1 files changed, 87 insertions, 0 deletions

diff --git a/arch/powerpc/mm/icswx_pid.c b/arch/powerpc/mm/icswx_pid.c
new file mode 100644
index 000000000000..91e30eb7d054
--- /dev/null
+++ b/arch/powerpc/mm/icswx_pid.c
@@ -0,0 +1,87 @@
+/*
+ *  ICSWX and ACOP/PID Management
+ *
+ *  Copyright (C) 2011 Anton Blanchard, IBM Corp. <anton@samba.org>
+ *
+ *  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/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/spinlock.h>
+#include <linux/idr.h>
+#include <linux/module.h>
+#include "icswx.h"
+
+#define COP_PID_MIN (COP_PID_NONE + 1)
+#define COP_PID_MAX (0xFFFF)
+
+static DEFINE_SPINLOCK(mmu_context_acop_lock);
+static DEFINE_IDA(cop_ida);
+
+static int new_cop_pid(struct ida *ida, int min_id, int max_id,
+                       spinlock_t *lock)
+{
+        int index;
+        int err;
+
+again:
+        if (!ida_pre_get(ida, GFP_KERNEL))
+                return -ENOMEM;
+
+        spin_lock(lock);
+        err = ida_get_new_above(ida, min_id, &index);
+        spin_unlock(lock);
+
+        if (err == -EAGAIN)
+                goto again;
+        else if (err)
+                return err;
+
+        if (index > max_id) {
+                spin_lock(lock);
+                ida_remove(ida, index);
+                spin_unlock(lock);
+                return -ENOMEM;
+        }
+
+        return index;
+}
+
+int get_cop_pid(struct mm_struct *mm)
+{
+        int pid;
+
+        if (mm->context.cop_pid == COP_PID_NONE) {
+                pid = new_cop_pid(&cop_ida, COP_PID_MIN, COP_PID_MAX,
+                                  &mmu_context_acop_lock);
+                if (pid >= 0)
+                        mm->context.cop_pid = pid;
+        }
+        return mm->context.cop_pid;
+}
+
+int disable_cop_pid(struct mm_struct *mm)
+{
+        int free_pid = COP_PID_NONE;
+
+        if ((!mm->context.acop) && (mm->context.cop_pid != COP_PID_NONE)) {
+                free_pid = mm->context.cop_pid;
+                mm->context.cop_pid = COP_PID_NONE;
+        }
+        return free_pid;
+}
+
+void free_cop_pid(int free_pid)
+{
+        spin_lock(&mmu_context_acop_lock);
+        ida_remove(&cop_ida, free_pid);
+        spin_unlock(&mmu_context_acop_lock);
+}