Пример #1
0
int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
		    pmd_t *pmdp, unsigned long trap, int local, int ssize,
		    unsigned int psize)
{
	unsigned int index, valid;
	unsigned char *hpte_slot_array;
	unsigned long rflags, pa, hidx;
	unsigned long old_pmd, new_pmd;
	int ret, lpsize = MMU_PAGE_16M;
	unsigned long vpn, hash, shift, slot;

	/*
	 * atomically mark the linux large page PMD busy and dirty
	 */
	do {
		old_pmd = pmd_val(*pmdp);
		/* If PMD busy, retry the access */
		if (unlikely(old_pmd & _PAGE_BUSY))
			return 0;
		/* If PMD is trans splitting retry the access */
		if (unlikely(old_pmd & _PAGE_SPLITTING))
			return 0;
		/* If PMD permissions don't match, take page fault */
		if (unlikely(access & ~old_pmd))
			return 1;
		/*
		 * Try to lock the PTE, add ACCESSED and DIRTY if it was
		 * a write access
		 */
		new_pmd = old_pmd | _PAGE_BUSY | _PAGE_ACCESSED;
		if (access & _PAGE_RW)
			new_pmd |= _PAGE_DIRTY;
	} while (old_pmd != __cmpxchg_u64((unsigned long *)pmdp,
					  old_pmd, new_pmd));
	/*
	 * PP bits. _PAGE_USER is already PP bit 0x2, so we only
	 * need to add in 0x1 if it's a read-only user page
	 */
	rflags = new_pmd & _PAGE_USER;
	if ((new_pmd & _PAGE_USER) && !((new_pmd & _PAGE_RW) &&
					   (new_pmd & _PAGE_DIRTY)))
		rflags |= 0x1;
	/*
	 * _PAGE_EXEC -> HW_NO_EXEC since it's inverted
	 */
	rflags |= ((new_pmd & _PAGE_EXEC) ? 0 : HPTE_R_N);

#if 0
	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);
	}
#endif
	/*
	 * Find the slot index details for this ea, using base page size.
	 */
	shift = mmu_psize_defs[psize].shift;
	index = (ea & ~HPAGE_PMD_MASK) >> shift;
	BUG_ON(index >= 4096);

	vpn = hpt_vpn(ea, vsid, ssize);
	hash = hpt_hash(vpn, shift, ssize);
	hpte_slot_array = get_hpte_slot_array(pmdp);

	valid = hpte_valid(hpte_slot_array, index);
	if (valid) {
		/* update the hpte bits */
		hidx =  hpte_hash_index(hpte_slot_array, index);
		if (hidx & _PTEIDX_SECONDARY)
			hash = ~hash;
		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
		slot += hidx & _PTEIDX_GROUP_IX;

		ret = ppc_md.hpte_updatepp(slot, rflags, vpn,
					   psize, lpsize, ssize, local);
		/*
		 * We failed to update, try to insert a new entry.
		 */
		if (ret == -1) {
			/*
			 * large pte is marked busy, so we can be sure
			 * nobody is looking at hpte_slot_array. hence we can
			 * safely update this here.
			 */
			valid = 0;
			new_pmd &= ~_PAGE_HPTEFLAGS;
			hpte_slot_array[index] = 0;
		} else
			/* clear the busy bits and set the hash pte bits */
			new_pmd = (new_pmd & ~_PAGE_HPTEFLAGS) | _PAGE_HASHPTE;
	}

	if (!valid) {
		unsigned long hpte_group;

		/* insert new entry */
		pa = pmd_pfn(__pmd(old_pmd)) << PAGE_SHIFT;
repeat:
		hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;

		/* clear the busy bits and set the hash pte bits */
		new_pmd = (new_pmd & ~_PAGE_HPTEFLAGS) | _PAGE_HASHPTE;

		/* Add in WIMG bits */
		rflags |= (new_pmd & (_PAGE_WRITETHRU | _PAGE_NO_CACHE |
				      _PAGE_COHERENT | _PAGE_GUARDED));

