xref: /openbmc/linux/arch/powerpc/kernel/setup_64.c (revision e8e0929d)
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 <linux/lockdep.h>
37 #include <linux/lmb.h>
38 #include <asm/io.h>
39 #include <asm/kdump.h>
40 #include <asm/prom.h>
41 #include <asm/processor.h>
42 #include <asm/pgtable.h>
43 #include <asm/smp.h>
44 #include <asm/elf.h>
45 #include <asm/machdep.h>
46 #include <asm/paca.h>
47 #include <asm/time.h>
48 #include <asm/cputable.h>
49 #include <asm/sections.h>
50 #include <asm/btext.h>
51 #include <asm/nvram.h>
52 #include <asm/setup.h>
53 #include <asm/system.h>
54 #include <asm/rtas.h>
55 #include <asm/iommu.h>
56 #include <asm/serial.h>
57 #include <asm/cache.h>
58 #include <asm/page.h>
59 #include <asm/mmu.h>
60 #include <asm/mmu-hash64.h>
61 #include <asm/firmware.h>
62 #include <asm/xmon.h>
63 #include <asm/udbg.h>
64 #include <asm/kexec.h>
65 #include <asm/swiotlb.h>
66 #include <asm/mmu_context.h>
67 
68 #include "setup.h"
69 
70 #ifdef DEBUG
71 #define DBG(fmt...) udbg_printf(fmt)
72 #else
73 #define DBG(fmt...)
74 #endif
75 
76 int boot_cpuid = 0;
77 u64 ppc64_pft_size;
78 
79 /* Pick defaults since we might want to patch instructions
80  * before we've read this from the device tree.
81  */
82 struct ppc64_caches ppc64_caches = {
83 	.dline_size = 0x40,
84 	.log_dline_size = 6,
85 	.iline_size = 0x40,
86 	.log_iline_size = 6
87 };
88 EXPORT_SYMBOL_GPL(ppc64_caches);
89 
90 /*
91  * These are used in binfmt_elf.c to put aux entries on the stack
92  * for each elf executable being started.
93  */
94 int dcache_bsize;
95 int icache_bsize;
96 int ucache_bsize;
97 
98 #ifdef CONFIG_SMP
99 
100 static int smt_enabled_cmdline;
101 
102 /* Look for ibm,smt-enabled OF option */
103 static void check_smt_enabled(void)
104 {
105 	struct device_node *dn;
106 	const char *smt_option;
107 
108 	/* Allow the command line to overrule the OF option */
109 	if (smt_enabled_cmdline)
110 		return;
111 
112 	dn = of_find_node_by_path("/options");
113 
114 	if (dn) {
115 		smt_option = of_get_property(dn, "ibm,smt-enabled", NULL);
116 
117                 if (smt_option) {
118 			if (!strcmp(smt_option, "on"))
119 				smt_enabled_at_boot = 1;
120 			else if (!strcmp(smt_option, "off"))
121 				smt_enabled_at_boot = 0;
122                 }
123         }
124 }
125 
126 /* Look for smt-enabled= cmdline option */
127 static int __init early_smt_enabled(char *p)
128 {
129 	smt_enabled_cmdline = 1;
130 
131 	if (!p)
132 		return 0;
133 
134 	if (!strcmp(p, "on") || !strcmp(p, "1"))
135 		smt_enabled_at_boot = 1;
136 	else if (!strcmp(p, "off") || !strcmp(p, "0"))
137 		smt_enabled_at_boot = 0;
138 
139 	return 0;
140 }
141 early_param("smt-enabled", early_smt_enabled);
142 
143 #else
144 #define check_smt_enabled()
145 #endif /* CONFIG_SMP */
146 
147 /* Put the paca pointer into r13 and SPRG_PACA */
148 void __init setup_paca(int cpu)
149 {
150 	local_paca = &paca[cpu];
151 	mtspr(SPRN_SPRG_PACA, local_paca);
152 #ifdef CONFIG_PPC_BOOK3E
153 	mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
154 #endif
155 }
156 
157 /*
158  * Early initialization entry point. This is called by head.S
159  * with MMU translation disabled. We rely on the "feature" of
160  * the CPU that ignores the top 2 bits of the address in real
161  * mode so we can access kernel globals normally provided we
162  * only toy with things in the RMO region. From here, we do
163  * some early parsing of the device-tree to setup out LMB
164  * data structures, and allocate & initialize the hash table
165  * and segment tables so we can start running with translation
166  * enabled.
