arch/openrisc/kernel/setup.c - linux - Git at Google

 /*
  * OpenRISC setup.c
  *
  * Linux architectural port borrowing liberally from similar works of
  * others.  All original copyrights apply as per the original source
  * declaration.
  *
  * Modifications for the OpenRISC architecture:
  * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
  *
  *      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.
  *
  * This file handles the architecture-dependent parts of initialization
  */

 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/stddef.h>
 #include <linux/unistd.h>
 #include <linux/ptrace.h>
 #include <linux/slab.h>
 #include <linux/tty.h>
 #include <linux/ioport.h>
 #include <linux/delay.h>
 #include <linux/console.h>
 #include <linux/init.h>
 #include <linux/memblock.h>
 #include <linux/seq_file.h>
 #include <linux/serial.h>
 #include <linux/initrd.h>
 #include <linux/of_fdt.h>
 #include <linux/of.h>
 #include <linux/device.h>

 #include <asm/sections.h>
 #include <asm/pgtable.h>
 #include <asm/types.h>
 #include <asm/setup.h>
 #include <asm/io.h>
 #include <asm/cpuinfo.h>
 #include <asm/delay.h>

 #include "vmlinux.h"

 static void __init setup_memory(void)
 {
 	unsigned long ram_start_pfn;
 	unsigned long ram_end_pfn;
 	phys_addr_t memory_start, memory_end;
 	struct memblock_region *region;

 	memory_end = memory_start = 0;

 	/* Find main memory where is the kernel, we assume its the only one */
 	for_each_memblock(memory, region) {
 		memory_start = region->base;
 		memory_end = region->base + region->size;
 		printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__,
 		       memory_start, memory_end);
 	}

 	if (!memory_end) {
 		panic("No memory!");
 	}

 	ram_start_pfn = PFN_UP(memory_start);
 	ram_end_pfn = PFN_DOWN(memblock_end_of_DRAM());

 	/* setup bootmem globals (we use no_bootmem, but mm still depends on this) */
 	min_low_pfn = ram_start_pfn;
 	max_low_pfn = ram_end_pfn;
 	max_pfn = ram_end_pfn;

 	/*
 	 * initialize the boot-time allocator (with low memory only).
 	 *
 	 * This makes the memory from the end of the kernel to the end of
 	 * RAM usable.
 	 */
 	memblock_reserve(__pa(_stext), _end - _stext);

 	early_init_fdt_reserve_self();
 	early_init_fdt_scan_reserved_mem();

 	memblock_dump_all();
 }

 struct cpuinfo_or1k cpuinfo_or1k[NR_CPUS];

 static void print_cpuinfo(void)
 {
 	unsigned long upr = mfspr(SPR_UPR);
 	unsigned long vr = mfspr(SPR_VR);
 	unsigned int version;
 	unsigned int revision;
 	struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];

 	version = (vr & SPR_VR_VER) >> 24;
 	revision = (vr & SPR_VR_REV);

 	printk(KERN_INFO "CPU: OpenRISC-%x (revision %d) @%d MHz\n",
 	       version, revision, cpuinfo->clock_frequency / 1000000);

 	if (!(upr & SPR_UPR_UP)) {
 		printk(KERN_INFO
 		       "-- no UPR register... unable to detect configuration\n");
 		return;
 	}

 	if (upr & SPR_UPR_DCP)
 		printk(KERN_INFO
 		       "-- dcache: %4d bytes total, %2d bytes/line, %d way(s)\n",
 		       cpuinfo->dcache_size, cpuinfo->dcache_block_size,
 		       cpuinfo->dcache_ways);
 	else
 		printk(KERN_INFO "-- dcache disabled\n");
 	if (upr & SPR_UPR_ICP)
 		printk(KERN_INFO
 		       "-- icache: %4d bytes total, %2d bytes/line, %d way(s)\n",
 		       cpuinfo->icache_size, cpuinfo->icache_block_size,
 		       cpuinfo->icache_ways);
 	else
 		printk(KERN_INFO "-- icache disabled\n");

