3 * Common boot and setup code.
5 * Copyright (C) 2001 PPC64 Team, IBM Corp
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.
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/memblock.h>
39 #include <asm/kdump.h>
41 #include <asm/processor.h>
42 #include <asm/pgtable.h>
45 #include <asm/machdep.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>
55 #include <asm/iommu.h>
56 #include <asm/serial.h>
57 #include <asm/cache.h>
60 #include <asm/firmware.h>
63 #include <asm/kexec.h>
64 #include <asm/mmu_context.h>
65 #include <asm/code-patching.h>
70 #define DBG(fmt...) udbg_printf(fmt)
76 int __initdata boot_cpu_count;
79 /* Pick defaults since we might want to patch instructions
80 * before we've read this from the device tree.
82 struct ppc64_caches ppc64_caches = {
88 EXPORT_SYMBOL_GPL(ppc64_caches);
91 * These are used in binfmt_elf.c to put aux entries on the stack
92 * for each elf executable being started.
100 static char *smt_enabled_cmdline;
102 /* Look for ibm,smt-enabled OF option */
103 static void check_smt_enabled(void)
105 struct device_node *dn;
106 const char *smt_option;
108 /* Default to enabling all threads */
109 smt_enabled_at_boot = threads_per_core;
111 /* Allow the command line to overrule the OF option */
112 if (smt_enabled_cmdline) {
113 if (!strcmp(smt_enabled_cmdline, "on"))
114 smt_enabled_at_boot = threads_per_core;
115 else if (!strcmp(smt_enabled_cmdline, "off"))
116 smt_enabled_at_boot = 0;
121 rc = strict_strtol(smt_enabled_cmdline, 10, &smt);
123 smt_enabled_at_boot =
124 min(threads_per_core, (int)smt);
127 dn = of_find_node_by_path("/options");
129 smt_option = of_get_property(dn, "ibm,smt-enabled",
133 if (!strcmp(smt_option, "on"))
134 smt_enabled_at_boot = threads_per_core;
135 else if (!strcmp(smt_option, "off"))
136 smt_enabled_at_boot = 0;
144 /* Look for smt-enabled= cmdline option */
145 static int __init early_smt_enabled(char *p)
147 smt_enabled_cmdline = p;
150 early_param("smt-enabled", early_smt_enabled);
153 #define check_smt_enabled()
154 #endif /* CONFIG_SMP */
157 * Early initialization entry point. This is called by head.S
158 * with MMU translation disabled. We rely on the "feature" of
159 * the CPU that ignores the top 2 bits of the address in real
160 * mode so we can access kernel globals normally provided we
161 * only toy with things in the RMO region. From here, we do
162 * some early parsing of the device-tree to setup out MEMBLOCK
163 * data structures, and allocate & initialize the hash table
164 * and segment tables so we can start running with translation
167 * It is this function which will call the probe() callback of
168 * the various platform types and copy the matching one to the
169 * global ppc_md structure. Your platform can eventually do
170 * some very early initializations from the probe() routine, but
171 * this is not recommended, be very careful as, for example, the
172 * device-tree is not accessible via normal means at this point.
175 void __init early_setup(unsigned long dt_ptr)
177 /* -------- printk is _NOT_ safe to use here ! ------- */
179 /* Identify CPU type */
180 identify_cpu(0, mfspr(SPRN_PVR));
182 /* Assume we're on cpu 0 for now. Don't write to the paca yet! */
183 initialise_paca(&boot_paca, 0);
184 setup_paca(&boot_paca);
186 /* Initialize lockdep early or else spinlocks will blow */
189 /* -------- printk is now safe to use ------- */
191 /* Enable early debugging if any specified (see udbg.h) */
194 DBG(" -> early_setup(), dt_ptr: 0x%lx\n", dt_ptr);
197 * Do early initialization using the flattened device
198 * tree, such as retrieving the physical memory map or
199 * calculating/retrieving the hash table size.
