1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * OpenRISC setup.c
4  *
5  * Linux architectural port borrowing liberally from similar works of
6  * others.  All original copyrights apply as per the original source
7  * declaration.
8  *
9  * Modifications for the OpenRISC architecture:
10  * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
11  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
12  *
13  * This file handles the architecture-dependent parts of initialization
14  */
15 
16 #include <linux/errno.h>
17 #include <linux/sched.h>
18 #include <linux/kernel.h>
19 #include <linux/mm.h>
20 #include <linux/stddef.h>
21 #include <linux/unistd.h>
22 #include <linux/ptrace.h>
23 #include <linux/slab.h>
24 #include <linux/tty.h>
25 #include <linux/ioport.h>
26 #include <linux/delay.h>
27 #include <linux/console.h>
28 #include <linux/init.h>
29 #include <linux/memblock.h>
30 #include <linux/seq_file.h>
31 #include <linux/serial.h>
32 #include <linux/initrd.h>
33 #include <linux/of_fdt.h>
34 #include <linux/of.h>
35 #include <linux/device.h>
36 
37 #include <asm/sections.h>
38 #include <asm/types.h>
39 #include <asm/setup.h>
40 #include <asm/io.h>
41 #include <asm/cpuinfo.h>
42 #include <asm/delay.h>
43 
44 #include "vmlinux.h"
45 
setup_memory(void)46 static void __init setup_memory(void)
47 {
48 	unsigned long ram_start_pfn;
49 	unsigned long ram_end_pfn;
50 	phys_addr_t memory_start, memory_end;
51 
52 	memory_end = memory_start = 0;
53 
54 	/* Find main memory where is the kernel, we assume its the only one */
55 	memory_start = memblock_start_of_DRAM();
56 	memory_end = memblock_end_of_DRAM();
57 
58 	if (!memory_end) {
59 		panic("No memory!");
60 	}
61 
62 	ram_start_pfn = PFN_UP(memory_start);
63 	ram_end_pfn = PFN_DOWN(memblock_end_of_DRAM());
64 
65 	/* setup bootmem globals (we use no_bootmem, but mm still depends on this) */
66 	min_low_pfn = ram_start_pfn;
67 	max_low_pfn = ram_end_pfn;
68 	max_pfn = ram_end_pfn;
69 
70 	/*
71 	 * initialize the boot-time allocator (with low memory only).
72 	 *
73 	 * This makes the memory from the end of the kernel to the end of
74 	 * RAM usable.
75 	 */
76 	memblock_reserve(__pa(_stext), _end - _stext);
77 
78 #ifdef CONFIG_BLK_DEV_INITRD
79 	/* Then reserve the initrd, if any */
80 	if (initrd_start && (initrd_end > initrd_start)) {
81 		unsigned long aligned_start = ALIGN_DOWN(initrd_start, PAGE_SIZE);
82 		unsigned long aligned_end = ALIGN(initrd_end, PAGE_SIZE);
83 
84 		memblock_reserve(__pa(aligned_start), aligned_end - aligned_start);
85 	}
86 #endif /* CONFIG_BLK_DEV_INITRD */
87 
88 	early_init_fdt_reserve_self();
89 	early_init_fdt_scan_reserved_mem();
90 
91 	memblock_dump_all();
92 }
93 
94 struct cpuinfo_or1k cpuinfo_or1k[NR_CPUS];
95 
print_cpuinfo(void)96 static void print_cpuinfo(void)
97 {
98 	unsigned long upr = mfspr(SPR_UPR);
99 	unsigned long vr = mfspr(SPR_VR);
100 	unsigned int version;
101 	unsigned int revision;
102 	struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];
103 
104 	version = (vr & SPR_VR_VER) >> 24;
105 	revision = (vr & SPR_VR_REV);
106 
107 	printk(KERN_INFO "CPU: OpenRISC-%x (revision %d) @%d MHz\n",
108 	       version, revision, cpuinfo->clock_frequency / 1000000);
109 
110 	if (!(upr & SPR_UPR_UP)) {