 	if (upr & SPR_UPR_DMP)
 		printk(KERN_INFO "-- dmmu: %4d entries, %lu way(s)\n",
 		       1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
 		       1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW));
 	if (upr & SPR_UPR_IMP)
 		printk(KERN_INFO "-- immu: %4d entries, %lu way(s)\n",
 		       1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
 		       1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW));

 	printk(KERN_INFO "-- additional features:\n");
 	if (upr & SPR_UPR_DUP)
 		printk(KERN_INFO "-- debug unit\n");
 	if (upr & SPR_UPR_PCUP)
 		printk(KERN_INFO "-- performance counters\n");
 	if (upr & SPR_UPR_PMP)
 		printk(KERN_INFO "-- power management\n");
 	if (upr & SPR_UPR_PICP)
 		printk(KERN_INFO "-- PIC\n");
 	if (upr & SPR_UPR_TTP)
 		printk(KERN_INFO "-- timer\n");
 	if (upr & SPR_UPR_CUP)
 		printk(KERN_INFO "-- custom unit(s)\n");
 }

 static struct device_node *setup_find_cpu_node(int cpu)
 {
 	u32 hwid;
 	struct device_node *cpun;

 	for_each_of_cpu_node(cpun) {
 		if (of_property_read_u32(cpun, "reg", &hwid))
 			continue;
 		if (hwid == cpu)
 			return cpun;
 	}

 	return NULL;
 }

 void __init setup_cpuinfo(void)
 {
 	struct device_node *cpu;
 	unsigned long iccfgr, dccfgr;
 	unsigned long cache_set_size;
 	int cpu_id = smp_processor_id();
 	struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[cpu_id];

 	cpu = setup_find_cpu_node(cpu_id);
 	if (!cpu)
 		panic("Couldn't find CPU%d in device tree...\n", cpu_id);

 	iccfgr = mfspr(SPR_ICCFGR);
 	cpuinfo->icache_ways = 1 << (iccfgr & SPR_ICCFGR_NCW);
 	cache_set_size = 1 << ((iccfgr & SPR_ICCFGR_NCS) >> 3);
 	cpuinfo->icache_block_size = 16 << ((iccfgr & SPR_ICCFGR_CBS) >> 7);
 	cpuinfo->icache_size =
 	    cache_set_size * cpuinfo->icache_ways * cpuinfo->icache_block_size;

 	dccfgr = mfspr(SPR_DCCFGR);
 	cpuinfo->dcache_ways = 1 << (dccfgr & SPR_DCCFGR_NCW);
 	cache_set_size = 1 << ((dccfgr & SPR_DCCFGR_NCS) >> 3);
 	cpuinfo->dcache_block_size = 16 << ((dccfgr & SPR_DCCFGR_CBS) >> 7);
 	cpuinfo->dcache_size =
 	    cache_set_size * cpuinfo->dcache_ways * cpuinfo->dcache_block_size;

 	if (of_property_read_u32(cpu, "clock-frequency",
 				 &cpuinfo->clock_frequency)) {
 		printk(KERN_WARNING
 		       "Device tree missing CPU 'clock-frequency' parameter."
 		       "Assuming frequency 25MHZ"
 		       "This is probably not what you want.");
 	}

 	cpuinfo->coreid = mfspr(SPR_COREID);

 	of_node_put(cpu);

 	print_cpuinfo();
 }

 /**
  * or32_early_setup
  *
  * Handles the pointer to the device tree that this kernel is to use
  * for establishing the available platform devices.
  *
  * Falls back on built-in device tree in case null pointer is passed.
  */

 void __init or32_early_setup(void *fdt)
 {
 	if (fdt)
 		pr_info("FDT at %p\n", fdt);
 	else {
 		fdt = __dtb_start;
 		pr_info("Compiled-in FDT at %p\n", fdt);
 	}
 	early_init_devtree(fdt);
 }

 static inline unsigned long extract_value_bits(unsigned long reg,
 					       short bit_nr, short width)
 {
 	return (reg >> bit_nr) & (0 << width);
 }

