xref: /openbmc/linux/arch/powerpc/kernel/setup_64.c (revision a1e58bbd)
1 /*
2  *
3  * Common boot and setup code.
4  *
5  * Copyright (C) 2001 PPC64 Team, IBM Corp
6  *
7  *      This program is free software; you can redistribute it and/or
8  *      modify it under the terms of the GNU General Public License
9  *      as published by the Free Software Foundation; either version
10  *      2 of the License, or (at your option) any later version.
11  */
12 
13 #undef DEBUG
14 
15 #include <linux/module.h>
16 #include <linux/string.h>
17 #include <linux/sched.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/reboot.h>
21 #include <linux/delay.h>
22 #include <linux/initrd.h>
23 #include <linux/seq_file.h>
24 #include <linux/ioport.h>
25 #include <linux/console.h>
26 #include <linux/utsname.h>
27 #include <linux/tty.h>
28 #include <linux/root_dev.h>
29 #include <linux/notifier.h>
30 #include <linux/cpu.h>
31 #include <linux/unistd.h>
32 #include <linux/serial.h>
33 #include <linux/serial_8250.h>
34 #include <linux/bootmem.h>
35 #include <linux/pci.h>
36 #include <asm/io.h>
37 #include <asm/kdump.h>
38 #include <asm/prom.h>
39 #include <asm/processor.h>
40 #include <asm/pgtable.h>
41 #include <asm/smp.h>
42 #include <asm/elf.h>
43 #include <asm/machdep.h>
44 #include <asm/paca.h>
45 #include <asm/time.h>
46 #include <asm/cputable.h>
47 #include <asm/sections.h>
48 #include <asm/btext.h>
49 #include <asm/nvram.h>
50 #include <asm/setup.h>
51 #include <asm/system.h>
52 #include <asm/rtas.h>
53 #include <asm/iommu.h>
54 #include <asm/serial.h>
55 #include <asm/cache.h>
56 #include <asm/page.h>
57 #include <asm/mmu.h>
58 #include <asm/lmb.h>
59 #include <asm/firmware.h>
60 #include <asm/xmon.h>
61 #include <asm/udbg.h>
62 #include <asm/kexec.h>
63 
64 #include "setup.h"
65 
66 #ifdef DEBUG
67 #define DBG(fmt...) udbg_printf(fmt)
68 #else
69 #define DBG(fmt...)
70 #endif
71 
72 int have_of = 1;
73 int boot_cpuid = 0;
74 u64 ppc64_pft_size;
75 
76 /* Pick defaults since we might want to patch instructions
77  * before we've read this from the device tree.
78  */
79 struct ppc64_caches ppc64_caches = {
80 	.dline_size = 0x40,
81 	.log_dline_size = 6,
82 	.iline_size = 0x40,
83 	.log_iline_size = 6
84 };
85 EXPORT_SYMBOL_GPL(ppc64_caches);
86 
87 /*
88  * These are used in binfmt_elf.c to put aux entries on the stack
89  * for each elf executable being started.
90  */
91 int dcache_bsize;
92 int icache_bsize;
93 int ucache_bsize;
94 
95 #ifdef CONFIG_SMP
96 
97 static int smt_enabled_cmdline;
98 
99 /* Look for ibm,smt-enabled OF option */
100 static void check_smt_enabled(void)
101 {
102 	struct device_node *dn;
103 	const char *smt_option;
104 
105 	/* Allow the command line to overrule the OF option */
106 	if (smt_enabled_cmdline)
107 		return;
108 
109 	dn = of_find_node_by_path("/options");
110 
111 	if (dn) {
112 		smt_option = of_get_property(dn, "ibm,smt-enabled", NULL);
113 
114                 if (smt_option) {
115 			if (!strcmp(smt_option, "on"))
116 				smt_enabled_at_boot = 1;
117 			else if (!strcmp(smt_option, "off"))
118 				smt_enabled_at_boot = 0;
119                 }
120         }
121 }
122 
123 /* Look for smt-enabled= cmdline option */
124 static int __init early_smt_enabled(char *p)
125 {
126 	smt_enabled_cmdline = 1;
127 
128 	if (!p)
129 		return 0;
130 
131 	if (!strcmp(p, "on") || !strcmp(p, "1"))
132 		smt_enabled_at_boot = 1;
133 	else if (!strcmp(p, "off") || !strcmp(p, "0"))
134 		smt_enabled_at_boot = 0;
135 
136 	return 0;
137 }
138 early_param("smt-enabled", early_smt_enabled);
139 
140 #else
141 #define check_smt_enabled()
142 #endif /* CONFIG_SMP */
143 
144 /* Put the paca pointer into r13 and SPRG3 */
145 void __init setup_paca(int cpu)
146 {
147 	local_paca = &paca[cpu];
148 	mtspr(SPRN_SPRG3, local_paca);
149 }
150 
151 /*
152  * Early initialization entry point. This is called by head.S
153  * with MMU translation disabled. We rely on the "feature" of
154  * the CPU that ignores the top 2 bits of the address in real
155  * mode so we can access kernel globals normally provided we
156  * only toy with things in the RMO region. From here, we do
157  * some early parsing of the device-tree to setup out LMB
158  * data structures, and allocate & initialize the hash table
159  * and segment tables so we can start running with translation
160  * enabled.
