2 * Procedures for creating, accessing and interpreting the device tree.
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/init.h>
22 #include <linux/threads.h>
23 #include <linux/spinlock.h>
24 #include <linux/types.h>
25 #include <linux/pci.h>
26 #include <linux/stringify.h>
27 #include <linux/delay.h>
28 #include <linux/initrd.h>
29 #include <linux/bitops.h>
30 #include <linux/export.h>
31 #include <linux/kexec.h>
32 #include <linux/irq.h>
33 #include <linux/memblock.h>
35 #include <linux/of_fdt.h>
36 #include <linux/libfdt.h>
37 #include <linux/cpu.h>
42 #include <asm/processor.h>
45 #include <asm/kdump.h>
49 #include <asm/pgtable.h>
50 #include <asm/iommu.h>
51 #include <asm/btext.h>
52 #include <asm/sections.h>
53 #include <asm/machdep.h>
54 #include <asm/pci-bridge.h>
55 #include <asm/kexec.h>
57 #include <asm/fadump.h>
58 #include <asm/debug.h>
59 #include <asm/epapr_hcalls.h>
60 #include <asm/firmware.h>
62 #include <mm/mmu_decl.h>
65 #define DBG(fmt...) printk(KERN_ERR fmt)
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_UP(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 overlaps_crashkernel(start, size) ||
127 overlaps_initrd(start, size)) {
128 p = __va(memblock_alloc(size, PAGE_SIZE));
129 memcpy(p, initial_boot_params, size);
130 initial_boot_params = p;
131 DBG("Moved device tree to 0x%px\n", p);
134 DBG("<- move_device_tree\n");
138 * ibm,pa-features is a per-cpu property that contains a string of
139 * attribute descriptors, each of which has a 2 byte header plus up
140 * to 254 bytes worth of processor attribute bits. First header
141 * byte specifies the number of bytes following the header.
142 * Second header byte is an "attribute-specifier" type, of which
143 * zero is the only currently-defined value.
144 * Implementation: Pass in the byte and bit offset for the feature
145 * that we are interested in. The function will return -1 if the
146 * pa-features property is missing, or a 1/0 to indicate if the feature
147 * is supported/not supported. Note that the bit numbers are
148 * big-endian to match the definition in PAPR.
150 static struct ibm_pa_feature {
151 unsigned long cpu_features; /* CPU_FTR_xxx bit */
152 unsigned long mmu_features; /* MMU_FTR_xxx bit */
153 unsigned int cpu_user_ftrs; /* PPC_FEATURE_xxx bit */
154 unsigned int cpu_user_ftrs2; /* PPC_FEATURE2_xxx bit */
155 unsigned char pabyte; /* byte number in ibm,pa-features */
156 unsigned char pabit; /* bit number (big-endian) */
157 unsigned char invert; /* if 1, pa bit set => clear feature */
158 } ibm_pa_features[] __initdata = {
159 {0, 0, PPC_FEATURE_HAS_MMU, 0, 0, 0, 0},
160 {0, 0, PPC_FEATURE_HAS_FPU, 0, 0, 1, 0},
161 {CPU_FTR_CTRL, 0, 0, 0, 0, 3, 0},
162 {CPU_FTR_NOEXECUTE, 0, 0, 0, 0, 6, 0},
163 {CPU_FTR_NODSISRALIGN, 0, 0, 0, 1, 1, 1},
164 {0, MMU_FTR_CI_LARGE_PAGE, 0, 0, 1, 2, 0},
165 {CPU_FTR_REAL_LE, 0, PPC_FEATURE_TRUE_LE, 0, 5, 0, 0},
167 * If the kernel doesn't support TM (ie CONFIG_PPC_TRANSACTIONAL_MEM=n),
168 * we don't want to turn on TM here, so we use the *_COMP versions
169 * which are 0 if the kernel doesn't support TM.