167  *
168  * It is this function which will call the probe() callback of
169  * the various platform types and copy the matching one to the
170  * global ppc_md structure. Your platform can eventually do
171  * some very early initializations from the probe() routine, but
172  * this is not recommended, be very careful as, for example, the
173  * device-tree is not accessible via normal means at this point.
174  */
175 
176 void __init early_setup(unsigned long dt_ptr)
177 {
178 	/* -------- printk is _NOT_ safe to use here ! ------- */
179 
180 	/* Fill in any unititialised pacas */
181 	initialise_pacas();
182 
183 	/* Identify CPU type */
184 	identify_cpu(0, mfspr(SPRN_PVR));
185 
186 	/* Assume we're on cpu 0 for now. Don't write to the paca yet! */
187 	setup_paca(0);
188 
189 	/* Initialize lockdep early or else spinlocks will blow */
190 	lockdep_init();
191 
192 	/* -------- printk is now safe to use ------- */
193 
194 	/* Enable early debugging if any specified (see udbg.h) */
195 	udbg_early_init();
196 
197  	DBG(" -> early_setup(), dt_ptr: 0x%lx\n", dt_ptr);
198 
199 	/*
200 	 * Do early initialization using the flattened device
201 	 * tree, such as retrieving the physical memory map or
202 	 * calculating/retrieving the hash table size.
203 	 */
204 	early_init_devtree(__va(dt_ptr));
205 
206 	/* Now we know the logical id of our boot cpu, setup the paca. */
207 	setup_paca(boot_cpuid);
208 
209 	/* Fix up paca fields required for the boot cpu */
210 	get_paca()->cpu_start = 1;
211 
212 	/* Probe the machine type */
213 	probe_machine();
214 
215 	setup_kdump_trampoline();
216 
217 	DBG("Found, Initializing memory management...\n");
218 
219 	/* Initialize the hash table or TLB handling */
220 	early_init_mmu();
221 
222 	DBG(" <- early_setup()\n");
223 }
224 
225 #ifdef CONFIG_SMP
226 void early_setup_secondary(void)
227 {
228 	/* Mark interrupts enabled in PACA */
229 	get_paca()->soft_enabled = 0;
230 
231 	/* Initialize the hash table or TLB handling */
232 	early_init_mmu_secondary();
233 }
234 
235 #endif /* CONFIG_SMP */
236 
237 #if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
238 void smp_release_cpus(void)
239 {
240 	unsigned long *ptr;
241 
242 	DBG(" -> smp_release_cpus()\n");
243 
244 	/* All secondary cpus are spinning on a common spinloop, release them
245 	 * all now so they can start to spin on their individual paca
246 	 * spinloops. For non SMP kernels, the secondary cpus never get out
247 	 * of the common spinloop.
248 	 */
249 
250 	ptr  = (unsigned long *)((unsigned long)&__secondary_hold_spinloop
251 			- PHYSICAL_START);
252 	*ptr = __pa(generic_secondary_smp_init);
253 	mb();
254 
255 	DBG(" <- smp_release_cpus()\n");
256 }
257 #endif /* CONFIG_SMP || CONFIG_KEXEC */
258 
259 /*
260  * Initialize some remaining members of the ppc64_caches and systemcfg
261  * structures
262  * (at least until we get rid of them completely). This is mostly some
263  * cache informations about the CPU that will be used by cache flush
264  * routines and/or provided to userland
265  */
266 static void __init initialize_cache_info(void)
267 {
268 	struct device_node *np;
269 	unsigned long num_cpus = 0;
270 
271 	DBG(" -> initialize_cache_info()\n");
272 
273 	for (np = NULL; (np = of_find_node_by_type(np, "cpu"));) {
274 		num_cpus += 1;
275 
276 		/* We're assuming *all* of the CPUs have the same
277 		 * d-cache and i-cache sizes... -Peter
278 		 */
279 
280 		if ( num_cpus == 1 ) {
281 			const u32 *sizep, *lsizep;
282 			u32 size, lsize;
283 
284 			size = 0;
285 			lsize = cur_cpu_spec->dcache_bsize;
286 			sizep = of_get_property(np, "d-cache-size", NULL);
