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>
69 #define DBG(fmt...) udbg_printf(fmt)
75 int __initdata boot_cpu_count;
78 /* Pick defaults since we might want to patch instructions
79 * before we've read this from the device tree.
81 struct ppc64_caches ppc64_caches = {
87 EXPORT_SYMBOL_GPL(ppc64_caches);
90 * These are used in binfmt_elf.c to put aux entries on the stack
91 * for each elf executable being started.
99 static char *smt_enabled_cmdline;
101 /* Look for ibm,smt-enabled OF option */
102 static void check_smt_enabled(void)
104 struct device_node *dn;
105 const char *smt_option;
107 /* Default to enabling all threads */
108 smt_enabled_at_boot = threads_per_core;
110 /* Allow the command line to overrule the OF option */
111 if (smt_enabled_cmdline) {
112 if (!strcmp(smt_enabled_cmdline, "on"))
113 smt_enabled_at_boot = threads_per_core;
114 else if (!strcmp(smt_enabled_cmdline, "off"))
115 smt_enabled_at_boot = 0;
120 rc = strict_strtol(smt_enabled_cmdline, 10, &smt);
122 smt_enabled_at_boot =
123 min(threads_per_core, (int)smt);
126 dn = of_find_node_by_path("/options");
128 smt_option = of_get_property(dn, "ibm,smt-enabled",
132 if (!strcmp(smt_option, "on"))
133 smt_enabled_at_boot = threads_per_core;
134 else if (!strcmp(smt_option, "off"))
135 smt_enabled_at_boot = 0;
143 /* Look for smt-enabled= cmdline option */
144 static int __init early_smt_enabled(char *p)
146 smt_enabled_cmdline = p;
149 early_param("smt-enabled", early_smt_enabled);
152 #define check_smt_enabled()
153 #endif /* CONFIG_SMP */
156 * Early initialization entry point. This is called by head.S
157 * with MMU translation disabled. We rely on the "feature" of
158 * the CPU that ignores the top 2 bits of the address in real
159 * mode so we can access kernel globals normally provided we
160 * only toy with things in the RMO region. From here, we do
161 * some early parsing of the device-tree to setup out MEMBLOCK
162 * data structures, and allocate & initialize the hash table
163 * and segment tables so we can start running with translation
166 * It is this function which will call the probe() callback of
167 * the various platform types and copy the matching one to the
168 * global ppc_md structure. Your platform can eventually do
169 * some very early initializations from the probe() routine, but
170 * this is not recommended, be very careful as, for example, the
171 * device-tree is not accessible via normal means at this point.
174 void __init early_setup(unsigned long dt_ptr)
176 /* -------- printk is _NOT_ safe to use here ! ------- */
178 /* Identify CPU type */
179 identify_cpu(0, mfspr(SPRN_PVR));
181 /* Assume we're on cpu 0 for now. Don't write to the paca yet! */
182 initialise_paca(&boot_paca, 0);
183 setup_paca(&boot_paca);
185 /* Initialize lockdep early or else spinlocks will blow */
188 /* -------- printk is now safe to use ------- */
190 /* Enable early debugging if any specified (see udbg.h) */
193 DBG(" -> early_setup(), dt_ptr: 0x%lx\n", dt_ptr);
196 * Do early initialization using the flattened device
197 * tree, such as retrieving the physical memory map or
198 * calculating/retrieving the hash table size.