		/* Insert into the hash table, primary slot */
		slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags, 0,
					  psize, lpsize, 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, vpn, pa,
						  rflags, HPTE_V_SECONDARY,
						  psize, lpsize, 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;
			}
		}
		/*
		 * Hypervisor failure. Restore old pmd and return -1
		 * similar to __hash_page_*
		 */
		if (unlikely(slot == -2)) {
			*pmdp = __pmd(old_pmd);
			hash_failure_debug(ea, access, vsid, trap, ssize,
					   psize, lpsize, old_pmd);
			return -1;
		}
		/*
		 * large pte is marked busy, so we can be sure
		 * nobody is looking at hpte_slot_array. hence we can
		 * safely update this here.
		 */
		mark_hpte_slot_valid(hpte_slot_array, index, slot);
	}
	/*
	 * No need to use ldarx/stdcx here
	 */
	*pmdp = __pmd(new_pmd & ~_PAGE_BUSY);
	return 0;
}
Пример #2
0
int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
		   pte_t *ptep, unsigned long trap, unsigned long flags,
		   int ssize, int subpg_prot)
{
	real_pte_t rpte;
	unsigned long *hidxp;
	unsigned long hpte_group;
	unsigned int subpg_index;
	unsigned long rflags, pa, hidx;
	unsigned long old_pte, new_pte, subpg_pte;
	unsigned long vpn, hash, slot;
	unsigned long shift = mmu_psize_defs[MMU_PAGE_4K].shift;

	/*
	 * atomically mark the linux large page PTE busy and dirty
	 */
	do {
		pte_t pte = READ_ONCE(*ptep);

		old_pte = pte_val(pte);
		/* 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. Since this is 4K insert of 64K page size
		 * also add H_PAGE_COMBO
		 */
		new_pte = old_pte | H_PAGE_BUSY | _PAGE_ACCESSED | H_PAGE_COMBO;
		if (access & _PAGE_WRITE)
			new_pte |= _PAGE_DIRTY;
	} while (!pte_xchg(ptep, __pte(old_pte), __pte(new_pte)));

	/*
	 * Handle the subpage protection bits
	 */
	subpg_pte = new_pte & ~subpg_prot;
	rflags = htab_convert_pte_flags(subpg_pte);

	if (!cpu_has_feature(CPU_FTR_NOEXECUTE) &&
	    !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);
	}

	subpg_index = (ea & (PAGE_SIZE - 1)) >> shift;
	vpn  = hpt_vpn(ea, vsid, ssize);
	rpte = __real_pte(__pte(old_pte), ptep);
	/*
	 *None of the sub 4k page is hashed
	 */
	if (!(old_pte & H_PAGE_HASHPTE))
		goto htab_insert_hpte;
	/*
	 * Check if the pte was already inserted into the hash table
	 * as a 64k HW page, and invalidate the 64k HPTE if so.
	 */
	if (!(old_pte & H_PAGE_COMBO)) {
		flush_hash_page(vpn, rpte, MMU_PAGE_64K, ssize, flags);
		/*
		 * clear the old slot details from the old and new pte.
		 * On hash insert failure we use old pte value and we don't
		 * want slot information there if we have a insert failure.
		 */
		old_pte &= ~(H_PAGE_HASHPTE | H_PAGE_F_GIX | H_PAGE_F_SECOND);
		new_pte &= ~(H_PAGE_HASHPTE | H_PAGE_F_GIX | H_PAGE_F_SECOND);
		goto htab_insert_hpte;
	}
	/*
	 * Check for sub page valid and update
	 */
	if (__rpte_sub_valid(rpte, subpg_index)) {
		int ret;

		hash = hpt_hash(vpn, shift, ssize);
		hidx = __rpte_to_hidx(rpte, subpg_index);
		if (hidx & _PTEIDX_SECONDARY)
			hash = ~hash;
		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
		slot += hidx & _PTEIDX_GROUP_IX;

		ret = mmu_hash_ops.hpte_updatepp(slot, rflags, vpn,
						 MMU_PAGE_4K, MMU_PAGE_4K,
						 ssize, flags);
		/*
		 *if we failed because typically the HPTE wasn't really here
		 * we try an insertion.
		 */
		if (ret == -1)
			goto htab_insert_hpte;

