xref: /openbmc/linux/arch/openrisc/kernel/setup.c (revision dea54fba)
1 /*
2  * OpenRISC setup.c
3  *
4  * Linux architectural port borrowing liberally from similar works of
5  * others.  All original copyrights apply as per the original source
6  * declaration.
7  *
8  * Modifications for the OpenRISC architecture:
9  * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
10  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
11  *
12  *      This program is free software; you can redistribute it and/or
13  *      modify it under the terms of the GNU General Public License
14  *      as published by the Free Software Foundation; either version
15  *      2 of the License, or (at your option) any later version.
16  *
17  * This file handles the architecture-dependent parts of initialization
18  */
19 
20 #include <linux/errno.h>
21 #include <linux/sched.h>
22 #include <linux/kernel.h>
23 #include <linux/mm.h>
24 #include <linux/stddef.h>
25 #include <linux/unistd.h>
26 #include <linux/ptrace.h>
27 #include <linux/slab.h>
28 #include <linux/tty.h>
29 #include <linux/ioport.h>
30 #include <linux/delay.h>
31 #include <linux/console.h>
32 #include <linux/init.h>
33 #include <linux/bootmem.h>
34 #include <linux/seq_file.h>
35 #include <linux/serial.h>
36 #include <linux/initrd.h>
37 #include <linux/of_fdt.h>
38 #include <linux/of.h>
39 #include <linux/memblock.h>
40 #include <linux/device.h>
41 
42 #include <asm/sections.h>
43 #include <asm/segment.h>
44 #include <asm/pgtable.h>
45 #include <asm/types.h>
46 #include <asm/setup.h>
47 #include <asm/io.h>
48 #include <asm/cpuinfo.h>
49 #include <asm/delay.h>
50 
51 #include "vmlinux.h"
52 
53 static void __init setup_memory(void)
54 {
55 	unsigned long ram_start_pfn;
56 	unsigned long ram_end_pfn;
57 	phys_addr_t memory_start, memory_end;
58 	struct memblock_region *region;
59 
60 	memory_end = memory_start = 0;
61 
62 	/* Find main memory where is the kernel, we assume its the only one */
63 	for_each_memblock(memory, region) {
64 		memory_start = region->base;
65 		memory_end = region->base + region->size;
66 		printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__,
67 		       memory_start, memory_end);
68 	}
69 
70 	if (!memory_end) {
71 		panic("No memory!");
72 	}
73 
74 	ram_start_pfn = PFN_UP(memory_start);
75 	ram_end_pfn = PFN_DOWN(memblock_end_of_DRAM());
76 
77 	/* setup bootmem globals (we use no_bootmem, but mm still depends on this) */
78 	min_low_pfn = ram_start_pfn;
79 	max_low_pfn = ram_end_pfn;
80 	max_pfn = ram_end_pfn;
81 
82 	/*
83 	 * initialize the boot-time allocator (with low memory only).
84 	 *
85 	 * This makes the memory from the end of the kernel to the end of
86 	 * RAM usable.
87 	 */
88 	memblock_reserve(__pa(_stext), _end - _stext);
89 
90 	early_init_fdt_reserve_self();
91 	early_init_fdt_scan_reserved_mem();
92 
93 	memblock_dump_all();
94 }
95 
96 struct cpuinfo cpuinfo;
97 
98 static void print_cpuinfo(void)
99 {
100 	unsigned long upr = mfspr(SPR_UPR);
101 	unsigned long vr = mfspr(SPR_VR);
102 	unsigned int version;
103 	unsigned int revision;
104 
105 	version = (vr & SPR_VR_VER) >> 24;
106 	revision = (vr & SPR_VR_REV);
107 
108 	printk(KERN_INFO "CPU: OpenRISC-%x (revision %d) @%d MHz\n",
109 	       version, revision, cpuinfo.clock_frequency / 1000000);
