powerpc/mm: Rename tlb_32.c and tlb_64.c to tlb_hash32.c and tlb_hash64.c

This renames the files to clarify the fact that they are used by
the hash based family of CPUs (the 603 being an exception in that
family but is still handled by that code).

This paves the way for the new tlb_nohash.c coming via a subsequent
commit.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 211 insertions, 0 deletions

diff --git a/arch/powerpc/mm/tlb_hash64.c b/arch/powerpc/mm/tlb_hash64.c
new file mode 100644
index 000000000000..c931bc7d1079
--- /dev/null
+++ b/arch/powerpc/mm/tlb_hash64.c
@@ -0,0 +1,211 @@
+/*
+ * This file contains the routines for flushing entries from the
+ * TLB and MMU hash table.
+ *
+ *  Derived from arch/ppc64/mm/init.c:
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
+ *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
+ *    Copyright (C) 1996 Paul Mackerras
+ *
+ *  Derived from "arch/i386/mm/init.c"
+ *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
+ *
+ *  Dave Engebretsen <engebret@us.ibm.com>
+ *      Rework for PPC64 port.
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/percpu.h>
+#include <linux/hardirq.h>
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+#include <asm/tlb.h>
+#include <asm/bug.h>
+
+DEFINE_PER_CPU(struct ppc64_tlb_batch, ppc64_tlb_batch);
+
+/* This is declared as we are using the more or less generic
+ * arch/powerpc/include/asm/tlb.h file -- tgall
+ */
+DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+
+/*
+ * A linux PTE was changed and the corresponding hash table entry
+ * neesd to be flushed. This function will either perform the flush
+ * immediately or will batch it up if the current CPU has an active
+ * batch on it.
+ *
+ * Must be called from within some kind of spinlock/non-preempt region...
+ */
+void hpte_need_flush(struct mm_struct *mm, unsigned long addr,
+		     pte_t *ptep, unsigned long pte, int huge)
+{
+	struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
+	unsigned long vsid, vaddr;
+	unsigned int psize;
+	int ssize;
+	real_pte_t rpte;
+	int i;
+
+	i = batch->index;
+
+	/* We mask the address for the base page size. Huge pages will
+	 * have applied their own masking already
+	 */
+	addr &= PAGE_MASK;
+
+	/* Get page size (maybe move back to caller).
+	 *
+	 * NOTE: when using special 64K mappings in 4K environment like
+	 * for SPEs, we obtain the page size from the slice, which thus
+	 * must still exist (and thus the VMA not reused) at the time
+	 * of this call
+	 */
+	if (huge) {
+#ifdef CONFIG_HUGETLB_PAGE
+		psize = get_slice_psize(mm, addr);;
+#else
+		BUG();
+		psize = pte_pagesize_index(mm, addr, pte); /* shutup gcc */
+#endif
+	} else
+		psize = pte_pagesize_index(mm, addr, pte);
+
+	/* Build full vaddr */
+	if (!is_kernel_addr(addr)) {
+		ssize = user_segment_size(addr);
+		vsid = get_vsid(mm->context.id, addr, ssize);
+		WARN_ON(vsid == 0);
+	} else {
+		vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
+		ssize = mmu_kernel_ssize;
+	}
+	vaddr = hpt_va(addr, vsid, ssize);
+	rpte = __real_pte(__pte(pte), ptep);
+
+	/*
+	 * Check if we have an active batch on this CPU. If not, just
+	 * flush now and return. For now, we don global invalidates
+	 * in that case, might be worth testing the mm cpu mask though
+	 * and decide to use local invalidates instead...
+	 */
+	if (!batch->active) {
+		flush_hash_page(vaddr, rpte, psize, ssize, 0);
+		return;
+	}
+
+	/*
+	 * This can happen when we are in the middle of a TLB batch and
+	 * we encounter memory pressure (eg copy_page_range when it tries
+	 * to allocate a new pte). If we have to reclaim memory and end
+	 * up scanning and resetting referenced bits then our batch context
+	 * will change mid stream.
+	 *
+	 * We also need to ensure only one page size is present in a given
+	 * batch
+	 */
+	if (i != 0 && (mm != batch->mm || batch->psize != psize ||
+		       batch->ssize != ssize)) {
+		__flush_tlb_pending(batch);
+		i = 0;
+	}
+	if (i == 0) {
+		batch->mm = mm;
+		batch->psize = psize;
+		batch->ssize = ssize;
+	}
+	batch->pte[i] = rpte;
+	batch->vaddr[i] = vaddr;
+	batch->index = ++i;
+	if (i >= PPC64_TLB_BATCH_NR)
+		__flush_tlb_pending(batch);
+}
+
+/*
+ * This function is called when terminating an mmu batch or when a batch
+ * is full. It will perform the flush of all the entries currently stored
+ * in a batch.
+ *
+ * Must be called from within some kind of spinlock/non-preempt region...
+ */
+void __flush_tlb_pending(struct ppc64_tlb_batch *batch)
+{
+	cpumask_t tmp;
+	int i, local = 0;
+
+	i = batch->index;
+	tmp = cpumask_of_cpu(smp_processor_id());
+	if (cpus_equal(batch->mm->cpu_vm_mask, tmp))
+		local = 1;
+	if (i == 1)
+		flush_hash_page(batch->vaddr[0], batch->pte[0],
+				batch->psize, batch->ssize, local);
+	else
+		flush_hash_range(i, local);
+	batch->index = 0;
+}
+
+/**
+ * __flush_hash_table_range - Flush all HPTEs for a given address range
+ *                            from the hash table (and the TLB). But keeps
+ *                            the linux PTEs intact.
+ *
+ * @mm		: mm_struct of the target address space (generally init_mm)
+ * @start	: starting address
+ * @end         : ending address (not included in the flush)
+ *
+ * This function is mostly to be used by some IO hotplug code in order
+ * to remove all hash entries from a given address range used to map IO
+ * space on a removed PCI-PCI bidge without tearing down the full mapping
+ * since 64K pages may overlap with other bridges when using 64K pages
+ * with 4K HW pages on IO space.
+ *
+ * Because of that usage pattern, it's only available with CONFIG_HOTPLUG
+ * and is implemented for small size rather than speed.
+ */
+#ifdef CONFIG_HOTPLUG
+
+void __flush_hash_table_range(struct mm_struct *mm, unsigned long start,
+			      unsigned long end)
+{
+	unsigned long flags;
+
+	start = _ALIGN_DOWN(start, PAGE_SIZE);
+	end = _ALIGN_UP(end, PAGE_SIZE);
+
+	BUG_ON(!mm->pgd);
+
+	/* Note: Normally, we should only ever use a batch within a
+	 * PTE locked section. This violates the rule, but will work
+	 * since we don't actually modify the PTEs, we just flush the
+	 * hash while leaving the PTEs intact (including their reference
+	 * to being hashed). This is not the most performance oriented
+	 * way to do things but is fine for our needs here.
+	 */
+	local_irq_save(flags);
+	arch_enter_lazy_mmu_mode();
+	for (; start < end; start += PAGE_SIZE) {
+		pte_t *ptep = find_linux_pte(mm->pgd, start);
+		unsigned long pte;
+
+		if (ptep == NULL)
+			continue;
+		pte = pte_val(*ptep);
+		if (!(pte & _PAGE_HASHPTE))
+			continue;
+		hpte_need_flush(mm, start, ptep, pte, 0);
+	}
+	arch_leave_lazy_mmu_mode();
+	local_irq_restore(flags);
+}
+
+#endif /* CONFIG_HOTPLUG */