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>
40 #include <linux/nmi.h>
43 #include <asm/kdump.h>
45 #include <asm/processor.h>
46 #include <asm/pgtable.h>
49 #include <asm/machdep.h>
52 #include <asm/cputable.h>
53 #include <asm/sections.h>
54 #include <asm/btext.h>
55 #include <asm/nvram.h>
56 #include <asm/setup.h>
58 #include <asm/iommu.h>
59 #include <asm/serial.h>
60 #include <asm/cache.h>
63 #include <asm/firmware.h>
66 #include <asm/kexec.h>
67 #include <asm/mmu_context.h>
68 #include <asm/code-patching.h>
69 #include <asm/kvm_ppc.h>
70 #include <asm/hugetlb.h>
71 #include <asm/epapr_hcalls.h>
74 #define DBG(fmt...) udbg_printf(fmt)
79 int spinning_secondaries
;
82 /* Pick defaults since we might want to patch instructions
83 * before we've read this from the device tree.
85 struct ppc64_caches ppc64_caches
= {
91 EXPORT_SYMBOL_GPL(ppc64_caches
);
94 * These are used in binfmt_elf.c to put aux entries on the stack
95 * for each elf executable being started.
101 #if defined(CONFIG_PPC_BOOK3E) && defined(CONFIG_SMP)
102 static void setup_tlb_core_data(void)
106 BUILD_BUG_ON(offsetof(struct tlb_core_data
, lock
) != 0);
108 for_each_possible_cpu(cpu
) {
109 int first
= cpu_first_thread_sibling(cpu
);
112 * If we boot via kdump on a non-primary thread,
113 * make sure we point at the thread that actually
116 if (cpu_first_thread_sibling(boot_cpuid
) == first
)
119 paca
[cpu
].tcd_ptr
= &paca
[first
].tcd
;
122 * If we have threads, we need either tlbsrx.
123 * or e6500 tablewalk mode, or else TLB handlers
124 * will be racy and could produce duplicate entries.
126 if (smt_enabled_at_boot
>= 2 &&
127 !mmu_has_feature(MMU_FTR_USE_TLBRSRV
) &&
128 book3e_htw_mode
!= PPC_HTW_E6500
) {
129 /* Should we panic instead? */
130 WARN_ONCE("%s: unsupported MMU configuration -- expect problems\n",
136 static void setup_tlb_core_data(void)
143 static char *smt_enabled_cmdline
;
145 /* Look for ibm,smt-enabled OF option */
146 static void check_smt_enabled(void)
148 struct device_node
*dn
;
149 const char *smt_option
;
151 /* Default to enabling all threads */
152 smt_enabled_at_boot
= threads_per_core
;
154 /* Allow the command line to overrule the OF option */
155 if (smt_enabled_cmdline
) {
156 if (!strcmp(smt_enabled_cmdline
, "on"))
157 smt_enabled_at_boot
= threads_per_core
;
158 else if (!strcmp(smt_enabled_cmdline
, "off"))
159 smt_enabled_at_boot
= 0;
164 rc
= kstrtoint(smt_enabled_cmdline
, 10, &smt
);
166 smt_enabled_at_boot
=
167 min(threads_per_core
, smt
);
170 dn
= of_find_node_by_path("/options");
172 smt_option
= of_get_property(dn
, "ibm,smt-enabled",
176 if (!strcmp(smt_option
, "on"))
177 smt_enabled_at_boot
= threads_per_core
;
178 else if (!strcmp(smt_option
, "off"))
179 smt_enabled_at_boot
= 0;
187 /* Look for smt-enabled= cmdline option */
188 static int __init
early_smt_enabled(char *p
)
190 smt_enabled_cmdline
= p
;
193 early_param("smt-enabled", early_smt_enabled
);
196 #define check_smt_enabled()
197 #endif /* CONFIG_SMP */
199 /** Fix up paca fields required for the boot cpu */
200 static void fixup_boot_paca(void)
202 /* The boot cpu is started */
203 get_paca()->cpu_start
= 1;
204 /* Allow percpu accesses to work until we setup percpu data */
205 get_paca()->data_offset
= 0;
208 static void cpu_ready_for_interrupts(void)
210 /* Set IR and DR in PACA MSR */
211 get_paca()->kernel_msr
= MSR_KERNEL
;
214 * Enable AIL if supported, and we are in hypervisor mode. If we are
215 * not in hypervisor mode, we enable relocation-on interrupts later
216 * in pSeries_setup_arch() using the H_SET_MODE hcall.
