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Diffstat (limited to 'arch/powerpc/mm/hash64_64k.c')
-rw-r--r--arch/powerpc/mm/hash64_64k.c322
1 files changed, 322 insertions, 0 deletions
diff --git a/arch/powerpc/mm/hash64_64k.c b/arch/powerpc/mm/hash64_64k.c
new file mode 100644
index 000000000000..0762c1e08c88
--- /dev/null
+++ b/arch/powerpc/mm/hash64_64k.c
@@ -0,0 +1,322 @@
+/*
+ * Copyright IBM Corporation, 2015
+ * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ */
+
+#include <linux/mm.h>
+#include <asm/machdep.h>
+#include <asm/mmu.h>
+/*
+ * index from 0 - 15
+ */
+bool __rpte_sub_valid(real_pte_t rpte, unsigned long index)
+{
+ unsigned long g_idx;
+ unsigned long ptev = pte_val(rpte.pte);
+
+ g_idx = (ptev & _PAGE_COMBO_VALID) >> _PAGE_F_GIX_SHIFT;
+ index = index >> 2;
+ if (g_idx & (0x1 << index))
+ return true;
+ else
+ return false;
+}
+/*
+ * index from 0 - 15
+ */
+static unsigned long mark_subptegroup_valid(unsigned long ptev, unsigned long index)
+{
+ unsigned long g_idx;
+
+ if (!(ptev & _PAGE_COMBO))
+ return ptev;
+ index = index >> 2;
+ g_idx = 0x1 << index;
+
+ return ptev | (g_idx << _PAGE_F_GIX_SHIFT);
+}
+
+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 & _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_COMBO;
+ if (access & _PAGE_RW)
+ new_pte |= _PAGE_DIRTY;
+ } while (old_pte != __cmpxchg_u64((unsigned long *)ptep,
+ old_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 & _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 & _PAGE_COMBO)) {
+ flush_hash_page(vpn, rpte, MMU_PAGE_64K, ssize, flags);
+ old_pte &= ~_PAGE_HASHPTE | _PAGE_F_GIX | _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 = ppc_md.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 & ~_PAGE_BUSY);
+ return 0;
+ }
+
+htab_insert_hpte:
+ /*
+ * handle _PAGE_4K_PFN case
+ */
+ if (old_pte & _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 = 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;
+ }
+ /*
+ * Insert slot number & secondary bit in PTE second half,
+ * clear _PAGE_BUSY and set appropriate HPTE slot bit
+ * Since we have _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 |= _PAGE_HASHPTE;
+ /*
+ * check __real_pte for details on matching smp_rmb()
+ */
+ smp_wmb();
+ *ptep = __pte(new_pte & ~_PAGE_BUSY);
+ return 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 & _PAGE_BUSY))
+ return 0;
+ /* If PTE permissions don't match, take page fault */
+ if (unlikely(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(old_pte & _PAGE_NO_CACHE))
+ return 0;
+ /*
+ * 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;
+ if (access & _PAGE_RW)
+ new_pte |= _PAGE_DIRTY;
+ } while (old_pte != __cmpxchg_u64((unsigned long *)ptep,
+ old_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 & _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_64K,
+ MMU_PAGE_64K, 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_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 = ppc_md.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;
+ 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_64K, MMU_PAGE_64K, 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;
+}
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