Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 180 insertions, 0 deletions

diff --git a/arch/ppc64/mm/tlb.c b/arch/ppc64/mm/tlb.c
new file mode 100644
index 000000000000..26f0172c4527
--- /dev/null
+++ b/arch/ppc64/mm/tlb.c
@@ -0,0 +1,180 @@
+/*
+ * 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
+ *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
+ *
+ *  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/config.h>
+#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 <linux/highmem.h>
+
+DEFINE_PER_CPU(struct ppc64_tlb_batch, ppc64_tlb_batch);
+
+/* This is declared as we are using the more or less generic
+ * include/asm-ppc64/tlb.h file -- tgall
+ */
+DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+DEFINE_PER_CPU(struct pte_freelist_batch *, pte_freelist_cur);
+unsigned long pte_freelist_forced_free;
+
+void __pte_free_tlb(struct mmu_gather *tlb, struct page *ptepage)
+{
+        /* This is safe as we are holding page_table_lock */
+        cpumask_t local_cpumask = cpumask_of_cpu(smp_processor_id());
+        struct pte_freelist_batch **batchp = &__get_cpu_var(pte_freelist_cur);
+
+        if (atomic_read(&tlb->mm->mm_users) < 2 ||
+            cpus_equal(tlb->mm->cpu_vm_mask, local_cpumask)) {
+                pte_free(ptepage);
+                return;
+        }
+
+        if (*batchp == NULL) {
+                *batchp = (struct pte_freelist_batch *)__get_free_page(GFP_ATOMIC);
+                if (*batchp == NULL) {
+                        pte_free_now(ptepage);
+                        return;
+                }
+                (*batchp)->index = 0;
+        }
+        (*batchp)->pages[(*batchp)->index++] = ptepage;
+        if ((*batchp)->index == PTE_FREELIST_SIZE) {
+                pte_free_submit(*batchp);
+                *batchp = NULL;
+        }
+}
+
+/*
+ * Update the MMU hash table to correspond with a change to
+ * a Linux PTE.  If wrprot is true, it is permissible to
+ * change the existing HPTE to read-only rather than removing it
+ * (if we remove it we should clear the _PTE_HPTEFLAGS bits).
+ */
+void hpte_update(struct mm_struct *mm, unsigned long addr,
+                 unsigned long pte, int wrprot)
+{
+        int i;
+        unsigned long context = 0;
+        struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
+
+        if (REGION_ID(addr) == USER_REGION_ID)
+                context = mm->context.id;
+        i = batch->index;
+
+        /*
+         * 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.
+         */
+        if (unlikely(i != 0 && context != batch->context)) {
+                flush_tlb_pending();
+                i = 0;
+        }
+
+        if (i == 0) {
+                batch->context = context;
+                batch->mm = mm;
+        }
+        batch->pte[i] = __pte(pte);
+        batch->addr[i] = addr;
+        batch->index = ++i;
+        if (i >= PPC64_TLB_BATCH_NR)
+                flush_tlb_pending();
+}
+
+void __flush_tlb_pending(struct ppc64_tlb_batch *batch)
+{
+        int i;
+        int cpu;
+        cpumask_t tmp;
+        int local = 0;
+
+        BUG_ON(in_interrupt());
+
+        cpu = get_cpu();
+        i = batch->index;
+        tmp = cpumask_of_cpu(cpu);
+        if (cpus_equal(batch->mm->cpu_vm_mask, tmp))
+                local = 1;
+
+        if (i == 1)
+                flush_hash_page(batch->context, batch->addr[0], batch->pte[0],
+                                local);
+        else
+                flush_hash_range(batch->context, i, local);
+        batch->index = 0;
+        put_cpu();
+}
+
+#ifdef CONFIG_SMP
+static void pte_free_smp_sync(void *arg)
+{
+        /* Do nothing, just ensure we sync with all CPUs */
+}
+#endif
+
+/* This is only called when we are critically out of memory
+ * (and fail to get a page in pte_free_tlb).
+ */
+void pte_free_now(struct page *ptepage)
+{
+        pte_freelist_forced_free++;
+
+        smp_call_function(pte_free_smp_sync, NULL, 0, 1);
+
+        pte_free(ptepage);
+}
+
+static void pte_free_rcu_callback(struct rcu_head *head)
+{
+        struct pte_freelist_batch *batch =
+                container_of(head, struct pte_freelist_batch, rcu);
+        unsigned int i;
+
+        for (i = 0; i < batch->index; i++)
+                pte_free(batch->pages[i]);
+        free_page((unsigned long)batch);
+}
+
+void pte_free_submit(struct pte_freelist_batch *batch)
+{
+        INIT_RCU_HEAD(&batch->rcu);
+        call_rcu(&batch->rcu, pte_free_rcu_callback);
+}
+
+void pte_free_finish(void)
+{
+        /* This is safe as we are holding page_table_lock */
+        struct pte_freelist_batch **batchp = &__get_cpu_var(pte_freelist_cur);
+
+        if (*batchp == NULL)
+                return;
+        pte_free_submit(*batchp);
+        *batchp = NULL;
+}