1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Procedures for creating, accessing and interpreting the device tree.
5 * Paul Mackerras August 1996.
6 * Copyright (C) 1996-2005 Paul Mackerras.
8 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
9 * {engebret|bergner}@us.ibm.com
15 #include <linux/kernel.h>
16 #include <linux/string.h>
17 #include <linux/init.h>
18 #include <linux/threads.h>
19 #include <linux/spinlock.h>
20 #include <linux/types.h>
21 #include <linux/pci.h>
22 #include <linux/delay.h>
23 #include <linux/initrd.h>
24 #include <linux/bitops.h>
25 #include <linux/export.h>
26 #include <linux/kexec.h>
27 #include <linux/irq.h>
28 #include <linux/memblock.h>
30 #include <linux/of_fdt.h>
31 #include <linux/libfdt.h>
32 #include <linux/cpu.h>
33 #include <linux/pgtable.h>
38 #include <asm/processor.h>
41 #include <asm/kdump.h>
45 #include <asm/powernv.h>
46 #include <asm/iommu.h>
47 #include <asm/btext.h>
48 #include <asm/sections.h>
49 #include <asm/machdep.h>
50 #include <asm/pci-bridge.h>
51 #include <asm/kexec.h>
53 #include <asm/fadump.h>
54 #include <asm/epapr_hcalls.h>
55 #include <asm/firmware.h>
56 #include <asm/dt_cpu_ftrs.h>
57 #include <asm/drmem.h>
58 #include <asm/ultravisor.h>
60 #include <mm/mmu_decl.h>
63 #define DBG(fmt...) printk(KERN_ERR fmt)
68 int *chip_id_lookup_table;
71 int __initdata iommu_is_off;
72 int __initdata iommu_force_on;
73 unsigned long tce_alloc_start, tce_alloc_end;
76 static phys_addr_t first_memblock_size;
77 static int __initdata boot_cpu_count;
79 static int __init early_parse_mem(char *p)
84 memory_limit = PAGE_ALIGN(memparse(p, &p));
85 DBG("memory limit = 0x%llx\n", memory_limit);
89 early_param("mem", early_parse_mem);
92 * overlaps_initrd - check for overlap with page aligned extension of
95 static inline int overlaps_initrd(unsigned long start, unsigned long size)
97 #ifdef CONFIG_BLK_DEV_INITRD
101 return (start + size) > ALIGN_DOWN(initrd_start, PAGE_SIZE) &&
102 start <= ALIGN(initrd_end, PAGE_SIZE);
109 * move_device_tree - move tree to an unused area, if needed.
111 * The device tree may be allocated beyond our memory limit, or inside the
112 * crash kernel region for kdump, or within the page aligned range of initrd.
113 * If so, move it out of the way.
115 static void __init move_device_tree(void)
117 unsigned long start, size;
120 DBG("-> move_device_tree\n");
122 start = __pa(initial_boot_params);
123 size = fdt_totalsize(initial_boot_params);
125 if ((memory_limit && (start + size) > PHYSICAL_START + memory_limit) ||
126 !memblock_is_memory(start + size - 1) ||
127 overlaps_crashkernel(start, size) || overlaps_initrd(start, size)) {
128 p = memblock_alloc_raw(size, PAGE_SIZE);
130 panic("Failed to allocate %lu bytes to move device tree\n",
132 memcpy(p, initial_boot_params, size);
133 initial_boot_params = p;
134 DBG("Moved device tree to 0x%px\n", p);
137 DBG("<- move_device_tree\n");
141 * ibm,pa-features is a per-cpu property that contains a string of
142 * attribute descriptors, each of which has a 2 byte header plus up
143 * to 254 bytes worth of processor attribute bits. First header
144 * byte specifies the number of bytes following the header.
145 * Second header byte is an "attribute-specifier" type, of which
146 * zero is the only currently-defined value.
147 * Implementation: Pass in the byte and bit offset for the feature
148 * that we are interested in. The function will return -1 if the
149 * pa-features property is missing, or a 1/0 to indicate if the feature
150 * is supported/not supported. Note that the bit numbers are
151 * big-endian to match the definition in PAPR.
