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/export.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>
38 #include <linux/hugetlb.h>
39 #include <linux/memory.h>
42 #include <asm/kdump.h>
44 #include <asm/processor.h>
45 #include <asm/pgtable.h>
48 #include <asm/machdep.h>
51 #include <asm/cputable.h>
52 #include <asm/sections.h>
53 #include <asm/btext.h>
54 #include <asm/nvram.h>
55 #include <asm/setup.h>
57 #include <asm/iommu.h>
58 #include <asm/serial.h>
59 #include <asm/cache.h>
62 #include <asm/firmware.h>
65 #include <asm/kexec.h>
66 #include <asm/mmu_context.h>
67 #include <asm/code-patching.h>
68 #include <asm/kvm_ppc.h>
69 #include <asm/hugetlb.h>
70 #include <asm/epapr_hcalls.h>
73 #define DBG(fmt...) udbg_printf(fmt)
78 int spinning_secondaries;
81 /* Pick defaults since we might want to patch instructions
82 * before we've read this from the device tree.
84 struct ppc64_caches ppc64_caches = {
90 EXPORT_SYMBOL_GPL(ppc64_caches);
93 * These are used in binfmt_elf.c to put aux entries on the stack
94 * for each elf executable being started.
100 #if defined(CONFIG_PPC_BOOK3E) && defined(CONFIG_SMP)
101 static void setup_tlb_core_data(void)
105 BUILD_BUG_ON(offsetof(struct tlb_core_data, lock) != 0);
107 for_each_possible_cpu(cpu) {
108 int first = cpu_first_thread_sibling(cpu);
110 paca[cpu].tcd_ptr = &paca[first].tcd;
113 * If we have threads, we need either tlbsrx.
114 * or e6500 tablewalk mode, or else TLB handlers
115 * will be racy and could produce duplicate entries.
117 if (smt_enabled_at_boot >= 2 &&
118 !mmu_has_feature(MMU_FTR_USE_TLBRSRV) &&
119 book3e_htw_mode != PPC_HTW_E6500) {
120 /* Should we panic instead? */
121 WARN_ONCE("%s: unsupported MMU configuration -- expect problems\n",
127 static void setup_tlb_core_data(void)
134 static char *smt_enabled_cmdline;
136 /* Look for ibm,smt-enabled OF option */
137 static void check_smt_enabled(void)
139 struct device_node *dn;
140 const char *smt_option;
142 /* Default to enabling all threads */
143 smt_enabled_at_boot = threads_per_core;
145 /* Allow the command line to overrule the OF option */
146 if (smt_enabled_cmdline) {
147 if (!strcmp(smt_enabled_cmdline, "on"))
148 smt_enabled_at_boot = threads_per_core;
149 else if (!strcmp(smt_enabled_cmdline, "off"))
150 smt_enabled_at_boot = 0;
155 rc = strict_strtol(smt_enabled_cmdline, 10, &smt);
157 smt_enabled_at_boot =
158 min(threads_per_core, (int)smt);
161 dn = of_find_node_by_path("/options");
163 smt_option = of_get_property(dn, "ibm,smt-enabled",
167 if (!strcmp(smt_option, "on"))
168 smt_enabled_at_boot = threads_per_core;
169 else if (!strcmp(smt_option, "off"))
170 smt_enabled_at_boot = 0;
178 /* Look for smt-enabled= cmdline option */
179 static int __init early_smt_enabled(char *p)
181 smt_enabled_cmdline = p;
184 early_param("smt-enabled", early_smt_enabled);
187 #define check_smt_enabled()
188 #endif /* CONFIG_SMP */
190 /** Fix up paca fields required for the boot cpu */
191 static void fixup_boot_paca(void)
193 /* The boot cpu is started */
194 get_paca()->cpu_start = 1;
195 /* Allow percpu accesses to work until we setup percpu data */
196 get_paca()->data_offset = 0;
199 static void cpu_ready_for_interrupts(void)
201 /* Set IR and DR in PACA MSR */
202 get_paca()->kernel_msr = MSR_KERNEL;
204 /* Enable AIL if supported */
205 if (cpu_has_feature(CPU_FTR_HVMODE) &&
206 cpu_has_feature(CPU_FTR_ARCH_207S)) {
207 unsigned long lpcr = mfspr(SPRN_LPCR);
208 mtspr(SPRN_LPCR, lpcr | LPCR_AIL_3);
213 * Early initialization entry point. This is called by head.S
214 * with MMU translation disabled. We rely on the "feature" of
215 * the CPU that ignores the top 2 bits of the address in real
216 * mode so we can access kernel globals normally provided we
217 * only toy with things in the RMO region. From here, we do
218 * some early parsing of the device-tree to setup out MEMBLOCK
219 * data structures, and allocate & initialize the hash table
220 * and segment tables so we can start running with translation
223 * It is this function which will call the probe() callback of
224 * the various platform types and copy the matching one to the
225 * global ppc_md structure. Your platform can eventually do
226 * some very early initializations from the probe() routine, but
227 * this is not recommended, be very careful as, for example, the
228 * device-tree is not accessible via normal means at this point.
