Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm...
[linux-flexiantxendom0-3.2.10.git] / arch / powerpc / kernel / setup_64.c
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/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
40 #include <asm/io.h>
41 #include <asm/kdump.h>
42 #include <asm/prom.h>
43 #include <asm/processor.h>
44 #include <asm/pgtable.h>
45 #include <asm/smp.h>
46 #include <asm/elf.h>
47 #include <asm/machdep.h>
48 #include <asm/paca.h>
49 #include <asm/time.h>
50 #include <asm/cputable.h>
51 #include <asm/sections.h>
52 #include <asm/btext.h>
53 #include <asm/nvram.h>
54 #include <asm/setup.h>
55 #include <asm/rtas.h>
56 #include <asm/iommu.h>
57 #include <asm/serial.h>
58 #include <asm/cache.h>
59 #include <asm/page.h>
60 #include <asm/mmu.h>
61 #include <asm/firmware.h>
62 #include <asm/xmon.h>
63 #include <asm/udbg.h>
64 #include <asm/kexec.h>
65 #include <asm/mmu_context.h>
66 #include <asm/code-patching.h>
67 #include <asm/kvm_ppc.h>
68 #include <asm/hugetlb.h>
69
70 #include "setup.h"
71
72 #ifdef DEBUG
73 #define DBG(fmt...) udbg_printf(fmt)
74 #else
75 #define DBG(fmt...)
76 #endif
77
78 int boot_cpuid = 0;
79 int __initdata spinning_secondaries;
80 u64 ppc64_pft_size;
81
82 /* Pick defaults since we might want to patch instructions
83  * before we've read this from the device tree.
84  */
85 struct ppc64_caches ppc64_caches = {
86         .dline_size = 0x40,
87         .log_dline_size = 6,
88         .iline_size = 0x40,
89         .log_iline_size = 6
90 };
91 EXPORT_SYMBOL_GPL(ppc64_caches);
92
93 /*
94  * These are used in binfmt_elf.c to put aux entries on the stack
95  * for each elf executable being started.
96  */
97 int dcache_bsize;
98 int icache_bsize;
99 int ucache_bsize;
100
101 #ifdef CONFIG_SMP
102
103 static char *smt_enabled_cmdline;
104
105 /* Look for ibm,smt-enabled OF option */
106 static void check_smt_enabled(void)
107 {
108         struct device_node *dn;
109         const char *smt_option;
110
111         /* Default to enabling all threads */
112         smt_enabled_at_boot = threads_per_core;
113
114         /* Allow the command line to overrule the OF option */
115         if (smt_enabled_cmdline) {
116                 if (!strcmp(smt_enabled_cmdline, "on"))
117                         smt_enabled_at_boot = threads_per_core;
118                 else if (!strcmp(smt_enabled_cmdline, "off"))
119                         smt_enabled_at_boot = 0;
120                 else {
121                         long smt;
122                         int rc;
123
124                         rc = strict_strtol(smt_enabled_cmdline, 10, &smt);
125                         if (!rc)
126                                 smt_enabled_at_boot =
127                                         min(threads_per_core, (int)smt);
128                 }
129         } else {
130                 dn = of_find_node_by_path("/options");
131                 if (dn) {
132                         smt_option = of_get_property(dn, "ibm,smt-enabled",
133                                                      NULL);
134
135                         if (smt_option) {
136                                 if (!strcmp(smt_option, "on"))
137                                         smt_enabled_at_boot = threads_per_core;
138                                 else if (!strcmp(smt_option, "off"))
139                                         smt_enabled_at_boot = 0;
140                         }
141
142                         of_node_put(dn);
143                 }
144         }
145 }
146
147 /* Look for smt-enabled= cmdline option */
148 static int __init early_smt_enabled(char *p)
149 {
150         smt_enabled_cmdline = p;
151         return 0;
152 }
153 early_param("smt-enabled", early_smt_enabled);
154
155 #else
156 #define check_smt_enabled()
157 #endif /* CONFIG_SMP */
158
159 /*
160  * Early initialization entry point. This is called by head.S
161  * with MMU translation disabled. We rely on the "feature" of
162  * the CPU that ignores the top 2 bits of the address in real
163  * mode so we can access kernel globals normally provided we
164  * only toy with things in the RMO region. From here, we do
165  * some early parsing of the device-tree to setup out MEMBLOCK
166  * data structures, and allocate & initialize the hash table
167  * and segment tables so we can start running with translation
168  * enabled.