153 static struct ibm_pa_feature {
154 unsigned long cpu_features; /* CPU_FTR_xxx bit */
155 unsigned long mmu_features; /* MMU_FTR_xxx bit */
156 unsigned int cpu_user_ftrs; /* PPC_FEATURE_xxx bit */
157 unsigned int cpu_user_ftrs2; /* PPC_FEATURE2_xxx bit */
158 unsigned char pabyte; /* byte number in ibm,pa-features */
159 unsigned char pabit; /* bit number (big-endian) */
160 unsigned char invert; /* if 1, pa bit set => clear feature */
161 } ibm_pa_features[] __initdata = {
162 { .pabyte = 0, .pabit = 0, .cpu_user_ftrs = PPC_FEATURE_HAS_MMU },
163 { .pabyte = 0, .pabit = 1, .cpu_user_ftrs = PPC_FEATURE_HAS_FPU },
164 { .pabyte = 0, .pabit = 3, .cpu_features = CPU_FTR_CTRL },
165 { .pabyte = 0, .pabit = 6, .cpu_features = CPU_FTR_NOEXECUTE },
166 { .pabyte = 1, .pabit = 2, .mmu_features = MMU_FTR_CI_LARGE_PAGE },
167 #ifdef CONFIG_PPC_RADIX_MMU
168 { .pabyte = 40, .pabit = 0, .mmu_features = MMU_FTR_TYPE_RADIX | MMU_FTR_GTSE },
170 { .pabyte = 5, .pabit = 0, .cpu_features = CPU_FTR_REAL_LE,
171 .cpu_user_ftrs = PPC_FEATURE_TRUE_LE },
173 * If the kernel doesn't support TM (ie CONFIG_PPC_TRANSACTIONAL_MEM=n),
174 * we don't want to turn on TM here, so we use the *_COMP versions
175 * which are 0 if the kernel doesn't support TM.
177 { .pabyte = 22, .pabit = 0, .cpu_features = CPU_FTR_TM_COMP,
178 .cpu_user_ftrs2 = PPC_FEATURE2_HTM_COMP | PPC_FEATURE2_HTM_NOSC_COMP },
180 { .pabyte = 64, .pabit = 0, .cpu_features = CPU_FTR_DAWR1 },
183 static void __init scan_features(unsigned long node, const unsigned char *ftrs,
184 unsigned long tablelen,
185 struct ibm_pa_feature *fp,
186 unsigned long ft_size)
188 unsigned long i, len, bit;
190 /* find descriptor with type == 0 */
196 return; /* descriptor 0 not found */
203 /* loop over bits we know about */
204 for (i = 0; i < ft_size; ++i, ++fp) {
205 if (fp->pabyte >= ftrs[0])
207 bit = (ftrs[2 + fp->pabyte] >> (7 - fp->pabit)) & 1;
208 if (bit ^ fp->invert) {
209 cur_cpu_spec->cpu_features |= fp->cpu_features;
210 cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftrs;
211 cur_cpu_spec->cpu_user_features2 |= fp->cpu_user_ftrs2;
212 cur_cpu_spec->mmu_features |= fp->mmu_features;
214 cur_cpu_spec->cpu_features &= ~fp->cpu_features;
215 cur_cpu_spec->cpu_user_features &= ~fp->cpu_user_ftrs;
216 cur_cpu_spec->cpu_user_features2 &= ~fp->cpu_user_ftrs2;
217 cur_cpu_spec->mmu_features &= ~fp->mmu_features;
222 static void __init check_cpu_pa_features(unsigned long node)
224 const unsigned char *pa_ftrs;
227 pa_ftrs = of_get_flat_dt_prop(node, "ibm,pa-features", &tablelen);
231 scan_features(node, pa_ftrs, tablelen,
232 ibm_pa_features, ARRAY_SIZE(ibm_pa_features));
235 #ifdef CONFIG_PPC_BOOK3S_64
236 static void __init init_mmu_slb_size(unsigned long node)
238 const __be32 *slb_size_ptr;
240 slb_size_ptr = of_get_flat_dt_prop(node, "slb-size", NULL) ? :
241 of_get_flat_dt_prop(node, "ibm,slb-size", NULL);
244 mmu_slb_size = be32_to_cpup(slb_size_ptr);
247 #define init_mmu_slb_size(node) do { } while(0)
250 static struct feature_property {
253 unsigned long cpu_feature;
254 unsigned long cpu_user_ftr;
