xref: /openbmc/linux/arch/arc/kernel/setup.c (revision 206204a1)
1 /*
2  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 #include <linux/seq_file.h>
10 #include <linux/fs.h>
11 #include <linux/delay.h>
12 #include <linux/root_dev.h>
13 #include <linux/console.h>
14 #include <linux/module.h>
15 #include <linux/cpu.h>
16 #include <linux/of_fdt.h>
17 #include <linux/cache.h>
18 #include <asm/sections.h>
19 #include <asm/arcregs.h>
20 #include <asm/tlb.h>
21 #include <asm/setup.h>
22 #include <asm/page.h>
23 #include <asm/irq.h>
24 #include <asm/unwind.h>
25 #include <asm/clk.h>
26 #include <asm/mach_desc.h>
27 
28 #define FIX_PTR(x)  __asm__ __volatile__(";" : "+r"(x))
29 
30 int running_on_hw = 1;	/* vs. on ISS */
31 
32 /* Part of U-boot ABI: see head.S */
33 int __initdata uboot_tag;
34 char __initdata *uboot_arg;
35 
36 const struct machine_desc *machine_desc;
37 
38 struct task_struct *_current_task[NR_CPUS];	/* For stack switching */
39 
40 struct cpuinfo_arc cpuinfo_arc700[NR_CPUS];
41 
42 static void read_arc_build_cfg_regs(void)
43 {
44 	struct bcr_perip uncached_space;
45 	struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
46 	FIX_PTR(cpu);
47 
48 	READ_BCR(AUX_IDENTITY, cpu->core);
49 
50 	cpu->timers = read_aux_reg(ARC_REG_TIMERS_BCR);
51 	cpu->vec_base = read_aux_reg(AUX_INTR_VEC_BASE);
52 
53 	READ_BCR(ARC_REG_D_UNCACH_BCR, uncached_space);
54 	cpu->uncached_base = uncached_space.start << 24;
55 
56 	cpu->extn.mul = read_aux_reg(ARC_REG_MUL_BCR);
57 	cpu->extn.swap = read_aux_reg(ARC_REG_SWAP_BCR);
58 	cpu->extn.norm = read_aux_reg(ARC_REG_NORM_BCR);
59 	cpu->extn.minmax = read_aux_reg(ARC_REG_MIXMAX_BCR);
60 	cpu->extn.barrel = read_aux_reg(ARC_REG_BARREL_BCR);
61 	READ_BCR(ARC_REG_MAC_BCR, cpu->extn_mac_mul);
62 
63 	cpu->extn.ext_arith = read_aux_reg(ARC_REG_EXTARITH_BCR);
64 	cpu->extn.crc = read_aux_reg(ARC_REG_CRC_BCR);
65 
66 	/* Note that we read the CCM BCRs independent of kernel config
67 	 * This is to catch the cases where user doesn't know that
68 	 * CCMs are present in hardware build
69 	 */
70 	{
71 		struct bcr_iccm iccm;
72 		struct bcr_dccm dccm;
73 		struct bcr_dccm_base dccm_base;
74 		unsigned int bcr_32bit_val;
75 
76 		bcr_32bit_val = read_aux_reg(ARC_REG_ICCM_BCR);
77 		if (bcr_32bit_val) {
78 			iccm = *((struct bcr_iccm *)&bcr_32bit_val);
79 			cpu->iccm.base_addr = iccm.base << 16;
80 			cpu->iccm.sz = 0x2000 << (iccm.sz - 1);
81 		}
82 
83 		bcr_32bit_val = read_aux_reg(ARC_REG_DCCM_BCR);
84 		if (bcr_32bit_val) {
85 			dccm = *((struct bcr_dccm *)&bcr_32bit_val);