171 {CPU_FTR_TM_COMP, 0, 0,
172 PPC_FEATURE2_HTM_COMP|PPC_FEATURE2_HTM_NOSC_COMP, 22, 0, 0},
173 {0, MMU_FTR_TYPE_RADIX, 0, 0, 40, 0, 0},
176 static void __init scan_features(unsigned long node, const unsigned char *ftrs,
177 unsigned long tablelen,
178 struct ibm_pa_feature *fp,
179 unsigned long ft_size)
181 unsigned long i, len, bit;
183 /* find descriptor with type == 0 */
189 return; /* descriptor 0 not found */
196 /* loop over bits we know about */
197 for (i = 0; i < ft_size; ++i, ++fp) {
198 if (fp->pabyte >= ftrs[0])
200 bit = (ftrs[2 + fp->pabyte] >> (7 - fp->pabit)) & 1;
201 if (bit ^ fp->invert) {
202 cur_cpu_spec->cpu_features |= fp->cpu_features;
203 cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftrs;
204 cur_cpu_spec->cpu_user_features2 |= fp->cpu_user_ftrs2;
205 cur_cpu_spec->mmu_features |= fp->mmu_features;
207 cur_cpu_spec->cpu_features &= ~fp->cpu_features;
208 cur_cpu_spec->cpu_user_features &= ~fp->cpu_user_ftrs;
209 cur_cpu_spec->cpu_user_features2 &= ~fp->cpu_user_ftrs2;
210 cur_cpu_spec->mmu_features &= ~fp->mmu_features;
215 static void __init check_cpu_pa_features(unsigned long node)
217 const unsigned char *pa_ftrs;
220 pa_ftrs = of_get_flat_dt_prop(node, "ibm,pa-features", &tablelen);
224 scan_features(node, pa_ftrs, tablelen,
225 ibm_pa_features, ARRAY_SIZE(ibm_pa_features));
228 #ifdef CONFIG_PPC_STD_MMU_64
229 static void __init init_mmu_slb_size(unsigned long node)
231 const __be32 *slb_size_ptr;
233 slb_size_ptr = of_get_flat_dt_prop(node, "slb-size", NULL) ? :
234 of_get_flat_dt_prop(node, "ibm,slb-size", NULL);
237 mmu_slb_size = be32_to_cpup(slb_size_ptr);
240 #define init_mmu_slb_size(node) do { } while(0)
243 static struct feature_property {
246 unsigned long cpu_feature;
247 unsigned long cpu_user_ftr;
248 } feature_properties[] __initdata = {
249 #ifdef CONFIG_ALTIVEC
250 {"altivec", 0, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
251 {"ibm,vmx", 1, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
252 #endif /* CONFIG_ALTIVEC */
254 /* Yes, this _really_ is ibm,vmx == 2 to enable VSX */
255 {"ibm,vmx", 2, CPU_FTR_VSX, PPC_FEATURE_HAS_VSX},
256 #endif /* CONFIG_VSX */
258 {"ibm,dfp", 1, 0, PPC_FEATURE_HAS_DFP},
259 {"ibm,purr", 1, CPU_FTR_PURR, 0},
260 {"ibm,spurr", 1, CPU_FTR_SPURR, 0},
261 #endif /* CONFIG_PPC64 */
264 #if defined(CONFIG_44x) && defined(CONFIG_PPC_FPU)
265 static __init void identical_pvr_fixup(unsigned long node)
268 const char *model = of_get_flat_dt_prop(node, "model", NULL);
271 * Since 440GR(x)/440EP(x) processors have the same pvr,
272 * we check the node path and set bit 28 in the cur_cpu_spec
273 * pvr for EP(x) processor version. This bit is always 0 in
274 * the "real" pvr. Then we call identify_cpu again with
275 * the new logical pvr to enable FPU support.