201 early_init_devtree(__va(dt_ptr));
203 /* Now we know the logical id of our boot cpu, setup the paca. */
204 setup_paca(&paca[boot_cpuid]);
206 /* Fix up paca fields required for the boot cpu */
207 get_paca()->cpu_start = 1;
209 /* Probe the machine type */
212 setup_kdump_trampoline();
214 DBG("Found, Initializing memory management...\n");
216 /* Initialize the hash table or TLB handling */
219 DBG(" <- early_setup()\n");
223 void early_setup_secondary(void)
225 /* Mark interrupts enabled in PACA */
226 get_paca()->soft_enabled = 0;
228 /* Initialize the hash table or TLB handling */
229 early_init_mmu_secondary();
232 #endif /* CONFIG_SMP */
234 #if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
235 void smp_release_cpus(void)
240 DBG(" -> smp_release_cpus()\n");
242 /* All secondary cpus are spinning on a common spinloop, release them
243 * all now so they can start to spin on their individual paca
244 * spinloops. For non SMP kernels, the secondary cpus never get out
245 * of the common spinloop.
248 ptr = (unsigned long *)((unsigned long)&__secondary_hold_spinloop
250 *ptr = __pa(generic_secondary_smp_init);
252 /* And wait a bit for them to catch up */
253 for (i = 0; i < 100000; i++) {
256 if (boot_cpu_count == 0)
260 DBG("boot_cpu_count = %d\n", boot_cpu_count);
262 DBG(" <- smp_release_cpus()\n");
264 #endif /* CONFIG_SMP || CONFIG_KEXEC */
267 * Initialize some remaining members of the ppc64_caches and systemcfg
269 * (at least until we get rid of them completely). This is mostly some
270 * cache informations about the CPU that will be used by cache flush
271 * routines and/or provided to userland
273 static void __init initialize_cache_info(void)
275 struct device_node *np;
276 unsigned long num_cpus = 0;
278 DBG(" -> initialize_cache_info()\n");
280 for (np = NULL; (np = of_find_node_by_type(np, "cpu"));) {
283 /* We're assuming *all* of the CPUs have the same
284 * d-cache and i-cache sizes... -Peter
287 if ( num_cpus == 1 ) {
288 const u32 *sizep, *lsizep;
292 lsize = cur_cpu_spec->dcache_bsize;
293 sizep = of_get_property(np, "d-cache-size", NULL);
296 lsizep = of_get_property(np, "d-cache-block-size", NULL);
297 /* fallback if block size missing */
299 lsizep = of_get_property(np, "d-cache-line-size", NULL);
302 if (sizep == 0 || lsizep == 0)
303 DBG("Argh, can't find dcache properties ! "
304 "sizep: %p, lsizep: %p\n", sizep, lsizep);
306 ppc64_caches.dsize = size;
307 ppc64_caches.dline_size = lsize;
308 ppc64_caches.log_dline_size = __ilog2(lsize);
309 ppc64_caches.dlines_per_page = PAGE_SIZE / lsize;
312 lsize = cur_cpu_spec->icache_bsize;
313 sizep = of_get_property(np, "i-cache-size", NULL);
316 lsizep = of_get_property(np, "i-cache-block-size", NULL);
318 lsizep = of_get_property(np, "i-cache-line-size", NULL);
321 if (sizep == 0 || lsizep == 0)
322 DBG("Argh, can't find icache properties ! "
323 "sizep: %p, lsizep: %p\n", sizep, lsizep);
325 ppc64_caches.isize = size;
326 ppc64_caches.iline_size = lsize;
327 ppc64_caches.log_iline_size = __ilog2(lsize);
328 ppc64_caches.ilines_per_page = PAGE_SIZE / lsize;
332 DBG(" <- initialize_cache_info()\n");
337 * Do some initial setup of the system. The parameters are those which
338 * were passed in from the bootloader.
340 void __init setup_system(void)
342 DBG(" -> setup_system()\n");
344 /* Apply the CPUs-specific and firmware specific fixups to kernel
345 * text (nop out sections not relevant to this CPU or this firmware)
347 do_feature_fixups(cur_cpu_spec->cpu_features,
348 &__start___ftr_fixup, &__stop___ftr_fixup);
349 do_feature_fixups(cur_cpu_spec->mmu_features,
350 &__start___mmu_ftr_fixup, &__stop___mmu_ftr_fixup);
351 do_feature_fixups(powerpc_firmware_features,
352 &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
353 do_lwsync_fixups(cur_cpu_spec->cpu_features,
354 &__start___lwsync_fixup, &__stop___lwsync_fixup);
357 * Unflatten the device-tree passed by prom_init or kexec
359 unflatten_device_tree();
362 * Fill the ppc64_caches & systemcfg structures with informations
363 * retrieved from the device-tree.