255 } feature_properties[] __initdata = {
256 #ifdef CONFIG_ALTIVEC
257 {"altivec", 0, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
258 {"ibm,vmx", 1, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
259 #endif /* CONFIG_ALTIVEC */
261 /* Yes, this _really_ is ibm,vmx == 2 to enable VSX */
262 {"ibm,vmx", 2, CPU_FTR_VSX, PPC_FEATURE_HAS_VSX},
263 #endif /* CONFIG_VSX */
265 {"ibm,dfp", 1, 0, PPC_FEATURE_HAS_DFP},
266 {"ibm,purr", 1, CPU_FTR_PURR, 0},
267 {"ibm,spurr", 1, CPU_FTR_SPURR, 0},
268 #endif /* CONFIG_PPC64 */
271 #if defined(CONFIG_44x) && defined(CONFIG_PPC_FPU)
272 static __init void identical_pvr_fixup(unsigned long node)
275 const char *model = of_get_flat_dt_prop(node, "model", NULL);
278 * Since 440GR(x)/440EP(x) processors have the same pvr,
279 * we check the node path and set bit 28 in the cur_cpu_spec
280 * pvr for EP(x) processor version. This bit is always 0 in
281 * the "real" pvr. Then we call identify_cpu again with
282 * the new logical pvr to enable FPU support.
284 if (model && strstr(model, "440EP")) {
285 pvr = cur_cpu_spec->pvr_value | 0x8;
286 identify_cpu(0, pvr);
287 DBG("Using logical pvr %x for %s\n", pvr, model);
291 #define identical_pvr_fixup(node) do { } while(0)
294 static void __init check_cpu_feature_properties(unsigned long node)
297 struct feature_property *fp = feature_properties;
300 for (i = 0; i < (int)ARRAY_SIZE(feature_properties); ++i, ++fp) {
301 prop = of_get_flat_dt_prop(node, fp->name, NULL);
302 if (prop && be32_to_cpup(prop) >= fp->min_value) {
303 cur_cpu_spec->cpu_features |= fp->cpu_feature;
304 cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftr;
309 static int __init early_init_dt_scan_cpus(unsigned long node,
310 const char *uname, int depth,
313 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
315 const __be32 *intserv;
319 int found_thread = 0;
321 /* We are scanning "cpu" nodes only */
322 if (type == NULL || strcmp(type, "cpu") != 0)
325 /* Get physical cpuid */
326 intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
328 intserv = of_get_flat_dt_prop(node, "reg", &len);
330 nthreads = len / sizeof(int);
333 * Now see if any of these threads match our boot cpu.
334 * NOTE: This must match the parsing done in smp_setup_cpu_maps.
336 for (i = 0; i < nthreads; i++) {
337 if (be32_to_cpu(intserv[i]) ==
338 fdt_boot_cpuid_phys(initial_boot_params)) {
339 found = boot_cpu_count;
343 /* logical cpu id is always 0 on UP kernels */
348 /* Not the boot CPU */
352 DBG("boot cpu: logical %d physical %d\n", found,
353 be32_to_cpu(intserv[found_thread]));
357 * PAPR defines "logical" PVR values for cpus that
358 * meet various levels of the architecture:
359 * 0x0f000001 Architecture version 2.04
360 * 0x0f000002 Architecture version 2.05
361 * If the cpu-version property in the cpu node contains
362 * such a value, we call identify_cpu again with the
363 * logical PVR value in order to use the cpu feature
364 * bits appropriate for the architecture level.
366 * A POWER6 partition in "POWER6 architected" mode
367 * uses the 0x0f000002 PVR value; in POWER5+ mode
368 * it uses 0x0f000001.