		*ptep = __pte(new_pte & ~H_PAGE_BUSY);
		return 0;
	}

htab_insert_hpte:
	/*
	 * handle H_PAGE_4K_PFN case
	 */
	if (old_pte & H_PAGE_4K_PFN) {
		/*
		 * All the sub 4k page have the same
		 * physical address.
		 */
		pa = pte_pfn(__pte(old_pte)) << HW_PAGE_SHIFT;
	} else {
		pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT;
		pa += (subpg_index << shift);
	}
	hash = hpt_hash(vpn, shift, ssize);
repeat:
	hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;

	/* Insert into the hash table, primary slot */
	slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, 0,
					MMU_PAGE_4K, MMU_PAGE_4K, ssize);
	/*
	 * Primary is full, try the secondary
	 */
	if (unlikely(slot == -1)) {
		hpte_group = ((~hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
		slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa,
						rflags, HPTE_V_SECONDARY,
						MMU_PAGE_4K, MMU_PAGE_4K,
						ssize);
		if (slot == -1) {
			if (mftb() & 0x1)
				hpte_group = ((hash & htab_hash_mask) *
					      HPTES_PER_GROUP) & ~0x7UL;
			mmu_hash_ops.hpte_remove(hpte_group);
			/*
			 * FIXME!! Should be try the group from which we removed ?
			 */
			goto repeat;
		}
	}
	/*
	 * 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_PAGE_4K, MMU_PAGE_4K, old_pte);
		return -1;
	}
	/*
	 * Insert slot number & secondary bit in PTE second half,
	 * clear H_PAGE_BUSY and set appropriate HPTE slot bit
	 * Since we have H_PAGE_BUSY set on ptep, we can be sure
	 * nobody is undating hidx.
	 */
	hidxp = (unsigned long *)(ptep + PTRS_PER_PTE);
	rpte.hidx &= ~(0xfUL << (subpg_index << 2));
	*hidxp = rpte.hidx  | (slot << (subpg_index << 2));
	new_pte = mark_subptegroup_valid(new_pte, subpg_index);
	new_pte |=  H_PAGE_HASHPTE;
	/*
	 * check __real_pte for details on matching smp_rmb()
	 */
	smp_wmb();
	*ptep = __pte(new_pte & ~H_PAGE_BUSY);
	return 0;
}
Пример #3
0
int __hash_page_64K(unsigned long ea, unsigned long access,
		    unsigned long vsid, pte_t *ptep, unsigned long trap,
		    unsigned long flags, int ssize)
{
	unsigned long hpte_group;
	unsigned long rflags, pa;
	unsigned long old_pte, new_pte;
	unsigned long vpn, hash, slot;
	unsigned long shift = mmu_psize_defs[MMU_PAGE_64K].shift;

	/*
	 * atomically mark the linux large page PTE busy and dirty
	 */
	do {
		pte_t pte = READ_ONCE(*ptep);

		old_pte = pte_val(pte);
		/* 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;
		/*
		 * Check if PTE has the cache-inhibit bit set
		 * If so, bail out and refault as a 4k page
		 */
		if (!mmu_has_feature(MMU_FTR_CI_LARGE_PAGE) &&
		    unlikely(pte_ci(pte)))
			return 0;
		/*
		 * 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)));

	rflags = htab_convert_pte_flags(new_pte);

	if (!cpu_has_feature(CPU_FTR_NOEXECUTE) &&
	    !cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
		rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);

	vpn  = hpt_vpn(ea, vsid, ssize);
	if (unlikely(old_pte & H_PAGE_HASHPTE)) {
		/*
		 * There MIGHT be an HPTE for this pte
		 */
		hash = hpt_hash(vpn, shift, ssize);
		if (old_pte & H_PAGE_F_SECOND)
			hash = ~hash;
		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
		slot += (old_pte & H_PAGE_F_GIX) >> H_PAGE_F_GIX_SHIFT;

		if (mmu_hash_ops.hpte_updatepp(slot, rflags, vpn, MMU_PAGE_64K,
					       MMU_PAGE_64K, ssize,
					       flags) == -1)
			old_pte &= ~_PAGE_HPTEFLAGS;
	}

	if (likely(!(old_pte & H_PAGE_HASHPTE))) {

		pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT;
		hash = hpt_hash(vpn, shift, ssize);

repeat:
		hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;

