1 files changed, 299 insertions, 0 deletions
diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c
new file mode 100644
index 000000000..20ee14739
--- /dev/null
+++ b/arch/sparc/mm/tlb.c
@@ -0,0 +1,299 @@
+// SPDX-License-Identifier: GPL-2.0
+/* arch/sparc64/mm/tlb.c
+ *
+ * Copyright (C) 2004 David S. Miller <davem@redhat.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/percpu.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/preempt.h>
+
+#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
+#include <asm/mmu_context.h>
+#include <asm/tlb.h>
+
+/* Heavily inspired by the ppc64 code.  */
+
+static DEFINE_PER_CPU(struct tlb_batch, tlb_batch);
+
+void flush_tlb_pending(void)
+{
+	struct tlb_batch *tb = &get_cpu_var(tlb_batch);
+	struct mm_struct *mm = tb->mm;
+
+	if (!tb->tlb_nr)
+		goto out;
+
+	flush_tsb_user(tb);
+
+	if (CTX_VALID(mm->context)) {
+		if (tb->tlb_nr == 1) {
+			global_flush_tlb_page(mm, tb->vaddrs[0]);
+		} else {
+#ifdef CONFIG_SMP
+			smp_flush_tlb_pending(tb->mm, tb->tlb_nr,
+					      &tb->vaddrs[0]);
+#else
+			__flush_tlb_pending(CTX_HWBITS(tb->mm->context),
+					    tb->tlb_nr, &tb->vaddrs[0]);
+#endif
+		}
+	}
+
+	tb->tlb_nr = 0;
+
+out:
+	put_cpu_var(tlb_batch);
+}
+
+void arch_enter_lazy_mmu_mode(void)
+{
+	struct tlb_batch *tb = this_cpu_ptr(&tlb_batch);
+
+	tb->active = 1;
+}
+
+void arch_leave_lazy_mmu_mode(void)
+{
+	struct tlb_batch *tb = this_cpu_ptr(&tlb_batch);
+
+	if (tb->tlb_nr)
+		flush_tlb_pending();
+	tb->active = 0;
+}
+
+static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr,
+			      bool exec, unsigned int hugepage_shift)
+{
+	struct tlb_batch *tb = &get_cpu_var(tlb_batch);
+	unsigned long nr;
+
+	vaddr &= PAGE_MASK;
+	if (exec)
+		vaddr |= 0x1UL;
+
+	nr = tb->tlb_nr;
+
+	if (unlikely(nr != 0 && mm != tb->mm)) {
+		flush_tlb_pending();
+		nr = 0;
+	}
+
+	if (!tb->active) {
+		flush_tsb_user_page(mm, vaddr, hugepage_shift);
+		global_flush_tlb_page(mm, vaddr);
+		goto out;
+	}
+
+	if (nr == 0) {
+		tb->mm = mm;
+		tb->hugepage_shift = hugepage_shift;
+	}
+
+	if (tb->hugepage_shift != hugepage_shift) {
+		flush_tlb_pending();
+		tb->hugepage_shift = hugepage_shift;
+		nr = 0;
+	}
+
+	tb->vaddrs[nr] = vaddr;
+	tb->tlb_nr = ++nr;
+	if (nr >= TLB_BATCH_NR)
+		flush_tlb_pending();
+
+out:
+	put_cpu_var(tlb_batch);
+}
+
+void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
+		   pte_t *ptep, pte_t orig, int fullmm,
+		   unsigned int hugepage_shift)
+{
+	if (tlb_type != hypervisor &&
+	    pte_dirty(orig)) {
+		unsigned long paddr, pfn = pte_pfn(orig);
+		struct address_space *mapping;
+		struct page *page;
+
+		if (!pfn_valid(pfn))
+			goto no_cache_flush;
+
+		page = pfn_to_page(pfn);
+		if (PageReserved(page))
+			goto no_cache_flush;
+
+		/* A real file page? */
+		mapping = page_mapping_file(page);
+		if (!mapping)
+			goto no_cache_flush;
+
+		paddr = (unsigned long) page_address(page);
+		if ((paddr ^ vaddr) & (1 << 13))
+			flush_dcache_page_all(mm, page);
+	}
+
+no_cache_flush:
+	if (!fullmm)
+		tlb_batch_add_one(mm, vaddr, pte_exec(orig), hugepage_shift);
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static void tlb_batch_pmd_scan(struct mm_struct *mm, unsigned long vaddr,
+			       pmd_t pmd)
+{
+	unsigned long end;
+	pte_t *pte;
+
+	pte = pte_offset_map(&pmd, vaddr);
+	end = vaddr + HPAGE_SIZE;
+	while (vaddr < end) {
+		if (pte_val(*pte) & _PAGE_VALID) {
+			bool exec = pte_exec(*pte);
+
+			tlb_batch_add_one(mm, vaddr, exec, PAGE_SHIFT);
+		}
+		pte++;
+		vaddr += PAGE_SIZE;
+	}
+	pte_unmap(pte);
+}
+
+
+static void __set_pmd_acct(struct mm_struct *mm, unsigned long addr,
+			   pmd_t orig, pmd_t pmd)
+{
+	if (mm == &init_mm)
+		return;
+
+	if ((pmd_val(pmd) ^ pmd_val(orig)) & _PAGE_PMD_HUGE) {
+		/*
+		 * Note that this routine only sets pmds for THP pages.