287 			if (sizep != NULL)
288 				size = *sizep;
289 			lsizep = of_get_property(np, "d-cache-block-size", NULL);
290 			/* fallback if block size missing */
291 			if (lsizep == NULL)
292 				lsizep = of_get_property(np, "d-cache-line-size", NULL);
293 			if (lsizep != NULL)
294 				lsize = *lsizep;
295 			if (sizep == 0 || lsizep == 0)
296 				DBG("Argh, can't find dcache properties ! "
297 				    "sizep: %p, lsizep: %p\n", sizep, lsizep);
298 
299 			ppc64_caches.dsize = size;
300 			ppc64_caches.dline_size = lsize;
301 			ppc64_caches.log_dline_size = __ilog2(lsize);
302 			ppc64_caches.dlines_per_page = PAGE_SIZE / lsize;
303 
304 			size = 0;
305 			lsize = cur_cpu_spec->icache_bsize;
306 			sizep = of_get_property(np, "i-cache-size", NULL);
307 			if (sizep != NULL)
308 				size = *sizep;
309 			lsizep = of_get_property(np, "i-cache-block-size", NULL);
310 			if (lsizep == NULL)
311 				lsizep = of_get_property(np, "i-cache-line-size", NULL);
312 			if (lsizep != NULL)
313 				lsize = *lsizep;
314 			if (sizep == 0 || lsizep == 0)
315 				DBG("Argh, can't find icache properties ! "
316 				    "sizep: %p, lsizep: %p\n", sizep, lsizep);
317 
318 			ppc64_caches.isize = size;
319 			ppc64_caches.iline_size = lsize;
320 			ppc64_caches.log_iline_size = __ilog2(lsize);
321 			ppc64_caches.ilines_per_page = PAGE_SIZE / lsize;
322 		}
323 	}
324 
325 	DBG(" <- initialize_cache_info()\n");
326 }
327 
328 
329 /*
330  * Do some initial setup of the system.  The parameters are those which
331  * were passed in from the bootloader.
332  */
333 void __init setup_system(void)
334 {
335 	DBG(" -> setup_system()\n");
336 
337 	/* Apply the CPUs-specific and firmware specific fixups to kernel
338 	 * text (nop out sections not relevant to this CPU or this firmware)
339 	 */
340 	do_feature_fixups(cur_cpu_spec->cpu_features,
341 			  &__start___ftr_fixup, &__stop___ftr_fixup);
342 	do_feature_fixups(cur_cpu_spec->mmu_features,
343 			  &__start___mmu_ftr_fixup, &__stop___mmu_ftr_fixup);
344 	do_feature_fixups(powerpc_firmware_features,
345 			  &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
346 	do_lwsync_fixups(cur_cpu_spec->cpu_features,
347 			 &__start___lwsync_fixup, &__stop___lwsync_fixup);
348 
349 	/*
350 	 * Unflatten the device-tree passed by prom_init or kexec
351 	 */
352 	unflatten_device_tree();
353 
354 	/*
355 	 * Fill the ppc64_caches & systemcfg structures with informations
356  	 * retrieved from the device-tree.
357 	 */
358 	initialize_cache_info();
359 
360 	/*
361 	 * Initialize irq remapping subsystem
362 	 */
363 	irq_early_init();
364 
365 #ifdef CONFIG_PPC_RTAS
366 	/*
367 	 * Initialize RTAS if available
368 	 */
369 	rtas_initialize();
370 #endif /* CONFIG_PPC_RTAS */
371 
372 	/*
373 	 * Check if we have an initrd provided via the device-tree
374 	 */
375 	check_for_initrd();
376 
377 	/*
378 	 * Do some platform specific early initializations, that includes
379 	 * setting up the hash table pointers. It also sets up some interrupt-mapping
380 	 * related options that will be used by finish_device_tree()
381 	 */
382 	if (ppc_md.init_early)
383 		ppc_md.init_early();
384 
385  	/*
386 	 * We can discover serial ports now since the above did setup the
387 	 * hash table management for us, thus ioremap works. We do that early
388 	 * so that further code can be debugged
389 	 */
390 	find_legacy_serial_ports();
391 
392 	/*
393 	 * Register early console
394 	 */
395 	register_early_udbg_console();
396 
397 	/*
398 	 * Initialize xmon
399 	 */
400 	xmon_setup();
401 
402 	check_smt_enabled();
403 	smp_setup_cpu_maps();
404 
405 #ifdef CONFIG_SMP