370 * If we're using device tree CPU feature discovery then we don't
371 * support the cpu-version property, and it's the responsibility of the
372 * firmware/hypervisor to provide the correct feature set for the
373 * architecture level via the ibm,powerpc-cpu-features binding.
375 if (!dt_cpu_ftrs_in_use()) {
376 prop = of_get_flat_dt_prop(node, "cpu-version", NULL);
377 if (prop && (be32_to_cpup(prop) & 0xff000000) == 0x0f000000)
378 identify_cpu(0, be32_to_cpup(prop));
380 check_cpu_feature_properties(node);
381 check_cpu_pa_features(node);
384 identical_pvr_fixup(node);
385 init_mmu_slb_size(node);
389 cur_cpu_spec->cpu_features &= ~CPU_FTR_SMT;
390 else if (!dt_cpu_ftrs_in_use())
391 cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
392 allocate_paca(boot_cpuid);
394 set_hard_smp_processor_id(found, be32_to_cpu(intserv[found_thread]));
399 static int __init early_init_dt_scan_chosen_ppc(unsigned long node,
401 int depth, void *data)
403 const unsigned long *lprop; /* All these set by kernel, so no need to convert endian */
405 /* Use common scan routine to determine if this is the chosen node */
406 if (early_init_dt_scan_chosen(node, uname, depth, data) == 0)
410 /* check if iommu is forced on or off */
411 if (of_get_flat_dt_prop(node, "linux,iommu-off", NULL) != NULL)
413 if (of_get_flat_dt_prop(node, "linux,iommu-force-on", NULL) != NULL)
417 /* mem=x on the command line is the preferred mechanism */
418 lprop = of_get_flat_dt_prop(node, "linux,memory-limit", NULL);
420 memory_limit = *lprop;
423 lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-start", NULL);
425 tce_alloc_start = *lprop;
426 lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-end", NULL);
428 tce_alloc_end = *lprop;
431 #ifdef CONFIG_KEXEC_CORE
432 lprop = of_get_flat_dt_prop(node, "linux,crashkernel-base", NULL);
434 crashk_res.start = *lprop;
436 lprop = of_get_flat_dt_prop(node, "linux,crashkernel-size", NULL);
438 crashk_res.end = crashk_res.start + *lprop - 1;
446 * Compare the range against max mem limit and update
447 * size if it cross the limit.
450 #ifdef CONFIG_SPARSEMEM
451 static bool validate_mem_limit(u64 base, u64 *size)
453 u64 max_mem = 1UL << (MAX_PHYSMEM_BITS);
457 if ((base + *size) > max_mem)
458 *size = max_mem - base;
462 static bool validate_mem_limit(u64 base, u64 *size)
468 #ifdef CONFIG_PPC_PSERIES
470 * Interpret the ibm dynamic reconfiguration memory LMBs.
471 * This contains a list of memory blocks along with NUMA affinity
474 static int __init early_init_drmem_lmb(struct drmem_lmb *lmb,
479 int is_kexec_kdump = 0, rngs;
481 base = lmb->base_addr;
482 size = drmem_lmb_size();
486 * Skip this block if the reserved bit is set in flags
487 * or if the block is not assigned to this partition.
