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Diffstat (limited to 'arch/powerpc/mm/icswx_pid.c')
-rw-r--r--arch/powerpc/mm/icswx_pid.c87
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);
+}