161  *
162  * It is this function which will call the probe() callback of
163  * the various platform types and copy the matching one to the
164  * global ppc_md structure. Your platform can eventually do
165  * some very early initializations from the probe() routine, but
166  * this is not recommended, be very careful as, for example, the
167  * device-tree is not accessible via normal means at this point.
168  */
169 
170 void __init early_setup(unsigned long dt_ptr)
171 {
172 	/* Identify CPU type */
173 	identify_cpu(0, mfspr(SPRN_PVR));
174 
175 	/* Assume we're on cpu 0 for now. Don't write to the paca yet! */
176 	setup_paca(0);
177 
178 	/* Enable early debugging if any specified (see udbg.h) */
179 	udbg_early_init();
180 
181  	DBG(" -> early_setup(), dt_ptr: 0x%lx\n", dt_ptr);
182 
183 	/*
184 	 * Do early initialization using the flattened device
185 	 * tree, such as retrieving the physical memory map or
186 	 * calculating/retrieving the hash table size.
187 	 */
188 	early_init_devtree(__va(dt_ptr));
189 
190 	/* Now we know the logical id of our boot cpu, setup the paca. */
191 	setup_paca(boot_cpuid);
192 
193 	/* Fix up paca fields required for the boot cpu */
194 	get_paca()->cpu_start = 1;
195 	get_paca()->stab_real = __pa((u64)&initial_stab);
196 	get_paca()->stab_addr = (u64)&initial_stab;
197 
198 	/* Probe the machine type */
199 	probe_machine();
200 
201 	setup_kdump_trampoline();
202 
203 	DBG("Found, Initializing memory management...\n");
204 
205 	/*
206 	 * Initialize the MMU Hash table and create the linear mapping
207 	 * of memory. Has to be done before stab/slb initialization as
208 	 * this is currently where the page size encoding is obtained
209 	 */
210 	htab_initialize();
211 
212 	/*
213 	 * Initialize stab / SLB management except on iSeries
214 	 */
215 	if (cpu_has_feature(CPU_FTR_SLB))
216 		slb_initialize();
217 	else if (!firmware_has_feature(FW_FEATURE_ISERIES))
218 		stab_initialize(get_paca()->stab_real);
219 
220 	DBG(" <- early_setup()\n");
221 }
222 
223 #ifdef CONFIG_SMP
224 void early_setup_secondary(void)
225 {
226 	struct paca_struct *lpaca = get_paca();
227 
228 	/* Mark interrupts enabled in PACA */
229 	lpaca->soft_enabled = 0;
230 
231 	/* Initialize hash table for that CPU */
232 	htab_initialize_secondary();
233 
234 	/* Initialize STAB/SLB. We use a virtual address as it works
235 	 * in real mode on pSeries and we want a virutal address on
236 	 * iSeries anyway
237 	 */
238 	if (cpu_has_feature(CPU_FTR_SLB))
239 		slb_initialize();
240 	else
241 		stab_initialize(lpaca->stab_addr);
242 }
243 
244 #endif /* CONFIG_SMP */
245 
246 #if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
247 void smp_release_cpus(void)
248 {
249 	extern unsigned long __secondary_hold_spinloop;
250 	unsigned long *ptr;
251 
252 	DBG(" -> smp_release_cpus()\n");
253 
254 	/* All secondary cpus are spinning on a common spinloop, release them
255 	 * all now so they can start to spin on their individual paca
256 	 * spinloops. For non SMP kernels, the secondary cpus never get out
257 	 * of the common spinloop.