218 if (cpu_has_feature(CPU_FTR_HVMODE
) &&
219 cpu_has_feature(CPU_FTR_ARCH_207S
)) {
220 unsigned long lpcr
= mfspr(SPRN_LPCR
);
221 mtspr(SPRN_LPCR
, lpcr
| LPCR_AIL_3
);
226 * Early initialization entry point. This is called by head.S
227 * with MMU translation disabled. We rely on the "feature" of
228 * the CPU that ignores the top 2 bits of the address in real
229 * mode so we can access kernel globals normally provided we
230 * only toy with things in the RMO region. From here, we do
231 * some early parsing of the device-tree to setup out MEMBLOCK
232 * data structures, and allocate & initialize the hash table
233 * and segment tables so we can start running with translation
236 * It is this function which will call the probe() callback of
237 * the various platform types and copy the matching one to the
238 * global ppc_md structure. Your platform can eventually do
239 * some very early initializations from the probe() routine, but
240 * this is not recommended, be very careful as, for example, the
241 * device-tree is not accessible via normal means at this point.
244 void __init
early_setup(unsigned long dt_ptr
)
246 static __initdata
struct paca_struct boot_paca
;
248 /* -------- printk is _NOT_ safe to use here ! ------- */
250 /* Identify CPU type */
251 identify_cpu(0, mfspr(SPRN_PVR
));
253 /* Assume we're on cpu 0 for now. Don't write to the paca yet! */
254 initialise_paca(&boot_paca
, 0);
255 setup_paca(&boot_paca
);
258 /* Initialize lockdep early or else spinlocks will blow */
261 /* -------- printk is now safe to use ------- */
263 /* Enable early debugging if any specified (see udbg.h) */
266 DBG(" -> early_setup(), dt_ptr: 0x%lx\n", dt_ptr
);
269 * Do early initialization using the flattened device
270 * tree, such as retrieving the physical memory map or
271 * calculating/retrieving the hash table size.
273 early_init_devtree(__va(dt_ptr
));
275 epapr_paravirt_early_init();
277 /* Now we know the logical id of our boot cpu, setup the paca. */
278 setup_paca(&paca
[boot_cpuid
]);
281 /* Probe the machine type */
284 setup_kdump_trampoline();
286 DBG("Found, Initializing memory management...\n");
288 /* Initialize the hash table or TLB handling */
292 * At this point, we can let interrupts switch to virtual mode
293 * (the MMU has been setup), so adjust the MSR in the PACA to
294 * have IR and DR set and enable AIL if it exists
296 cpu_ready_for_interrupts();
298 /* Reserve large chunks of memory for use by CMA for KVM */
302 * Reserve any gigantic pages requested on the command line.
303 * memblock needs to have been initialized by the time this is
304 * called since this will reserve memory.
306 reserve_hugetlb_gpages();
308 DBG(" <- early_setup()\n");
310 #ifdef CONFIG_PPC_EARLY_DEBUG_BOOTX
312 * This needs to be done *last* (after the above DBG() even)
314 * Right after we return from this function, we turn on the MMU
315 * which means the real-mode access trick that btext does will
316 * no longer work, it needs to switch to using a real MMU
317 * mapping. This call will ensure that it does
320 #endif /* CONFIG_PPC_EARLY_DEBUG_BOOTX */
324 void early_setup_secondary(void)
326 /* Mark interrupts enabled in PACA */
327 get_paca()->soft_enabled
= 0;
329 /* Initialize the hash table or TLB handling */
330 early_init_mmu_secondary();
333 * At this point, we can let interrupts switch to virtual mode
334 * (the MMU has been setup), so adjust the MSR in the PACA to
335 * have IR and DR set.