169  *
170  * It is this function which will call the probe() callback of
171  * the various platform types and copy the matching one to the
172  * global ppc_md structure. Your platform can eventually do
173  * some very early initializations from the probe() routine, but
174  * this is not recommended, be very careful as, for example, the
175  * device-tree is not accessible via normal means at this point.
176  */
177
178 void __init early_setup(unsigned long dt_ptr)
179 {
180         /* -------- printk is _NOT_ safe to use here ! ------- */
181
182         /* Identify CPU type */
183         identify_cpu(0, mfspr(SPRN_PVR));
184
185         /* Assume we're on cpu 0 for now. Don't write to the paca yet! */
186         initialise_paca(&boot_paca, 0);
187         setup_paca(&boot_paca);
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(&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         /*
223          * Reserve any gigantic pages requested on the command line.
224          * memblock needs to have been initialized by the time this is
225          * called since this will reserve memory.
226          */
227         reserve_hugetlb_gpages();
228
229         DBG(" <- early_setup()\n");
230 }
231
232 #ifdef CONFIG_SMP
233 void early_setup_secondary(void)
234 {
235         /* Mark interrupts enabled in PACA */
236         get_paca()->soft_enabled = 0;
237
238         /* Initialize the hash table or TLB handling */
239         early_init_mmu_secondary();
240 }
241
242 #endif /* CONFIG_SMP */
243
244 #if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
245 void smp_release_cpus(void)
246 {
247         unsigned long *ptr;
248         int i;
249
250         DBG(" -> smp_release_cpus()\n");
251
252         /* All secondary cpus are spinning on a common spinloop, release them
253          * all now so they can start to spin on their individual paca
254          * spinloops. For non SMP kernels, the secondary cpus never get out
255          * of the common spinloop.
256          */
257
258         ptr  = (unsigned long *)((unsigned long)&__secondary_hold_spinloop
259                         - PHYSICAL_START);
260         *ptr = __pa(generic_secondary_smp_init);
261
262         /* And wait a bit for them to catch up */
263         for (i = 0; i < 100000; i++) {
264                 mb();
265                 HMT_low();
266                 if (spinning_secondaries == 0)
267                         break;
268                 udelay(1);
269         }
270         DBG("spinning_secondaries = %d\n", spinning_secondaries);
271
272         DBG(" <- smp_release_cpus()\n");
273 }
274 #endif /* CONFIG_SMP || CONFIG_KEXEC */
275
276 /*
277  * Initialize some remaining members of the ppc64_caches and systemcfg
278  * structures
279  * (at least until we get rid of them completely). This is mostly some
280  * cache informations about the CPU that will be used by cache flush
281  * routines and/or provided to userland
282  */
283 static void __init initialize_cache_info(void)
284 {
285         struct device_node *np;
286         unsigned long num_cpus = 0;
287
288         DBG(" -> initialize_cache_info()\n");
289
290         for_each_node_by_type(np, "cpu") {
291                 num_cpus += 1;
292
293                 /*
294                  * We're assuming *all* of the CPUs have the same
295                  * d-cache and i-cache sizes... -Peter
296                  */
297                 if (num_cpus == 1) {
298                         const u32 *sizep, *lsizep;
299                         u32 size, lsize;
300
301                         size = 0;
302                         lsize = cur_cpu_spec->dcache_bsize;
303                         sizep = of_get_property(np, "d-cache-size", NULL);
304                         if (sizep != NULL)
305                                 size = *sizep;
306                         lsizep = of_get_property(np, "d-cache-block-size",
307                                                  NULL);
308                         /* fallback if block size missing */
309                         if (lsizep == NULL)
310                                 lsizep = of_get_property(np,
311                                                          "d-cache-line-size",
312                                                          NULL);
313                         if (lsizep != NULL)
314                                 lsize = *lsizep;
315                         if (sizep == 0 || lsizep == 0)
316                                 DBG("Argh, can't find dcache properties ! "
317                                     "sizep: %p, lsizep: %p\n", sizep, lsizep);
318
319                         ppc64_caches.dsize = size;
320                         ppc64_caches.dline_size = lsize;
321                         ppc64_caches.log_dline_size = __ilog2(lsize);
322                         ppc64_caches.dlines_per_page = PAGE_SIZE / lsize;
323
324                         size = 0;
325                         lsize = cur_cpu_spec->icache_bsize;
326                         sizep = of_get_property(np, "i-cache-size", NULL);
327                         if (sizep != NULL)
328                                 size = *sizep;
329                         lsizep = of_get_property(np, "i-cache-block-size",
330                                                  NULL);
331                         if (lsizep == NULL)
332                                 lsizep = of_get_property(np,
333                                                          "i-cache-line-size",
334                                                          NULL);
335                         if (lsizep != NULL)
336                                 lsize = *lsizep;
337                         if (sizep == 0 || lsizep == 0)
338                                 DBG("Argh, can't find icache properties ! "
339                                     "sizep: %p, lsizep: %p\n", sizep, lsizep);
340
341                         ppc64_caches.isize = size;
342                         ppc64_caches.iline_size = lsize;
343                         ppc64_caches.log_iline_size = __ilog2(lsize);
344                         ppc64_caches.ilines_per_page = PAGE_SIZE / lsize;
345                 }
346         }
347
348         DBG(" <- initialize_cache_info()\n");
349 }
350
351
352 /*
353  * Do some initial setup of the system.  The parameters are those which 
354  * were passed in from the bootloader.