 static inline unsigned long extract_value(unsigned long reg, unsigned long mask)
 {
 	while (!(mask & 0x1)) {
 		reg = reg >> 1;
 		mask = mask >> 1;
 	}
 	return mask & reg;
 }

 void __init detect_unit_config(unsigned long upr, unsigned long mask,
 			       char *text, void (*func) (void))
 {
 	if (text != NULL)
 		printk("%s", text);

 	if (upr & mask) {
 		if (func != NULL)
 			func();
 		else
 			printk("present\n");
 	} else
 		printk("not present\n");
 }

 /*
  * calibrate_delay
  *
  * Lightweight calibrate_delay implementation that calculates loops_per_jiffy
  * from the clock frequency passed in via the device tree
  *
  */

 void calibrate_delay(void)
 {
 	const int *val;
 	struct device_node *cpu = setup_find_cpu_node(smp_processor_id());

 	val = of_get_property(cpu, "clock-frequency", NULL);
 	if (!val)
 		panic("no cpu 'clock-frequency' parameter in device tree");
 	loops_per_jiffy = *val / HZ;
 	pr_cont("%lu.%02lu BogoMIPS (lpj=%lu)\n",
 		loops_per_jiffy / (500000 / HZ),
 		(loops_per_jiffy / (5000 / HZ)) % 100, loops_per_jiffy);
 }

 void __init setup_arch(char **cmdline_p)
 {
 	unflatten_and_copy_device_tree();

 	setup_cpuinfo();

 #ifdef CONFIG_SMP
 	smp_init_cpus();
 #endif

 	/* process 1's initial memory region is the kernel code/data */
 	init_mm.start_code = (unsigned long)_stext;
 	init_mm.end_code = (unsigned long)_etext;
 	init_mm.end_data = (unsigned long)_edata;
 	init_mm.brk = (unsigned long)_end;

 #ifdef CONFIG_BLK_DEV_INITRD
 	initrd_start = (unsigned long)&__initrd_start;
 	initrd_end = (unsigned long)&__initrd_end;
 	if (initrd_start == initrd_end) {
 		initrd_start = 0;
 		initrd_end = 0;
 	}
 	initrd_below_start_ok = 1;
 #endif

 	/* setup memblock allocator */
 	setup_memory();

 	/* paging_init() sets up the MMU and marks all pages as reserved */
 	paging_init();

 #if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
 	if (!conswitchp)
 		conswitchp = &dummy_con;
 #endif

 	*cmdline_p = boot_command_line;

 	printk(KERN_INFO "OpenRISC Linux -- http://openrisc.io\n");
 }

 static int show_cpuinfo(struct seq_file *m, void *v)
 {
 	unsigned int vr, cpucfgr;
 	unsigned int avr;
 	unsigned int version;
 	struct cpuinfo_or1k *cpuinfo = v;

 	vr = mfspr(SPR_VR);
 	cpucfgr = mfspr(SPR_CPUCFGR);

