1 files changed, 88 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/powernv/opal-nvram.c b/arch/powerpc/platforms/powernv/opal-nvram.c
new file mode 100644
index 00000000000..3f83e1ae26a
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-nvram.c
@@ -0,0 +1,88 @@
+/*
+ * PowerNV nvram code.
+ *
+ * Copyright 2011 IBM Corp.
+ *
+ * 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.
+ */
+
+#define DEBUG
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/of.h>
+
+#include <asm/opal.h>
+#include <asm/machdep.h>
+
+static unsigned int nvram_size;
+
+static ssize_t opal_nvram_size(void)
+{
+        return nvram_size;
+}
+
+static ssize_t opal_nvram_read(char *buf, size_t count, loff_t *index)
+{
+        s64 rc;
+        int off;
+
+        if (*index >= nvram_size)
+                return 0;
+        off = *index;
+        if ((off + count) > nvram_size)
+                count = nvram_size - off;
+        rc = opal_read_nvram(__pa(buf), count, off);
+        if (rc != OPAL_SUCCESS)
+                return -EIO;
+        *index += count;
+        return count;
+}
+
+static ssize_t opal_nvram_write(char *buf, size_t count, loff_t *index)
+{
+        s64 rc = OPAL_BUSY;
+        int off;
+
+        if (*index >= nvram_size)
+                return 0;
+        off = *index;
+        if ((off + count) > nvram_size)
+                count = nvram_size - off;
+
+        while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+                rc = opal_write_nvram(__pa(buf), count, off);
+                if (rc == OPAL_BUSY_EVENT)
+                        opal_poll_events(NULL);
+        }
+        *index += count;
+        return count;
+}
+
+void __init opal_nvram_init(void)
+{
+        struct device_node *np;
+        const u32 *nbytes_p;
+
+        np = of_find_compatible_node(NULL, NULL, "ibm,opal-nvram");
+        if (np == NULL)
+                return;
+
+        nbytes_p = of_get_property(np, "#bytes", NULL);
+        if (!nbytes_p) {
+                of_node_put(np);
+                return;
+        }
+        nvram_size = *nbytes_p;
+
+        printk(KERN_INFO "OPAL nvram setup, %u bytes\n", nvram_size);
+        of_node_put(np);
+
+        ppc_md.nvram_read = opal_nvram_read;
+        ppc_md.nvram_write = opal_nvram_write;
+        ppc_md.nvram_size = opal_nvram_size;
+}
+