powerpc: Merge enough to start building in arch/powerpc.
This creates the directory structure under arch/powerpc and a bunch
of Kconfig files. It does a first-cut merge of arch/powerpc/mm,
arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough
to build a 32-bit powermac kernel with ARCH=powerpc.
For now we are getting some unmerged files from arch/ppc/kernel and
arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes
to files in those directories and files outside arch/powerpc.
The boot directory is still not merged. That's going to be interesting.
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/mm/mmu_context64.c b/arch/powerpc/mm/mmu_context64.c
new file mode 100644
index 0000000..714a84d
--- /dev/null
+++ b/arch/powerpc/mm/mmu_context64.c
@@ -0,0 +1,63 @@
+/*
+ * MMU context allocation for 64-bit kernels.
+ *
+ * Copyright (C) 2004 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/config.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/spinlock.h>
+#include <linux/idr.h>
+
+#include <asm/mmu_context.h>
+
+static DEFINE_SPINLOCK(mmu_context_lock);
+static DEFINE_IDR(mmu_context_idr);
+
+int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
+{
+ int index;
+ int err;
+
+again:
+ if (!idr_pre_get(&mmu_context_idr, GFP_KERNEL))
+ return -ENOMEM;
+
+ spin_lock(&mmu_context_lock);
+ err = idr_get_new_above(&mmu_context_idr, NULL, 1, &index);
+ spin_unlock(&mmu_context_lock);
+
+ if (err == -EAGAIN)
+ goto again;
+ else if (err)
+ return err;
+
+ if (index > MAX_CONTEXT) {
+ idr_remove(&mmu_context_idr, index);
+ return -ENOMEM;
+ }
+
+ mm->context.id = index;
+
+ return 0;
+}
+
+void destroy_context(struct mm_struct *mm)
+{
+ spin_lock(&mmu_context_lock);
+ idr_remove(&mmu_context_idr, mm->context.id);
+ spin_unlock(&mmu_context_lock);
+
+ mm->context.id = NO_CONTEXT;
+}