200 early_init_devtree(__va(dt_ptr));
202 /* Now we know the logical id of our boot cpu, setup the paca. */
203 setup_paca(&paca[boot_cpuid]);
205 /* Fix up paca fields required for the boot cpu */
206 get_paca()->cpu_start = 1;
208 /* Probe the machine type */
211 setup_kdump_trampoline();
213 DBG("Found, Initializing memory management...\n");
215 /* Initialize the hash table or TLB handling */
218 DBG(" <- early_setup()\n");
222 void early_setup_secondary(void)
224 /* Mark interrupts enabled in PACA */
225 get_paca()->soft_enabled = 0;
227 /* Initialize the hash table or TLB handling */
228 early_init_mmu_secondary();
231 #endif /* CONFIG_SMP */
233 #if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
234 void smp_release_cpus(void)
239 DBG(" -> smp_release_cpus()\n");
241 /* All secondary cpus are spinning on a common spinloop, release them
242 * all now so they can start to spin on their individual paca
243 * spinloops. For non SMP kernels, the secondary cpus never get out
244 * of the common spinloop.
247 ptr = (unsigned long *)((unsigned long)&__secondary_hold_spinloop
249 *ptr = __pa(generic_secondary_smp_init);
251 /* And wait a bit for them to catch up */
252 for (i = 0; i < 100000; i++) {
255 if (boot_cpu_count == 0)
259 DBG("boot_cpu_count = %d\n", boot_cpu_count);
261 DBG(" <- smp_release_cpus()\n");
263 #endif /* CONFIG_SMP || CONFIG_KEXEC */
266 * Initialize some remaining members of the ppc64_caches and systemcfg
268 * (at least until we get rid of them completely). This is mostly some
269 * cache informations about the CPU that will be used by cache flush
270 * routines and/or provided to userland
272 static void __init initialize_cache_info(void)
274 struct device_node *np;
275 unsigned long num_cpus = 0;
277 DBG(" -> initialize_cache_info()\n");
279 for (np = NULL; (np = of_find_node_by_type(np, "cpu"));) {
282 /* We're assuming *all* of the CPUs have the same
283 * d-cache and i-cache sizes... -Peter
286 if ( num_cpus == 1 ) {
287 const u32 *sizep, *lsizep;
291 lsize = cur_cpu_spec->dcache_bsize;
292 sizep = of_get_property(np, "d-cache-size", NULL);
295 lsizep = of_get_property(np, "d-cache-block-size", NULL);
296 /* fallback if block size missing */
298 lsizep = of_get_property(np, "d-cache-line-size", NULL);
301 if (sizep == 0 || lsizep == 0)
302 DBG("Argh, can't find dcache properties ! "
303 "sizep: %p, lsizep: %p\n", sizep, lsizep);
305 ppc64_caches.dsize = size;
306 ppc64_caches.dline_size = lsize;
307 ppc64_caches.log_dline_size = __ilog2(lsize);
308 ppc64_caches.dlines_per_page = PAGE_SIZE / lsize;
311 lsize = cur_cpu_spec->icache_bsize;
312 sizep = of_get_property(np, "i-cache-size", NULL);
315 lsizep = of_get_property(np, "i-cache-block-size", NULL);
317 lsizep = of_get_property(np, "i-cache-line-size", NULL);
320 if (sizep == 0 || lsizep == 0)
321 DBG("Argh, can't find icache properties ! "
322 "sizep: %p, lsizep: %p\n", sizep, lsizep);
324 ppc64_caches.isize = size;
325 ppc64_caches.iline_size = lsize;
326 ppc64_caches.log_iline_size = __ilog2(lsize);
327 ppc64_caches.ilines_per_page = PAGE_SIZE / lsize;
331 DBG(" <- initialize_cache_info()\n");
336 * Do some initial setup of the system. The parameters are those which
337 * were passed in from the bootloader.
339 void __init setup_system(void)
341 DBG(" -> setup_system()\n");
343 /* Apply the CPUs-specific and firmware specific fixups to kernel
344 * text (nop out sections not relevant to this CPU or this firmware)
346 do_feature_fixups(cur_cpu_spec->cpu_features,
347 &__start___ftr_fixup, &__stop___ftr_fixup);
348 do_feature_fixups(cur_cpu_spec->mmu_features,
349 &__start___mmu_ftr_fixup, &__stop___mmu_ftr_fixup);
350 do_feature_fixups(powerpc_firmware_features,
351 &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
352 do_lwsync_fixups(cur_cpu_spec->cpu_features,
353 &__start___lwsync_fixup, &__stop___lwsync_fixup);
356 * Unflatten the device-tree passed by prom_init or kexec
358 unflatten_device_tree();
361 * Fill the ppc64_caches & systemcfg structures with informations
362 * retrieved from the device-tree.