231 void __init early_setup(unsigned long dt_ptr)
233 static __initdata struct paca_struct boot_paca;
235 /* -------- printk is _NOT_ safe to use here ! ------- */
237 /* Identify CPU type */
238 identify_cpu(0, mfspr(SPRN_PVR));
240 /* Assume we're on cpu 0 for now. Don't write to the paca yet! */
241 initialise_paca(&boot_paca, 0);
242 setup_paca(&boot_paca);
245 /* Initialize lockdep early or else spinlocks will blow */
248 /* -------- printk is now safe to use ------- */
250 /* Enable early debugging if any specified (see udbg.h) */
253 DBG(" -> early_setup(), dt_ptr: 0x%lx\n", dt_ptr);
256 * Do early initialization using the flattened device
257 * tree, such as retrieving the physical memory map or
258 * calculating/retrieving the hash table size.
260 early_init_devtree(__va(dt_ptr));
262 epapr_paravirt_early_init();
264 /* Now we know the logical id of our boot cpu, setup the paca. */
265 setup_paca(&paca[boot_cpuid]);
268 /* Probe the machine type */
271 setup_kdump_trampoline();
273 DBG("Found, Initializing memory management...\n");
275 /* Initialize the hash table or TLB handling */
279 * At this point, we can let interrupts switch to virtual mode
280 * (the MMU has been setup), so adjust the MSR in the PACA to
281 * have IR and DR set and enable AIL if it exists
283 cpu_ready_for_interrupts();
285 /* Reserve large chunks of memory for use by CMA for KVM */
289 * Reserve any gigantic pages requested on the command line.
290 * memblock needs to have been initialized by the time this is
291 * called since this will reserve memory.
293 reserve_hugetlb_gpages();
295 DBG(" <- early_setup()\n");
297 #ifdef CONFIG_PPC_EARLY_DEBUG_BOOTX
299 * This needs to be done *last* (after the above DBG() even)
301 * Right after we return from this function, we turn on the MMU
302 * which means the real-mode access trick that btext does will
303 * no longer work, it needs to switch to using a real MMU
304 * mapping. This call will ensure that it does
307 #endif /* CONFIG_PPC_EARLY_DEBUG_BOOTX */
311 void early_setup_secondary(void)
313 /* Mark interrupts enabled in PACA */
314 get_paca()->soft_enabled = 0;
316 /* Initialize the hash table or TLB handling */
317 early_init_mmu_secondary();
320 * At this point, we can let interrupts switch to virtual mode
321 * (the MMU has been setup), so adjust the MSR in the PACA to
322 * have IR and DR set.
324 cpu_ready_for_interrupts();
327 #endif /* CONFIG_SMP */
329 #if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
330 void smp_release_cpus(void)
335 DBG(" -> smp_release_cpus()\n");
337 /* All secondary cpus are spinning on a common spinloop, release them
338 * all now so they can start to spin on their individual paca
339 * spinloops. For non SMP kernels, the secondary cpus never get out
340 * of the common spinloop.