337 cpu_ready_for_interrupts();
340 #endif /* CONFIG_SMP */
342 #if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
343 static bool use_spinloop(void)
345 if (!IS_ENABLED(CONFIG_PPC_BOOK3E
))
349 * When book3e boots from kexec, the ePAPR spin table does
352 return of_property_read_bool(of_chosen
, "linux,booted-from-kexec");
355 void smp_release_cpus(void)
363 DBG(" -> smp_release_cpus()\n");
365 /* All secondary cpus are spinning on a common spinloop, release them
366 * all now so they can start to spin on their individual paca
367 * spinloops. For non SMP kernels, the secondary cpus never get out
368 * of the common spinloop.
371 ptr
= (unsigned long *)((unsigned long)&__secondary_hold_spinloop
373 *ptr
= ppc_function_entry(generic_secondary_smp_init
);
375 /* And wait a bit for them to catch up */
376 for (i
= 0; i
< 100000; i
++) {
379 if (spinning_secondaries
== 0)
383 DBG("spinning_secondaries = %d\n", spinning_secondaries
);
385 DBG(" <- smp_release_cpus()\n");
387 #endif /* CONFIG_SMP || CONFIG_KEXEC */
390 * Initialize some remaining members of the ppc64_caches and systemcfg
392 * (at least until we get rid of them completely). This is mostly some
393 * cache informations about the CPU that will be used by cache flush
394 * routines and/or provided to userland
396 static void __init
initialize_cache_info(void)
398 struct device_node
*np
;
399 unsigned long num_cpus
= 0;
401 DBG(" -> initialize_cache_info()\n");
403 for_each_node_by_type(np
, "cpu") {
407 * We're assuming *all* of the CPUs have the same
408 * d-cache and i-cache sizes... -Peter
411 const __be32
*sizep
, *lsizep
;
415 lsize
= cur_cpu_spec
->dcache_bsize
;
416 sizep
= of_get_property(np
, "d-cache-size", NULL
);
418 size
= be32_to_cpu(*sizep
);
419 lsizep
= of_get_property(np
, "d-cache-block-size",
421 /* fallback if block size missing */
423 lsizep
= of_get_property(np
,
427 lsize
= be32_to_cpu(*lsizep
);
428 if (sizep
== NULL
|| lsizep
== NULL
)
429 DBG("Argh, can't find dcache properties ! "
430 "sizep: %p, lsizep: %p\n", sizep
, lsizep
);
432 ppc64_caches
.dsize
= size
;
433 ppc64_caches
.dline_size
= lsize
;
434 ppc64_caches
.log_dline_size
= __ilog2(lsize
);
435 ppc64_caches
.dlines_per_page
= PAGE_SIZE
/ lsize
;
438 lsize
= cur_cpu_spec
->icache_bsize
;
439 sizep
= of_get_property(np
, "i-cache-size", NULL
);
441 size
= be32_to_cpu(*sizep
);
442 lsizep
= of_get_property(np
, "i-cache-block-size",
445 lsizep
= of_get_property(np
,
449 lsize
= be32_to_cpu(*lsizep
);
450 if (sizep
== NULL
|| lsizep
== NULL
)
451 DBG("Argh, can't find icache properties ! "
452 "sizep: %p, lsizep: %p\n", sizep
, lsizep
);
454 ppc64_caches
.isize
= size
;
455 ppc64_caches
.iline_size
= lsize
;
456 ppc64_caches
.log_iline_size
= __ilog2(lsize
);
457 ppc64_caches
.ilines_per_page
= PAGE_SIZE
/ lsize
;
461 DBG(" <- initialize_cache_info()\n");
466 * Do some initial setup of the system. The parameters are those which
467 * were passed in from the bootloader.