364 initialize_cache_info();
366 #ifdef CONFIG_PPC_RTAS
368 * Initialize RTAS if available
371 #endif /* CONFIG_PPC_RTAS */
374 * Check if we have an initrd provided via the device-tree
379 * Do some platform specific early initializations, that includes
380 * setting up the hash table pointers. It also sets up some interrupt-mapping
381 * related options that will be used by finish_device_tree()
383 if (ppc_md.init_early)
387 * We can discover serial ports now since the above did setup the
388 * hash table management for us, thus ioremap works. We do that early
389 * so that further code can be debugged
391 find_legacy_serial_ports();
394 * Register early console
396 register_early_udbg_console();
403 smp_setup_cpu_maps();
407 /* Release secondary cpus out of their spinloops at 0x60 now that
408 * we can map physical -> logical CPU ids
413 printk("Starting Linux PPC64 %s\n", init_utsname()->version);
415 printk("-----------------------------------------------------\n");
416 printk("ppc64_pft_size = 0x%llx\n", ppc64_pft_size);
417 printk("physicalMemorySize = 0x%llx\n", memblock_phys_mem_size());
418 if (ppc64_caches.dline_size != 0x80)
419 printk("ppc64_caches.dcache_line_size = 0x%x\n",
420 ppc64_caches.dline_size);
421 if (ppc64_caches.iline_size != 0x80)
422 printk("ppc64_caches.icache_line_size = 0x%x\n",
423 ppc64_caches.iline_size);
424 #ifdef CONFIG_PPC_STD_MMU_64
426 printk("htab_address = 0x%p\n", htab_address);
427 printk("htab_hash_mask = 0x%lx\n", htab_hash_mask);
428 #endif /* CONFIG_PPC_STD_MMU_64 */
429 if (PHYSICAL_START > 0)
430 printk("physical_start = 0x%llx\n",
431 (unsigned long long)PHYSICAL_START);
432 printk("-----------------------------------------------------\n");
434 DBG(" <- setup_system()\n");
437 static u64 slb0_limit(void)
439 if (cpu_has_feature(CPU_FTR_1T_SEGMENT)) {
440 return 1UL << SID_SHIFT_1T;
442 return 1UL << SID_SHIFT;
445 static void __init irqstack_early_init(void)
447 u64 limit = slb0_limit();
451 * Interrupt stacks must be in the first segment since we
452 * cannot afford to take SLB misses on them.
454 for_each_possible_cpu(i) {
455 softirq_ctx[i] = (struct thread_info *)
456 __va(memblock_alloc_base(THREAD_SIZE,
457 THREAD_SIZE, limit));
458 hardirq_ctx[i] = (struct thread_info *)
459 __va(memblock_alloc_base(THREAD_SIZE,
460 THREAD_SIZE, limit));
464 #ifdef CONFIG_PPC_BOOK3E
465 static void __init exc_lvl_early_init(void)
469 for_each_possible_cpu(i) {
470 critirq_ctx[i] = (struct thread_info *)
471 __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
472 dbgirq_ctx[i] = (struct thread_info *)
473 __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
474 mcheckirq_ctx[i] = (struct thread_info *)
475 __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
479 #define exc_lvl_early_init()
483 * Stack space used when we detect a bad kernel stack pointer, and
484 * early in SMP boots before relocation is enabled.