343 ptr = (unsigned long *)((unsigned long)&__secondary_hold_spinloop
345 *ptr = ppc_function_entry(generic_secondary_smp_init);
347 /* And wait a bit for them to catch up */
348 for (i = 0; i < 100000; i++) {
351 if (spinning_secondaries == 0)
355 DBG("spinning_secondaries = %d\n", spinning_secondaries);
357 DBG(" <- smp_release_cpus()\n");
359 #endif /* CONFIG_SMP || CONFIG_KEXEC */
362 * Initialize some remaining members of the ppc64_caches and systemcfg
364 * (at least until we get rid of them completely). This is mostly some
365 * cache informations about the CPU that will be used by cache flush
366 * routines and/or provided to userland
368 static void __init initialize_cache_info(void)
370 struct device_node *np;
371 unsigned long num_cpus = 0;
373 DBG(" -> initialize_cache_info()\n");
375 for_each_node_by_type(np, "cpu") {
379 * We're assuming *all* of the CPUs have the same
380 * d-cache and i-cache sizes... -Peter
383 const __be32 *sizep, *lsizep;
387 lsize = cur_cpu_spec->dcache_bsize;
388 sizep = of_get_property(np, "d-cache-size", NULL);
390 size = be32_to_cpu(*sizep);
391 lsizep = of_get_property(np, "d-cache-block-size",
393 /* fallback if block size missing */
395 lsizep = of_get_property(np,
399 lsize = be32_to_cpu(*lsizep);
400 if (sizep == NULL || lsizep == NULL)
401 DBG("Argh, can't find dcache properties ! "
402 "sizep: %p, lsizep: %p\n", sizep, lsizep);
404 ppc64_caches.dsize = size;
405 ppc64_caches.dline_size = lsize;
406 ppc64_caches.log_dline_size = __ilog2(lsize);
407 ppc64_caches.dlines_per_page = PAGE_SIZE / lsize;
410 lsize = cur_cpu_spec->icache_bsize;
411 sizep = of_get_property(np, "i-cache-size", NULL);
413 size = be32_to_cpu(*sizep);
414 lsizep = of_get_property(np, "i-cache-block-size",
417 lsizep = of_get_property(np,
421 lsize = be32_to_cpu(*lsizep);
422 if (sizep == NULL || lsizep == NULL)
423 DBG("Argh, can't find icache properties ! "
424 "sizep: %p, lsizep: %p\n", sizep, lsizep);
426 ppc64_caches.isize = size;
427 ppc64_caches.iline_size = lsize;
428 ppc64_caches.log_iline_size = __ilog2(lsize);
429 ppc64_caches.ilines_per_page = PAGE_SIZE / lsize;
433 DBG(" <- initialize_cache_info()\n");
438 * Do some initial setup of the system. The parameters are those which
439 * were passed in from the bootloader.
441 void __init setup_system(void)
443 DBG(" -> setup_system()\n");
445 /* Apply the CPUs-specific and firmware specific fixups to kernel
446 * text (nop out sections not relevant to this CPU or this firmware)
448 do_feature_fixups(cur_cpu_spec->cpu_features,
449 &__start___ftr_fixup, &__stop___ftr_fixup);
450 do_feature_fixups(cur_cpu_spec->mmu_features,
451 &__start___mmu_ftr_fixup, &__stop___mmu_ftr_fixup);
452 do_feature_fixups(powerpc_firmware_features,
453 &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
454 do_lwsync_fixups(cur_cpu_spec->cpu_features,
455 &__start___lwsync_fixup, &__stop___lwsync_fixup);
459 * Unflatten the device-tree passed by prom_init or kexec
461 unflatten_device_tree();
464 * Fill the ppc64_caches & systemcfg structures with informations
465 * retrieved from the device-tree.