		/* Insert into the hash table, primary slot */
		slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, 0,
						MMU_PAGE_64K, MMU_PAGE_64K,
						ssize);
		/*
		 * Primary is full, try the secondary
		 */
		if (unlikely(slot == -1)) {
			hpte_group = ((~hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
			slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa,
							rflags,
							HPTE_V_SECONDARY,
							MMU_PAGE_64K,
							MMU_PAGE_64K, ssize);
			if (slot == -1) {
				if (mftb() & 0x1)
					hpte_group = ((hash & htab_hash_mask) *
						      HPTES_PER_GROUP) & ~0x7UL;
				mmu_hash_ops.hpte_remove(hpte_group);
				/*
				 * FIXME!! Should be try the group from which we removed ?
				 */
				goto repeat;
			}
		}
		/*
		 * 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_PAGE_64K, MMU_PAGE_64K, old_pte);
			return -1;
		}
		new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | H_PAGE_HASHPTE;
		new_pte |= (slot << H_PAGE_F_GIX_SHIFT) &
			(H_PAGE_F_SECOND | H_PAGE_F_GIX);
	}
	*ptep = __pte(new_pte & ~H_PAGE_BUSY);
	return 0;
}
Пример #4
0
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 vpn;
	unsigned long old_pte, new_pte;
	unsigned long rflags, pa, sz;
	long slot;

	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 & _PAGE_BUSY))
			return 0;
		/* If PTE permissions don't match, take page fault */
		if (unlikely(access & ~old_pte))
			return 1;
		/* Try to lock the PTE, add ACCESSED and DIRTY if it was
		 * a write access */
		new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED;
		if (access & _PAGE_RW)
			new_pte |= _PAGE_DIRTY;
	} 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(vpn, 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, vpn, mmu_psize,
					 ssize, local) == -1)
			old_pte &= ~_PAGE_HPTEFLAGS;
	}

	if (likely(!(old_pte & _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 */
#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));

		slot = hpte_insert_repeating(hash, vpn, pa,
					     rflags, 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, old_pte);
			return -1;
		}

		new_pte |= (slot << 12) & (_PAGE_F_SECOND | _PAGE_F_GIX);
	}

	/*
	 * No need to use ldarx/stdcx here
	 */
	*ptep = __pte(new_pte & ~_PAGE_BUSY);
	return 0;
}
Пример #5
0
int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
		   pte_t *ptep, unsigned long trap, unsigned long flags,
		   int ssize, int subpg_prot)
{
	real_pte_t rpte;
	unsigned long hpte_group;
	unsigned int subpg_index;
	unsigned long rflags, pa;
	unsigned long old_pte, new_pte, subpg_pte;
	unsigned long vpn, hash, slot, gslot;
	unsigned long shift = mmu_psize_defs[MMU_PAGE_4K].shift;

	/*
	 * atomically mark the linux large page PTE busy and dirty
	 */
	do {
		pte_t pte = READ_ONCE(*ptep);

		old_pte = pte_val(pte);
		/* 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. Since this is 4K insert of 64K page size
		 * also add H_PAGE_COMBO
		 */
		new_pte = old_pte | H_PAGE_BUSY | _PAGE_ACCESSED | H_PAGE_COMBO;
		if (access & _PAGE_WRITE)
			new_pte |= _PAGE_DIRTY;
	} while (!pte_xchg(ptep, __pte(old_pte), __pte(new_pte)));

