OpenRISC: Boot code

/*

 * OpenRISC init_task.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.

 */

#include <linux/init_task.h>

#include <linux/mqueue.h>

static struct signal_struct init_signals = INIT_SIGNALS(init_signals);

static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);

/*

 * Initial thread structure.

 *

 * We need to make sure that this is THREAD_SIZE aligned due to the

 * way process stacks are handled. This is done by having a special

 * "init_task" linker map entry..

 */

union thread_union init_thread_union __init_task_data = {

	INIT_THREAD_INFO(init_task)

};

/*

 * Initial task structure.

 *

 * All other task structs will be allocated on slabs in fork.c

 */

struct task_struct init_task = INIT_TASK(init_task);

EXPORT_SYMBOL(init_task);

/*

 * 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/bootmem.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/memblock.h>

#include <linux/device.h>

#include <linux/of_platform.h>

#include <asm/segment.h>

#include <asm/system.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"

char __initdata cmd_line[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;

static unsigned long __init setup_memory(void)

{

	unsigned long bootmap_size;

	unsigned long ram_start_pfn;

	unsigned long free_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 */

	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);

	/* free_ram_start_pfn is first page after kernel */

	free_ram_start_pfn = PFN_UP(__pa(&_end));

	ram_end_pfn = PFN_DOWN(memblock_end_of_DRAM());

	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.

	 * init_bootmem sets the global values min_low_pfn, max_low_pfn.

	 */

	bootmap_size = init_bootmem(free_ram_start_pfn,

				    ram_end_pfn - ram_start_pfn);

	free_bootmem(PFN_PHYS(free_ram_start_pfn),

		     (ram_end_pfn - free_ram_start_pfn) << PAGE_SHIFT);

	reserve_bootmem(PFN_PHYS(free_ram_start_pfn), bootmap_size,

			BOOTMEM_DEFAULT);

	for_each_memblock(reserved, region) {

		printk(KERN_INFO "Reserved - 0x%08x-0x%08x\n",

		       (u32) region->base, (u32) region->size);

		reserve_bootmem(region->base, region->size, BOOTMEM_DEFAULT);

	}

	return ram_end_pfn;

}

struct cpuinfo cpuinfo;

static void print_cpuinfo(void)

{

	unsigned long upr = mfspr(SPR_UPR);

	unsigned long vr = mfspr(SPR_VR);

	unsigned int version;

	unsigned int revision;

	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, 1);

	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, 1);

	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");

}

void __init setup_cpuinfo(void)

{

	struct device_node *cpu;

	unsigned long iccfgr, dccfgr;

	unsigned long cache_set_size, cache_ways;

	cpu = of_find_compatible_node(NULL, NULL, "opencores,or1200-rtlsvn481");

	if (!cpu)

		panic("No compatible CPU found in device tree...\n");

	iccfgr = mfspr(SPR_ICCFGR);

	cache_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 * cache_ways * cpuinfo.icache_block_size;

	dccfgr = mfspr(SPR_DCCFGR);

	cache_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 * cache_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.");

	}

	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.

 *

 * For now, this is limited to using the built-in device tree.  In the future,

 * it is intended that this function will take a pointer to the device tree

 * that is potentially built-in, but potentially also passed in by the

 * bootloader, or discovered by some equally clever means...

 */

void __init or32_early_setup(void)

{

	early_init_devtree(__dtb_start);

	printk(KERN_INFO "Compiled-in FDT at 0x%p\n", __dtb_start);

}

static int __init openrisc_device_probe(void)

{

	of_platform_populate(NULL, NULL, NULL, NULL);

	return 0;

}

device_initcall(openrisc_device_probe);

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 __cpuinit calibrate_delay(void)

{

	const int *val;

	struct device_node *cpu = NULL;

	cpu = of_find_compatible_node(NULL, NULL, "opencores,or1200-rtlsvn481");

	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)

{

	unsigned long max_low_pfn;

	unflatten_device_tree();

	setup_cpuinfo();

	/* 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 bootmem allocator */

	max_low_pfn = 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 = cmd_line;

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

}

static int show_cpuinfo(struct seq_file *m, void *v)

{

	unsigned long vr;

	int version, revision;

	vr = mfspr(SPR_VR);

	version = (vr & SPR_VR_VER) >> 24;

	revision = vr & SPR_VR_REV;

	return seq_printf(m,

			  "cpu\t\t: OpenRISC-%x\n"

			  "revision\t: %d\n"

			  "frequency\t: %ld\n"

			  "dcache size\t: %d bytes\n"

			  "dcache block size\t: %d bytes\n"

			  "icache size\t: %d bytes\n"

			  "icache block size\t: %d bytes\n"

			  "immu\t\t: %d entries, %lu ways\n"

			  "dmmu\t\t: %d entries, %lu ways\n"

			  "bogomips\t: %lu.%02lu\n",

			  version,

			  revision,

			  loops_per_jiffy * HZ,

			  cpuinfo.dcache_size,

			  cpuinfo.dcache_block_size,

			  cpuinfo.icache_size,

			  cpuinfo.icache_block_size,

			  1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),

			  1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW),

			  1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),

			  1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW),

			  (loops_per_jiffy * HZ) / 500000,

			  ((loops_per_jiffy * HZ) / 5000) % 100);

}

static void *c_start(struct seq_file *m, loff_t * pos)

{

	/* We only have one CPU... */

	return *pos < 1 ? (void *)1 : NULL;

}

static void *c_next(struct seq_file *m, void *v, loff_t * pos)

{

	++*pos;

	return NULL;

}

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,

};