Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
new file mode 100644
index 0000000..75483b4
--- /dev/null
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -0,0 +1,518 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
+ */
+
+#include <linux/sched.h>
+#include <linux/mm_types.h>
+#include <linux/memblock.h>
+#include <misc/cxl-base.h>
+
+#include <asm/debugfs.h>
+#include <asm/pgalloc.h>
+#include <asm/tlb.h>
+#include <asm/trace.h>
+#include <asm/powernv.h>
+#include <asm/firmware.h>
+#include <asm/ultravisor.h>
+
+#include <mm/mmu_decl.h>
+#include <trace/events/thp.h>
+
+unsigned long __pmd_frag_nr;
+EXPORT_SYMBOL(__pmd_frag_nr);
+unsigned long __pmd_frag_size_shift;
+EXPORT_SYMBOL(__pmd_frag_size_shift);
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+/*
+ * This is called when relaxing access to a hugepage. It's also called in the page
+ * fault path when we don't hit any of the major fault cases, ie, a minor
+ * update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have
+ * handled those two for us, we additionally deal with missing execute
+ * permission here on some processors
+ */
+int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
+ pmd_t *pmdp, pmd_t entry, int dirty)
+{
+ int changed;
+#ifdef CONFIG_DEBUG_VM
+ WARN_ON(!pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp));
+ assert_spin_locked(pmd_lockptr(vma->vm_mm, pmdp));
+#endif
+ changed = !pmd_same(*(pmdp), entry);
+ if (changed) {
+ /*
+ * We can use MMU_PAGE_2M here, because only radix
+ * path look at the psize.
+ */
+ __ptep_set_access_flags(vma, pmdp_ptep(pmdp),
+ pmd_pte(entry), address, MMU_PAGE_2M);
+ }
+ return changed;
+}
+
+int pmdp_test_and_clear_young(struct vm_area_struct *vma,
+ unsigned long address, pmd_t *pmdp)
+{
+ return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
+}
+/*
+ * set a new huge pmd. We should not be called for updating
+ * an existing pmd entry. That should go via pmd_hugepage_update.
+ */
+void set_pmd_at(struct mm_struct *mm, unsigned long addr,
+ pmd_t *pmdp, pmd_t pmd)
+{
+#ifdef CONFIG_DEBUG_VM
+ /*
+ * Make sure hardware valid bit is not set. We don't do
+ * tlb flush for this update.
+ */
+
+ WARN_ON(pte_hw_valid(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp)));
+ assert_spin_locked(pmd_lockptr(mm, pmdp));
+ WARN_ON(!(pmd_large(pmd)));
+#endif
+ trace_hugepage_set_pmd(addr, pmd_val(pmd));
+ return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
+}
+
+static void do_nothing(void *unused)
+{
+
+}
+/*
+ * Serialize against find_current_mm_pte which does lock-less
+ * lookup in page tables with local interrupts disabled. For huge pages
+ * it casts pmd_t to pte_t. Since format of pte_t is different from
+ * pmd_t we want to prevent transit from pmd pointing to page table
+ * to pmd pointing to huge page (and back) while interrupts are disabled.
+ * We clear pmd to possibly replace it with page table pointer in
+ * different code paths. So make sure we wait for the parallel
+ * find_current_mm_pte to finish.
+ */
+void serialize_against_pte_lookup(struct mm_struct *mm)
+{
+ smp_mb();
+ smp_call_function_many(mm_cpumask(mm), do_nothing, NULL, 1);
+}
+
+/*
+ * We use this to invalidate a pmdp entry before switching from a
+ * hugepte to regular pmd entry.
+ */
+pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
+ pmd_t *pmdp)
+{
+ unsigned long old_pmd;
+
+ old_pmd = pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, _PAGE_INVALID);
+ flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+ /*
+ * This ensures that generic code that rely on IRQ disabling
+ * to prevent a parallel THP split work as expected.
+ *
+ * Marking the entry with _PAGE_INVALID && ~_PAGE_PRESENT requires
+ * a special case check in pmd_access_permitted.