	/*
	 * Handle the subpage protection bits
	 */
	subpg_pte = new_pte & ~subpg_prot;
	rflags = htab_convert_pte_flags(subpg_pte);

	if (cpu_has_feature(CPU_FTR_NOEXECUTE) &&
	    !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);
	}

	subpg_index = (ea & (PAGE_SIZE - 1)) >> shift;
	vpn  = hpt_vpn(ea, vsid, ssize);
	rpte = __real_pte(__pte(old_pte), ptep);
	/*
	 *None of the sub 4k page is hashed
	 */
	if (!(old_pte & H_PAGE_HASHPTE))
		goto htab_insert_hpte;
	/*
	 * Check if the pte was already inserted into the hash table
	 * as a 64k HW page, and invalidate the 64k HPTE if so.
	 */
	if (!(old_pte & H_PAGE_COMBO)) {
		flush_hash_page(vpn, rpte, MMU_PAGE_64K, ssize, flags);
		/*
		 * clear the old slot details from the old and new pte.
		 * On hash insert failure we use old pte value and we don't
		 * want slot information there if we have a insert failure.
		 */
		old_pte &= ~H_PAGE_HASHPTE;
		new_pte &= ~H_PAGE_HASHPTE;
		goto htab_insert_hpte;
	}
	/*
	 * Check for sub page valid and update
	 */
	if (__rpte_sub_valid(rpte, subpg_index)) {
		int ret;

		gslot = pte_get_hash_gslot(vpn, shift, ssize, rpte,
					   subpg_index);
		ret = mmu_hash_ops.hpte_updatepp(gslot, rflags, vpn,
						 MMU_PAGE_4K, MMU_PAGE_4K,
						 ssize, flags);

		/*
		 * If we failed because typically the HPTE wasn't really here
		 * we try an insertion.
		 */
		if (ret == -1)
			goto htab_insert_hpte;

		*ptep = __pte(new_pte & ~H_PAGE_BUSY);
		return 0;
	}

htab_insert_hpte:

	/*
	 * Initialize all hidx entries to invalid value, the first time
	 * the PTE is about to allocate a 4K HPTE.
	 */
	if (!(old_pte & H_PAGE_COMBO))
		rpte.hidx = INVALID_RPTE_HIDX;

	/*
	 * handle H_PAGE_4K_PFN case
	 */
	if (old_pte & H_PAGE_4K_PFN) {
		/*
		 * All the sub 4k page have the same
		 * physical address.
		 */
		pa = pte_pfn(__pte(old_pte)) << HW_PAGE_SHIFT;
	} else {
		pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT;
		pa += (subpg_index << shift);
	}
	hash = hpt_hash(vpn, shift, ssize);
repeat:
	hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;

	/* Insert into the hash table, primary slot */
	slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, 0,
					MMU_PAGE_4K, MMU_PAGE_4K, ssize);
	/*
	 * Primary is full, try the secondary
	 */
	if (unlikely(slot == -1)) {
		bool soft_invalid;

		hpte_group = ((~hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
		slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa,
						rflags, HPTE_V_SECONDARY,
						MMU_PAGE_4K, MMU_PAGE_4K,
						ssize);

		soft_invalid = hpte_soft_invalid(slot);
		if (unlikely(soft_invalid)) {
			/*
			 * We got a valid slot from a hardware point of view.
			 * but we cannot use it, because we use this special
			 * value; as defined by hpte_soft_invalid(), to track
			 * invalid slots. We cannot use it. So invalidate it.
			 */
			gslot = slot & _PTEIDX_GROUP_IX;
			mmu_hash_ops.hpte_invalidate(hpte_group + gslot, vpn,
						     MMU_PAGE_4K, MMU_PAGE_4K,
						     ssize, 0);
		}

		if (unlikely(slot == -1 || soft_invalid)) {
			/*
			 * For soft invalid slot, let's ensure that we release a
			 * slot from the primary, with the hope that we will
			 * acquire that slot next time we try. This will ensure
			 * that we do not get the same soft-invalid slot.
			 */
			if (soft_invalid || (mftb() & 0x1))
				hpte_group = ((hash & htab_hash_mask) *
					      HPTES_PER_GROUP) & ~0x7UL;

			mmu_hash_ops.hpte_remove(hpte_group);
			/*
			 * FIXME!! Should be try the group from which we removed ?
			 */
			goto repeat;
		}
	}
	/*
	 * 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_PAGE_4K, MMU_PAGE_4K, old_pte);
		return -1;
	}

	new_pte |= pte_set_hidx(ptep, rpte, subpg_index, slot);
	new_pte |= H_PAGE_HASHPTE;

