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 */