+ */
+ serialize_against_pte_lookup(vma->vm_mm);
+ return __pmd(old_pmd);
+}
+
+static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
+{
+ return __pmd(pmd_val(pmd) | pgprot_val(pgprot));
+}
+
+pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
+{
+ unsigned long pmdv;
+
+ pmdv = (pfn << PAGE_SHIFT) & PTE_RPN_MASK;
+ return pmd_set_protbits(__pmd(pmdv), pgprot);
+}
+
+pmd_t mk_pmd(struct page *page, pgprot_t pgprot)
+{
+ return pfn_pmd(page_to_pfn(page), pgprot);
+}
+
+pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
+{
+ unsigned long pmdv;
+
+ pmdv = pmd_val(pmd);
+ pmdv &= _HPAGE_CHG_MASK;
+ return pmd_set_protbits(__pmd(pmdv), newprot);
+}
+
+/*
+ * This is called at the end of handling a user page fault, when the
+ * fault has been handled by updating a HUGE PMD entry in the linux page tables.
+ * We use it to preload an HPTE into the hash table corresponding to
+ * the updated linux HUGE PMD entry.
+ */
+void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
+ pmd_t *pmd)
+{
+ if (radix_enabled())
+ prefetch((void *)addr);
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+/* For use by kexec */
+void mmu_cleanup_all(void)
+{
+ if (radix_enabled())
+ radix__mmu_cleanup_all();
+ else if (mmu_hash_ops.hpte_clear_all)
+ mmu_hash_ops.hpte_clear_all();
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+int __meminit create_section_mapping(unsigned long start, unsigned long end, int nid)
+{
+ if (radix_enabled())
+ return radix__create_section_mapping(start, end, nid);
+
+ return hash__create_section_mapping(start, end, nid);
+}
+
+int __meminit remove_section_mapping(unsigned long start, unsigned long end)
+{
+ if (radix_enabled())
+ return radix__remove_section_mapping(start, end);
+
+ return hash__remove_section_mapping(start, end);
+}
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+void __init mmu_partition_table_init(void)
+{
+ unsigned long patb_size = 1UL << PATB_SIZE_SHIFT;
+ unsigned long ptcr;
+
+ BUILD_BUG_ON_MSG((PATB_SIZE_SHIFT > 36), "Partition table size too large.");
+ /* Initialize the Partition Table with no entries */
+ partition_tb = memblock_alloc(patb_size, patb_size);
+ if (!partition_tb)
+ panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+ __func__, patb_size, patb_size);
+
+ /*
+ * update partition table control register,
+ * 64 K size.
+ */
+ ptcr = __pa(partition_tb) | (PATB_SIZE_SHIFT - 12);
+ set_ptcr_when_no_uv(ptcr);
+ powernv_set_nmmu_ptcr(ptcr);
+}
+
+static void flush_partition(unsigned int lpid, bool radix)
+{
+ if (radix) {
+ radix__flush_all_lpid(lpid);
+ radix__flush_all_lpid_guest(lpid);
+ } else {
+ asm volatile("ptesync" : : : "memory");
+ asm volatile(PPC_TLBIE_5(%0,%1,2,0,0) : :
+ "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
+ /* do we need fixup here ?*/
+ asm volatile("eieio; tlbsync; ptesync" : : : "memory");
+ trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 0);
+ }
+}
+
+void mmu_partition_table_set_entry(unsigned int lpid, unsigned long dw0,
+ unsigned long dw1, bool flush)
+{
+ unsigned long old = be64_to_cpu(partition_tb[lpid].patb0);
+
+ /*
+ * When ultravisor is enabled, the partition table is stored in secure
+ * memory and can only be accessed doing an ultravisor call. However, we
+ * maintain a copy of the partition table in normal memory to allow Nest
+ * MMU translations to occur (for normal VMs).
+ *
+ * Therefore, here we always update partition_tb, regardless of whether
+ * we are running under an ultravisor or not.
+ */
+ partition_tb[lpid].patb0 = cpu_to_be64(dw0);
+ partition_tb[lpid].patb1 = cpu_to_be64(dw1);
+
+ /*
+ * If ultravisor is enabled, we do an ultravisor call to register the
+ * partition table entry (PATE), which also do a global flush of TLBs
+ * and partition table caches for the lpid. Otherwise, just do the
+ * flush. The type of flush (hash or radix) depends on what the previous
+ * use of the partition ID was, not the new use.