355  */
356 void __init setup_system(void)
357 {
358         DBG(" -> setup_system()\n");
359
360         /* Apply the CPUs-specific and firmware specific fixups to kernel
361          * text (nop out sections not relevant to this CPU or this firmware)
362          */
363         do_feature_fixups(cur_cpu_spec->cpu_features,
364                           &__start___ftr_fixup, &__stop___ftr_fixup);
365         do_feature_fixups(cur_cpu_spec->mmu_features,
366                           &__start___mmu_ftr_fixup, &__stop___mmu_ftr_fixup);
367         do_feature_fixups(powerpc_firmware_features,
368                           &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
369         do_lwsync_fixups(cur_cpu_spec->cpu_features,
370                          &__start___lwsync_fixup, &__stop___lwsync_fixup);
371         do_final_fixups();
372
373         /*
374          * Unflatten the device-tree passed by prom_init or kexec
375          */
376         unflatten_device_tree();
377
378         /*
379          * Fill the ppc64_caches & systemcfg structures with informations
380          * retrieved from the device-tree.
381          */
382         initialize_cache_info();
383
384 #ifdef CONFIG_PPC_RTAS
385         /*
386          * Initialize RTAS if available
387          */
388         rtas_initialize();
389 #endif /* CONFIG_PPC_RTAS */
390
391         /*
392          * Check if we have an initrd provided via the device-tree
393          */
394         check_for_initrd();
395
396         /*
397          * Do some platform specific early initializations, that includes
398          * setting up the hash table pointers. It also sets up some interrupt-mapping
399          * related options that will be used by finish_device_tree()
400          */
401         if (ppc_md.init_early)
402                 ppc_md.init_early();
403
404         /*
405          * We can discover serial ports now since the above did setup the
406          * hash table management for us, thus ioremap works. We do that early
407          * so that further code can be debugged
408          */
409         find_legacy_serial_ports();
410
411         /*
412          * Register early console
413          */
414         register_early_udbg_console();
415
416         /*
417          * Initialize xmon
418          */
419         xmon_setup();
420
421         smp_setup_cpu_maps();
422         check_smt_enabled();
423
424 #ifdef CONFIG_SMP
425         /* Release secondary cpus out of their spinloops at 0x60 now that
426          * we can map physical -> logical CPU ids
427          */
428         smp_release_cpus();
429 #endif
430
431         printk("Starting Linux PPC64 %s\n", init_utsname()->version);
432
433         printk("-----------------------------------------------------\n");
434         printk("ppc64_pft_size                = 0x%llx\n", ppc64_pft_size);
435         printk("physicalMemorySize            = 0x%llx\n", memblock_phys_mem_size());
436         if (ppc64_caches.dline_size != 0x80)
437                 printk("ppc64_caches.dcache_line_size = 0x%x\n",
438                        ppc64_caches.dline_size);
439         if (ppc64_caches.iline_size != 0x80)
440                 printk("ppc64_caches.icache_line_size = 0x%x\n",
441                        ppc64_caches.iline_size);
442 #ifdef CONFIG_PPC_STD_MMU_64
443         if (htab_address)
444                 printk("htab_address                  = 0x%p\n", htab_address);
445         printk("htab_hash_mask                = 0x%lx\n", htab_hash_mask);
446 #endif /* CONFIG_PPC_STD_MMU_64 */
447         if (PHYSICAL_START > 0)
448                 printk("physical_start                = 0x%llx\n",
449                        (unsigned long long)PHYSICAL_START);
450         printk("-----------------------------------------------------\n");
451
452         DBG(" <- setup_system()\n");
453 }
454
455 /* This returns the limit below which memory accesses to the linear
456  * mapping are guarnateed not to cause a TLB or SLB miss. This is
457  * used to allocate interrupt or emergency stacks for which our
458  * exception entry path doesn't deal with being interrupted.
