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>
66 #include <asm/kvm_ppc.h>
71 #define DBG(fmt...) udbg_printf(fmt)
77 int __initdata spinning_secondaries;
80 /* Pick defaults since we might want to patch instructions
81 * before we've read this from the device tree.
83 struct ppc64_caches ppc64_caches = {
89 EXPORT_SYMBOL_GPL(ppc64_caches);
92 * These are used in binfmt_elf.c to put aux entries on the stack
93 * for each elf executable being started.
101 static char *smt_enabled_cmdline;
103 /* Look for ibm,smt-enabled OF option */
104 static void check_smt_enabled(void)
106 struct device_node *dn;
107 const char *smt_option;
109 /* Default to enabling all threads */
110 smt_enabled_at_boot = threads_per_core;
112 /* Allow the command line to overrule the OF option */
113 if (smt_enabled_cmdline) {
114 if (!strcmp(smt_enabled_cmdline, "on"))
115 smt_enabled_at_boot = threads_per_core;
116 else if (!strcmp(smt_enabled_cmdline, "off"))
117 smt_enabled_at_boot = 0;
122 rc = strict_strtol(smt_enabled_cmdline, 10, &smt);
124 smt_enabled_at_boot =
125 min(threads_per_core, (int)smt);
128 dn = of_find_node_by_path("/options");
130 smt_option = of_get_property(dn, "ibm,smt-enabled",
134 if (!strcmp(smt_option, "on"))
135 smt_enabled_at_boot = threads_per_core;
136 else if (!strcmp(smt_option, "off"))
137 smt_enabled_at_boot = 0;
145 /* Look for smt-enabled= cmdline option */
146 static int __init early_smt_enabled(char *p)
148 smt_enabled_cmdline = p;
151 early_param("smt-enabled", early_smt_enabled);
154 #define check_smt_enabled()
155 #endif /* CONFIG_SMP */
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 MEMBLOCK
164 * data structures, and allocate & initialize the hash table
165 * and segment tables so we can start running with translation
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.
176 void __init early_setup(unsigned long dt_ptr)
178 /* -------- printk is _NOT_ safe to use here ! ------- */
180 /* Identify CPU type */
181 identify_cpu(0, mfspr(SPRN_PVR));
183 /* Assume we're on cpu 0 for now. Don't write to the paca yet! */
184 initialise_paca(&boot_paca, 0);
185 setup_paca(&boot_paca);
187 /* Initialize lockdep early or else spinlocks will blow */
190 /* -------- printk is now safe to use ------- */
192 /* Enable early debugging if any specified (see udbg.h) */
195 DBG(" -> early_setup(), dt_ptr: 0x%lx\n", dt_ptr);
198 * Do early initialization using the flattened device
199 * tree, such as retrieving the physical memory map or
200 * calculating/retrieving the hash table size.
202 early_init_devtree(__va(dt_ptr));
204 /* Now we know the logical id of our boot cpu, setup the paca. */
205 setup_paca(&paca[boot_cpuid]);
207 /* Fix up paca fields required for the boot cpu */
208 get_paca()->cpu_start = 1;
210 /* Probe the machine type */
213 setup_kdump_trampoline();
215 DBG("Found, Initializing memory management...\n");
217 /* Initialize the hash table or TLB handling */
220 DBG(" <- early_setup()\n");
224 void early_setup_secondary(void)
226 /* Mark interrupts enabled in PACA */
227 get_paca()->soft_enabled = 0;
229 /* Initialize the hash table or TLB handling */
230 early_init_mmu_secondary();
233 #endif /* CONFIG_SMP */
235 #if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
236 void smp_release_cpus(void)
241 DBG(" -> smp_release_cpus()\n");
243 /* All secondary cpus are spinning on a common spinloop, release them
244 * all now so they can start to spin on their individual paca
245 * spinloops. For non SMP kernels, the secondary cpus never get out
246 * of the common spinloop.