86 			cpu->dccm.sz = 0x800 << (dccm.sz);
87 
88 			READ_BCR(ARC_REG_DCCMBASE_BCR, dccm_base);
89 			cpu->dccm.base_addr = dccm_base.addr << 8;
90 		}
91 	}
92 
93 	READ_BCR(ARC_REG_XY_MEM_BCR, cpu->extn_xymem);
94 
95 	read_decode_mmu_bcr();
96 	read_decode_cache_bcr();
97 
98 	READ_BCR(ARC_REG_FP_BCR, cpu->fp);
99 	READ_BCR(ARC_REG_DPFP_BCR, cpu->dpfp);
100 }
101 
102 static const struct cpuinfo_data arc_cpu_tbl[] = {
103 	{ {0x10, "ARCTangent A5"}, 0x1F},
104 	{ {0x20, "ARC 600"      }, 0x2F},
105 	{ {0x30, "ARC 700"      }, 0x33},
106 	{ {0x34, "ARC 700 R4.10"}, 0x34},
107 	{ {0x00, NULL		} }
108 };
109 
110 static char *arc_cpu_mumbojumbo(int cpu_id, char *buf, int len)
111 {
112 	int n = 0;
113 	struct cpuinfo_arc *cpu = &cpuinfo_arc700[cpu_id];
114 	struct bcr_identity *core = &cpu->core;
115 	const struct cpuinfo_data *tbl;
116 	int be = 0;
117 #ifdef CONFIG_CPU_BIG_ENDIAN
118 	be = 1;
119 #endif
120 	FIX_PTR(cpu);
121 
122 	n += scnprintf(buf + n, len - n,
123 		       "\nARC IDENTITY\t: Family [%#02x]"
124 		       " Cpu-id [%#02x] Chip-id [%#4x]\n",
125 		       core->family, core->cpu_id,
126 		       core->chip_id);
127 
128 	for (tbl = &arc_cpu_tbl[0]; tbl->info.id != 0; tbl++) {
129 		if ((core->family >= tbl->info.id) &&
130 		    (core->family <= tbl->up_range)) {
131 			n += scnprintf(buf + n, len - n,
132 				       "processor\t: %s %s\n",
133 				       tbl->info.str,
134 				       be ? "[Big Endian]" : "");
135 			break;
136 		}
137 	}
138 
139 	if (tbl->info.id == 0)
140 		n += scnprintf(buf + n, len - n, "UNKNOWN ARC Processor\n");
141 
142 	n += scnprintf(buf + n, len - n, "CPU speed\t: %u.%02u Mhz\n",
143 		       (unsigned int)(arc_get_core_freq() / 1000000),
144 		       (unsigned int)(arc_get_core_freq() / 10000) % 100);
145 
146 	n += scnprintf(buf + n, len - n, "Timers\t\t: %s %s\n",
147 		       (cpu->timers & 0x200) ? "TIMER1" : "",
148 		       (cpu->timers & 0x100) ? "TIMER0" : "");
149 
150 	n += scnprintf(buf + n, len - n, "Vect Tbl Base\t: %#x\n",
151 		       cpu->vec_base);
152 
153 	n += scnprintf(buf + n, len - n, "UNCACHED Base\t: %#x\n",
154 		       cpu->uncached_base);
155 
156 	return buf;
157 }
158 
159 static const struct id_to_str mul_type_nm[] = {
160 	{ 0x0, "N/A"},
161 	{ 0x1, "32x32 (spl Result Reg)" },
162 	{ 0x2, "32x32 (ANY Result Reg)" }
163 };
164 
165 static const struct id_to_str mac_mul_nm[] = {
166 	{0x0, "N/A"},
167 	{0x1, "N/A"},
168 	{0x2, "Dual 16 x 16"},
169 	{0x3, "N/A"},
170 	{0x4, "32x16"},
171 	{0x5, "N/A"},
172 	{0x6, "Dual 16x16 and 32x16"}