467 initialize_cache_info();
469 #ifdef CONFIG_PPC_RTAS
471 * Initialize RTAS if available
474 #endif /* CONFIG_PPC_RTAS */
477 * Check if we have an initrd provided via the device-tree
482 * Do some platform specific early initializations, that includes
483 * setting up the hash table pointers. It also sets up some interrupt-mapping
484 * related options that will be used by finish_device_tree()
486 if (ppc_md.init_early)
490 * We can discover serial ports now since the above did setup the
491 * hash table management for us, thus ioremap works. We do that early
492 * so that further code can be debugged
494 find_legacy_serial_ports();
497 * Register early console
499 register_early_udbg_console();
506 smp_setup_cpu_maps();
508 setup_tlb_core_data();
511 /* Release secondary cpus out of their spinloops at 0x60 now that
512 * we can map physical -> logical CPU ids
517 printk("Starting Linux PPC64 %s\n", init_utsname()->version);
519 printk("-----------------------------------------------------\n");
520 printk("ppc64_pft_size = 0x%llx\n", ppc64_pft_size);
521 printk("physicalMemorySize = 0x%llx\n", memblock_phys_mem_size());
522 if (ppc64_caches.dline_size != 0x80)
523 printk("ppc64_caches.dcache_line_size = 0x%x\n",
524 ppc64_caches.dline_size);
525 if (ppc64_caches.iline_size != 0x80)
526 printk("ppc64_caches.icache_line_size = 0x%x\n",
527 ppc64_caches.iline_size);
528 #ifdef CONFIG_PPC_STD_MMU_64
530 printk("htab_address = 0x%p\n", htab_address);
531 printk("htab_hash_mask = 0x%lx\n", htab_hash_mask);
532 #endif /* CONFIG_PPC_STD_MMU_64 */
533 if (PHYSICAL_START > 0)
534 printk("physical_start = 0x%llx\n",
535 (unsigned long long)PHYSICAL_START);
536 printk("-----------------------------------------------------\n");
538 DBG(" <- setup_system()\n");
541 /* This returns the limit below which memory accesses to the linear
542 * mapping are guarnateed not to cause a TLB or SLB miss. This is
543 * used to allocate interrupt or emergency stacks for which our
544 * exception entry path doesn't deal with being interrupted.
546 static u64 safe_stack_limit(void)
548 #ifdef CONFIG_PPC_BOOK3E
549 /* Freescale BookE bolts the entire linear mapping */
550 if (mmu_has_feature(MMU_FTR_TYPE_FSL_E))
551 return linear_map_top;
552 /* Other BookE, we assume the first GB is bolted */
555 /* BookS, the first segment is bolted */
556 if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
557 return 1UL << SID_SHIFT_1T;
558 return 1UL << SID_SHIFT;
562 static void __init irqstack_early_init(void)
564 u64 limit = safe_stack_limit();
568 * Interrupt stacks must be in the first segment since we
569 * cannot afford to take SLB misses on them.
571 for_each_possible_cpu(i) {
572 softirq_ctx[i] = (struct thread_info *)
573 __va(memblock_alloc_base(THREAD_SIZE,
574 THREAD_SIZE, limit));
575 hardirq_ctx[i] = (struct thread_info *)
576 __va(memblock_alloc_base(THREAD_SIZE,
577 THREAD_SIZE, limit));
581 #ifdef CONFIG_PPC_BOOK3E
582 static void __init exc_lvl_early_init(void)
587 for_each_possible_cpu(i) {
588 sp = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
589 critirq_ctx[i] = (struct thread_info *)__va(sp);
590 paca[i].crit_kstack = __va(sp + THREAD_SIZE);
592 sp = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
593 dbgirq_ctx[i] = (struct thread_info *)__va(sp);
594 paca[i].dbg_kstack = __va(sp + THREAD_SIZE);
596 sp = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
597 mcheckirq_ctx[i] = (struct thread_info *)__va(sp);
598 paca[i].mc_kstack = __va(sp + THREAD_SIZE);
601 if (cpu_has_feature(CPU_FTR_DEBUG_LVL_EXC))
602 patch_exception(0x040, exc_debug_debug_book3e);
605 #define exc_lvl_early_init()
609 * Stack space used when we detect a bad kernel stack pointer, and
610 * early in SMP boots before relocation is enabled. Exclusive emergency
611 * stack for machine checks.
613 static void __init emergency_stack_init(void)
619 * Emergency stacks must be under 256MB, we cannot afford to take
620 * SLB misses on them. The ABI also requires them to be 128-byte
623 * Since we use these as temporary stacks during secondary CPU
624 * bringup, we need to get at them in real mode. This means they
625 * must also be within the RMO region.
627 limit = min(safe_stack_limit(), ppc64_rma_size);
629 for_each_possible_cpu(i) {
631 sp = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
633 paca[i].emergency_sp = __va(sp);
635 #ifdef CONFIG_PPC_BOOK3S_64
636 /* emergency stack for machine check exception handling. */
637 sp = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
639 paca[i].mc_emergency_sp = __va(sp);
645 * Called into from start_kernel this initializes bootmem, which is used
646 * to manage page allocation until mem_init is called.