249 ptr = (unsigned long *)((unsigned long)&__secondary_hold_spinloop
251 *ptr = __pa(generic_secondary_smp_init);
253 /* And wait a bit for them to catch up */
254 for (i = 0; i < 100000; i++) {
257 if (spinning_secondaries == 0)
261 DBG("spinning_secondaries = %d\n", spinning_secondaries);
263 DBG(" <- smp_release_cpus()\n");
265 #endif /* CONFIG_SMP || CONFIG_KEXEC */
268 * Initialize some remaining members of the ppc64_caches and systemcfg
270 * (at least until we get rid of them completely). This is mostly some
271 * cache informations about the CPU that will be used by cache flush
272 * routines and/or provided to userland
274 static void __init initialize_cache_info(void)
276 struct device_node *np;
277 unsigned long num_cpus = 0;
279 DBG(" -> initialize_cache_info()\n");
281 for (np = NULL; (np = of_find_node_by_type(np, "cpu"));) {
284 /* We're assuming *all* of the CPUs have the same
285 * d-cache and i-cache sizes... -Peter
288 if ( num_cpus == 1 ) {
289 const u32 *sizep, *lsizep;
293 lsize = cur_cpu_spec->dcache_bsize;
294 sizep = of_get_property(np, "d-cache-size", NULL);
297 lsizep = of_get_property(np, "d-cache-block-size", NULL);
298 /* fallback if block size missing */
300 lsizep = of_get_property(np, "d-cache-line-size", NULL);
303 if (sizep == 0 || lsizep == 0)
304 DBG("Argh, can't find dcache properties ! "
305 "sizep: %p, lsizep: %p\n", sizep, lsizep);
307 ppc64_caches.dsize = size;
308 ppc64_caches.dline_size = lsize;
309 ppc64_caches.log_dline_size = __ilog2(lsize);
310 ppc64_caches.dlines_per_page = PAGE_SIZE / lsize;
313 lsize = cur_cpu_spec->icache_bsize;
314 sizep = of_get_property(np, "i-cache-size", NULL);
317 lsizep = of_get_property(np, "i-cache-block-size", NULL);
319 lsizep = of_get_property(np, "i-cache-line-size", NULL);
322 if (sizep == 0 || lsizep == 0)
323 DBG("Argh, can't find icache properties ! "
324 "sizep: %p, lsizep: %p\n", sizep, lsizep);
326 ppc64_caches.isize = size;
327 ppc64_caches.iline_size = lsize;
328 ppc64_caches.log_iline_size = __ilog2(lsize);
329 ppc64_caches.ilines_per_page = PAGE_SIZE / lsize;
333 DBG(" <- initialize_cache_info()\n");
338 * Do some initial setup of the system. The parameters are those which
339 * were passed in from the bootloader.
341 void __init setup_system(void)
343 DBG(" -> setup_system()\n");
345 /* Apply the CPUs-specific and firmware specific fixups to kernel
346 * text (nop out sections not relevant to this CPU or this firmware)
348 do_feature_fixups(cur_cpu_spec->cpu_features,
349 &__start___ftr_fixup, &__stop___ftr_fixup);
350 do_feature_fixups(cur_cpu_spec->mmu_features,
351 &__start___mmu_ftr_fixup, &__stop___mmu_ftr_fixup);
352 do_feature_fixups(powerpc_firmware_features,
353 &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
354 do_lwsync_fixups(cur_cpu_spec->cpu_features,
355 &__start___lwsync_fixup, &__stop___lwsync_fixup);
358 * Unflatten the device-tree passed by prom_init or kexec
360 unflatten_device_tree();
363 * Fill the ppc64_caches & systemcfg structures with informations
364 * retrieved from the device-tree.