110 
111 	if (!(upr & SPR_UPR_UP)) {
112 		printk(KERN_INFO
113 		       "-- no UPR register... unable to detect configuration\n");
114 		return;
115 	}
116 
117 	if (upr & SPR_UPR_DCP)
118 		printk(KERN_INFO
119 		       "-- dcache: %4d bytes total, %2d bytes/line, %d way(s)\n",
120 		       cpuinfo.dcache_size, cpuinfo.dcache_block_size,
121 		       cpuinfo.dcache_ways);
122 	else
123 		printk(KERN_INFO "-- dcache disabled\n");
124 	if (upr & SPR_UPR_ICP)
125 		printk(KERN_INFO
126 		       "-- icache: %4d bytes total, %2d bytes/line, %d way(s)\n",
127 		       cpuinfo.icache_size, cpuinfo.icache_block_size,
128 		       cpuinfo.icache_ways);
129 	else
130 		printk(KERN_INFO "-- icache disabled\n");
131 
132 	if (upr & SPR_UPR_DMP)
133 		printk(KERN_INFO "-- dmmu: %4d entries, %lu way(s)\n",
134 		       1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
135 		       1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW));
136 	if (upr & SPR_UPR_IMP)
137 		printk(KERN_INFO "-- immu: %4d entries, %lu way(s)\n",
138 		       1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
139 		       1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW));
140 
141 	printk(KERN_INFO "-- additional features:\n");
142 	if (upr & SPR_UPR_DUP)
143 		printk(KERN_INFO "-- debug unit\n");
144 	if (upr & SPR_UPR_PCUP)
145 		printk(KERN_INFO "-- performance counters\n");
146 	if (upr & SPR_UPR_PMP)
147 		printk(KERN_INFO "-- power management\n");
148 	if (upr & SPR_UPR_PICP)
149 		printk(KERN_INFO "-- PIC\n");
150 	if (upr & SPR_UPR_TTP)
151 		printk(KERN_INFO "-- timer\n");
152 	if (upr & SPR_UPR_CUP)
153 		printk(KERN_INFO "-- custom unit(s)\n");
154 }
155 
156 void __init setup_cpuinfo(void)
157 {
158 	struct device_node *cpu;
159 	unsigned long iccfgr, dccfgr;
160 	unsigned long cache_set_size;
161 
162 	cpu = of_find_compatible_node(NULL, NULL, "opencores,or1200-rtlsvn481");
163 	if (!cpu)
164 		panic("No compatible CPU found in device tree...\n");
165 
166 	iccfgr = mfspr(SPR_ICCFGR);
167 	cpuinfo.icache_ways = 1 << (iccfgr & SPR_ICCFGR_NCW);
168 	cache_set_size = 1 << ((iccfgr & SPR_ICCFGR_NCS) >> 3);
169 	cpuinfo.icache_block_size = 16 << ((iccfgr & SPR_ICCFGR_CBS) >> 7);
170 	cpuinfo.icache_size =
171 	    cache_set_size * cpuinfo.icache_ways * cpuinfo.icache_block_size;
172 
173 	dccfgr = mfspr(SPR_DCCFGR);
174 	cpuinfo.dcache_ways = 1 << (dccfgr & SPR_DCCFGR_NCW);
175 	cache_set_size = 1 << ((dccfgr & SPR_DCCFGR_NCS) >> 3);
176 	cpuinfo.dcache_block_size = 16 << ((dccfgr & SPR_DCCFGR_CBS) >> 7);
177 	cpuinfo.dcache_size =
178 	    cache_set_size * cpuinfo.dcache_ways * cpuinfo.dcache_block_size;
179 
180 	if (of_property_read_u32(cpu, "clock-frequency",
181 				 &cpuinfo.clock_frequency)) {
182 		printk(KERN_WARNING
183 		       "Device tree missing CPU 'clock-frequency' parameter."
184 		       "Assuming frequency 25MHZ"
185 		       "This is probably not what you want.");
186 	}
187 
188 	of_node_put(cpu);
189 
190 	print_cpuinfo();
191 }
192 
193 /**
194  * or32_early_setup
195  *
196  * Handles the pointer to the device tree that this kernel is to use
197  * for establishing the available platform devices.
198  *
199  * Falls back on built-in device tree in case null pointer is passed.