277 if (model && strstr(model, "440EP")) {
278 pvr = cur_cpu_spec->pvr_value | 0x8;
279 identify_cpu(0, pvr);
280 DBG("Using logical pvr %x for %s\n", pvr, model);
284 #define identical_pvr_fixup(node) do { } while(0)
287 static void __init check_cpu_feature_properties(unsigned long node)
290 struct feature_property *fp = feature_properties;
293 for (i = 0; i < ARRAY_SIZE(feature_properties); ++i, ++fp) {
294 prop = of_get_flat_dt_prop(node, fp->name, NULL);
295 if (prop && be32_to_cpup(prop) >= fp->min_value) {
296 cur_cpu_spec->cpu_features |= fp->cpu_feature;
297 cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftr;
302 static int __init early_init_dt_scan_cpus(unsigned long node,
303 const char *uname, int depth,
306 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
308 const __be32 *intserv;
312 int found_thread = 0;
314 /* We are scanning "cpu" nodes only */
315 if (type == NULL || strcmp(type, "cpu") != 0)
318 /* Get physical cpuid */
319 intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
321 intserv = of_get_flat_dt_prop(node, "reg", &len);
323 nthreads = len / sizeof(int);
326 * Now see if any of these threads match our boot cpu.
327 * NOTE: This must match the parsing done in smp_setup_cpu_maps.
329 for (i = 0; i < nthreads; i++) {
331 * version 2 of the kexec param format adds the phys cpuid of
334 if (fdt_version(initial_boot_params) >= 2) {
335 if (be32_to_cpu(intserv[i]) ==
336 fdt_boot_cpuid_phys(initial_boot_params)) {
337 found = boot_cpu_count;
342 * Check if it's the boot-cpu, set it's hw index now,
343 * unfortunately this format did not support booting
344 * off secondary threads.
346 if (of_get_flat_dt_prop(node,
347 "linux,boot-cpu", NULL) != NULL)
348 found = boot_cpu_count;
351 /* logical cpu id is always 0 on UP kernels */
356 /* Not the boot CPU */
360 DBG("boot cpu: logical %d physical %d\n", found,
361 be32_to_cpu(intserv[found_thread]));
363 set_hard_smp_processor_id(found, be32_to_cpu(intserv[found_thread]));
366 * PAPR defines "logical" PVR values for cpus that
367 * meet various levels of the architecture:
368 * 0x0f000001 Architecture version 2.04
369 * 0x0f000002 Architecture version 2.05
370 * If the cpu-version property in the cpu node contains
371 * such a value, we call identify_cpu again with the
372 * logical PVR value in order to use the cpu feature
373 * bits appropriate for the architecture level.
375 * A POWER6 partition in "POWER6 architected" mode
376 * uses the 0x0f000002 PVR value; in POWER5+ mode
377 * it uses 0x0f000001.
379 prop = of_get_flat_dt_prop(node, "cpu-version", NULL);
380 if (prop && (be32_to_cpup(prop) & 0xff000000) == 0x0f000000)
381 identify_cpu(0, be32_to_cpup(prop));
383 identical_pvr_fixup(node);
385 check_cpu_feature_properties(node);
386 check_cpu_pa_features(node);
387 init_mmu_slb_size(node);
391 cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
393 cur_cpu_spec->cpu_features &= ~CPU_FTR_SMT;
398 static int __init early_init_dt_scan_chosen_ppc(unsigned long node,
400 int depth, void *data)
402 const unsigned long *lprop; /* All these set by kernel, so no need to convert endian */
404 /* Use common scan routine to determine if this is the chosen node */
405 if (early_init_dt_scan_chosen(node, uname, depth, data) == 0)
409 /* check if iommu is forced on or off */
410 if (of_get_flat_dt_prop(node, "linux,iommu-off", NULL) != NULL)
412 if (of_get_flat_dt_prop(node, "linux,iommu-force-on", NULL) != NULL)
416 /* mem=x on the command line is the preferred mechanism */
417 lprop = of_get_flat_dt_prop(node, "linux,memory-limit", NULL);
419 memory_limit = *lprop;
422 lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-start", NULL);
424 tce_alloc_start = *lprop;
425 lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-end", NULL);
427 tce_alloc_end = *lprop;
431 lprop = of_get_flat_dt_prop(node, "linux,crashkernel-base", NULL);
433 crashk_res.start = *lprop;
435 lprop = of_get_flat_dt_prop(node, "linux,crashkernel-size", NULL);
437 crashk_res.end = crashk_res.start + *lprop - 1;
444 #ifdef CONFIG_PPC_PSERIES
446 * Interpret the ibm,dynamic-memory property in the
447 * /ibm,dynamic-reconfiguration-memory node.