365 initialize_cache_info();
367 #ifdef CONFIG_PPC_RTAS
369 * Initialize RTAS if available
372 #endif /* CONFIG_PPC_RTAS */
375 * Check if we have an initrd provided via the device-tree
380 * Do some platform specific early initializations, that includes
381 * setting up the hash table pointers. It also sets up some interrupt-mapping
382 * related options that will be used by finish_device_tree()
384 if (ppc_md.init_early)
388 * We can discover serial ports now since the above did setup the
389 * hash table management for us, thus ioremap works. We do that early
390 * so that further code can be debugged
392 find_legacy_serial_ports();
395 * Register early console
397 register_early_udbg_console();
404 smp_setup_cpu_maps();
408 /* Release secondary cpus out of their spinloops at 0x60 now that
409 * we can map physical -> logical CPU ids
414 printk("Starting Linux PPC64 %s\n", init_utsname()->version);
416 printk("-----------------------------------------------------\n");
417 printk("ppc64_pft_size = 0x%llx\n", ppc64_pft_size);
418 printk("physicalMemorySize = 0x%llx\n", memblock_phys_mem_size());
419 if (ppc64_caches.dline_size != 0x80)
420 printk("ppc64_caches.dcache_line_size = 0x%x\n",
421 ppc64_caches.dline_size);
422 if (ppc64_caches.iline_size != 0x80)
423 printk("ppc64_caches.icache_line_size = 0x%x\n",
424 ppc64_caches.iline_size);
425 #ifdef CONFIG_PPC_STD_MMU_64
427 printk("htab_address = 0x%p\n", htab_address);
428 printk("htab_hash_mask = 0x%lx\n", htab_hash_mask);
429 #endif /* CONFIG_PPC_STD_MMU_64 */
430 if (PHYSICAL_START > 0)
431 printk("physical_start = 0x%llx\n",
432 (unsigned long long)PHYSICAL_START);
433 printk("-----------------------------------------------------\n");
435 DBG(" <- setup_system()\n");
438 /* This returns the limit below which memory accesses to the linear
439 * mapping are guarnateed not to cause a TLB or SLB miss. This is
440 * used to allocate interrupt or emergency stacks for which our
441 * exception entry path doesn't deal with being interrupted.
443 static u64 safe_stack_limit(void)
445 #ifdef CONFIG_PPC_BOOK3E
446 /* Freescale BookE bolts the entire linear mapping */
447 if (mmu_has_feature(MMU_FTR_TYPE_FSL_E))
448 return linear_map_top;
449 /* Other BookE, we assume the first GB is bolted */
452 /* BookS, the first segment is bolted */
453 if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
454 return 1UL << SID_SHIFT_1T;
455 return 1UL << SID_SHIFT;
459 static void __init irqstack_early_init(void)
461 u64 limit = safe_stack_limit();
465 * Interrupt stacks must be in the first segment since we
466 * cannot afford to take SLB misses on them.
468 for_each_possible_cpu(i) {
469 softirq_ctx[i] = (struct thread_info *)
470 __va(memblock_alloc_base(THREAD_SIZE,
471 THREAD_SIZE, limit));
472 hardirq_ctx[i] = (struct thread_info *)
473 __va(memblock_alloc_base(THREAD_SIZE,
474 THREAD_SIZE, limit));
478 #ifdef CONFIG_PPC_BOOK3E
479 static void __init exc_lvl_early_init(void)
481 extern unsigned int interrupt_base_book3e;
482 extern unsigned int exc_debug_debug_book3e;
486 for_each_possible_cpu(i) {
487 critirq_ctx[i] = (struct thread_info *)
488 __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
489 dbgirq_ctx[i] = (struct thread_info *)
490 __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
491 mcheckirq_ctx[i] = (struct thread_info *)
492 __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
495 if (cpu_has_feature(CPU_FTR_DEBUG_LVL_EXC))
496 patch_branch(&interrupt_base_book3e + (0x040 / 4) + 1,
497 (unsigned long)&exc_debug_debug_book3e, 0);
500 #define exc_lvl_early_init()
504 * Stack space used when we detect a bad kernel stack pointer, and
505 * early in SMP boots before relocation is enabled.