173 };
174 
175 static char *arc_extn_mumbojumbo(int cpu_id, char *buf, int len)
176 {
177 	int n = 0;
178 	struct cpuinfo_arc *cpu = &cpuinfo_arc700[cpu_id];
179 
180 	FIX_PTR(cpu);
181 #define IS_AVAIL1(var, str)	((var) ? str : "")
182 #define IS_AVAIL2(var, str)	((var == 0x2) ? str : "")
183 #define IS_USED(cfg)		(IS_ENABLED(cfg) ? "(in-use)" : "(not used)")
184 
185 	n += scnprintf(buf + n, len - n,
186 		       "Extn [700-Base]\t: %s %s %s %s %s %s\n",
187 		       IS_AVAIL2(cpu->extn.norm, "norm,"),
188 		       IS_AVAIL2(cpu->extn.barrel, "barrel-shift,"),
189 		       IS_AVAIL1(cpu->extn.swap, "swap,"),
190 		       IS_AVAIL2(cpu->extn.minmax, "minmax,"),
191 		       IS_AVAIL1(cpu->extn.crc, "crc,"),
192 		       IS_AVAIL2(cpu->extn.ext_arith, "ext-arith"));
193 
194 	n += scnprintf(buf + n, len - n, "Extn [700-MPY]\t: %s",
195 		       mul_type_nm[cpu->extn.mul].str);
196 
197 	n += scnprintf(buf + n, len - n, "   MAC MPY: %s\n",
198 		       mac_mul_nm[cpu->extn_mac_mul.type].str);
199 
200 	if (cpu->core.family == 0x34) {
201 		n += scnprintf(buf + n, len - n,
202 		"Extn [700-4.10]\t: LLOCK/SCOND %s, SWAPE %s, RTSC %s\n",
203 			       IS_USED(CONFIG_ARC_HAS_LLSC),
204 			       IS_USED(CONFIG_ARC_HAS_SWAPE),
205 			       IS_USED(CONFIG_ARC_HAS_RTSC));
206 	}
207 
208 	n += scnprintf(buf + n, len - n, "Extn [CCM]\t: %s",
209 		       !(cpu->dccm.sz || cpu->iccm.sz) ? "N/A" : "");
210 
211 	if (cpu->dccm.sz)
212 		n += scnprintf(buf + n, len - n, "DCCM: @ %x, %d KB ",
213 			       cpu->dccm.base_addr, TO_KB(cpu->dccm.sz));
214 
215 	if (cpu->iccm.sz)
216 		n += scnprintf(buf + n, len - n, "ICCM: @ %x, %d KB",
217 			       cpu->iccm.base_addr, TO_KB(cpu->iccm.sz));
218 
219 	n += scnprintf(buf + n, len - n, "\nExtn [FPU]\t: %s",
220 		       !(cpu->fp.ver || cpu->dpfp.ver) ? "N/A" : "");
221 
222 	if (cpu->fp.ver)
223 		n += scnprintf(buf + n, len - n, "SP [v%d] %s",
224 			       cpu->fp.ver, cpu->fp.fast ? "(fast)" : "");
225 
226 	if (cpu->dpfp.ver)
227 		n += scnprintf(buf + n, len - n, "DP [v%d] %s",
228 			       cpu->dpfp.ver, cpu->dpfp.fast ? "(fast)" : "");
229 
230 	n += scnprintf(buf + n, len - n, "\n");
231 
232 	n += scnprintf(buf + n, len - n,
233 		       "OS ABI [v3]\t: no-legacy-syscalls\n");
234 
235 	return buf;
236 }
237 
238 static void arc_chk_ccms(void)
239 {
240 #if defined(CONFIG_ARC_HAS_DCCM) || defined(CONFIG_ARC_HAS_ICCM)
241 	struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
242 
243 #ifdef CONFIG_ARC_HAS_DCCM
244 	/*
245 	 * DCCM can be arbit placed in hardware.