200  */
201 
202 void __init or32_early_setup(void *fdt)
203 {
204 	if (fdt)
205 		pr_info("FDT at %p\n", fdt);
206 	else {
207 		fdt = __dtb_start;
208 		pr_info("Compiled-in FDT at %p\n", fdt);
209 	}
210 	early_init_devtree(fdt);
211 }
212 
213 static inline unsigned long extract_value_bits(unsigned long reg,
214 					       short bit_nr, short width)
215 {
216 	return (reg >> bit_nr) & (0 << width);
217 }
218 
219 static inline unsigned long extract_value(unsigned long reg, unsigned long mask)
220 {
221 	while (!(mask & 0x1)) {
222 		reg = reg >> 1;
223 		mask = mask >> 1;
224 	}
225 	return mask & reg;
226 }
227 
228 void __init detect_unit_config(unsigned long upr, unsigned long mask,
229 			       char *text, void (*func) (void))
230 {
231 	if (text != NULL)
232 		printk("%s", text);
233 
234 	if (upr & mask) {
235 		if (func != NULL)
236 			func();
237 		else
238 			printk("present\n");
239 	} else
240 		printk("not present\n");
241 }
242 
243 /*
244  * calibrate_delay
245  *
246  * Lightweight calibrate_delay implementation that calculates loops_per_jiffy
247  * from the clock frequency passed in via the device tree
248  *
249  */
250 
251 void calibrate_delay(void)
252 {
253 	const int *val;
254 	struct device_node *cpu = NULL;
255 	cpu = of_find_compatible_node(NULL, NULL, "opencores,or1200-rtlsvn481");
256 	val = of_get_property(cpu, "clock-frequency", NULL);
257 	if (!val)
258 		panic("no cpu 'clock-frequency' parameter in device tree");
259 	loops_per_jiffy = *val / HZ;
260 	pr_cont("%lu.%02lu BogoMIPS (lpj=%lu)\n",
261 		loops_per_jiffy / (500000 / HZ),
262 		(loops_per_jiffy / (5000 / HZ)) % 100, loops_per_jiffy);
263 }
264 
265 void __init setup_arch(char **cmdline_p)
266 {
267 	unflatten_and_copy_device_tree();
268 
269 	setup_cpuinfo();
270 
271 	/* process 1's initial memory region is the kernel code/data */
272 	init_mm.start_code = (unsigned long)_stext;
273 	init_mm.end_code = (unsigned long)_etext;
274 	init_mm.end_data = (unsigned long)_edata;
275 	init_mm.brk = (unsigned long)_end;
276 
277 #ifdef CONFIG_BLK_DEV_INITRD
278 	initrd_start = (unsigned long)&__initrd_start;
279 	initrd_end = (unsigned long)&__initrd_end;
280 	if (initrd_start == initrd_end) {
281 		initrd_start = 0;
282 		initrd_end = 0;
283 	}
284 	initrd_below_start_ok = 1;
285 #endif
286 
287 	/* setup memblock allocator */
288 	setup_memory();
289 
290 	/* paging_init() sets up the MMU and marks all pages as reserved */
291 	paging_init();
292 
293 #if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
294 	if (!conswitchp)
295 		conswitchp = &dummy_con;
296 #endif
297 
298 	*cmdline_p = boot_command_line;
299 
300 	printk(KERN_INFO "OpenRISC Linux -- http://openrisc.io\n");
301 }
302 
303 static int show_cpuinfo(struct seq_file *m, void *v)
304 {
305 	unsigned long vr;
306 	int version, revision;
307 
308 	vr = mfspr(SPR_VR);
309 	version = (vr & SPR_VR_VER) >> 24;
310 	revision = vr & SPR_VR_REV;
311 
312 	seq_printf(m,
313 		  "cpu\t\t: OpenRISC-%x\n"
314 		  "revision\t: %d\n"
315 		  "frequency\t: %ld\n"
316 		  "dcache size\t: %d bytes\n"
317 		  "dcache block size\t: %d bytes\n"
318 		  "dcache ways\t: %d\n"
319 		  "icache size\t: %d bytes\n"
320 		  "icache block size\t: %d bytes\n"
321 		  "icache ways\t: %d\n"
322 		  "immu\t\t: %d entries, %lu ways\n"
323 		  "dmmu\t\t: %d entries, %lu ways\n"
324 		  "bogomips\t: %lu.%02lu\n",
325 		  version,
326 		  revision,
327 		  loops_per_jiffy * HZ,
328 		  cpuinfo.dcache_size,
329 		  cpuinfo.dcache_block_size,
330 		  cpuinfo.dcache_ways,
331 		  cpuinfo.icache_size,
332 		  cpuinfo.icache_block_size,
333 		  cpuinfo.icache_ways,
334 		  1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
335 		  1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW),
336 		  1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
337 		  1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW),
338 		  (loops_per_jiffy * HZ) / 500000,
339 		  ((loops_per_jiffy * HZ) / 5000) % 100);
340 	return 0;
341 }
342 
343 static void *c_start(struct seq_file *m, loff_t * pos)
344 {
345 	/* We only have one CPU... */
346 	return *pos < 1 ? (void *)1 : NULL;
347 }
348 
349 static void *c_next(struct seq_file *m, void *v, loff_t * pos)
350 {
351 	++*pos;
352 	return NULL;
353 }
354 
355 static void c_stop(struct seq_file *m, void *v)
356 {
357 }
358 
359 const struct seq_operations cpuinfo_op = {
360 	.start = c_start,
361 	.next = c_next,
362 	.stop = c_stop,
363 	.show = show_cpuinfo,
364 };
365