1 files changed, 575 insertions, 0 deletions
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
new file mode 100644
index 000000000..f6151a589
--- /dev/null
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -0,0 +1,575 @@
+// 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 <linux/memremap.h>
+#include <linux/pkeys.h>
+#include <linux/debugfs.h>
+#include <misc/cxl-base.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 <asm/kexec.h>
+
+#include <mm/mmu_decl.h>
+#include <trace/events/thp.h>
+
+#include "internal.h"
+
+struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
+EXPORT_SYMBOL_GPL(mmu_psize_defs);
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+int mmu_vmemmap_psize = MMU_PAGE_4K;
+#endif
+
+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_serialize(void *arg)
+{
+	/* We've taken the IPI, so try to trim the mask while here */
+	if (radix_enabled()) {
+		struct mm_struct *mm = arg;
+		exit_lazy_flush_tlb(mm, false);
+	}
+}
+
+/*
+ * 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_serialize, mm, 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);
+	return __pmd(old_pmd);
+}
+
+pmd_t pmdp_huge_get_and_clear_full(struct vm_area_struct *vma,
+				   unsigned long addr, pmd_t *pmdp, int full)
+{
+	pmd_t pmd;
+	VM_BUG_ON(addr & ~HPAGE_PMD_MASK);
+	VM_BUG_ON((pmd_present(*pmdp) && !pmd_trans_huge(*pmdp) &&
+		   !pmd_devmap(*pmdp)) || !pmd_present(*pmdp));
+	pmd = pmdp_huge_get_and_clear(vma->vm_mm, addr, pmdp);
+	/*
+	 * if it not a fullmm flush, then we can possibly end up converting
+	 * this PMD pte entry to a regular level 0 PTE by a parallel page fault.
+	 * Make sure we flush the tlb in this case.
+	 */
+	if (!full)
+		flush_pmd_tlb_range(vma, addr, addr + HPAGE_PMD_SIZE);
+	return pmd;
+}
+
+static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
+{
+	return __pmd(pmd_val(pmd) | pgprot_val(pgprot));
+}
+
+/*
+ * At some point we should be able to get rid of
+ * pmd_mkhuge() and mk_huge_pmd() when we update all the
+ * other archs to mark the pmd huge in pfn_pmd()
+ */
+pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
+{
+	unsigned long pmdv;
+
+	pmdv = (pfn << PAGE_SHIFT) & PTE_RPN_MASK;
+
+	return __pmd_mkhuge(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);
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+/* For use by kexec, called with MMU off */
+notrace 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();
+
+	reset_sprs();
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+int __meminit create_section_mapping(unsigned long start, unsigned long end,
+				     int nid, pgprot_t prot)
+{
+	if (radix_enabled())
+		return radix__create_section_mapping(start, end, nid, prot);
+
+	return hash__create_section_mapping(start, end, nid, prot);
+}
+
+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;
+
+	/* 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);
+
+	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 fragment
+	 * 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);
+
+	if (PageReserved(page))
+		return free_reserved_page(page);
+
+	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:
+		__pud_free(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();
+	}
+}
+
+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);
+}
+
+#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,
+			arch_debugfs_dir,
+			&tlbie_enabled);
+
+	return 0;
+}
+arch_initcall(pgtable_debugfs_setup);
+
+#if defined(CONFIG_ZONE_DEVICE) && defined(CONFIG_ARCH_HAS_MEMREMAP_COMPAT_ALIGN)
+/*
+ * Override the generic version in mm/memremap.c.
+ *
+ * With hash translation, the direct-map range is mapped with just one
+ * page size selected by htab_init_page_sizes(). Consult
+ * mmu_psize_defs[] to determine the minimum page size alignment.
+*/
+unsigned long memremap_compat_align(void)
+{
+	if (!radix_enabled()) {
+		unsigned int shift = mmu_psize_defs[mmu_linear_psize].shift;
+		return max(SUBSECTION_SIZE, 1UL << shift);
+	}
+
+	return SUBSECTION_SIZE;
+}
+EXPORT_SYMBOL_GPL(memremap_compat_align);
+#endif
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+	unsigned long prot;
+
+	/* Radix supports execute-only, but protection_map maps X -> RX */
+	if (radix_enabled() && ((vm_flags & VM_ACCESS_FLAGS) == VM_EXEC)) {
+		prot = pgprot_val(PAGE_EXECONLY);
+	} else {
+		prot = pgprot_val(protection_map[vm_flags &
+						 (VM_ACCESS_FLAGS | VM_SHARED)]);
+	}
+
+	if (vm_flags & VM_SAO)
+		prot |= _PAGE_SAO;
+
+#ifdef CONFIG_PPC_MEM_KEYS
+	prot |= vmflag_to_pte_pkey_bits(vm_flags);
+#endif
+
+	return __pgprot(prot);
+}
+EXPORT_SYMBOL(vm_get_page_prot);