246 	 * Make sure it's placement/sz matches what Linux is built with
247 	 */
248 	if ((unsigned int)__arc_dccm_base != cpu->dccm.base_addr)
249 		panic("Linux built with incorrect DCCM Base address\n");
250 
251 	if (CONFIG_ARC_DCCM_SZ != cpu->dccm.sz)
252 		panic("Linux built with incorrect DCCM Size\n");
253 #endif
254 
255 #ifdef CONFIG_ARC_HAS_ICCM
256 	if (CONFIG_ARC_ICCM_SZ != cpu->iccm.sz)
257 		panic("Linux built with incorrect ICCM Size\n");
258 #endif
259 #endif
260 }
261 
262 /*
263  * Ensure that FP hardware and kernel config match
264  * -If hardware contains DPFP, kernel needs to save/restore FPU state
265  *  across context switches
266  * -If hardware lacks DPFP, but kernel configured to save FPU state then
267  *  kernel trying to access non-existant DPFP regs will crash
268  *
269  * We only check for Dbl precision Floating Point, because only DPFP
270  * hardware has dedicated regs which need to be saved/restored on ctx-sw
271  * (Single Precision uses core regs), thus kernel is kind of oblivious to it
272  */
273 static void arc_chk_fpu(void)
274 {
275 	struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
276 
277 	if (cpu->dpfp.ver) {
278 #ifndef CONFIG_ARC_FPU_SAVE_RESTORE
279 		pr_warn("DPFP support broken in this kernel...\n");
280 #endif
281 	} else {
282 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE
283 		panic("H/w lacks DPFP support, apps won't work\n");
284 #endif
285 	}
286 }
287 
288 /*
289  * Initialize and setup the processor core
290  * This is called by all the CPUs thus should not do special case stuff
291  *    such as only for boot CPU etc
292  */
293 
294 void setup_processor(void)
295 {
296 	char str[512];
297 	int cpu_id = smp_processor_id();
298 
299 	read_arc_build_cfg_regs();
300 	arc_init_IRQ();
301 
302 	printk(arc_cpu_mumbojumbo(cpu_id, str, sizeof(str)));
303 
304 	arc_mmu_init();
305 	arc_cache_init();
306 	arc_chk_ccms();
307 
308 	printk(arc_extn_mumbojumbo(cpu_id, str, sizeof(str)));
309 
310 #ifdef CONFIG_SMP
311 	printk(arc_platform_smp_cpuinfo());
312 #endif
313 
314 	arc_chk_fpu();
315 }
316 
317 static inline int is_kernel(unsigned long addr)
318 {
319 	if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
320 		return 1;
321 	return 0;
322 }
323 
324 void __init setup_arch(char **cmdline_p)
325 {
326 	/* make sure that uboot passed pointer to cmdline/dtb is valid */
327 	if (uboot_tag && is_kernel((unsigned long)uboot_arg))
328 		panic("Invalid uboot arg\n");
329 
330 	/* See if u-boot passed an external Device Tree blob */
331 	machine_desc = setup_machine_fdt(uboot_arg);	/* uboot_tag == 2 */
332 	if (!machine_desc) {
333 		/* No, so try the embedded one */
334 		machine_desc = setup_machine_fdt(__dtb_start);
335 		if (!machine_desc)
336 			panic("Embedded DT invalid\n");
337 
338 		/*
339 		 * If we are here, it is established that @uboot_arg didn't
340 		 * point to DT blob. Instead if u-boot says it is cmdline,
341 		 * Appent to embedded DT cmdline.