459  */
460 static u64 safe_stack_limit(void)
461 {
462 #ifdef CONFIG_PPC_BOOK3E
463         /* Freescale BookE bolts the entire linear mapping */
464         if (mmu_has_feature(MMU_FTR_TYPE_FSL_E))
465                 return linear_map_top;
466         /* Other BookE, we assume the first GB is bolted */
467         return 1ul << 30;
468 #else
469         /* BookS, the first segment is bolted */
470         if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
471                 return 1UL << SID_SHIFT_1T;
472         return 1UL << SID_SHIFT;
473 #endif
474 }
475
476 static void __init irqstack_early_init(void)
477 {
478         u64 limit = safe_stack_limit();
479         unsigned int i;
480
481         /*
482          * Interrupt stacks must be in the first segment since we
483          * cannot afford to take SLB misses on them.
484          */
485         for_each_possible_cpu(i) {
486                 softirq_ctx[i] = (struct thread_info *)
487                         __va(memblock_alloc_base(THREAD_SIZE,
488                                             THREAD_SIZE, limit));
489                 hardirq_ctx[i] = (struct thread_info *)
490                         __va(memblock_alloc_base(THREAD_SIZE,
491                                             THREAD_SIZE, limit));
492         }
493 }
494
495 #ifdef CONFIG_PPC_BOOK3E
496 static void __init exc_lvl_early_init(void)
497 {
498         extern unsigned int interrupt_base_book3e;
499         extern unsigned int exc_debug_debug_book3e;
500
501         unsigned int i;
502
503         for_each_possible_cpu(i) {
504                 critirq_ctx[i] = (struct thread_info *)
505                         __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
506                 dbgirq_ctx[i] = (struct thread_info *)
507                         __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
508                 mcheckirq_ctx[i] = (struct thread_info *)
509                         __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
510         }
511
512         if (cpu_has_feature(CPU_FTR_DEBUG_LVL_EXC))
513                 patch_branch(&interrupt_base_book3e + (0x040 / 4) + 1,
514                              (unsigned long)&exc_debug_debug_book3e, 0);
515 }
516 #else
517 #define exc_lvl_early_init()
518 #endif
519
520 /*
521  * Stack space used when we detect a bad kernel stack pointer, and
522  * early in SMP boots before relocation is enabled.
523  */
524 static void __init emergency_stack_init(void)
525 {
526         u64 limit;
527         unsigned int i;
528
529         /*
530          * Emergency stacks must be under 256MB, we cannot afford to take
531          * SLB misses on them. The ABI also requires them to be 128-byte
532          * aligned.
533          *
534          * Since we use these as temporary stacks during secondary CPU
535          * bringup, we need to get at them in real mode. This means they
536          * must also be within the RMO region.
537          */
538         limit = min(safe_stack_limit(), ppc64_rma_size);
539
540         for_each_possible_cpu(i) {
541                 unsigned long sp;
542                 sp  = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
543                 sp += THREAD_SIZE;
544                 paca[i].emergency_sp = __va(sp);
545         }
546 }
547
548 /*
549  * Called into from start_kernel this initializes bootmem, which is used
550  * to manage page allocation until mem_init is called.
551  */
552 void __init setup_arch(char **cmdline_p)
553 {
554         ppc64_boot_msg(0x12, "Setup Arch");
555
556         *cmdline_p = cmd_line;
557
558         /*
559          * Set cache line size based on type of cpu as a default.
560          * Systems with OF can look in the properties on the cpu node(s)
561          * for a possibly more accurate value.