406 	/* Release secondary cpus out of their spinloops at 0x60 now that
407 	 * we can map physical -> logical CPU ids
408 	 */
409 	smp_release_cpus();
410 #endif
411 
412 	printk("Starting Linux PPC64 %s\n", init_utsname()->version);
413 
414 	printk("-----------------------------------------------------\n");
415 	printk("ppc64_pft_size                = 0x%llx\n", ppc64_pft_size);
416 	printk("physicalMemorySize            = 0x%llx\n", lmb_phys_mem_size());
417 	if (ppc64_caches.dline_size != 0x80)
418 		printk("ppc64_caches.dcache_line_size = 0x%x\n",
419 		       ppc64_caches.dline_size);
420 	if (ppc64_caches.iline_size != 0x80)
421 		printk("ppc64_caches.icache_line_size = 0x%x\n",
422 		       ppc64_caches.iline_size);
423 #ifdef CONFIG_PPC_STD_MMU_64
424 	if (htab_address)
425 		printk("htab_address                  = 0x%p\n", htab_address);
426 	printk("htab_hash_mask                = 0x%lx\n", htab_hash_mask);
427 #endif /* CONFIG_PPC_STD_MMU_64 */
428 	if (PHYSICAL_START > 0)
429 		printk("physical_start                = 0x%llx\n",
430 		       (unsigned long long)PHYSICAL_START);
431 	printk("-----------------------------------------------------\n");
432 
433 	DBG(" <- setup_system()\n");
434 }
435 
436 #ifdef CONFIG_IRQSTACKS
437 static void __init irqstack_early_init(void)
438 {
439 	unsigned int i;
440 
441 	/*
442 	 * interrupt stacks must be under 256MB, we cannot afford to take
443 	 * SLB misses on them.
444 	 */
445 	for_each_possible_cpu(i) {
446 		softirq_ctx[i] = (struct thread_info *)
447 			__va(lmb_alloc_base(THREAD_SIZE,
448 					    THREAD_SIZE, 0x10000000));
449 		hardirq_ctx[i] = (struct thread_info *)
450 			__va(lmb_alloc_base(THREAD_SIZE,
451 					    THREAD_SIZE, 0x10000000));
452 	}
453 }
454 #else
455 #define irqstack_early_init()
456 #endif
457 
458 #ifdef CONFIG_PPC_BOOK3E
459 static void __init exc_lvl_early_init(void)
460 {
461 	unsigned int i;
462 
463 	for_each_possible_cpu(i) {
464 		critirq_ctx[i] = (struct thread_info *)
465 			__va(lmb_alloc(THREAD_SIZE, THREAD_SIZE));
466 		dbgirq_ctx[i] = (struct thread_info *)
467 			__va(lmb_alloc(THREAD_SIZE, THREAD_SIZE));
468 		mcheckirq_ctx[i] = (struct thread_info *)
469 			__va(lmb_alloc(THREAD_SIZE, THREAD_SIZE));
470 	}
471 }
472 #else
473 #define exc_lvl_early_init()
474 #endif
475 
476 /*
477  * Stack space used when we detect a bad kernel stack pointer, and
478  * early in SMP boots before relocation is enabled.
479  */
480 static void __init emergency_stack_init(void)
481 {
482 	unsigned long limit;
483 	unsigned int i;
484 
485 	/*
486 	 * Emergency stacks must be under 256MB, we cannot afford to take
487 	 * SLB misses on them. The ABI also requires them to be 128-byte
488 	 * aligned.
489 	 *
490 	 * Since we use these as temporary stacks during secondary CPU
491 	 * bringup, we need to get at them in real mode. This means they
492 	 * must also be within the RMO region.
493 	 */
494 	limit = min(0x10000000ULL, lmb.rmo_size);
495 
496 	for_each_possible_cpu(i) {
497 		unsigned long sp;
498 		sp  = lmb_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
499 		sp += THREAD_SIZE;
500 		paca[i].emergency_sp = __va(sp);
501 	}
502 }
503 
504 /*
505  * Called into from start_kernel, after lock_kernel has been called.
506  * Initializes bootmem, which is unsed to manage page allocation until
507  * mem_init is called.
508  */
509 void __init setup_arch(char **cmdline_p)
510 {
511 	ppc64_boot_msg(0x12, "Setup Arch");
512 
513 	*cmdline_p = cmd_line;
514 
515 	/*
516 	 * Set cache line size based on type of cpu as a default.
517 	 * Systems with OF can look in the properties on the cpu node(s)
518 	 * for a possibly more accurate value.