342 		 * setup_machine_fdt() would have populated @boot_command_line
343 		 */
344 		if (uboot_tag == 1) {
345 			/* Ensure a whitespace between the 2 cmdlines */
346 			strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
347 			strlcat(boot_command_line, uboot_arg,
348 				COMMAND_LINE_SIZE);
349 		}
350 	}
351 
352 	/* Save unparsed command line copy for /proc/cmdline */
353 	*cmdline_p = boot_command_line;
354 
355 	/* To force early parsing of things like mem=xxx */
356 	parse_early_param();
357 
358 	/* Platform/board specific: e.g. early console registration */
359 	if (machine_desc->init_early)
360 		machine_desc->init_early();
361 
362 	setup_processor();
363 
364 #ifdef CONFIG_SMP
365 	smp_init_cpus();
366 #endif
367 
368 	setup_arch_memory();
369 
370 	/* copy flat DT out of .init and then unflatten it */
371 	unflatten_and_copy_device_tree();
372 
373 	/* Can be issue if someone passes cmd line arg "ro"
374 	 * But that is unlikely so keeping it as it is
375 	 */
376 	root_mountflags &= ~MS_RDONLY;
377 
378 #if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
379 	conswitchp = &dummy_con;
380 #endif
381 
382 	arc_unwind_init();
383 	arc_unwind_setup();
384 }
385 
386 static int __init customize_machine(void)
387 {
388 	/* Add platform devices */
389 	if (machine_desc->init_machine)
390 		machine_desc->init_machine();
391 
392 	return 0;
393 }
394 arch_initcall(customize_machine);
395 
396 static int __init init_late_machine(void)
397 {
398 	if (machine_desc->init_late)
399 		machine_desc->init_late();
400 
401 	return 0;
402 }
403 late_initcall(init_late_machine);
404 /*
405  *  Get CPU information for use by the procfs.
406  */
407 
408 #define cpu_to_ptr(c)	((void *)(0xFFFF0000 | (unsigned int)(c)))
409 #define ptr_to_cpu(p)	(~0xFFFF0000UL & (unsigned int)(p))
410 
411 static int show_cpuinfo(struct seq_file *m, void *v)
412 {
413 	char *str;
414 	int cpu_id = ptr_to_cpu(v);
415 
416 	str = (char *)__get_free_page(GFP_TEMPORARY);
417 	if (!str)
418 		goto done;
419 
420 	seq_printf(m, arc_cpu_mumbojumbo(cpu_id, str, PAGE_SIZE));
421 
422 	seq_printf(m, "Bogo MIPS : \t%lu.%02lu\n",
423 		   loops_per_jiffy / (500000 / HZ),
424 		   (loops_per_jiffy / (5000 / HZ)) % 100);
425 
426 	seq_printf(m, arc_mmu_mumbojumbo(cpu_id, str, PAGE_SIZE));
427 
428 	seq_printf(m, arc_cache_mumbojumbo(cpu_id, str, PAGE_SIZE));
429 
430 	seq_printf(m, arc_extn_mumbojumbo(cpu_id, str, PAGE_SIZE));
431 
432 #ifdef CONFIG_SMP
433 	seq_printf(m, arc_platform_smp_cpuinfo());
434 #endif
435 
436 	free_page((unsigned long)str);
437 done:
438 	seq_printf(m, "\n\n");
439 
440 	return 0;
441 }
442 
443 static void *c_start(struct seq_file *m, loff_t *pos)
444 {
445 	/*
446 	 * Callback returns cpu-id to iterator for show routine, NULL to stop.
447 	 * However since NULL is also a valid cpu-id (0), we use a round-about
448 	 * way to pass it w/o having to kmalloc/free a 2 byte string.
449 	 * Encode cpu-id as 0xFFcccc, which is decoded by show routine.
450 	 */
451 	return *pos < num_possible_cpus() ? cpu_to_ptr(*pos) : NULL;
452 }
453 
454 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
455 {
456 	++*pos;
457 	return c_start(m, pos);
458 }
459 
460 static void c_stop(struct seq_file *m, void *v)
461 {
462 }
463 
464 const struct seq_operations cpuinfo_op = {
465 	.start	= c_start,
466 	.next	= c_next,
467 	.stop	= c_stop,
468 	.show	= show_cpuinfo
469 };
470 
471 static DEFINE_PER_CPU(struct cpu, cpu_topology);
472 
473 static int __init topology_init(void)
474 {
475 	int cpu;
476 
477 	for_each_present_cpu(cpu)
478 	    register_cpu(&per_cpu(cpu_topology, cpu), cpu);
479 
480 	return 0;
481 }
482 
483 subsys_initcall(topology_init);
484