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/*
* 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 __be32 *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 = be32_to_cpup(nbytes_p);
pr_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;
}
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