+ */
+ if (firmware_has_feature(FW_FEATURE_ULTRAVISOR)) {
+ uv_register_pate(lpid, dw0, dw1);
+ pr_info("PATE registered by ultravisor: dw0 = 0x%lx, dw1 = 0x%lx\n",
+ dw0, dw1);
+ } else if (flush) {
+ /*
+ * Boot does not need to flush, because MMU is off and each
+ * CPU does a tlbiel_all() before switching them on, which
+ * flushes everything.
+ */
+ flush_partition(lpid, (old & PATB_HR));
+ }
+}
+EXPORT_SYMBOL_GPL(mmu_partition_table_set_entry);
+
+static pmd_t *get_pmd_from_cache(struct mm_struct *mm)
+{
+ void *pmd_frag, *ret;
+
+ if (PMD_FRAG_NR == 1)
+ return NULL;
+
+ spin_lock(&mm->page_table_lock);
+ ret = mm->context.pmd_frag;
+ if (ret) {
+ pmd_frag = ret + PMD_FRAG_SIZE;
+ /*
+ * If we have taken up all the fragments mark PTE page NULL
+ */
+ if (((unsigned long)pmd_frag & ~PAGE_MASK) == 0)
+ pmd_frag = NULL;
+ mm->context.pmd_frag = pmd_frag;
+ }
+ spin_unlock(&mm->page_table_lock);
+ return (pmd_t *)ret;
+}
+
+static pmd_t *__alloc_for_pmdcache(struct mm_struct *mm)
+{
+ void *ret = NULL;
+ struct page *page;
+ gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO;
+
+ if (mm == &init_mm)
+ gfp &= ~__GFP_ACCOUNT;
+ page = alloc_page(gfp);
+ if (!page)
+ return NULL;
+ if (!pgtable_pmd_page_ctor(page)) {
+ __free_pages(page, 0);
+ return NULL;
+ }
+
+ atomic_set(&page->pt_frag_refcount, 1);
+
+ ret = page_address(page);
+ /*
+ * if we support only one fragment just return the
+ * allocated page.
+ */
+ if (PMD_FRAG_NR == 1)
+ return ret;
+
+ spin_lock(&mm->page_table_lock);
+ /*
+ * If we find pgtable_page set, we return
+ * the allocated page with single fragement
+ * count.
+ */
+ if (likely(!mm->context.pmd_frag)) {
+ atomic_set(&page->pt_frag_refcount, PMD_FRAG_NR);
+ mm->context.pmd_frag = ret + PMD_FRAG_SIZE;
+ }
+ spin_unlock(&mm->page_table_lock);
+
+ return (pmd_t *)ret;
+}
+
+pmd_t *pmd_fragment_alloc(struct mm_struct *mm, unsigned long vmaddr)
+{
+ pmd_t *pmd;
+
+ pmd = get_pmd_from_cache(mm);
+ if (pmd)
+ return pmd;
+
+ return __alloc_for_pmdcache(mm);
+}
+
+void pmd_fragment_free(unsigned long *pmd)
+{
+ struct page *page = virt_to_page(pmd);
+
+ BUG_ON(atomic_read(&page->pt_frag_refcount) <= 0);
+ if (atomic_dec_and_test(&page->pt_frag_refcount)) {
+ pgtable_pmd_page_dtor(page);
+ __free_page(page);
+ }
+}
+
+static inline void pgtable_free(void *table, int index)
+{
+ switch (index) {
+ case PTE_INDEX:
+ pte_fragment_free(table, 0);
+ break;
+ case PMD_INDEX:
+ pmd_fragment_free(table);
+ break;
+ case PUD_INDEX:
+ kmem_cache_free(PGT_CACHE(PUD_CACHE_INDEX), table);
+ break;
+#if defined(CONFIG_PPC_4K_PAGES) && defined(CONFIG_HUGETLB_PAGE)
+ /* 16M hugepd directory at pud level */
+ case HTLB_16M_INDEX:
+ BUILD_BUG_ON(H_16M_CACHE_INDEX <= 0);
+ kmem_cache_free(PGT_CACHE(H_16M_CACHE_INDEX), table);
+ break;
+ /* 16G hugepd directory at the pgd level */
+ case HTLB_16G_INDEX:
+ BUILD_BUG_ON(H_16G_CACHE_INDEX <= 0);
+ kmem_cache_free(PGT_CACHE(H_16G_CACHE_INDEX), table);
+ break;
+#endif
+ /* We don't free pgd table via RCU callback */
+ default:
+ BUG();
+ }
+}
+
+#ifdef CONFIG_SMP
+void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int index)
+{
+ unsigned long pgf = (unsigned long)table;
+
+ BUG_ON(index > MAX_PGTABLE_INDEX_SIZE);
+ pgf |= index;
+ tlb_remove_table(tlb, (void *)pgf);
+}
+
+void __tlb_remove_table(void *_table)
+{
+ void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
+ unsigned int index = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
+
+ return pgtable_free(table, index);
+}
+#else
+void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int index)
+{
+ return pgtable_free(table, index);
+}
+#endif
+
+#ifdef CONFIG_PROC_FS
+atomic_long_t direct_pages_count[MMU_PAGE_COUNT];
+
+void arch_report_meminfo(struct seq_file *m)
+{
+ /*
+ * Hash maps the memory with one size mmu_linear_psize.
