1 files changed, 209 insertions, 0 deletions

diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c
new file mode 100644
index 000000000000..803a64c02b06
--- /dev/null
+++ b/arch/powerpc/mm/tlb_nohash.c
@@ -0,0 +1,209 @@
+/*
+ * This file contains the routines for TLB flushing.
+ * On machines where the MMU does not use a hash table to store virtual to
+ * physical translations (ie, SW loaded TLBs or Book3E compilant processors,
+ * this does -not- include 603 however which shares the implementation with
+ * hash based processors)
+ *
+ *  -- BenH
+ *
+ * Copyright 2008 Ben Herrenschmidt <benh@kernel.crashing.org>
+ *                IBM Corp.
+ *
+ *  Derived from arch/ppc/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
+ *
+ *  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/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/preempt.h>
+#include <linux/spinlock.h>
+
+#include <asm/tlbflush.h>
+#include <asm/tlb.h>
+
+#include "mmu_decl.h"
+
+/*
+ * Base TLB flushing operations:
+ *
+ *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
+ *  - flush_tlb_page(vma, vmaddr) flushes one page
+ *  - flush_tlb_range(vma, start, end) flushes a range of pages
+ *  - flush_tlb_kernel_range(start, end) flushes kernel pages
+ *
+ *  - local_* variants of page and mm only apply to the current
+ *    processor
+ */
+
+/*
+ * These are the base non-SMP variants of page and mm flushing
+ */
+void local_flush_tlb_mm(struct mm_struct *mm)
+{
+        unsigned int pid;
+
+        preempt_disable();
+        pid = mm->context.id;
+        if (pid != MMU_NO_CONTEXT)
+                _tlbil_pid(pid);
+        preempt_enable();
+}
+EXPORT_SYMBOL(local_flush_tlb_mm);
+
+void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
+{
+        unsigned int pid;
+
+        preempt_disable();
+        pid = vma ? vma->vm_mm->context.id : 0;
+        if (pid != MMU_NO_CONTEXT)
+                _tlbil_va(vmaddr, pid);
+        preempt_enable();
+}
+EXPORT_SYMBOL(local_flush_tlb_page);
+
+
+/*
+ * And here are the SMP non-local implementations
+ */
+#ifdef CONFIG_SMP
+
+static DEFINE_SPINLOCK(tlbivax_lock);
+
+struct tlb_flush_param {
+        unsigned long addr;
+        unsigned int pid;
+};
+
+static void do_flush_tlb_mm_ipi(void *param)
+{
+        struct tlb_flush_param *p = param;
+
+        _tlbil_pid(p ? p->pid : 0);
+}
+
+static void do_flush_tlb_page_ipi(void *param)
+{
+        struct tlb_flush_param *p = param;
+
+        _tlbil_va(p->addr, p->pid);
+}
+
+
+/* Note on invalidations and PID:
+ *
+ * We snapshot the PID with preempt disabled. At this point, it can still
+ * change either because:
+ * - our context is being stolen (PID -> NO_CONTEXT) on another CPU
+ * - we are invaliating some target that isn't currently running here
+ *   and is concurrently acquiring a new PID on another CPU
+ * - some other CPU is re-acquiring a lost PID for this mm
+ * etc...
+ *
+ * However, this shouldn't be a problem as we only guarantee
+ * invalidation of TLB entries present prior to this call, so we
+ * don't care about the PID changing, and invalidating a stale PID
+ * is generally harmless.
+ */
+
+void flush_tlb_mm(struct mm_struct *mm)
+{
+        cpumask_t cpu_mask;
+        unsigned int pid;
+
+        preempt_disable();
+        pid = mm->context.id;
+        if (unlikely(pid == MMU_NO_CONTEXT))
+                goto no_context;
+        cpu_mask = mm->cpu_vm_mask;
+        cpu_clear(smp_processor_id(), cpu_mask);
+        if (!cpus_empty(cpu_mask)) {
+                struct tlb_flush_param p = { .pid = pid };
+                smp_call_function_mask(cpu_mask, do_flush_tlb_mm_ipi, &p, 1);
+        }
+        _tlbil_pid(pid);
+ no_context:
+        preempt_enable();
+}
+EXPORT_SYMBOL(flush_tlb_mm);
+
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
+{
+        cpumask_t cpu_mask;
+        unsigned int pid;
+
+        preempt_disable();
+        pid = vma ? vma->vm_mm->context.id : 0;
+        if (unlikely(pid == MMU_NO_CONTEXT))
+                goto bail;
+        cpu_mask = vma->vm_mm->cpu_vm_mask;
+        cpu_clear(smp_processor_id(), cpu_mask);
+        if (!cpus_empty(cpu_mask)) {
+                /* If broadcast tlbivax is supported, use it */
+                if (mmu_has_feature(MMU_FTR_USE_TLBIVAX_BCAST)) {
+                        int lock = mmu_has_feature(MMU_FTR_LOCK_BCAST_INVAL);
+                        if (lock)
+                                spin_lock(&tlbivax_lock);
+                        _tlbivax_bcast(vmaddr, pid);
+                        if (lock)
+                                spin_unlock(&tlbivax_lock);
+                        goto bail;
+                } else {
+                        struct tlb_flush_param p = { .pid = pid, .addr = vmaddr };
+                        smp_call_function_mask(cpu_mask,
+                                               do_flush_tlb_page_ipi, &p, 1);
+                }
+        }
+        _tlbil_va(vmaddr, pid);
+ bail:
+        preempt_enable();
+}
+EXPORT_SYMBOL(flush_tlb_page);
+
+#endif /* CONFIG_SMP */
+
+/*
+ * Flush kernel TLB entries in the given range
+ */
+void flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+#ifdef CONFIG_SMP
+        preempt_disable();
+        smp_call_function(do_flush_tlb_mm_ipi, NULL, 1);
+        _tlbil_pid(0);
+        preempt_enable();
+#endif
+        _tlbil_pid(0);
+}
+EXPORT_SYMBOL(flush_tlb_kernel_range);
+
+/*
+ * Currently, for range flushing, we just do a full mm flush. This should
+ * be optimized based on a threshold on the size of the range, since
+ * some implementation can stack multiple tlbivax before a tlbsync but
+ * for now, we keep it that way
+ */
+void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+                     unsigned long end)
+
+{
+        flush_tlb_mm(vma->vm_mm);
+}
+EXPORT_SYMBOL(flush_tlb_range);