489 if ((lmb->flags & DRCONF_MEM_RESERVED) ||
490 !(lmb->flags & DRCONF_MEM_ASSIGNED))
496 if (is_kexec_kdump) {
498 * For each memblock in ibm,dynamic-memory, a
499 * corresponding entry in linux,drconf-usable-memory
500 * property contains a counter 'p' followed by 'p'
501 * (base, size) duple. Now read the counter from
502 * linux,drconf-usable-memory property
504 rngs = dt_mem_next_cell(dt_root_size_cells, usm);
505 if (!rngs) /* there are no (base, size) duple */
510 if (is_kexec_kdump) {
511 base = dt_mem_next_cell(dt_root_addr_cells, usm);
512 size = dt_mem_next_cell(dt_root_size_cells, usm);
516 if (base >= 0x80000000ul)
518 if ((base + size) > 0x80000000ul)
519 size = 0x80000000ul - base;
522 if (!validate_mem_limit(base, &size))
525 DBG("Adding: %llx -> %llx\n", base, size);
526 memblock_add(base, size);
528 if (lmb->flags & DRCONF_MEM_HOTREMOVABLE)
529 memblock_mark_hotplug(base, size);
534 #endif /* CONFIG_PPC_PSERIES */
536 static int __init early_init_dt_scan_memory_ppc(unsigned long node,
538 int depth, void *data)
540 #ifdef CONFIG_PPC_PSERIES
542 strcmp(uname, "ibm,dynamic-reconfiguration-memory") == 0) {
543 walk_drmem_lmbs_early(node, NULL, early_init_drmem_lmb);
548 return early_init_dt_scan_memory(node, uname, depth, data);
552 * For a relocatable kernel, we need to get the memstart_addr first,
553 * then use it to calculate the virtual kernel start address. This has
554 * to happen at a very early stage (before machine_init). In this case,
555 * we just want to get the memstart_address and would not like to mess the
556 * memblock at this stage. So introduce a variable to skip the memblock_add()
559 #ifdef CONFIG_RELOCATABLE
560 static int add_mem_to_memblock = 1;
562 #define add_mem_to_memblock 1
565 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
569 if (base >= 0x80000000ul)
571 if ((base + size) > 0x80000000ul)
572 size = 0x80000000ul - base;
575 /* Keep track of the beginning of memory -and- the size of
576 * the very first block in the device-tree as it represents
577 * the RMA on ppc64 server
579 if (base < memstart_addr) {
580 memstart_addr = base;
581 first_memblock_size = size;
584 /* Add the chunk to the MEMBLOCK list */
585 if (add_mem_to_memblock) {
586 if (validate_mem_limit(base, &size))
587 memblock_add(base, size);
591 static void __init early_reserve_mem_dt(void)
593 unsigned long i, dt_root;
597 early_init_fdt_reserve_self();
598 early_init_fdt_scan_reserved_mem();
600 dt_root = of_get_flat_dt_root();
602 prop = of_get_flat_dt_prop(dt_root, "reserved-ranges", &len);
607 DBG("Found new-style reserved-ranges\n");
609 /* Each reserved range is an (address,size) pair, 2 cells each,
610 * totalling 4 cells per range. */
611 for (i = 0; i < len / (sizeof(*prop) * 4); i++) {
614 base = of_read_number(prop + (i * 4) + 0, 2);
615 size = of_read_number(prop + (i * 4) + 2, 2);
618 DBG("reserving: %llx -> %llx\n", base, size);
619 memblock_reserve(base, size);
624 static void __init early_reserve_mem(void)
628 reserve_map = (__be64 *)(((unsigned long)initial_boot_params) +
629 fdt_off_mem_rsvmap(initial_boot_params));
631 /* Look for the new "reserved-regions" property in the DT */
632 early_reserve_mem_dt();
634 #ifdef CONFIG_BLK_DEV_INITRD
635 /* Then reserve the initrd, if any */
636 if (initrd_start && (initrd_end > initrd_start)) {
637 memblock_reserve(ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
638 ALIGN(initrd_end, PAGE_SIZE) -
639 ALIGN_DOWN(initrd_start, PAGE_SIZE));
641 #endif /* CONFIG_BLK_DEV_INITRD */
645 * Handle the case where we might be booting from an old kexec
646 * image that setup the mem_rsvmap as pairs of 32-bit values
648 if (be64_to_cpup(reserve_map) > 0xffffffffull) {
649 u32 base_32, size_32;
650 __be32 *reserve_map_32 = (__be32 *)reserve_map;
652 DBG("Found old 32-bit reserve map\n");
655 base_32 = be32_to_cpup(reserve_map_32++);
656 size_32 = be32_to_cpup(reserve_map_32++);
659 DBG("reserving: %x -> %x\n", base_32, size_32);
660 memblock_reserve(base_32, size_32);
667 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
668 static bool tm_disabled __initdata;
670 static int __init parse_ppc_tm(char *str)
674 if (kstrtobool(str, &res))
681 early_param("ppc_tm", parse_ppc_tm);
683 static void __init tm_init(void)
686 pr_info("Disabling hardware transactional memory (HTM)\n");
687 cur_cpu_spec->cpu_user_features2 &=
688 ~(PPC_FEATURE2_HTM_NOSC | PPC_FEATURE2_HTM);
689 cur_cpu_spec->cpu_features &= ~CPU_FTR_TM;
696 static void tm_init(void) { }
697 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
700 static void __init save_fscr_to_task(void)
703 * Ensure the init_task (pid 0, aka swapper) uses the value of FSCR we
704 * have configured via the device tree features or via __init_FSCR().