486 static void __init emergency_stack_init(void)
492 * Emergency stacks must be under 256MB, we cannot afford to take
493 * SLB misses on them. The ABI also requires them to be 128-byte
496 * Since we use these as temporary stacks during secondary CPU
497 * bringup, we need to get at them in real mode. This means they
498 * must also be within the RMO region.
500 limit = min(slb0_limit(), ppc64_rma_size);
502 for_each_possible_cpu(i) {
504 sp = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
506 paca[i].emergency_sp = __va(sp);
511 * Called into from start_kernel this initializes bootmem, which is used
512 * to manage page allocation until mem_init is called.
514 void __init setup_arch(char **cmdline_p)
516 ppc64_boot_msg(0x12, "Setup Arch");
518 *cmdline_p = cmd_line;
521 * Set cache line size based on type of cpu as a default.
522 * Systems with OF can look in the properties on the cpu node(s)
523 * for a possibly more accurate value.
525 dcache_bsize = ppc64_caches.dline_size;
526 icache_bsize = ppc64_caches.iline_size;
528 /* reboot on panic */
534 init_mm.start_code = (unsigned long)_stext;
535 init_mm.end_code = (unsigned long) _etext;
536 init_mm.end_data = (unsigned long) _edata;
537 init_mm.brk = klimit;
539 irqstack_early_init();
540 exc_lvl_early_init();
541 emergency_stack_init();
543 #ifdef CONFIG_PPC_STD_MMU_64
546 /* set up the bootmem stuff with available memory */
550 #ifdef CONFIG_DUMMY_CONSOLE
551 conswitchp = &dummy_con;
554 if (ppc_md.setup_arch)
559 /* Initialize the MMU context management stuff */
562 ppc64_boot_msg(0x15, "Setup Done");
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
571 static void ppc64_do_msg(unsigned int src, const char *msg)
573 if (ppc_md.progress) {
576 sprintf(buf, "%08X\n", src);
577 ppc_md.progress(buf, 0);
578 snprintf(buf, 128, "%s", msg);
579 ppc_md.progress(buf, 0);
583 /* Print a boot progress message. */
584 void ppc64_boot_msg(unsigned int src, const char *msg)
586 ppc64_do_msg(PPC64_LINUX_FUNCTION|PPC64_IPL_MESSAGE|src, msg);
587 printk("[boot]%04x %s\n", src, msg);
591 #define PCPU_DYN_SIZE ()
593 static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
595 return __alloc_bootmem_node(NODE_DATA(cpu_to_node(cpu)), size, align,
596 __pa(MAX_DMA_ADDRESS));
599 static void __init pcpu_fc_free(void *ptr, size_t size)
601 free_bootmem(__pa(ptr), size);
604 static int pcpu_cpu_distance(unsigned int from, unsigned int to)
606 if (cpu_to_node(from) == cpu_to_node(to))
607 return LOCAL_DISTANCE;
609 return REMOTE_DISTANCE;
612 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
613 EXPORT_SYMBOL(__per_cpu_offset);
615 void __init setup_per_cpu_areas(void)
617 const size_t dyn_size = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
624 * Linear mapping is one of 4K, 1M and 16M. For 4K, no need
625 * to group units. For larger mappings, use 1M atom which
626 * should be large enough to contain a number of units.
628 if (mmu_linear_psize == MMU_PAGE_4K)
629 atom_size = PAGE_SIZE;
633 rc = pcpu_embed_first_chunk(0, dyn_size, atom_size, pcpu_cpu_distance,
634 pcpu_fc_alloc, pcpu_fc_free);
636 panic("cannot initialize percpu area (err=%d)", rc);
638 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
639 for_each_possible_cpu(cpu) {
640 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
641 paca[cpu].data_offset = __per_cpu_offset[cpu];
647 #ifdef CONFIG_PPC_INDIRECT_IO
648 struct ppc_pci_io ppc_pci_io;
649 EXPORT_SYMBOL(ppc_pci_io);
650 #endif /* CONFIG_PPC_INDIRECT_IO */