 #ifdef CONFIG_SMP
 	seq_printf(m, "processor\t\t: %d\n", cpuinfo->coreid);
 #endif
 	if (vr & SPR_VR_UVRP) {
 		vr = mfspr(SPR_VR2);
 		version = vr & SPR_VR2_VER;
 		avr = mfspr(SPR_AVR);
 		seq_printf(m, "cpu architecture\t: "
 			   "OpenRISC 1000 (%d.%d-rev%d)\n",
 			   (avr >> 24) & 0xff,
 			   (avr >> 16) & 0xff,
 			   (avr >> 8) & 0xff);
 		seq_printf(m, "cpu implementation id\t: 0x%x\n",
 			   (vr & SPR_VR2_CPUID) >> 24);
 		seq_printf(m, "cpu version\t\t: 0x%x\n", version);
 	} else {
 		version = (vr & SPR_VR_VER) >> 24;
 		seq_printf(m, "cpu\t\t\t: OpenRISC-%x\n", version);
 		seq_printf(m, "revision\t\t: %d\n", vr & SPR_VR_REV);
 	}
 	seq_printf(m, "frequency\t\t: %ld\n", loops_per_jiffy * HZ);
 	seq_printf(m, "dcache size\t\t: %d bytes\n", cpuinfo->dcache_size);
 	seq_printf(m, "dcache block size\t: %d bytes\n",
 		   cpuinfo->dcache_block_size);
 	seq_printf(m, "dcache ways\t\t: %d\n", cpuinfo->dcache_ways);
 	seq_printf(m, "icache size\t\t: %d bytes\n", cpuinfo->icache_size);
 	seq_printf(m, "icache block size\t: %d bytes\n",
 		   cpuinfo->icache_block_size);
 	seq_printf(m, "icache ways\t\t: %d\n", cpuinfo->icache_ways);
 	seq_printf(m, "immu\t\t\t: %d entries, %lu ways\n",
 		   1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
 		   1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW));
 	seq_printf(m, "dmmu\t\t\t: %d entries, %lu ways\n",
 		   1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
 		   1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW));
 	seq_printf(m, "bogomips\t\t: %lu.%02lu\n",
 		   (loops_per_jiffy * HZ) / 500000,
 		   ((loops_per_jiffy * HZ) / 5000) % 100);

 	seq_puts(m, "features\t\t: ");
 	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OB32S ? "orbis32" : "");
 	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OB64S ? "orbis64" : "");
 	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OF32S ? "orfpx32" : "");
 	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OF64S ? "orfpx64" : "");
 	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OV64S ? "orvdx64" : "");
 	seq_puts(m, "\n");

 	seq_puts(m, "\n");

 	return 0;
 }

 static void *c_start(struct seq_file *m, loff_t *pos)
 {
 	*pos = cpumask_next(*pos - 1, cpu_online_mask);
 	if ((*pos) < nr_cpu_ids)
 		return &cpuinfo_or1k[*pos];
 	return NULL;
 }

 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 {
 	(*pos)++;
 	return c_start(m, pos);
 }

 static void c_stop(struct seq_file *m, void *v)
 {
 }

 const struct seq_operations cpuinfo_op = {
 	.start = c_start,
 	.next = c_next,
 	.stop = c_stop,
 	.show = show_cpuinfo,
 };
	/*
	* OpenRISC setup.c
	*
	* Linux architectural port borrowing liberally from similar works of
	* others. All original copyrights apply as per the original source
	* declaration.
	*
	* Modifications for the OpenRISC architecture:
	* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
	* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
	*
	* 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.
	*
	* This file handles the architecture-dependent parts of initialization
	*/

	#include <linux/errno.h>
	#include <linux/sched.h>
	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/stddef.h>
	#include <linux/unistd.h>
	#include <linux/ptrace.h>
	#include <linux/slab.h>
	#include <linux/tty.h>
	#include <linux/ioport.h>
	#include <linux/delay.h>
	#include <linux/console.h>
	#include <linux/init.h>
	#include <linux/memblock.h>
	#include <linux/seq_file.h>
	#include <linux/serial.h>
	#include <linux/initrd.h>
	#include <linux/of_fdt.h>
	#include <linux/of.h>
	#include <linux/device.h>

	#include <asm/sections.h>
	#include <asm/pgtable.h>
	#include <asm/types.h>
	#include <asm/setup.h>
	#include <asm/io.h>
	#include <asm/cpuinfo.h>
	#include <asm/delay.h>

	#include "vmlinux.h"

	static void __init setup_memory(void)
	{
	unsigned long ram_start_pfn;
	unsigned long ram_end_pfn;
	phys_addr_t memory_start, memory_end;
	struct memblock_region *region;

	memory_end = memory_start = 0;

	/* Find main memory where is the kernel, we assume its the only one */
	for_each_memblock(memory, region) {
	memory_start = region->base;
	memory_end = region->base + region->size;
	printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__,
	memory_start, memory_end);
	}

	if (!memory_end) {
	panic("No memory!");
	}

	ram_start_pfn = PFN_UP(memory_start);
	ram_end_pfn = PFN_DOWN(memblock_end_of_DRAM());