562          */
563         dcache_bsize = ppc64_caches.dline_size;
564         icache_bsize = ppc64_caches.iline_size;
565
566         /* reboot on panic */
567         panic_timeout = 180;
568
569         if (ppc_md.panic)
570                 setup_panic();
571
572         init_mm.start_code = (unsigned long)_stext;
573         init_mm.end_code = (unsigned long) _etext;
574         init_mm.end_data = (unsigned long) _edata;
575         init_mm.brk = klimit;
576         
577         irqstack_early_init();
578         exc_lvl_early_init();
579         emergency_stack_init();
580
581 #ifdef CONFIG_PPC_STD_MMU_64
582         stabs_alloc();
583 #endif
584         /* set up the bootmem stuff with available memory */
585         do_init_bootmem();
586         sparse_init();
587
588 #ifdef CONFIG_DUMMY_CONSOLE
589         conswitchp = &dummy_con;
590 #endif
591
592         if (ppc_md.setup_arch)
593                 ppc_md.setup_arch();
594
595         paging_init();
596
597         /* Initialize the MMU context management stuff */
598         mmu_context_init();
599
600         kvm_linear_init();
601
602         ppc64_boot_msg(0x15, "Setup Done");
603 }
604
605
606 /* ToDo: do something useful if ppc_md is not yet setup. */
607 #define PPC64_LINUX_FUNCTION 0x0f000000
608 #define PPC64_IPL_MESSAGE 0xc0000000
609 #define PPC64_TERM_MESSAGE 0xb0000000
610
611 static void ppc64_do_msg(unsigned int src, const char *msg)
612 {
613         if (ppc_md.progress) {
614                 char buf[128];
615
616                 sprintf(buf, "%08X\n", src);
617                 ppc_md.progress(buf, 0);
618                 snprintf(buf, 128, "%s", msg);
619                 ppc_md.progress(buf, 0);
620         }
621 }
622
623 /* Print a boot progress message. */
624 void ppc64_boot_msg(unsigned int src, const char *msg)
625 {
626         ppc64_do_msg(PPC64_LINUX_FUNCTION|PPC64_IPL_MESSAGE|src, msg);
627         printk("[boot]%04x %s\n", src, msg);
628 }
629
630 #ifdef CONFIG_SMP
631 #define PCPU_DYN_SIZE           ()
632
633 static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
634 {
635         return __alloc_bootmem_node(NODE_DATA(cpu_to_node(cpu)), size, align,
636                                     __pa(MAX_DMA_ADDRESS));
637 }
638
639 static void __init pcpu_fc_free(void *ptr, size_t size)
640 {
641         free_bootmem(__pa(ptr), size);
642 }
643
644 static int pcpu_cpu_distance(unsigned int from, unsigned int to)
645 {
646         if (cpu_to_node(from) == cpu_to_node(to))
647                 return LOCAL_DISTANCE;
648         else
649                 return REMOTE_DISTANCE;
650 }
651
652 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
653 EXPORT_SYMBOL(__per_cpu_offset);
654
655 void __init setup_per_cpu_areas(void)
656 {
657         const size_t dyn_size = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
658         size_t atom_size;
659         unsigned long delta;
660         unsigned int cpu;
661         int rc;
662
663         /*
664          * Linear mapping is one of 4K, 1M and 16M.  For 4K, no need
665          * to group units.  For larger mappings, use 1M atom which
666          * should be large enough to contain a number of units.
667          */
668         if (mmu_linear_psize == MMU_PAGE_4K)
669                 atom_size = PAGE_SIZE;
670         else
671                 atom_size = 1 << 20;
672
673         rc = pcpu_embed_first_chunk(0, dyn_size, atom_size, pcpu_cpu_distance,
674                                     pcpu_fc_alloc, pcpu_fc_free);
675         if (rc < 0)
676                 panic("cannot initialize percpu area (err=%d)", rc);
677
678         delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
679         for_each_possible_cpu(cpu) {
680                 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
681                 paca[cpu].data_offset = __per_cpu_offset[cpu];
682         }
683 }
684 #endif
685
686
687 #ifdef CONFIG_PPC_INDIRECT_IO
688 struct ppc_pci_io ppc_pci_io;
689 EXPORT_SYMBOL(ppc_pci_io);
690 #endif /* CONFIG_PPC_INDIRECT_IO */
691