648 void __init setup_arch(char **cmdline_p)
650 ppc64_boot_msg(0x12, "Setup Arch");
652 *cmdline_p = cmd_line;
655 * Set cache line size based on type of cpu as a default.
656 * Systems with OF can look in the properties on the cpu node(s)
657 * for a possibly more accurate value.
659 dcache_bsize = ppc64_caches.dline_size;
660 icache_bsize = ppc64_caches.iline_size;
665 init_mm.start_code = (unsigned long)_stext;
666 init_mm.end_code = (unsigned long) _etext;
667 init_mm.end_data = (unsigned long) _edata;
668 init_mm.brk = klimit;
669 #ifdef CONFIG_PPC_64K_PAGES
670 init_mm.context.pte_frag = NULL;
672 irqstack_early_init();
673 exc_lvl_early_init();
674 emergency_stack_init();
676 #ifdef CONFIG_PPC_STD_MMU_64
679 /* set up the bootmem stuff with available memory */
683 #ifdef CONFIG_DUMMY_CONSOLE
684 conswitchp = &dummy_con;
687 if (ppc_md.setup_arch)
692 /* Initialize the MMU context management stuff */
695 /* Interrupt code needs to be 64K-aligned */
696 if ((unsigned long)_stext & 0xffff)
697 panic("Kernelbase not 64K-aligned (0x%lx)!\n",
698 (unsigned long)_stext);
700 ppc64_boot_msg(0x15, "Setup Done");
704 /* ToDo: do something useful if ppc_md is not yet setup. */
705 #define PPC64_LINUX_FUNCTION 0x0f000000
706 #define PPC64_IPL_MESSAGE 0xc0000000
707 #define PPC64_TERM_MESSAGE 0xb0000000
709 static void ppc64_do_msg(unsigned int src, const char *msg)
711 if (ppc_md.progress) {
714 sprintf(buf, "%08X\n", src);
715 ppc_md.progress(buf, 0);
716 snprintf(buf, 128, "%s", msg);
717 ppc_md.progress(buf, 0);
721 /* Print a boot progress message. */
722 void ppc64_boot_msg(unsigned int src, const char *msg)
724 ppc64_do_msg(PPC64_LINUX_FUNCTION|PPC64_IPL_MESSAGE|src, msg);
725 printk("[boot]%04x %s\n", src, msg);
729 #define PCPU_DYN_SIZE ()
731 static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
733 return __alloc_bootmem_node(NODE_DATA(cpu_to_node(cpu)), size, align,
734 __pa(MAX_DMA_ADDRESS));
737 static void __init pcpu_fc_free(void *ptr, size_t size)
739 free_bootmem(__pa(ptr), size);
742 static int pcpu_cpu_distance(unsigned int from, unsigned int to)
744 if (cpu_to_node(from) == cpu_to_node(to))
745 return LOCAL_DISTANCE;
747 return REMOTE_DISTANCE;
750 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
751 EXPORT_SYMBOL(__per_cpu_offset);
753 void __init setup_per_cpu_areas(void)
755 const size_t dyn_size = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
762 * Linear mapping is one of 4K, 1M and 16M. For 4K, no need
763 * to group units. For larger mappings, use 1M atom which
764 * should be large enough to contain a number of units.
766 if (mmu_linear_psize == MMU_PAGE_4K)
767 atom_size = PAGE_SIZE;
771 rc = pcpu_embed_first_chunk(0, dyn_size, atom_size, pcpu_cpu_distance,
772 pcpu_fc_alloc, pcpu_fc_free);
774 panic("cannot initialize percpu area (err=%d)", rc);
776 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
777 for_each_possible_cpu(cpu) {
778 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
779 paca[cpu].data_offset = __per_cpu_offset[cpu];
784 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
785 unsigned long memory_block_size_bytes(void)
787 if (ppc_md.memory_block_size)
788 return ppc_md.memory_block_size();
790 return MIN_MEMORY_BLOCK_SIZE;
794 #if defined(CONFIG_PPC_INDIRECT_PIO) || defined(CONFIG_PPC_INDIRECT_MMIO)
795 struct ppc_pci_io ppc_pci_io;
796 EXPORT_SYMBOL(ppc_pci_io);