+ * So don't bother to print these on hash
+ */
+ if (!radix_enabled())
+ return;
+ seq_printf(m, "DirectMap4k: %8lu kB\n",
+ atomic_long_read(&direct_pages_count[MMU_PAGE_4K]) << 2);
+ seq_printf(m, "DirectMap64k: %8lu kB\n",
+ atomic_long_read(&direct_pages_count[MMU_PAGE_64K]) << 6);
+ seq_printf(m, "DirectMap2M: %8lu kB\n",
+ atomic_long_read(&direct_pages_count[MMU_PAGE_2M]) << 11);
+ seq_printf(m, "DirectMap1G: %8lu kB\n",
+ atomic_long_read(&direct_pages_count[MMU_PAGE_1G]) << 20);
+}
+#endif /* CONFIG_PROC_FS */
+
+pte_t 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, 0);
+
+ return __pte(pte_val);
+
+}
+
+void 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__ptep_modify_prot_commit(vma, addr,
+ ptep, old_pte, pte);
+ set_pte_at(vma->vm_mm, addr, ptep, pte);
+}
+
+/*
+ * For hash translation mode, we use the deposited table to store hash slot
+ * information and they are stored at PTRS_PER_PMD offset from related pmd
+ * location. Hence a pmd move requires deposit and withdraw.
+ *
+ * For radix translation with split pmd ptl, we store the deposited table in the
+ * pmd page. Hence if we have different pmd page we need to withdraw during pmd
+ * move.
+ *
+ * With hash we use deposited table always irrespective of anon or not.
+ * With radix we use deposited table only for anonymous mapping.
+ */
+int pmd_move_must_withdraw(struct spinlock *new_pmd_ptl,
+ struct spinlock *old_pmd_ptl,
+ struct vm_area_struct *vma)
+{
+ if (radix_enabled())
+ return (new_pmd_ptl != old_pmd_ptl) && vma_is_anonymous(vma);
+
+ return true;
+}
+
+/*
+ * Does the CPU support tlbie?
+ */
+bool tlbie_capable __read_mostly = true;
+EXPORT_SYMBOL(tlbie_capable);
+
+/*
+ * Should tlbie be used for management of CPU TLBs, for kernel and process
+ * address spaces? tlbie may still be used for nMMU accelerators, and for KVM
+ * guest address spaces.
+ */
+bool tlbie_enabled __read_mostly = true;
+
+static int __init setup_disable_tlbie(char *str)
+{
+ if (!radix_enabled()) {
+ pr_err("disable_tlbie: Unable to disable TLBIE with Hash MMU.\n");
+ return 1;
+ }
+
+ tlbie_capable = false;
+ tlbie_enabled = false;
+
+ return 1;
+}
+__setup("disable_tlbie", setup_disable_tlbie);
+
+static int __init pgtable_debugfs_setup(void)
+{
+ if (!tlbie_capable)
+ return 0;
+
+ /*
+ * There is no locking vs tlb flushing when changing this value.
+ * The tlb flushers will see one value or another, and use either
+ * tlbie or tlbiel with IPIs. In both cases the TLBs will be
+ * invalidated as expected.
+ */
+ debugfs_create_bool("tlbie_enabled", 0600,
+ powerpc_debugfs_root,
+ &tlbie_enabled);
+
+ return 0;
+}
+arch_initcall(pgtable_debugfs_setup);