111 		printk(KERN_INFO
112 		       "-- no UPR register... unable to detect configuration\n");
113 		return;
114 	}
115 
116 	if (upr & SPR_UPR_DCP)
117 		printk(KERN_INFO
118 		       "-- dcache: %4d bytes total, %2d bytes/line, %d way(s)\n",
119 		       cpuinfo->dcache_size, cpuinfo->dcache_block_size,
120 		       cpuinfo->dcache_ways);
121 	else
122 		printk(KERN_INFO "-- dcache disabled\n");
123 	if (upr & SPR_UPR_ICP)
124 		printk(KERN_INFO
125 		       "-- icache: %4d bytes total, %2d bytes/line, %d way(s)\n",
126 		       cpuinfo->icache_size, cpuinfo->icache_block_size,
127 		       cpuinfo->icache_ways);
128 	else
129 		printk(KERN_INFO "-- icache disabled\n");
130 
131 	if (upr & SPR_UPR_DMP)
132 		printk(KERN_INFO "-- dmmu: %4d entries, %lu way(s)\n",
133 		       1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
134 		       1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW));
135 	if (upr & SPR_UPR_IMP)
136 		printk(KERN_INFO "-- immu: %4d entries, %lu way(s)\n",
137 		       1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
138 		       1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW));
139 
140 	printk(KERN_INFO "-- additional features:\n");
141 	if (upr & SPR_UPR_DUP)
142 		printk(KERN_INFO "-- debug unit\n");
143 	if (upr & SPR_UPR_PCUP)
144 		printk(KERN_INFO "-- performance counters\n");
145 	if (upr & SPR_UPR_PMP)
146 		printk(KERN_INFO "-- power management\n");
147 	if (upr & SPR_UPR_PICP)
148 		printk(KERN_INFO "-- PIC\n");
149 	if (upr & SPR_UPR_TTP)
150 		printk(KERN_INFO "-- timer\n");
151 	if (upr & SPR_UPR_CUP)
152 		printk(KERN_INFO "-- custom unit(s)\n");
153 }
154 
setup_find_cpu_node(int cpu)155 static struct device_node *setup_find_cpu_node(int cpu)
156 {
157 	u32 hwid;
158 	struct device_node *cpun;
159 
160 	for_each_of_cpu_node(cpun) {
161 		if (of_property_read_u32(cpun, "reg", &hwid))
162 			continue;
163 		if (hwid == cpu)
164 			return cpun;
165 	}
166 
167 	return NULL;
168 }
169 
setup_cpuinfo(void)170 void __init setup_cpuinfo(void)
171 {
172 	struct device_node *cpu;
173 	unsigned long iccfgr, dccfgr;
174 	unsigned long cache_set_size;
175 	int cpu_id = smp_processor_id();
176 	struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[cpu_id];
177 
178 	cpu = setup_find_cpu_node(cpu_id);
179 	if (!cpu)
180 		panic("Couldn't find CPU%d in device tree...\n", cpu_id);
181 
182 	iccfgr = mfspr(SPR_ICCFGR);
183 	cpuinfo->icache_ways = 1 << (iccfgr & SPR_ICCFGR_NCW);
184 	cache_set_size = 1 << ((iccfgr & SPR_ICCFGR_NCS) >> 3);
185 	cpuinfo->icache_block_size = 16 << ((iccfgr & SPR_ICCFGR_CBS) >> 7);
186 	cpuinfo->icache_size =
187 	    cache_set_size * cpuinfo->icache_ways * cpuinfo->icache_block_size;
188 
189 	dccfgr = mfspr(SPR_DCCFGR);
190 	cpuinfo->dcache_ways = 1 << (dccfgr & SPR_DCCFGR_NCW);
191 	cache_set_size = 1 << ((dccfgr & SPR_DCCFGR_NCS) >> 3);
192 	cpuinfo->dcache_block_size = 16 << ((dccfgr & SPR_DCCFGR_CBS) >> 7);
193 	cpuinfo->dcache_size =
194 	    cache_set_size * cpuinfo->dcache_ways * cpuinfo->dcache_block_size;
195 
196 	if (of_property_read_u32(cpu, "clock-frequency",
197 				 &cpuinfo->clock_frequency)) {
198 		printk(KERN_WARNING
199 		       "Device tree missing CPU 'clock-frequency' parameter."