469 void __init
setup_system(void)
471 DBG(" -> setup_system()\n");
473 /* Apply the CPUs-specific and firmware specific fixups to kernel
474 * text (nop out sections not relevant to this CPU or this firmware)
476 do_feature_fixups(cur_cpu_spec
->cpu_features
,
477 &__start___ftr_fixup
, &__stop___ftr_fixup
);
478 do_feature_fixups(cur_cpu_spec
->mmu_features
,
479 &__start___mmu_ftr_fixup
, &__stop___mmu_ftr_fixup
);
480 do_feature_fixups(powerpc_firmware_features
,
481 &__start___fw_ftr_fixup
, &__stop___fw_ftr_fixup
);
482 do_lwsync_fixups(cur_cpu_spec
->cpu_features
,
483 &__start___lwsync_fixup
, &__stop___lwsync_fixup
);
487 * Unflatten the device-tree passed by prom_init or kexec
489 unflatten_device_tree();
492 * Fill the ppc64_caches & systemcfg structures with informations
493 * retrieved from the device-tree.
495 initialize_cache_info();
497 #ifdef CONFIG_PPC_RTAS
499 * Initialize RTAS if available
502 #endif /* CONFIG_PPC_RTAS */
505 * Check if we have an initrd provided via the device-tree
510 * Do some platform specific early initializations, that includes
511 * setting up the hash table pointers. It also sets up some interrupt-mapping
512 * related options that will be used by finish_device_tree()
514 if (ppc_md
.init_early
)
518 * We can discover serial ports now since the above did setup the
519 * hash table management for us, thus ioremap works. We do that early
520 * so that further code can be debugged
522 find_legacy_serial_ports();
525 * Register early console
527 register_early_udbg_console();
534 smp_setup_cpu_maps();
536 setup_tlb_core_data();
539 * Freescale Book3e parts spin in a loop provided by firmware,
540 * so smp_release_cpus() does nothing for them
542 #if defined(CONFIG_SMP)
543 /* Release secondary cpus out of their spinloops at 0x60 now that
544 * we can map physical -> logical CPU ids
549 pr_info("Starting Linux %s %s\n", init_utsname()->machine
,
550 init_utsname()->version
);
552 pr_info("-----------------------------------------------------\n");
553 pr_info("ppc64_pft_size = 0x%llx\n", ppc64_pft_size
);
554 pr_info("phys_mem_size = 0x%llx\n", memblock_phys_mem_size());
556 if (ppc64_caches
.dline_size
!= 0x80)
557 pr_info("dcache_line_size = 0x%x\n", ppc64_caches
.dline_size
);
558 if (ppc64_caches
.iline_size
!= 0x80)
559 pr_info("icache_line_size = 0x%x\n", ppc64_caches
.iline_size
);
561 pr_info("cpu_features = 0x%016lx\n", cur_cpu_spec
->cpu_features
);
562 pr_info(" possible = 0x%016lx\n", CPU_FTRS_POSSIBLE
);
563 pr_info(" always = 0x%016lx\n", CPU_FTRS_ALWAYS
);
564 pr_info("cpu_user_features = 0x%08x 0x%08x\n", cur_cpu_spec
->cpu_user_features
,
565 cur_cpu_spec
->cpu_user_features2
);
566 pr_info("mmu_features = 0x%08x\n", cur_cpu_spec
->mmu_features
);
567 pr_info("firmware_features = 0x%016lx\n", powerpc_firmware_features
);
569 #ifdef CONFIG_PPC_STD_MMU_64
571 pr_info("htab_address = 0x%p\n", htab_address
);
573 pr_info("htab_hash_mask = 0x%lx\n", htab_hash_mask
);
576 if (PHYSICAL_START
> 0)
577 pr_info("physical_start = 0x%llx\n",
578 (unsigned long long)PHYSICAL_START
);
579 pr_info("-----------------------------------------------------\n");
581 DBG(" <- setup_system()\n");
584 /* This returns the limit below which memory accesses to the linear
585 * mapping are guarnateed not to cause a TLB or SLB miss. This is
586 * used to allocate interrupt or emergency stacks for which our
587 * exception entry path doesn't deal with being interrupted.