	/* setup bootmem globals (we use no_bootmem, but mm still depends on this) */
	min_low_pfn = ram_start_pfn;
	max_low_pfn = ram_end_pfn;
	max_pfn = ram_end_pfn;

	/*
	* initialize the boot-time allocator (with low memory only).
	*
	* This makes the memory from the end of the kernel to the end of
	* RAM usable.
	*/
	memblock_reserve(__pa(_stext), _end - _stext);

	early_init_fdt_reserve_self();
	early_init_fdt_scan_reserved_mem();

	memblock_dump_all();
	}

	struct cpuinfo_or1k cpuinfo_or1k[NR_CPUS];

	static void print_cpuinfo(void)
	{
	unsigned long upr = mfspr(SPR_UPR);
	unsigned long vr = mfspr(SPR_VR);
	unsigned int version;
	unsigned int revision;
	struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];

	version = (vr & SPR_VR_VER) >> 24;
	revision = (vr & SPR_VR_REV);

	printk(KERN_INFO "CPU: OpenRISC-%x (revision %d) @%d MHz\n",
	version, revision, cpuinfo->clock_frequency / 1000000);

	if (!(upr & SPR_UPR_UP)) {
	printk(KERN_INFO
	"-- no UPR register... unable to detect configuration\n");
	return;
	}

	if (upr & SPR_UPR_DCP)
	printk(KERN_INFO
	"-- dcache: %4d bytes total, %2d bytes/line, %d way(s)\n",
	cpuinfo->dcache_size, cpuinfo->dcache_block_size,
	cpuinfo->dcache_ways);
	else
	printk(KERN_INFO "-- dcache disabled\n");
	if (upr & SPR_UPR_ICP)
	printk(KERN_INFO
	"-- icache: %4d bytes total, %2d bytes/line, %d way(s)\n",
	cpuinfo->icache_size, cpuinfo->icache_block_size,
	cpuinfo->icache_ways);
	else
	printk(KERN_INFO "-- icache disabled\n");

	if (upr & SPR_UPR_DMP)
	printk(KERN_INFO "-- dmmu: %4d entries, %lu way(s)\n",
	1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
	1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW));
	if (upr & SPR_UPR_IMP)
	printk(KERN_INFO "-- immu: %4d entries, %lu way(s)\n",
	1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
	1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW));

	printk(KERN_INFO "-- additional features:\n");
	if (upr & SPR_UPR_DUP)
	printk(KERN_INFO "-- debug unit\n");
	if (upr & SPR_UPR_PCUP)
	printk(KERN_INFO "-- performance counters\n");
	if (upr & SPR_UPR_PMP)
	printk(KERN_INFO "-- power management\n");
	if (upr & SPR_UPR_PICP)
	printk(KERN_INFO "-- PIC\n");
	if (upr & SPR_UPR_TTP)
	printk(KERN_INFO "-- timer\n");
	if (upr & SPR_UPR_CUP)
	printk(KERN_INFO "-- custom unit(s)\n");
	}

	static struct device_node *setup_find_cpu_node(int cpu)
	{
	u32 hwid;
	struct device_node *cpun;

	for_each_of_cpu_node(cpun) {
	if (of_property_read_u32(cpun, "reg", &hwid))
	continue;
	if (hwid == cpu)
	return cpun;
	}

	return NULL;
	}

	void __init setup_cpuinfo(void)
	{
	struct device_node *cpu;
	unsigned long iccfgr, dccfgr;
	unsigned long cache_set_size;
	int cpu_id = smp_processor_id();
	struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[cpu_id];

	cpu = setup_find_cpu_node(cpu_id);
	if (!cpu)
	panic("Couldn't find CPU%d in device tree...\n", cpu_id);