366 initialize_cache_info();
368 #ifdef CONFIG_PPC_RTAS
370 * Initialize RTAS if available
373 #endif /* CONFIG_PPC_RTAS */
376 * Check if we have an initrd provided via the device-tree
381 * Do some platform specific early initializations, that includes
382 * setting up the hash table pointers. It also sets up some interrupt-mapping
383 * related options that will be used by finish_device_tree()
385 if (ppc_md.init_early)
389 * We can discover serial ports now since the above did setup the
390 * hash table management for us, thus ioremap works. We do that early
391 * so that further code can be debugged
393 find_legacy_serial_ports();
396 * Register early console
398 register_early_udbg_console();
405 smp_setup_cpu_maps();
409 /* Release secondary cpus out of their spinloops at 0x60 now that
410 * we can map physical -> logical CPU ids
415 printk("Starting Linux PPC64 %s\n", init_utsname()->version);
417 printk("-----------------------------------------------------\n");
418 printk("ppc64_pft_size = 0x%llx\n", ppc64_pft_size);
419 printk("physicalMemorySize = 0x%llx\n", memblock_phys_mem_size());
420 if (ppc64_caches.dline_size != 0x80)
421 printk("ppc64_caches.dcache_line_size = 0x%x\n",
422 ppc64_caches.dline_size);
423 if (ppc64_caches.iline_size != 0x80)
424 printk("ppc64_caches.icache_line_size = 0x%x\n",
425 ppc64_caches.iline_size);
426 #ifdef CONFIG_PPC_STD_MMU_64
428 printk("htab_address = 0x%p\n", htab_address);
429 printk("htab_hash_mask = 0x%lx\n", htab_hash_mask);
430 #endif /* CONFIG_PPC_STD_MMU_64 */
431 if (PHYSICAL_START > 0)
432 printk("physical_start = 0x%llx\n",
433 (unsigned long long)PHYSICAL_START);
434 printk("-----------------------------------------------------\n");
436 DBG(" <- setup_system()\n");
439 /* This returns the limit below which memory accesses to the linear
440 * mapping are guarnateed not to cause a TLB or SLB miss. This is
441 * used to allocate interrupt or emergency stacks for which our
442 * exception entry path doesn't deal with being interrupted.
444 static u64 safe_stack_limit(void)
446 #ifdef CONFIG_PPC_BOOK3E
447 /* Freescale BookE bolts the entire linear mapping */
448 if (mmu_has_feature(MMU_FTR_TYPE_FSL_E))
449 return linear_map_top;
450 /* Other BookE, we assume the first GB is bolted */
453 /* BookS, the first segment is bolted */
454 if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
455 return 1UL << SID_SHIFT_1T;
456 return 1UL << SID_SHIFT;
460 static void __init irqstack_early_init(void)
462 u64 limit = safe_stack_limit();
466 * Interrupt stacks must be in the first segment since we
467 * cannot afford to take SLB misses on them.
469 for_each_possible_cpu(i) {
470 softirq_ctx[i] = (struct thread_info *)
471 __va(memblock_alloc_base(THREAD_SIZE,
472 THREAD_SIZE, limit));
473 hardirq_ctx[i] = (struct thread_info *)
474 __va(memblock_alloc_base(THREAD_SIZE,
475 THREAD_SIZE, limit));
479 #ifdef CONFIG_PPC_BOOK3E
480 static void __init exc_lvl_early_init(void)
482 extern unsigned int interrupt_base_book3e;
483 extern unsigned int exc_debug_debug_book3e;
487 for_each_possible_cpu(i) {
488 critirq_ctx[i] = (struct thread_info *)
489 __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
490 dbgirq_ctx[i] = (struct thread_info *)
491 __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
492 mcheckirq_ctx[i] = (struct thread_info *)
493 __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
496 if (cpu_has_feature(CPU_FTR_DEBUG_LVL_EXC))
497 patch_branch(&interrupt_base_book3e + (0x040 / 4) + 1,
498 (unsigned long)&exc_debug_debug_book3e, 0);
501 #define exc_lvl_early_init()
505 * Stack space used when we detect a bad kernel stack pointer, and
506 * early in SMP boots before relocation is enabled.
508 static void __init emergency_stack_init(void)
514 * Emergency stacks must be under 256MB, we cannot afford to take
515 * SLB misses on them. The ABI also requires them to be 128-byte
518 * Since we use these as temporary stacks during secondary CPU
519 * bringup, we need to get at them in real mode. This means they
520 * must also be within the RMO region.