200 		       "Assuming frequency 25MHZ"
201 		       "This is probably not what you want.");
202 	}
203 
204 	cpuinfo->coreid = mfspr(SPR_COREID);
205 
206 	of_node_put(cpu);
207 
208 	print_cpuinfo();
209 }
210 
211 /**
212  * or1k_early_setup
213  * @fdt: pointer to the start of the device tree in memory or NULL
214  *
215  * Handles the pointer to the device tree that this kernel is to use
216  * for establishing the available platform devices.
217  *
218  * Falls back on built-in device tree in case null pointer is passed.
219  */
220 
or1k_early_setup(void * fdt)221 void __init or1k_early_setup(void *fdt)
222 {
223 	if (fdt)
224 		pr_info("FDT at %p\n", fdt);
225 	else {
226 		fdt = __dtb_start;
227 		pr_info("Compiled-in FDT at %p\n", fdt);
228 	}
229 	early_init_devtree(fdt);
230 }
231 
extract_value_bits(unsigned long reg,short bit_nr,short width)232 static inline unsigned long extract_value_bits(unsigned long reg,
233 					       short bit_nr, short width)
234 {
235 	return (reg >> bit_nr) & (0 << width);
236 }
237 
extract_value(unsigned long reg,unsigned long mask)238 static inline unsigned long extract_value(unsigned long reg, unsigned long mask)
239 {
240 	while (!(mask & 0x1)) {
241 		reg = reg >> 1;
242 		mask = mask >> 1;
243 	}
244 	return mask & reg;
245 }
246 
247 /*
248  * calibrate_delay
249  *
250  * Lightweight calibrate_delay implementation that calculates loops_per_jiffy
251  * from the clock frequency passed in via the device tree
252  *
253  */
254 
calibrate_delay(void)255 void calibrate_delay(void)
256 {
257 	const int *val;
258 	struct device_node *cpu = setup_find_cpu_node(smp_processor_id());
259 
260 	val = of_get_property(cpu, "clock-frequency", NULL);
261 	if (!val)
262 		panic("no cpu 'clock-frequency' parameter in device tree");
263 	loops_per_jiffy = *val / HZ;
264 	pr_cont("%lu.%02lu BogoMIPS (lpj=%lu)\n",
265 		loops_per_jiffy / (500000 / HZ),
266 		(loops_per_jiffy / (5000 / HZ)) % 100, loops_per_jiffy);
267 
268 	of_node_put(cpu);
269 }
270 
setup_arch(char ** cmdline_p)271 void __init setup_arch(char **cmdline_p)
272 {
273 	unflatten_and_copy_device_tree();
274 
275 	setup_cpuinfo();
276 
277 #ifdef CONFIG_SMP
278 	smp_init_cpus();
279 #endif
280 
281 	/* process 1's initial memory region is the kernel code/data */
282 	setup_initial_init_mm(_stext, _etext, _edata, _end);
283 
284 #ifdef CONFIG_BLK_DEV_INITRD
285 	if (initrd_start == initrd_end) {
286 		printk(KERN_INFO "Initial ramdisk not found\n");
287 		initrd_start = 0;
288 		initrd_end = 0;
289 	} else {
290 		printk(KERN_INFO "Initial ramdisk at: 0x%p (%lu bytes)\n",
291 		       (void *)(initrd_start), initrd_end - initrd_start);
292 		initrd_below_start_ok = 1;
293 	}
294 #endif
295 
296 	/* setup memblock allocator */
297 	setup_memory();
298 
299 	/* paging_init() sets up the MMU and marks all pages as reserved */
300 	paging_init();
301 
302 	*cmdline_p = boot_command_line;
303 
304 	printk(KERN_INFO "OpenRISC Linux -- http://openrisc.io\n");
305 }
306 
show_cpuinfo(struct seq_file * m,void * v)307 static int show_cpuinfo(struct seq_file *m, void *v)
308 {
309 	unsigned int vr, cpucfgr;
