it was
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* a write access. Since this is 4K insert of 64K page size
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* also add H_PAGE_COMBO
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*/
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new_pte = old_pte | H_PAGE_BUSY | _PAGE_ACCESSED | H_PAGE_COMBO;
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if (access & _PAGE_WRITE)
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new_pte |= _PAGE_DIRTY;
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} while (!pte_xchg(ptep, __pte(old_pte), __pte(new_pte)));
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/*
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* Handle the subpage protection bits
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*/
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subpg_pte = new_pte & ~subpg_prot;
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rflags = htab_convert_pte_flags(subpg_pte);
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if (!cpu_has_feature(CPU_FTR_NOEXECUTE) &&
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!cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) {
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/*
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* No CPU has hugepages but lacks no execute, so we
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* don't need to worry about that case
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*/
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rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);
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}
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subpg_index = (ea & (PAGE_SIZE - 1)) >> shift;
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vpn = hpt_vpn(ea, vsid, ssize);
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rpte = __real_pte(__pte(old_pte), ptep);
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/*
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*None of the sub 4k page is hashed
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*/
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if (!(old_pte & H_PAGE_HASHPTE))
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goto htab_insert_hpte;
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/*
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* Check if the pte was already inserted into the hash table
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* as a 64k HW page, and invalidate the 64k HPTE if so.
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*/
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if (!(old_pte & H_PAGE_COMBO)) {
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flush_hash_page(vpn, rpte, MMU_PAGE_64K, ssize, flags);
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/*
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* clear the old slot details from the old and new pte.
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* On hash insert failure we use old pte value and we don't
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* want slot information there if we have a insert failure.
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*/
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old_pte &= ~(H_PAGE_HASHPTE | H_PAGE_F_GIX | H_PAGE_F_SECOND);
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new_pte &= ~(H_PAGE_HASHPTE | H_PAGE_F_GIX | H_PAGE_F_SECOND);
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goto htab_insert_hpte;
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}
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/*
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* Check for sub page valid and update
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*/
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if (__rpte_sub_valid(rpte, subpg_index)) {
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int ret;
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hash = hpt_hash(vpn, shift, ssize);
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hidx = __rpte_to_hidx(rpte, subpg_index);
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if (hidx & _PTEIDX_SECONDARY)
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hash = ~hash;
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slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
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slot += hidx & _PTEIDX_GROUP_IX;
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ret = ppc_md.hpte_updatepp(slot, rflags, vpn,
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MMU_PAGE_4K, MMU_PAGE_4K,
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ssize, flags);
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/*
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*if we failed because typically the HPTE wasn't really here
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* we try an insertion.
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*/
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if (ret == -1)
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goto htab_insert_hpte;
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*ptep = __pte(new_pte & ~H_PAGE_BUSY);
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return 0;
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}
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htab_insert_hpte:
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/*
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* handle H_PAGE_4K_PFN case
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*/
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if (old_pte & H_PAGE_4K_PFN) {
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/*
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* All the sub 4k page have the same
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* physical address.
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*/
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pa = pte_pfn(__pte(old_pte)) << HW_PAGE_SHIFT;
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} else {
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pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT;
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pa += (subpg_index << shift);
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}
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hash = hpt_hash(vpn, shift, ssize);
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repeat:
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hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
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/* Insert into the hash table, primary slot */
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slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags, 0,
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MMU_PAGE_4K, MMU_PAGE_4K, ssize);
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/*
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* Primary is full, try the secondary
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*/
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if (unlikely(slot == -1)) {
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hpte_group = ((~hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
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slot = ppc_md.hpte_insert(hpte_group, vpn, pa,
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rflags, HPTE_V_SECONDARY,
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MMU_PAGE_4K, MMU_PAGE_4K, ssize);
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if (slot == -1) {
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if (mftb() & 0x1)
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hpte_group = ((hash & htab_hash_mask) *
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HPTES_PER_GROUP) & ~0x7UL;
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ppc_md.hpte_remove(hpte_group);
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/*
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* FIXME!! Should be try the group from which we removed ?
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*/
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goto repeat;
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}
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}
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/*
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* Hypervisor failure. Restore old pte and return -1
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* similar to __hash_page_*
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*/
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if (unlikely(slot == -2)) {
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*ptep = __pte(old_pte);
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hash_failure_debug(ea, access, vsid, trap, ssize,
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MMU_PAGE_4K, MMU_PAGE_4K, old_pte);
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return -1;
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}
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/*
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* Insert slot number & secondary bit in PTE second half,
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* clear H_PAGE_BUSY and set appropriate HPTE slot bit
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* Since we have H_PAGE_BUSY set on ptep, we can be sure
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* nobody is undating hidx.