589 static u64
safe_stack_limit(void)
591 #ifdef CONFIG_PPC_BOOK3E
592 /* Freescale BookE bolts the entire linear mapping */
593 if (mmu_has_feature(MMU_FTR_TYPE_FSL_E
))
594 return linear_map_top
;
595 /* Other BookE, we assume the first GB is bolted */
598 /* BookS, the first segment is bolted */
599 if (mmu_has_feature(MMU_FTR_1T_SEGMENT
))
600 return 1UL << SID_SHIFT_1T
;
601 return 1UL << SID_SHIFT
;
605 static void __init
irqstack_early_init(void)
607 u64 limit
= safe_stack_limit();
611 * Interrupt stacks must be in the first segment since we
612 * cannot afford to take SLB misses on them.
614 for_each_possible_cpu(i
) {
615 softirq_ctx
[i
] = (struct thread_info
*)
616 __va(memblock_alloc_base(THREAD_SIZE
,
617 THREAD_SIZE
, limit
));
618 hardirq_ctx
[i
] = (struct thread_info
*)
619 __va(memblock_alloc_base(THREAD_SIZE
,
620 THREAD_SIZE
, limit
));
624 #ifdef CONFIG_PPC_BOOK3E
625 static void __init
exc_lvl_early_init(void)
630 for_each_possible_cpu(i
) {
631 sp
= memblock_alloc(THREAD_SIZE
, THREAD_SIZE
);
632 critirq_ctx
[i
] = (struct thread_info
*)__va(sp
);
633 paca
[i
].crit_kstack
= __va(sp
+ THREAD_SIZE
);
635 sp
= memblock_alloc(THREAD_SIZE
, THREAD_SIZE
);
636 dbgirq_ctx
[i
] = (struct thread_info
*)__va(sp
);
637 paca
[i
].dbg_kstack
= __va(sp
+ THREAD_SIZE
);
639 sp
= memblock_alloc(THREAD_SIZE
, THREAD_SIZE
);
640 mcheckirq_ctx
[i
] = (struct thread_info
*)__va(sp
);
641 paca
[i
].mc_kstack
= __va(sp
+ THREAD_SIZE
);
644 if (cpu_has_feature(CPU_FTR_DEBUG_LVL_EXC
))
645 patch_exception(0x040, exc_debug_debug_book3e
);
648 #define exc_lvl_early_init()
652 * Stack space used when we detect a bad kernel stack pointer, and
653 * early in SMP boots before relocation is enabled. Exclusive emergency
654 * stack for machine checks.
656 static void __init
emergency_stack_init(void)
662 * Emergency stacks must be under 256MB, we cannot afford to take
663 * SLB misses on them. The ABI also requires them to be 128-byte
666 * Since we use these as temporary stacks during secondary CPU
667 * bringup, we need to get at them in real mode. This means they
668 * must also be within the RMO region.
670 limit
= min(safe_stack_limit(), ppc64_rma_size
);
672 for_each_possible_cpu(i
) {
674 sp
= memblock_alloc_base(THREAD_SIZE
, THREAD_SIZE
, limit
);
676 paca
[i
].emergency_sp
= __va(sp
);
678 #ifdef CONFIG_PPC_BOOK3S_64
679 /* emergency stack for machine check exception handling. */
680 sp
= memblock_alloc_base(THREAD_SIZE
, THREAD_SIZE
, limit
);
682 paca
[i
].mc_emergency_sp
= __va(sp
);
688 * Called into from start_kernel this initializes memblock, which is used
689 * to manage page allocation until mem_init is called.
691 void __init
setup_arch(char **cmdline_p
)
693 *cmdline_p
= boot_command_line
;
696 * Set cache line size based on type of cpu as a default.
697 * Systems with OF can look in the properties on the cpu node(s)
698 * for a possibly more accurate value.