310 	unsigned int avr;
311 	unsigned int version;
312 	struct cpuinfo_or1k *cpuinfo = v;
313 
314 	vr = mfspr(SPR_VR);
315 	cpucfgr = mfspr(SPR_CPUCFGR);
316 
317 #ifdef CONFIG_SMP
318 	seq_printf(m, "processor\t\t: %d\n", cpuinfo->coreid);
319 #endif
320 	if (vr & SPR_VR_UVRP) {
321 		vr = mfspr(SPR_VR2);
322 		version = vr & SPR_VR2_VER;
323 		avr = mfspr(SPR_AVR);
324 		seq_printf(m, "cpu architecture\t: "
325 			   "OpenRISC 1000 (%d.%d-rev%d)\n",
326 			   (avr >> 24) & 0xff,
327 			   (avr >> 16) & 0xff,
328 			   (avr >> 8) & 0xff);
329 		seq_printf(m, "cpu implementation id\t: 0x%x\n",
330 			   (vr & SPR_VR2_CPUID) >> 24);
331 		seq_printf(m, "cpu version\t\t: 0x%x\n", version);
332 	} else {
333 		version = (vr & SPR_VR_VER) >> 24;
334 		seq_printf(m, "cpu\t\t\t: OpenRISC-%x\n", version);
335 		seq_printf(m, "revision\t\t: %d\n", vr & SPR_VR_REV);
336 	}
337 	seq_printf(m, "frequency\t\t: %ld\n", loops_per_jiffy * HZ);
338 	seq_printf(m, "dcache size\t\t: %d bytes\n", cpuinfo->dcache_size);
339 	seq_printf(m, "dcache block size\t: %d bytes\n",
340 		   cpuinfo->dcache_block_size);
341 	seq_printf(m, "dcache ways\t\t: %d\n", cpuinfo->dcache_ways);
342 	seq_printf(m, "icache size\t\t: %d bytes\n", cpuinfo->icache_size);
343 	seq_printf(m, "icache block size\t: %d bytes\n",
344 		   cpuinfo->icache_block_size);
345 	seq_printf(m, "icache ways\t\t: %d\n", cpuinfo->icache_ways);
346 	seq_printf(m, "immu\t\t\t: %d entries, %lu ways\n",
347 		   1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
348 		   1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW));
349 	seq_printf(m, "dmmu\t\t\t: %d entries, %lu ways\n",
350 		   1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
351 		   1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW));
352 	seq_printf(m, "bogomips\t\t: %lu.%02lu\n",
353 		   (loops_per_jiffy * HZ) / 500000,
354 		   ((loops_per_jiffy * HZ) / 5000) % 100);
355 
356 	seq_puts(m, "features\t\t: ");
357 	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OB32S ? "orbis32" : "");
358 	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OB64S ? "orbis64" : "");
359 	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OF32S ? "orfpx32" : "");
360 	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OF64S ? "orfpx64" : "");
361 	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OV64S ? "orvdx64" : "");
362 	seq_puts(m, "\n");
363 
364 	seq_puts(m, "\n");
365 
366 	return 0;
367 }
368 
c_start(struct seq_file * m,loff_t * pos)369 static void *c_start(struct seq_file *m, loff_t *pos)
370 {
371 	*pos = cpumask_next(*pos - 1, cpu_online_mask);
372 	if ((*pos) < nr_cpu_ids)
373 		return &cpuinfo_or1k[*pos];
374 	return NULL;
375 }
376 
c_next(struct seq_file * m,void * v,loff_t * pos)377 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
378 {
379 	(*pos)++;
380 	return c_start(m, pos);
381 }
382 
c_stop(struct seq_file * m,void * v)383 static void c_stop(struct seq_file *m, void *v)
384 {
385 }
386 
387 const struct seq_operations cpuinfo_op = {
388 	.start = c_start,
389 	.next = c_next,
390 	.stop = c_stop,
391 	.show = show_cpuinfo,
392 };
393