OpenRISC: Boot code

Architecture code and early setup routines for booting Linux.
Signed-off-by: NJonas Bonn <jonas@southpole.se>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>

arch/openrisc/kernel/init_task.c

+/*
+ * 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);

arch/openrisc/kernel/setup.c

+/*
+ * 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,
+};