522 limit = min(safe_stack_limit(), ppc64_rma_size);
524 for_each_possible_cpu(i) {
526 sp = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
528 paca[i].emergency_sp = __va(sp);
533 * Called into from start_kernel this initializes bootmem, which is used
534 * to manage page allocation until mem_init is called.
536 void __init setup_arch(char **cmdline_p)
538 ppc64_boot_msg(0x12, "Setup Arch");
540 *cmdline_p = cmd_line;
543 * Set cache line size based on type of cpu as a default.
544 * Systems with OF can look in the properties on the cpu node(s)
545 * for a possibly more accurate value.
547 dcache_bsize = ppc64_caches.dline_size;
548 icache_bsize = ppc64_caches.iline_size;
550 /* reboot on panic */
556 init_mm.start_code = (unsigned long)_stext;
557 init_mm.end_code = (unsigned long) _etext;
558 init_mm.end_data = (unsigned long) _edata;
559 init_mm.brk = klimit;
561 irqstack_early_init();
562 exc_lvl_early_init();
563 emergency_stack_init();
565 #ifdef CONFIG_PPC_STD_MMU_64
568 /* set up the bootmem stuff with available memory */
572 #ifdef CONFIG_DUMMY_CONSOLE
573 conswitchp = &dummy_con;
576 if (ppc_md.setup_arch)
581 /* Initialize the MMU context management stuff */
586 ppc64_boot_msg(0x15, "Setup Done");
590 /* ToDo: do something useful if ppc_md is not yet setup. */
591 #define PPC64_LINUX_FUNCTION 0x0f000000
592 #define PPC64_IPL_MESSAGE 0xc0000000
593 #define PPC64_TERM_MESSAGE 0xb0000000
595 static void ppc64_do_msg(unsigned int src, const char *msg)
597 if (ppc_md.progress) {
600 sprintf(buf, "%08X\n", src);
601 ppc_md.progress(buf, 0);
602 snprintf(buf, 128, "%s", msg);
603 ppc_md.progress(buf, 0);
607 /* Print a boot progress message. */
608 void ppc64_boot_msg(unsigned int src, const char *msg)
610 ppc64_do_msg(PPC64_LINUX_FUNCTION|PPC64_IPL_MESSAGE|src, msg);
611 printk("[boot]%04x %s\n", src, msg);
615 #define PCPU_DYN_SIZE ()
617 static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
619 return __alloc_bootmem_node(NODE_DATA(cpu_to_node(cpu)), size, align,
620 __pa(MAX_DMA_ADDRESS));
623 static void __init pcpu_fc_free(void *ptr, size_t size)
625 free_bootmem(__pa(ptr), size);
628 static int pcpu_cpu_distance(unsigned int from, unsigned int to)
630 if (cpu_to_node(from) == cpu_to_node(to))
631 return LOCAL_DISTANCE;
633 return REMOTE_DISTANCE;
636 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
637 EXPORT_SYMBOL(__per_cpu_offset);
639 void __init setup_per_cpu_areas(void)
641 const size_t dyn_size = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
648 * Linear mapping is one of 4K, 1M and 16M. For 4K, no need
649 * to group units. For larger mappings, use 1M atom which
650 * should be large enough to contain a number of units.
652 if (mmu_linear_psize == MMU_PAGE_4K)
653 atom_size = PAGE_SIZE;
657 rc = pcpu_embed_first_chunk(0, dyn_size, atom_size, pcpu_cpu_distance,
658 pcpu_fc_alloc, pcpu_fc_free);
660 panic("cannot initialize percpu area (err=%d)", rc);
662 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
663 for_each_possible_cpu(cpu) {
664 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
665 paca[cpu].data_offset = __per_cpu_offset[cpu];
671 #ifdef CONFIG_PPC_INDIRECT_IO
672 struct ppc_pci_io ppc_pci_io;
673 EXPORT_SYMBOL(ppc_pci_io);
674 #endif /* CONFIG_PPC_INDIRECT_IO */