258 	 * This is useless but harmless on iSeries, secondaries are already
259 	 * waiting on their paca spinloops. */
260 
261 	ptr  = (unsigned long *)((unsigned long)&__secondary_hold_spinloop
262 			- PHYSICAL_START);
263 	*ptr = 1;
264 	mb();
265 
266 	DBG(" <- smp_release_cpus()\n");
267 }
268 #endif /* CONFIG_SMP || CONFIG_KEXEC */
269 
270 /*
271  * Initialize some remaining members of the ppc64_caches and systemcfg
272  * structures
273  * (at least until we get rid of them completely). This is mostly some
274  * cache informations about the CPU that will be used by cache flush
275  * routines and/or provided to userland
276  */
277 static void __init initialize_cache_info(void)
278 {
279 	struct device_node *np;
280 	unsigned long num_cpus = 0;
281 
282 	DBG(" -> initialize_cache_info()\n");
283 
284 	for (np = NULL; (np = of_find_node_by_type(np, "cpu"));) {
285 		num_cpus += 1;
286 
287 		/* We're assuming *all* of the CPUs have the same
288 		 * d-cache and i-cache sizes... -Peter
289 		 */
290 
291 		if ( num_cpus == 1 ) {
292 			const u32 *sizep, *lsizep;
293 			u32 size, lsize;
294 
295 			size = 0;
296 			lsize = cur_cpu_spec->dcache_bsize;
297 			sizep = of_get_property(np, "d-cache-size", NULL);
298 			if (sizep != NULL)
299 				size = *sizep;
300 			lsizep = of_get_property(np, "d-cache-block-size", NULL);
301 			/* fallback if block size missing */
302 			if (lsizep == NULL)
303 				lsizep = of_get_property(np, "d-cache-line-size", NULL);
304 			if (lsizep != NULL)
305 				lsize = *lsizep;
306 			if (sizep == 0 || lsizep == 0)
307 				DBG("Argh, can't find dcache properties ! "
308 				    "sizep: %p, lsizep: %p\n", sizep, lsizep);
309 
310 			ppc64_caches.dsize = size;
311 			ppc64_caches.dline_size = lsize;
312 			ppc64_caches.log_dline_size = __ilog2(lsize);
313 			ppc64_caches.dlines_per_page = PAGE_SIZE / lsize;
314 
315 			size = 0;
316 			lsize = cur_cpu_spec->icache_bsize;
317 			sizep = of_get_property(np, "i-cache-size", NULL);
318 			if (sizep != NULL)
319 				size = *sizep;
320 			lsizep = of_get_property(np, "i-cache-block-size", NULL);
321 			if (lsizep == NULL)
322 				lsizep = of_get_property(np, "i-cache-line-size", NULL);
323 			if (lsizep != NULL)
324 				lsize = *lsizep;
325 			if (sizep == 0 || lsizep == 0)
326 				DBG("Argh, can't find icache properties ! "
327 				    "sizep: %p, lsizep: %p\n", sizep, lsizep);
328 
329 			ppc64_caches.isize = size;
330 			ppc64_caches.iline_size = lsize;
331 			ppc64_caches.log_iline_size = __ilog2(lsize);
332 			ppc64_caches.ilines_per_page = PAGE_SIZE / lsize;
333 		}
334 	}
335 
336 	DBG(" <- initialize_cache_info()\n");
337 }
338 
339 
340 /*
341  * Do some initial setup of the system.  The parameters are those which
342  * were passed in from the bootloader.
343  */
344 void __init setup_system(void)
345 {
346 	DBG(" -> setup_system()\n");
347 
348 	/* Apply the CPUs-specific and firmware specific fixups to kernel
349 	 * text (nop out sections not relevant to this CPU or this firmware)
350 	 */
351 	do_feature_fixups(cur_cpu_spec->cpu_features,
352 			  &__start___ftr_fixup, &__stop___ftr_fixup);
353 	do_feature_fixups(powerpc_firmware_features,
354 			  &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
355 
356 	/*
357 	 * Unflatten the device-tree passed by prom_init or kexec
358 	 */
359 	unflatten_device_tree();
360 
361 	/*
362 	 * Fill the ppc64_caches & systemcfg structures with informations
363  	 * retrieved from the device-tree.