	iccfgr = mfspr(SPR_ICCFGR);
	cpuinfo->icache_ways = 1 << (iccfgr & SPR_ICCFGR_NCW);
	cache_set_size = 1 << ((iccfgr & SPR_ICCFGR_NCS) >> 3);
	cpuinfo->icache_block_size = 16 << ((iccfgr & SPR_ICCFGR_CBS) >> 7);
	cpuinfo->icache_size =
	cache_set_size * cpuinfo->icache_ways * cpuinfo->icache_block_size;

	dccfgr = mfspr(SPR_DCCFGR);
	cpuinfo->dcache_ways = 1 << (dccfgr & SPR_DCCFGR_NCW);
	cache_set_size = 1 << ((dccfgr & SPR_DCCFGR_NCS) >> 3);
	cpuinfo->dcache_block_size = 16 << ((dccfgr & SPR_DCCFGR_CBS) >> 7);
	cpuinfo->dcache_size =
	cache_set_size * cpuinfo->dcache_ways * cpuinfo->dcache_block_size;

	if (of_property_read_u32(cpu, "clock-frequency",
	&cpuinfo->clock_frequency)) {
	printk(KERN_WARNING
	"Device tree missing CPU 'clock-frequency' parameter."
	"Assuming frequency 25MHZ"
	"This is probably not what you want.");
	}

	cpuinfo->coreid = mfspr(SPR_COREID);

	of_node_put(cpu);

	print_cpuinfo();
	}

	/**
	* or32_early_setup
	*
	* Handles the pointer to the device tree that this kernel is to use
	* for establishing the available platform devices.
	*
	* Falls back on built-in device tree in case null pointer is passed.
	*/

	void __init or32_early_setup(void *fdt)
	{
	if (fdt)
	pr_info("FDT at %p\n", fdt);
	else {
	fdt = __dtb_start;
	pr_info("Compiled-in FDT at %p\n", fdt);
	}
	early_init_devtree(fdt);
	}

	static inline unsigned long extract_value_bits(unsigned long reg,
	short bit_nr, short width)
	{
	return (reg >> bit_nr) & (0 << width);
	}

	static inline unsigned long extract_value(unsigned long reg, unsigned long mask)
	{
	while (!(mask & 0x1)) {
	reg = reg >> 1;
	mask = mask >> 1;
	}
	return mask & reg;
	}

	void __init detect_unit_config(unsigned long upr, unsigned long mask,
	char text, void (func) (void))
	{
	if (text != NULL)
	printk("%s", text);

	if (upr & mask) {
	if (func != NULL)
	func();
	else
	printk("present\n");
	} else
	printk("not present\n");
	}

	/*
	* calibrate_delay
	*
	* Lightweight calibrate_delay implementation that calculates loops_per_jiffy
	* from the clock frequency passed in via the device tree
	*
	*/

	void calibrate_delay(void)
	{
	const int *val;
	struct device_node *cpu = setup_find_cpu_node(smp_processor_id());

	val = of_get_property(cpu, "clock-frequency", NULL);
	if (!val)
	panic("no cpu 'clock-frequency' parameter in device tree");
	loops_per_jiffy = *val / HZ;
	pr_cont("%lu.%02lu BogoMIPS (lpj=%lu)\n",
	loops_per_jiffy / (500000 / HZ),
	(loops_per_jiffy / (5000 / HZ)) % 100, loops_per_jiffy);
	}

	void __init setup_arch(char **cmdline_p)
	{
	unflatten_and_copy_device_tree();

	setup_cpuinfo();

	#ifdef CONFIG_SMP
	smp_init_cpus();
	#endif

	/* process 1's initial memory region is the kernel code/data */
	init_mm.start_code = (unsigned long)_stext;
	init_mm.end_code = (unsigned long)_etext;
	init_mm.end_data = (unsigned long)_edata;
	init_mm.brk = (unsigned long)_end;

	#ifdef CONFIG_BLK_DEV_INITRD
	initrd_start = (unsigned long)&__initrd_start;
	initrd_end = (unsigned long)&__initrd_end;
	if (initrd_start == initrd_end) {
	initrd_start = 0;
	initrd_end = 0;
	}
	initrd_below_start_ok = 1;
	#endif