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*/
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hidxp = (unsigned long *)(ptep + PTRS_PER_PTE);
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rpte.hidx &= ~(0xfUL << (subpg_index << 2));
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*hidxp = rpte.hidx | (slot << (subpg_index << 2));
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new_pte = mark_subptegroup_valid(new_pte, subpg_index);
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new_pte |= H_PAGE_HASHPTE;
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/*
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* check __real_pte for details on matching smp_rmb()
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*/
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smp_wmb();
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*ptep = __pte(new_pte & ~H_PAGE_BUSY);
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return 0;
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}
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int __hash_page_64K(unsigned long ea, unsigned long access,
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unsigned long vsid, pte_t *ptep, unsigned long trap,
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unsigned long flags, int ssize)
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{
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unsigned long hpte_group;
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unsigned long rflags, pa;
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unsigned long old_pte, new_pte;
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unsigned long vpn, hash, slot;
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unsigned long shift = mmu_psize_defs[MMU_PAGE_64K].shift;
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/*
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* atomically mark the linux large page PTE busy and dirty
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*/
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do {
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pte_t pte = READ_ONCE(*ptep);
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old_pte = pte_val(pte);
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/* If PTE busy, retry the access */
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if (unlikely(old_pte & H_PAGE_BUSY))
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return 0;
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/* If PTE permissions don't match, take page fault */
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if (unlikely(!check_pte_access(access, old_pte)))
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return 1;
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/*
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* Check if PTE has the cache-inhibit bit set
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* If so, bail out and refault as a 4k page
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*/
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if (!mmu_has_feature(MMU_FTR_CI_LARGE_PAGE) &&
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unlikely(pte_ci(pte)))
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return 0;
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/*
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* Try to lock the PTE, add ACCESSED and DIRTY if it was
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* a write access.
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*/
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new_pte = old_pte | H_PAGE_BUSY | _PAGE_ACCESSED;
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if (access & _PAGE_WRITE)
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new_pte |= _PAGE_DIRTY;
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} while (!pte_xchg(ptep, __pte(old_pte), __pte(new_pte)));
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rflags = htab_convert_pte_flags(new_pte);
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if (!cpu_has_feature(CPU_FTR_NOEXECUTE) &&
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!cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
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rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);
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vpn = hpt_vpn(ea, vsid, ssize);
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if (unlikely(old_pte & H_PAGE_HASHPTE)) {
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/*
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* There MIGHT be an HPTE for this pte
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*/
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hash = hpt_hash(vpn, shift, ssize);
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if (old_pte & H_PAGE_F_SECOND)
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hash = ~hash;
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slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
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slot += (old_pte & H_PAGE_F_GIX) >> H_PAGE_F_GIX_SHIFT;
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if (ppc_md.hpte_updatepp(slot, rflags, vpn, MMU_PAGE_64K,
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MMU_PAGE_64K, ssize, flags) == -1)
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old_pte &= ~_PAGE_HPTEFLAGS;
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}
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if (likely(!(old_pte & H_PAGE_HASHPTE))) {
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pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT;
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hash = hpt_hash(vpn, shift, ssize);
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repeat:
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hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
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/* Insert into the hash table, primary slot */
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slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags, 0,
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MMU_PAGE_64K, MMU_PAGE_64K, ssize);
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/*
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* Primary is full, try the secondary
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*/
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if (unlikely(slot == -1)) {
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hpte_group = ((~hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
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slot = ppc_md.hpte_insert(hpte_group, vpn, pa,
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rflags, HPTE_V_SECONDARY,
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MMU_PAGE_64K, MMU_PAGE_64K, ssize);
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if (slot == -1) {
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if (mftb() & 0x1)
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hpte_group = ((hash & htab_hash_mask) *
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HPTES_PER_GROUP) & ~0x7UL;
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ppc_md.hpte_remove(hpte_group);
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/*
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* FIXME!! Should be try the group from which we removed ?
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*/
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goto repeat;
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}
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}
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/*
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* Hypervisor failure. Restore old pte and return -1
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* similar to __hash_page_*
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*/
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if (unlikely(slot == -2)) {
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*ptep = __pte(old_pte);
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hash_failure_debug(ea, access, vsid, trap, ssize,
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MMU_PAGE_64K, MMU_PAGE_64K, old_pte);
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return -1;
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}
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new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | H_PAGE_HASHPTE;
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new_pte |= (slot << H_PAGE_F_GIX_SHIFT) &
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(H_PAGE_F_SECOND | H_PAGE_F_GIX);
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}
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*ptep = __pte(new_pte & ~H_PAGE_BUSY);
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return 0;
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}
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