705 * That value will then be propagated to pid 1 (init) and all future
708 if (early_cpu_has_feature(CPU_FTR_ARCH_207S))
709 init_task.thread.fscr = mfspr(SPRN_FSCR);
712 static inline void save_fscr_to_task(void) {}
716 void __init early_init_devtree(void *params)
720 DBG(" -> early_init_devtree(%px)\n", params);
722 /* Too early to BUG_ON(), do it by hand */
723 if (!early_init_dt_verify(params))
724 panic("BUG: Failed verifying flat device tree, bad version?");
726 #ifdef CONFIG_PPC_RTAS
727 /* Some machines might need RTAS info for debugging, grab it now. */
728 of_scan_flat_dt(early_init_dt_scan_rtas, NULL);
731 #ifdef CONFIG_PPC_POWERNV
732 /* Some machines might need OPAL info for debugging, grab it now. */
733 of_scan_flat_dt(early_init_dt_scan_opal, NULL);
735 /* Scan tree for ultravisor feature */
736 of_scan_flat_dt(early_init_dt_scan_ultravisor, NULL);
739 #if defined(CONFIG_FA_DUMP) || defined(CONFIG_PRESERVE_FA_DUMP)
740 /* scan tree to see if dump is active during last boot */
741 of_scan_flat_dt(early_init_dt_scan_fw_dump, NULL);
744 /* Retrieve various informations from the /chosen node of the
745 * device-tree, including the platform type, initrd location and
746 * size, TCE reserve, and more ...
748 of_scan_flat_dt(early_init_dt_scan_chosen_ppc, boot_command_line);
750 /* Scan memory nodes and rebuild MEMBLOCKs */
751 of_scan_flat_dt(early_init_dt_scan_root, NULL);
752 of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
756 /* make sure we've parsed cmdline for mem= before this */
758 first_memblock_size = min_t(u64, first_memblock_size, memory_limit);
759 setup_initial_memory_limit(memstart_addr, first_memblock_size);
760 /* Reserve MEMBLOCK regions used by kernel, initrd, dt, etc... */
761 memblock_reserve(PHYSICAL_START, __pa(_end) - PHYSICAL_START);
762 /* If relocatable, reserve first 32k for interrupt vectors etc. */
763 if (PHYSICAL_START > MEMORY_START)
764 memblock_reserve(MEMORY_START, 0x8000);
765 reserve_kdump_trampoline();
766 #if defined(CONFIG_FA_DUMP) || defined(CONFIG_PRESERVE_FA_DUMP)
768 * If we fail to reserve memory for firmware-assisted dump then
769 * fallback to kexec based kdump.
771 if (fadump_reserve_mem() == 0)
773 reserve_crashkernel();
776 /* Ensure that total memory size is page-aligned. */
777 limit = ALIGN(memory_limit ?: memblock_phys_mem_size(), PAGE_SIZE);
778 memblock_enforce_memory_limit(limit);
780 #if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_PPC_4K_PAGES)
781 if (!early_radix_enabled())
782 memblock_cap_memory_range(0, 1UL << (H_MAX_PHYSMEM_BITS));
785 memblock_allow_resize();
788 DBG("Phys. mem: %llx\n", (unsigned long long)memblock_phys_mem_size());
790 /* We may need to relocate the flat tree, do it now.