	/* setup memblock allocator */
	setup_memory();

	/* paging_init() sets up the MMU and marks all pages as reserved */
	paging_init();

	#if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
	if (!conswitchp)
	conswitchp = &dummy_con;
	#endif

	*cmdline_p = boot_command_line;

	printk(KERN_INFO "OpenRISC Linux -- http://openrisc.io\n");
	}

	static int show_cpuinfo(struct seq_file m, void v)
	{
	unsigned int vr, cpucfgr;
	unsigned int avr;
	unsigned int version;
	struct cpuinfo_or1k *cpuinfo = v;

	vr = mfspr(SPR_VR);
	cpucfgr = mfspr(SPR_CPUCFGR);

	#ifdef CONFIG_SMP
	seq_printf(m, "processor\t\t: %d\n", cpuinfo->coreid);
	#endif
	if (vr & SPR_VR_UVRP) {
	vr = mfspr(SPR_VR2);
	version = vr & SPR_VR2_VER;
	avr = mfspr(SPR_AVR);
	seq_printf(m, "cpu architecture\t: "
	"OpenRISC 1000 (%d.%d-rev%d)\n",
	(avr >> 24) & 0xff,
	(avr >> 16) & 0xff,
	(avr >> 8) & 0xff);
	seq_printf(m, "cpu implementation id\t: 0x%x\n",
	(vr & SPR_VR2_CPUID) >> 24);
	seq_printf(m, "cpu version\t\t: 0x%x\n", version);
	} else {
	version = (vr & SPR_VR_VER) >> 24;
	seq_printf(m, "cpu\t\t\t: OpenRISC-%x\n", version);
	seq_printf(m, "revision\t\t: %d\n", vr & SPR_VR_REV);
	}
	seq_printf(m, "frequency\t\t: %ld\n", loops_per_jiffy * HZ);
	seq_printf(m, "dcache size\t\t: %d bytes\n", cpuinfo->dcache_size);
	seq_printf(m, "dcache block size\t: %d bytes\n",
	cpuinfo->dcache_block_size);
	seq_printf(m, "dcache ways\t\t: %d\n", cpuinfo->dcache_ways);
	seq_printf(m, "icache size\t\t: %d bytes\n", cpuinfo->icache_size);
	seq_printf(m, "icache block size\t: %d bytes\n",
	cpuinfo->icache_block_size);
	seq_printf(m, "icache ways\t\t: %d\n", cpuinfo->icache_ways);
	seq_printf(m, "immu\t\t\t: %d entries, %lu ways\n",
	1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
	1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW));
	seq_printf(m, "dmmu\t\t\t: %d entries, %lu ways\n",
	1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
	1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW));
	seq_printf(m, "bogomips\t\t: %lu.%02lu\n",
	(loops_per_jiffy * HZ) / 500000,
	((loops_per_jiffy * HZ) / 5000) % 100);

	seq_puts(m, "features\t\t: ");
	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OB32S ? "orbis32" : "");
	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OB64S ? "orbis64" : "");
	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OF32S ? "orfpx32" : "");
	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OF64S ? "orfpx64" : "");
	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OV64S ? "orvdx64" : "");
	seq_puts(m, "\n");

	seq_puts(m, "\n");

	return 0;
	}

	static void c_start(struct seq_file m, loff_t *pos)
	{
	pos = cpumask_next(pos - 1, cpu_online_mask);
	if ((*pos) < nr_cpu_ids)
	return &cpuinfo_or1k[*pos];
	return NULL;
	}

	static void c_next(struct seq_file m, void v, loff_t pos)
	{
	(*pos)++;
	return c_start(m, pos);
	}

	static void c_stop(struct seq_file m, void v)
	{
	}

	const struct seq_operations cpuinfo_op = {
	.start = c_start,
	.next = c_next,
	.stop = c_stop,
	.show = show_cpuinfo,
	};