+		 * Hugetlb pages are handled elsewhere.  We need to check
+		 * for huge zero page.  Huge zero pages are like hugetlb
+		 * pages in that there is no RSS, but there is the need
+		 * for TSB entries.  So, huge zero page counts go into
+		 * hugetlb_pte_count.
+		 */
+		if (pmd_val(pmd) & _PAGE_PMD_HUGE) {
+			if (is_huge_zero_page(pmd_page(pmd)))
+				mm->context.hugetlb_pte_count++;
+			else
+				mm->context.thp_pte_count++;
+		} else {
+			if (is_huge_zero_page(pmd_page(orig)))
+				mm->context.hugetlb_pte_count--;
+			else
+				mm->context.thp_pte_count--;
+		}
+
+		/* Do not try to allocate the TSB hash table if we
+		 * don't have one already.  We have various locks held
+		 * and thus we'll end up doing a GFP_KERNEL allocation
+		 * in an atomic context.
+		 *
+		 * Instead, we let the first TLB miss on a hugepage
+		 * take care of this.
+		 */
+	}
+
+	if (!pmd_none(orig)) {
+		addr &= HPAGE_MASK;
+		if (pmd_trans_huge(orig)) {
+			pte_t orig_pte = __pte(pmd_val(orig));
+			bool exec = pte_exec(orig_pte);
+
+			tlb_batch_add_one(mm, addr, exec, REAL_HPAGE_SHIFT);
+			tlb_batch_add_one(mm, addr + REAL_HPAGE_SIZE, exec,
+					  REAL_HPAGE_SHIFT);
+		} else {
+			tlb_batch_pmd_scan(mm, addr, orig);
+		}
+	}
+}
+
+void set_pmd_at(struct mm_struct *mm, unsigned long addr,
+		pmd_t *pmdp, pmd_t pmd)
+{
+	pmd_t orig = *pmdp;
+
+	*pmdp = pmd;
+	__set_pmd_acct(mm, addr, orig, pmd);
+}
+
+static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
+		unsigned long address, pmd_t *pmdp, pmd_t pmd)
+{
+	pmd_t old;
+
+	do {
+		old = *pmdp;
+	} while (cmpxchg64(&pmdp->pmd, old.pmd, pmd.pmd) != old.pmd);
+	__set_pmd_acct(vma->vm_mm, address, old, pmd);
+
+	return old;
+}
+
+/*
+ * This routine is only called when splitting a THP
+ */
+pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
+		     pmd_t *pmdp)
+{
+	pmd_t old, entry;
+
+	entry = __pmd(pmd_val(*pmdp) & ~_PAGE_VALID);
+	old = pmdp_establish(vma, address, pmdp, entry);
+	flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+
+	/*
+	 * set_pmd_at() will not be called in a way to decrement
+	 * thp_pte_count when splitting a THP, so do it now.
+	 * Sanity check pmd before doing the actual decrement.
+	 */
+	if ((pmd_val(entry) & _PAGE_PMD_HUGE) &&
+	    !is_huge_zero_page(pmd_page(entry)))
+		(vma->vm_mm)->context.thp_pte_count--;
+
+	return old;
+}
+
+void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+				pgtable_t pgtable)
+{
+	struct list_head *lh = (struct list_head *) pgtable;
+
+	assert_spin_locked(&mm->page_table_lock);
+
+	/* FIFO */
+	if (!pmd_huge_pte(mm, pmdp))
+		INIT_LIST_HEAD(lh);
+	else
+		list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
+	pmd_huge_pte(mm, pmdp) = pgtable;
+}
+
+pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
+{
+	struct list_head *lh;
+	pgtable_t pgtable;
+
+	assert_spin_locked(&mm->page_table_lock);
+
+	/* FIFO */
+	pgtable = pmd_huge_pte(mm, pmdp);
+	lh = (struct list_head *) pgtable;
+	if (list_empty(lh))
+		pmd_huge_pte(mm, pmdp) = NULL;
+	else {
+		pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
+		list_del(lh);
+	}
+	pte_val(pgtable[0]) = 0;
+	pte_val(pgtable[1]) = 0;
+
+	return pgtable;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */