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awilliam
GitHub Repository: awilliam/linux-vfio
 Path: blob/master/arch/mips/loongson/common/env.c
10818 views
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/*

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 * Based on Ocelot Linux port, which is

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 * Copyright 2001 MontaVista Software Inc.

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 * Author: [email protected] or [email protected]

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 *

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 * Copyright 2003 ICT CAS

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 * Author: Michael Guo <[email protected]>

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 *

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 * Copyright (C) 2007 Lemote Inc. & Insititute of Computing Technology

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 * Author: Fuxin Zhang, [email protected]

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 *

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 * Copyright (C) 2009 Lemote Inc.

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 * Author: Wu Zhangjin, [email protected]

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 *

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 * This program is free software; you can redistribute  it and/or modify it

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 * under  the terms of  the GNU General  Public License as published by the

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 * Free Software Foundation;  either version 2 of the  License, or (at your

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 * option) any later version.

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 */

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#include <linux/module.h>

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#include <asm/bootinfo.h>

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#include <loongson.h>

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unsigned long cpu_clock_freq;

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EXPORT_SYMBOL(cpu_clock_freq);

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unsigned long memsize, highmemsize;

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#define parse_even_earlier(res, option, p)				\

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do {									\

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	unsigned int tmp __maybe_unused;				\

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									\

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	if (strncmp(option, (char *)p, strlen(option)) == 0)		\

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		tmp = strict_strtol((char *)p + strlen(option"="), 10, &res); \

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} while (0)

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void __init prom_init_env(void)

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{

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	/* pmon passes arguments in 32bit pointers */

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	int *_prom_envp;

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	unsigned long bus_clock;

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	unsigned int processor_id;

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	long l;

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	/* firmware arguments are initialized in head.S */

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	_prom_envp = (int *)fw_arg2;

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	l = (long)*_prom_envp;

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	while (l != 0) {

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		parse_even_earlier(bus_clock, "busclock", l);

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		parse_even_earlier(cpu_clock_freq, "cpuclock", l);

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		parse_even_earlier(memsize, "memsize", l);

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		parse_even_earlier(highmemsize, "highmemsize", l);

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		_prom_envp++;

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		l = (long)*_prom_envp;

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	}

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	if (memsize == 0)

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		memsize = 256;

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	if (bus_clock == 0)

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		bus_clock = 66000000;

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	if (cpu_clock_freq == 0) {

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		processor_id = (&current_cpu_data)->processor_id;

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		switch (processor_id & PRID_REV_MASK) {

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		case PRID_REV_LOONGSON2E:

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			cpu_clock_freq = 533080000;

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			break;

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		case PRID_REV_LOONGSON2F:

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			cpu_clock_freq = 797000000;

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			break;

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		default:

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			cpu_clock_freq = 100000000;

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			break;

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		}

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	}

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	pr_info("busclock=%ld, cpuclock=%ld, memsize=%ld, highmemsize=%ld\n",

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		bus_clock, cpu_clock_freq, memsize, highmemsize);

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}

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