791 * FIXME .. and the initrd too? */
794 allocate_paca_ptrs();
796 DBG("Scanning CPUs ...\n");
800 /* Retrieve CPU related informations from the flat tree
801 * (altivec support, boot CPU ID, ...)
803 of_scan_flat_dt(early_init_dt_scan_cpus, NULL);
804 if (boot_cpuid < 0) {
805 printk("Failed to identify boot CPU !\n");
811 #if defined(CONFIG_SMP) && defined(CONFIG_PPC64)
812 /* We'll later wait for secondaries to check in; there are
813 * NCPUS-1 non-boot CPUs :-)
815 spinning_secondaries = boot_cpu_count - 1;
818 mmu_early_init_devtree();
820 #ifdef CONFIG_PPC_POWERNV
821 /* Scan and build the list of machine check recoverable ranges */
822 of_scan_flat_dt(early_init_dt_scan_recoverable_ranges, NULL);
824 epapr_paravirt_early_init();
826 /* Now try to figure out if we are running on LPAR and so on */
827 pseries_probe_fw_features();
830 * Initialize pkey features and default AMR/IAMR values
832 pkey_early_init_devtree();
834 #ifdef CONFIG_PPC_PS3
835 /* Identify PS3 firmware */
836 if (of_flat_dt_is_compatible(of_get_flat_dt_root(), "sony,ps3"))
837 powerpc_firmware_features |= FW_FEATURE_PS3_POSSIBLE;
842 DBG(" <- early_init_devtree()\n");
845 #ifdef CONFIG_RELOCATABLE
847 * This function run before early_init_devtree, so we have to init
848 * initial_boot_params.
850 void __init early_get_first_memblock_info(void *params, phys_addr_t *size)
852 /* Setup flat device-tree pointer */
853 initial_boot_params = params;
856 * Scan the memory nodes and set add_mem_to_memblock to 0 to avoid
859 add_mem_to_memblock = 0;
860 of_scan_flat_dt(early_init_dt_scan_root, NULL);
861 of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
862 add_mem_to_memblock = 1;
865 *size = first_memblock_size;
871 * New implementation of the OF "find" APIs, return a refcounted
872 * object, call of_node_put() when done. The device tree and list
873 * are protected by a rw_lock.
875 * Note that property management will need some locking as well,
876 * this isn't dealt with yet.
881 * of_get_ibm_chip_id - Returns the IBM "chip-id" of a device
882 * @np: device node of the device
884 * This looks for a property "ibm,chip-id" in the node or any
885 * of its parents and returns its content, or -1 if it cannot
888 int of_get_ibm_chip_id(struct device_node *np)
895 * Skiboot may produce memory nodes that contain more than one
896 * cell in chip-id, we only read the first one here.
898 if (!of_property_read_u32(np, "ibm,chip-id", &chip_id)) {
903 np = of_get_next_parent(np);
907 EXPORT_SYMBOL(of_get_ibm_chip_id);
910 * cpu_to_chip_id - Return the cpus chip-id
911 * @cpu: The logical cpu number.
913 * Return the value of the ibm,chip-id property corresponding to the given
914 * logical cpu number. If the chip-id can not be found, returns -1.
916 int cpu_to_chip_id(int cpu)
918 struct device_node *np;
921 idx = cpu / threads_per_core;
922 if (chip_id_lookup_table && chip_id_lookup_table[idx] != -1)
923 return chip_id_lookup_table[idx];
925 np = of_get_cpu_node(cpu, NULL);
927 ret = of_get_ibm_chip_id(np);
930 if (chip_id_lookup_table)
931 chip_id_lookup_table[idx] = ret;
936 EXPORT_SYMBOL(cpu_to_chip_id);
938 bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
942 * Early firmware scanning must use this rather than
943 * get_hard_smp_processor_id because we don't have pacas allocated
944 * until memory topology is discovered.
946 if (cpu_to_phys_id != NULL)
947 return (int)phys_id == cpu_to_phys_id[cpu];
950 return (int)phys_id == get_hard_smp_processor_id(cpu);