364 	 */
365 	initialize_cache_info();
366 
367 	/*
368 	 * Initialize irq remapping subsystem
369 	 */
370 	irq_early_init();
371 
372 #ifdef CONFIG_PPC_RTAS
373 	/*
374 	 * Initialize RTAS if available
375 	 */
376 	rtas_initialize();
377 #endif /* CONFIG_PPC_RTAS */
378 
379 	/*
380 	 * Check if we have an initrd provided via the device-tree
381 	 */
382 	check_for_initrd();
383 
384 	/*
385 	 * Do some platform specific early initializations, that includes
386 	 * setting up the hash table pointers. It also sets up some interrupt-mapping
387 	 * related options that will be used by finish_device_tree()
388 	 */
389 	if (ppc_md.init_early)
390 		ppc_md.init_early();
391 
392  	/*
393 	 * We can discover serial ports now since the above did setup the
394 	 * hash table management for us, thus ioremap works. We do that early
395 	 * so that further code can be debugged
396 	 */
397 	find_legacy_serial_ports();
398 
399 	/*
400 	 * Register early console
401 	 */
402 	register_early_udbg_console();
403 
404 	/*
405 	 * Initialize xmon
406 	 */
407 	xmon_setup();
408 
409 	check_smt_enabled();
410 	smp_setup_cpu_maps();
411 
412 #ifdef CONFIG_SMP
413 	/* Release secondary cpus out of their spinloops at 0x60 now that
414 	 * we can map physical -> logical CPU ids
415 	 */
416 	smp_release_cpus();
417 #endif
418 
419 	printk("Starting Linux PPC64 %s\n", init_utsname()->version);
420 
421 	printk("-----------------------------------------------------\n");
422 	printk("ppc64_pft_size                = 0x%lx\n", ppc64_pft_size);
423 	printk("physicalMemorySize            = 0x%lx\n", lmb_phys_mem_size());
424 	if (ppc64_caches.dline_size != 0x80)
425 		printk("ppc64_caches.dcache_line_size = 0x%x\n",
426 		       ppc64_caches.dline_size);
427 	if (ppc64_caches.iline_size != 0x80)
428 		printk("ppc64_caches.icache_line_size = 0x%x\n",
429 		       ppc64_caches.iline_size);
430 	if (htab_address)
431 		printk("htab_address                  = 0x%p\n", htab_address);
432 	printk("htab_hash_mask                = 0x%lx\n", htab_hash_mask);
433 #if PHYSICAL_START > 0
434 	printk("physical_start                = 0x%x\n", PHYSICAL_START);
435 #endif
436 	printk("-----------------------------------------------------\n");
437 
438 	DBG(" <- setup_system()\n");
439 }
440 
441 #ifdef CONFIG_IRQSTACKS
442 static void __init irqstack_early_init(void)
443 {
444 	unsigned int i;
445 
446 	/*
447 	 * interrupt stacks must be under 256MB, we cannot afford to take
448 	 * SLB misses on them.
449 	 */
450 	for_each_possible_cpu(i) {
451 		softirq_ctx[i] = (struct thread_info *)
452 			__va(lmb_alloc_base(THREAD_SIZE,
453 					    THREAD_SIZE, 0x10000000));
454 		hardirq_ctx[i] = (struct thread_info *)
455 			__va(lmb_alloc_base(THREAD_SIZE,
456 					    THREAD_SIZE, 0x10000000));
457 	}
458 }
459 #else
460 #define irqstack_early_init()
461 #endif
462 
463 /*
464  * Stack space used when we detect a bad kernel stack pointer, and
465  * early in SMP boots before relocation is enabled.
466  */
467 static void __init emergency_stack_init(void)
468 {
469 	unsigned long limit;
470 	unsigned int i;
471 
472 	/*
473 	 * Emergency stacks must be under 256MB, we cannot afford to take
474 	 * SLB misses on them. The ABI also requires them to be 128-byte
475 	 * aligned.
476 	 *
477 	 * Since we use these as temporary stacks during secondary CPU
478 	 * bringup, we need to get at them in real mode. This means they
479 	 * must also be within the RMO region.
480 	 */
481 	limit = min(0x10000000UL, lmb.rmo_size);
482 
483 	for_each_possible_cpu(i)
484 		paca[i].emergency_sp =
485 		__va(lmb_alloc_base(HW_PAGE_SIZE, 128, limit)) + HW_PAGE_SIZE;
486 }
487 
488 /*
489  * Called into from start_kernel, after lock_kernel has been called.