	*ptep = __pte(new_pte & ~H_PAGE_BUSY);
	return 0;
}
Пример #6
0
int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
		   pte_t *ptep, unsigned long trap, unsigned long flags,
		   int ssize, int subpg_prot)
{
	unsigned long hpte_group;
	unsigned long rflags, pa;
	unsigned long old_pte, new_pte;
	unsigned long vpn, hash, slot;
	unsigned long shift = mmu_psize_defs[MMU_PAGE_4K].shift;

	/*
	 * atomically mark the linux large page PTE busy and dirty
	 */
	do {
		pte_t pte = READ_ONCE(*ptep);

		old_pte = pte_val(pte);
		/* If PTE busy, retry the access */
		if (unlikely(old_pte & _PAGE_BUSY))
			return 0;
		/* If PTE permissions don't match, take page fault */
		if (unlikely(access & ~old_pte))
			return 1;
		/*
		 * Try to lock the PTE, add ACCESSED and DIRTY if it was
		 * a write access. Since this is 4K insert of 64K page size
		 * also add _PAGE_COMBO
		 */
		new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED | _PAGE_HASHPTE;
		if (access & _PAGE_RW)
			new_pte |= _PAGE_DIRTY;
	} while (old_pte != __cmpxchg_u64((unsigned long *)ptep,
					  old_pte, new_pte));
	/*
	 * PP bits. _PAGE_USER is already PP bit 0x2, so we only
	 * need to add in 0x1 if it's a read-only user page
	 */
	rflags = htab_convert_pte_flags(new_pte);

	if (!cpu_has_feature(CPU_FTR_NOEXECUTE) &&
	    !cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
		rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);

	vpn  = hpt_vpn(ea, vsid, ssize);
	if (unlikely(old_pte & _PAGE_HASHPTE)) {
		/*
		 * There MIGHT be an HPTE for this pte
		 */
		hash = hpt_hash(vpn, shift, ssize);
		if (old_pte & _PAGE_F_SECOND)
			hash = ~hash;
		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
		slot += (old_pte & _PAGE_F_GIX) >> _PAGE_F_GIX_SHIFT;

		if (ppc_md.hpte_updatepp(slot, rflags, vpn, MMU_PAGE_4K,
					 MMU_PAGE_4K, ssize, flags) == -1)
			old_pte &= ~_PAGE_HPTEFLAGS;
	}

	if (likely(!(old_pte & _PAGE_HASHPTE))) {

		pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT;
		hash = hpt_hash(vpn, shift, ssize);

repeat:
		hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;

		/* Insert into the hash table, primary slot */
		slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags, 0,
				  MMU_PAGE_4K, MMU_PAGE_4K, 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, vpn, pa,
						  rflags, HPTE_V_SECONDARY,
						  MMU_PAGE_4K, MMU_PAGE_4K, ssize);
			if (slot == -1) {
				if (mftb() & 0x1)
					hpte_group = ((hash & htab_hash_mask) *
						      HPTES_PER_GROUP) & ~0x7UL;
				ppc_md.hpte_remove(hpte_group);
				/*
				 * FIXME!! Should be try the group from which we removed ?
				 */
				goto repeat;
			}
		}
		/*
		 * Hypervisor failure. Restore old pmd and return -1
		 * similar to __hash_page_*
		 */
		if (unlikely(slot == -2)) {
			*ptep = __pte(old_pte);
			hash_failure_debug(ea, access, vsid, trap, ssize,
					   MMU_PAGE_4K, MMU_PAGE_4K, old_pte);
			return -1;
		}
		new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | _PAGE_HASHPTE;
		new_pte |= (slot << _PAGE_F_GIX_SHIFT) & (_PAGE_F_SECOND | _PAGE_F_GIX);
	}
	*ptep = __pte(new_pte & ~_PAGE_BUSY);
	return 0;
}