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authorLinus Torvalds <torvalds@linux-foundation.org>2008-12-28 16:54:33 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2008-12-28 16:54:33 -0800
commit3c92ec8ae91ecf59d88c798301833d7cf83f2179 (patch)
tree08a38cd3523c42bd49882f17cd501fd879e7ca1c /arch/powerpc/mm/pgtable.c
parentc4c9f0183b7c4e97836e8fecbb67898b06c47e78 (diff)
parentca9153a3a2a7556d091dfe080e42b0e67881fff6 (diff)
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (144 commits) powerpc/44x: Support 16K/64K base page sizes on 44x powerpc: Force memory size to be a multiple of PAGE_SIZE powerpc/32: Wire up the trampoline code for kdump powerpc/32: Add the ability for a classic ppc kernel to be loaded at 32M powerpc/32: Allow __ioremap on RAM addresses for kdump kernel powerpc/32: Setup OF properties for kdump powerpc/32/kdump: Implement crash_setup_regs() using ppc_save_regs() powerpc: Prepare xmon_save_regs for use with kdump powerpc: Remove default kexec/crash_kernel ops assignments powerpc: Make default kexec/crash_kernel ops implicit powerpc: Setup OF properties for ppc32 kexec powerpc/pseries: Fix cpu hotplug powerpc: Fix KVM build on ppc440 powerpc/cell: add QPACE as a separate Cell platform powerpc/cell: fix build breakage with CONFIG_SPUFS disabled powerpc/mpc5200: fix error paths in PSC UART probe function powerpc/mpc5200: add rts/cts handling in PSC UART driver powerpc/mpc5200: Make PSC UART driver update serial errors counters powerpc/mpc5200: Remove obsolete code from mpc5200 MDIO driver powerpc/mpc5200: Add MDMA/UDMA support to MPC5200 ATA driver ... Fix trivial conflict in drivers/char/Makefile as per Paul's directions
Diffstat (limited to 'arch/powerpc/mm/pgtable.c')
-rw-r--r--arch/powerpc/mm/pgtable.c117
1 files changed, 117 insertions, 0 deletions
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
new file mode 100644
index 000000000000..6d94116fdea1
--- /dev/null
+++ b/arch/powerpc/mm/pgtable.c
@@ -0,0 +1,117 @@
+/*
+ * This file contains common routines for dealing with free of page tables
+ *
+ * Derived from arch/powerpc/mm/tlb_64.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>
+
+static DEFINE_PER_CPU(struct pte_freelist_batch *, pte_freelist_cur);
+static unsigned long pte_freelist_forced_free;
+
+struct pte_freelist_batch
+{
+ struct rcu_head rcu;
+ unsigned int index;
+ pgtable_free_t tables[0];
+};
+
+#define PTE_FREELIST_SIZE \
+ ((PAGE_SIZE - sizeof(struct pte_freelist_batch)) \
+ / sizeof(pgtable_free_t))
+
+static void pte_free_smp_sync(void *arg)
+{
+ /* Do nothing, just ensure we sync with all CPUs */
+}
+
+/* This is only called when we are critically out of memory
+ * (and fail to get a page in pte_free_tlb).
+ */
+static void pgtable_free_now(pgtable_free_t pgf)
+{
+ pte_freelist_forced_free++;
+
+ smp_call_function(pte_free_smp_sync, NULL, 1);
+
+ pgtable_free(pgf);
+}
+
+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++)
+ pgtable_free(batch->tables[i]);
+
+ free_page((unsigned long)batch);
+}
+
+static void pte_free_submit(struct pte_freelist_batch *batch)
+{
+ INIT_RCU_HEAD(&batch->rcu);
+ call_rcu(&batch->rcu, pte_free_rcu_callback);
+}
+
+void pgtable_free_tlb(struct mmu_gather *tlb, pgtable_free_t pgf)
+{
+ /* This is safe since tlb_gather_mmu has disabled preemption */
+ 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)) {
+ pgtable_free(pgf);
+ return;
+ }
+
+ if (*batchp == NULL) {
+ *batchp = (struct pte_freelist_batch *)__get_free_page(GFP_ATOMIC);
+ if (*batchp == NULL) {
+ pgtable_free_now(pgf);
+ return;
+ }
+ (*batchp)->index = 0;
+ }
+ (*batchp)->tables[(*batchp)->index++] = pgf;
+ if ((*batchp)->index == PTE_FREELIST_SIZE) {
+ pte_free_submit(*batchp);
+ *batchp = NULL;
+ }
+}
+
+void pte_free_finish(void)
+{
+ /* This is safe since tlb_gather_mmu has disabled preemption */
+ struct pte_freelist_batch **batchp = &__get_cpu_var(pte_freelist_cur);
+
+ if (*batchp == NULL)
+ return;
+ pte_free_submit(*batchp);
+ *batchp = NULL;
+}