700 dcache_bsize
= ppc64_caches
.dline_size
;
701 icache_bsize
= ppc64_caches
.iline_size
;
706 init_mm
.start_code
= (unsigned long)_stext
;
707 init_mm
.end_code
= (unsigned long) _etext
;
708 init_mm
.end_data
= (unsigned long) _edata
;
709 init_mm
.brk
= klimit
;
710 #ifdef CONFIG_PPC_64K_PAGES
711 init_mm
.context
.pte_frag
= NULL
;
713 #ifdef CONFIG_SPAPR_TCE_IOMMU
714 mm_iommu_init(&init_mm
.context
);
716 irqstack_early_init();
717 exc_lvl_early_init();
718 emergency_stack_init();
722 #ifdef CONFIG_DUMMY_CONSOLE
723 conswitchp
= &dummy_con
;
726 if (ppc_md
.setup_arch
)
731 /* Initialize the MMU context management stuff */
734 /* Interrupt code needs to be 64K-aligned */
735 if ((unsigned long)_stext
& 0xffff)
736 panic("Kernelbase not 64K-aligned (0x%lx)!\n",
737 (unsigned long)_stext
);
741 #define PCPU_DYN_SIZE ()
743 static void * __init
pcpu_fc_alloc(unsigned int cpu
, size_t size
, size_t align
)
745 return __alloc_bootmem_node(NODE_DATA(cpu_to_node(cpu
)), size
, align
,
746 __pa(MAX_DMA_ADDRESS
));
749 static void __init
pcpu_fc_free(void *ptr
, size_t size
)
751 free_bootmem(__pa(ptr
), size
);
754 static int pcpu_cpu_distance(unsigned int from
, unsigned int to
)
756 if (cpu_to_node(from
) == cpu_to_node(to
))
757 return LOCAL_DISTANCE
;
759 return REMOTE_DISTANCE
;
762 unsigned long __per_cpu_offset
[NR_CPUS
] __read_mostly
;
763 EXPORT_SYMBOL(__per_cpu_offset
);
765 void __init
setup_per_cpu_areas(void)
767 const size_t dyn_size
= PERCPU_MODULE_RESERVE
+ PERCPU_DYNAMIC_RESERVE
;
774 * Linear mapping is one of 4K, 1M and 16M. For 4K, no need
775 * to group units. For larger mappings, use 1M atom which
776 * should be large enough to contain a number of units.
778 if (mmu_linear_psize
== MMU_PAGE_4K
)
779 atom_size
= PAGE_SIZE
;
783 rc
= pcpu_embed_first_chunk(0, dyn_size
, atom_size
, pcpu_cpu_distance
,
784 pcpu_fc_alloc
, pcpu_fc_free
);
786 panic("cannot initialize percpu area (err=%d)", rc
);
788 delta
= (unsigned long)pcpu_base_addr
- (unsigned long)__per_cpu_start
;
789 for_each_possible_cpu(cpu
) {
790 __per_cpu_offset
[cpu
] = delta
+ pcpu_unit_offsets
[cpu
];
791 paca
[cpu
].data_offset
= __per_cpu_offset
[cpu
];
796 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
797 unsigned long memory_block_size_bytes(void)
799 if (ppc_md
.memory_block_size
)
800 return ppc_md
.memory_block_size();
802 return MIN_MEMORY_BLOCK_SIZE
;
806 #if defined(CONFIG_PPC_INDIRECT_PIO) || defined(CONFIG_PPC_INDIRECT_MMIO)
807 struct ppc_pci_io ppc_pci_io
;
808 EXPORT_SYMBOL(ppc_pci_io
);
811 #ifdef CONFIG_HARDLOCKUP_DETECTOR
812 u64
hw_nmi_get_sample_period(int watchdog_thresh
)
814 return ppc_proc_freq
* watchdog_thresh
;
818 * The hardlockup detector breaks PMU event based branches and is likely
819 * to get false positives in KVM guests, so disable it by default.
821 static int __init
disable_hardlockup_detector(void)
823 hardlockup_detector_disable();
827 early_initcall(disable_hardlockup_detector
);