507 static void __init emergency_stack_init(void)
513 * Emergency stacks must be under 256MB, we cannot afford to take
514 * SLB misses on them. The ABI also requires them to be 128-byte
517 * Since we use these as temporary stacks during secondary CPU
518 * bringup, we need to get at them in real mode. This means they
519 * must also be within the RMO region.
521 limit = min(safe_stack_limit(), ppc64_rma_size);
523 for_each_possible_cpu(i) {
525 sp = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
527 paca[i].emergency_sp = __va(sp);
532 * Called into from start_kernel this initializes bootmem, which is used
533 * to manage page allocation until mem_init is called.
535 void __init setup_arch(char **cmdline_p)
537 ppc64_boot_msg(0x12, "Setup Arch");
539 *cmdline_p = cmd_line;
542 * Set cache line size based on type of cpu as a default.
543 * Systems with OF can look in the properties on the cpu node(s)
544 * for a possibly more accurate value.
546 dcache_bsize = ppc64_caches.dline_size;
547 icache_bsize = ppc64_caches.iline_size;
549 /* reboot on panic */
555 init_mm.start_code = (unsigned long)_stext;
556 init_mm.end_code = (unsigned long) _etext;
557 init_mm.end_data = (unsigned long) _edata;
558 init_mm.brk = klimit;
560 irqstack_early_init();
561 exc_lvl_early_init();
562 emergency_stack_init();
564 #ifdef CONFIG_PPC_STD_MMU_64
567 /* set up the bootmem stuff with available memory */
571 #ifdef CONFIG_DUMMY_CONSOLE
572 conswitchp = &dummy_con;
575 if (ppc_md.setup_arch)
580 /* Initialize the MMU context management stuff */
583 ppc64_boot_msg(0x15, "Setup Done");
587 /* ToDo: do something useful if ppc_md is not yet setup. */
588 #define PPC64_LINUX_FUNCTION 0x0f000000
589 #define PPC64_IPL_MESSAGE 0xc0000000
590 #define PPC64_TERM_MESSAGE 0xb0000000
592 static void ppc64_do_msg(unsigned int src, const char *msg)
594 if (ppc_md.progress) {
597 sprintf(buf, "%08X\n", src);
598 ppc_md.progress(buf, 0);
599 snprintf(buf, 128, "%s", msg);
600 ppc_md.progress(buf, 0);
604 /* Print a boot progress message. */
605 void ppc64_boot_msg(unsigned int src, const char *msg)
607 ppc64_do_msg(PPC64_LINUX_FUNCTION|PPC64_IPL_MESSAGE|src, msg);
608 printk("[boot]%04x %s\n", src, msg);
612 #define PCPU_DYN_SIZE ()
614 static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
616 return __alloc_bootmem_node(NODE_DATA(cpu_to_node(cpu)), size, align,
617 __pa(MAX_DMA_ADDRESS));
620 static void __init pcpu_fc_free(void *ptr, size_t size)
622 free_bootmem(__pa(ptr), size);
625 static int pcpu_cpu_distance(unsigned int from, unsigned int to)
627 if (cpu_to_node(from) == cpu_to_node(to))
628 return LOCAL_DISTANCE;
630 return REMOTE_DISTANCE;
633 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
634 EXPORT_SYMBOL(__per_cpu_offset);
636 void __init setup_per_cpu_areas(void)
638 const size_t dyn_size = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
645 * Linear mapping is one of 4K, 1M and 16M. For 4K, no need
646 * to group units. For larger mappings, use 1M atom which
647 * should be large enough to contain a number of units.
649 if (mmu_linear_psize == MMU_PAGE_4K)
650 atom_size = PAGE_SIZE;
654 rc = pcpu_embed_first_chunk(0, dyn_size, atom_size, pcpu_cpu_distance,
655 pcpu_fc_alloc, pcpu_fc_free);
657 panic("cannot initialize percpu area (err=%d)", rc);
659 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
660 for_each_possible_cpu(cpu) {
661 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
662 paca[cpu].data_offset = __per_cpu_offset[cpu];
668 #ifdef CONFIG_PPC_INDIRECT_IO
669 struct ppc_pci_io ppc_pci_io;
670 EXPORT_SYMBOL(ppc_pci_io);
671 #endif /* CONFIG_PPC_INDIRECT_IO */