490  * Initializes bootmem, which is unsed to manage page allocation until
491  * mem_init is called.
492  */
493 void __init setup_arch(char **cmdline_p)
494 {
495 	ppc64_boot_msg(0x12, "Setup Arch");
496 
497 	*cmdline_p = cmd_line;
498 
499 	/*
500 	 * Set cache line size based on type of cpu as a default.
501 	 * Systems with OF can look in the properties on the cpu node(s)
502 	 * for a possibly more accurate value.
503 	 */
504 	dcache_bsize = ppc64_caches.dline_size;
505 	icache_bsize = ppc64_caches.iline_size;
506 
507 	/* reboot on panic */
508 	panic_timeout = 180;
509 
510 	if (ppc_md.panic)
511 		setup_panic();
512 
513 	init_mm.start_code = PAGE_OFFSET;
514 	init_mm.end_code = (unsigned long) _etext;
515 	init_mm.end_data = (unsigned long) _edata;
516 	init_mm.brk = klimit;
517 
518 	irqstack_early_init();
519 	emergency_stack_init();
520 
521 	stabs_alloc();
522 
523 	/* set up the bootmem stuff with available memory */
524 	do_init_bootmem();
525 	sparse_init();
526 
527 #ifdef CONFIG_DUMMY_CONSOLE
528 	conswitchp = &dummy_con;
529 #endif
530 
531 	if (ppc_md.setup_arch)
532 		ppc_md.setup_arch();
533 
534 	paging_init();
535 	ppc64_boot_msg(0x15, "Setup Done");
536 }
537 
538 
539 /* ToDo: do something useful if ppc_md is not yet setup. */
540 #define PPC64_LINUX_FUNCTION 0x0f000000
541 #define PPC64_IPL_MESSAGE 0xc0000000
542 #define PPC64_TERM_MESSAGE 0xb0000000
543 
544 static void ppc64_do_msg(unsigned int src, const char *msg)
545 {
546 	if (ppc_md.progress) {
547 		char buf[128];
548 
549 		sprintf(buf, "%08X\n", src);
550 		ppc_md.progress(buf, 0);
551 		snprintf(buf, 128, "%s", msg);
552 		ppc_md.progress(buf, 0);
553 	}
554 }
555 
556 /* Print a boot progress message. */
557 void ppc64_boot_msg(unsigned int src, const char *msg)
558 {
559 	ppc64_do_msg(PPC64_LINUX_FUNCTION|PPC64_IPL_MESSAGE|src, msg);
560 	printk("[boot]%04x %s\n", src, msg);
561 }
562 
563 /* Print a termination message (print only -- does not stop the kernel) */
564 void ppc64_terminate_msg(unsigned int src, const char *msg)
565 {
566 	ppc64_do_msg(PPC64_LINUX_FUNCTION|PPC64_TERM_MESSAGE|src, msg);
567 	printk("[terminate]%04x %s\n", src, msg);
568 }
569 
570 void cpu_die(void)
571 {
572 	if (ppc_md.cpu_die)
573 		ppc_md.cpu_die();
574 }
575 
576 #ifdef CONFIG_SMP
577 void __init setup_per_cpu_areas(void)
578 {
579 	int i;
580 	unsigned long size;
581 	char *ptr;
582 
583 	/* Copy section for each CPU (we discard the original) */
584 	size = ALIGN(__per_cpu_end - __per_cpu_start, PAGE_SIZE);
585 #ifdef CONFIG_MODULES
586 	if (size < PERCPU_ENOUGH_ROOM)
587 		size = PERCPU_ENOUGH_ROOM;
588 #endif
589 
590 	for_each_possible_cpu(i) {
591 		ptr = alloc_bootmem_pages_node(NODE_DATA(cpu_to_node(i)), size);
592 		if (!ptr)
593 			panic("Cannot allocate cpu data for CPU %d\n", i);
594 
595 		paca[i].data_offset = ptr - __per_cpu_start;
596 		memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
597 	}
598 
599 	/* Now that per_cpu is setup, initialize cpu_sibling_map */
600 	smp_setup_cpu_sibling_map();
601 }
602 #endif
603 
604 
605 #ifdef CONFIG_PPC_INDIRECT_IO
606 struct ppc_pci_io ppc_pci_io;
607 EXPORT_SYMBOL(ppc_pci_io);
608 #endif /* CONFIG_PPC_INDIRECT_IO */
609 
610