forked from Minki/linux
2874c5fd28
Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
114 lines
2.2 KiB
C
114 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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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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#define DEBUG
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#include <linux/delay.h>
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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/nvram.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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/*
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* This can be called in the panic path with interrupts off, so use
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* mdelay in that case.
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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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if (in_interrupt() || irqs_disabled())
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mdelay(OPAL_BUSY_DELAY_MS);
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else
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msleep(OPAL_BUSY_DELAY_MS);
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opal_poll_events(NULL);
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} else if (rc == OPAL_BUSY) {
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if (in_interrupt() || irqs_disabled())
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mdelay(OPAL_BUSY_DELAY_MS);
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else
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msleep(OPAL_BUSY_DELAY_MS);
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}
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}
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if (rc)
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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 int __init opal_nvram_init_log_partitions(void)
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{
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/* Scan nvram for partitions */
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nvram_scan_partitions();
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nvram_init_oops_partition(0);
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return 0;
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}
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machine_arch_initcall(powernv, opal_nvram_init_log_partitions);
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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 __be32 *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 = be32_to_cpup(nbytes_p);
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pr_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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