mirror of https://gitee.com/openkylin/linux.git
89 lines
1.8 KiB
C
89 lines
1.8 KiB
C
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/*
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* PowerNV nvram code.
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*
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* Copyright 2011 IBM Corp.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#define DEBUG
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/of.h>
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#include <asm/opal.h>
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#include <asm/machdep.h>
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static unsigned int nvram_size;
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static ssize_t opal_nvram_size(void)
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{
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return nvram_size;
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}
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static ssize_t opal_nvram_read(char *buf, size_t count, loff_t *index)
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{
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s64 rc;
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int off;
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if (*index >= nvram_size)
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return 0;
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off = *index;
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if ((off + count) > nvram_size)
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count = nvram_size - off;
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rc = opal_read_nvram(__pa(buf), count, off);
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if (rc != OPAL_SUCCESS)
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return -EIO;
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*index += count;
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return count;
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}
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static ssize_t opal_nvram_write(char *buf, size_t count, loff_t *index)
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{
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s64 rc = OPAL_BUSY;
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int off;
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if (*index >= nvram_size)
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return 0;
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off = *index;
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if ((off + count) > nvram_size)
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count = nvram_size - off;
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while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
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rc = opal_write_nvram(__pa(buf), count, off);
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if (rc == OPAL_BUSY_EVENT)
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opal_poll_events(NULL);
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}
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*index += count;
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return count;
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}
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void __init opal_nvram_init(void)
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{
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struct device_node *np;
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const u32 *nbytes_p;
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np = of_find_compatible_node(NULL, NULL, "ibm,opal-nvram");
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if (np == NULL)
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return;
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nbytes_p = of_get_property(np, "#bytes", NULL);
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if (!nbytes_p) {
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of_node_put(np);
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return;
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}
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nvram_size = *nbytes_p;
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printk(KERN_INFO "OPAL nvram setup, %u bytes\n", nvram_size);
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of_node_put(np);
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ppc_md.nvram_read = opal_nvram_read;
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ppc_md.nvram_write = opal_nvram_write;
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ppc_md.nvram_size = opal_nvram_size;
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}
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