519 	 */
520 	dcache_bsize = ppc64_caches.dline_size;
521 	icache_bsize = ppc64_caches.iline_size;
522 
523 	/* reboot on panic */
524 	panic_timeout = 180;
525 
526 	if (ppc_md.panic)
527 		setup_panic();
528 
529 	init_mm.start_code = (unsigned long)_stext;
530 	init_mm.end_code = (unsigned long) _etext;
531 	init_mm.end_data = (unsigned long) _edata;
532 	init_mm.brk = klimit;
533 
534 	irqstack_early_init();
535 	exc_lvl_early_init();
536 	emergency_stack_init();
537 
538 #ifdef CONFIG_PPC_STD_MMU_64
539 	stabs_alloc();
540 #endif
541 	/* set up the bootmem stuff with available memory */
542 	do_init_bootmem();
543 	sparse_init();
544 
545 #ifdef CONFIG_DUMMY_CONSOLE
546 	conswitchp = &dummy_con;
547 #endif
548 
549 	if (ppc_md.setup_arch)
550 		ppc_md.setup_arch();
551 
552 #ifdef CONFIG_SWIOTLB
553 	if (ppc_swiotlb_enable)
554 		swiotlb_init();
555 #endif
556 
557 	paging_init();
558 
559 	/* Initialize the MMU context management stuff */
560 	mmu_context_init();
561 
562 	ppc64_boot_msg(0x15, "Setup Done");
563 }
564 
565 
566 /* ToDo: do something useful if ppc_md is not yet setup. */
567 #define PPC64_LINUX_FUNCTION 0x0f000000
568 #define PPC64_IPL_MESSAGE 0xc0000000
569 #define PPC64_TERM_MESSAGE 0xb0000000
570 
571 static void ppc64_do_msg(unsigned int src, const char *msg)
572 {
573 	if (ppc_md.progress) {
574 		char buf[128];
575 
576 		sprintf(buf, "%08X\n", src);
577 		ppc_md.progress(buf, 0);
578 		snprintf(buf, 128, "%s", msg);
579 		ppc_md.progress(buf, 0);
580 	}
581 }
582 
583 /* Print a boot progress message. */
584 void ppc64_boot_msg(unsigned int src, const char *msg)
585 {
586 	ppc64_do_msg(PPC64_LINUX_FUNCTION|PPC64_IPL_MESSAGE|src, msg);
587 	printk("[boot]%04x %s\n", src, msg);
588 }
589 
590 void cpu_die(void)
591 {
592 	if (ppc_md.cpu_die)
593 		ppc_md.cpu_die();
594 }
595 
596 #ifdef CONFIG_SMP
597 #define PCPU_DYN_SIZE		()
598 
599 static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
600 {
601 	return __alloc_bootmem_node(NODE_DATA(cpu_to_node(cpu)), size, align,
602 				    __pa(MAX_DMA_ADDRESS));
603 }
604 
605 static void __init pcpu_fc_free(void *ptr, size_t size)
606 {
607 	free_bootmem(__pa(ptr), size);
608 }
609 
610 static int pcpu_cpu_distance(unsigned int from, unsigned int to)
611 {
612 	if (cpu_to_node(from) == cpu_to_node(to))
613 		return LOCAL_DISTANCE;
614 	else
615 		return REMOTE_DISTANCE;
616 }
617 
618 void __init setup_per_cpu_areas(void)
619 {
620 	const size_t dyn_size = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
621 	size_t atom_size;
622 	unsigned long delta;
623 	unsigned int cpu;
624 	int rc;
625 
626 	/*
627 	 * Linear mapping is one of 4K, 1M and 16M.  For 4K, no need
628 	 * to group units.  For larger mappings, use 1M atom which
629 	 * should be large enough to contain a number of units.
630 	 */
631 	if (mmu_linear_psize == MMU_PAGE_4K)
632 		atom_size = PAGE_SIZE;
633 	else
634 		atom_size = 1 << 20;
635 
636 	rc = pcpu_embed_first_chunk(0, dyn_size, atom_size, pcpu_cpu_distance,
637 				    pcpu_fc_alloc, pcpu_fc_free);
638 	if (rc < 0)
639 		panic("cannot initialize percpu area (err=%d)", rc);
640 
641 	delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
642 	for_each_possible_cpu(cpu)
643 		paca[cpu].data_offset = delta + pcpu_unit_offsets[cpu];
644 }
645 #endif
646 
647 
648 #ifdef CONFIG_PPC_INDIRECT_IO
649 struct ppc_pci_io ppc_pci_io;
650 EXPORT_SYMBOL(ppc_pci_io);
651 #endif /* CONFIG_PPC_INDIRECT_IO */
652 
653