448 * This contains a list of memory blocks along with NUMA affinity
451 static int __init early_init_dt_scan_drconf_memory(unsigned long node)
453 const __be32 *dm, *ls, *usm;
455 unsigned long n, flags;
456 u64 base, size, memblock_size;
457 unsigned int is_kexec_kdump = 0, rngs;
459 ls = of_get_flat_dt_prop(node, "ibm,lmb-size", &l);
460 if (ls == NULL || l < dt_root_size_cells * sizeof(__be32))
462 memblock_size = dt_mem_next_cell(dt_root_size_cells, &ls);
464 dm = of_get_flat_dt_prop(node, "ibm,dynamic-memory", &l);
465 if (dm == NULL || l < sizeof(__be32))
468 n = of_read_number(dm++, 1); /* number of entries */
469 if (l < (n * (dt_root_addr_cells + 4) + 1) * sizeof(__be32))
472 /* check if this is a kexec/kdump kernel. */
473 usm = of_get_flat_dt_prop(node, "linux,drconf-usable-memory",
478 for (; n != 0; --n) {
479 base = dt_mem_next_cell(dt_root_addr_cells, &dm);
480 flags = of_read_number(&dm[3], 1);
481 /* skip DRC index, pad, assoc. list index, flags */
483 /* skip this block if the reserved bit is set in flags
484 or if the block is not assigned to this partition */
485 if ((flags & DRCONF_MEM_RESERVED) ||
486 !(flags & DRCONF_MEM_ASSIGNED))
488 size = memblock_size;
490 if (is_kexec_kdump) {
492 * For each memblock in ibm,dynamic-memory, a corresponding
493 * entry in linux,drconf-usable-memory property contains
494 * a counter 'p' followed by 'p' (base, size) duple.
495 * Now read the counter from
496 * linux,drconf-usable-memory property
498 rngs = dt_mem_next_cell(dt_root_size_cells, &usm);
499 if (!rngs) /* there are no (base, size) duple */
503 if (is_kexec_kdump) {
504 base = dt_mem_next_cell(dt_root_addr_cells,
506 size = dt_mem_next_cell(dt_root_size_cells,
510 if (base >= 0x80000000ul)
512 if ((base + size) > 0x80000000ul)
513 size = 0x80000000ul - base;
515 memblock_add(base, size);
522 #define early_init_dt_scan_drconf_memory(node) 0
523 #endif /* CONFIG_PPC_PSERIES */
525 static int __init early_init_dt_scan_memory_ppc(unsigned long node,
527 int depth, void *data)
530 strcmp(uname, "ibm,dynamic-reconfiguration-memory") == 0)
531 return early_init_dt_scan_drconf_memory(node);
533 return early_init_dt_scan_memory(node, uname, depth, data);
537 * For a relocatable kernel, we need to get the memstart_addr first,
538 * then use it to calculate the virtual kernel start address. This has
539 * to happen at a very early stage (before machine_init). In this case,
540 * we just want to get the memstart_address and would not like to mess the
541 * memblock at this stage. So introduce a variable to skip the memblock_add()
544 #ifdef CONFIG_RELOCATABLE
545 static int add_mem_to_memblock = 1;
547 #define add_mem_to_memblock 1
550 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
554 if (base >= 0x80000000ul)
556 if ((base + size) > 0x80000000ul)
557 size = 0x80000000ul - base;
560 /* Keep track of the beginning of memory -and- the size of
561 * the very first block in the device-tree as it represents
562 * the RMA on ppc64 server
564 if (base < memstart_addr) {
565 memstart_addr = base;
566 first_memblock_size = size;
569 /* Add the chunk to the MEMBLOCK list */
570 if (add_mem_to_memblock)
571 memblock_add(base, size);
574 static void __init early_reserve_mem_dt(void)
576 unsigned long i, dt_root;
580 early_init_fdt_reserve_self();
581 early_init_fdt_scan_reserved_mem();
583 dt_root = of_get_flat_dt_root();
585 prop = of_get_flat_dt_prop(dt_root, "reserved-ranges", &len);
590 DBG("Found new-style reserved-ranges\n");
592 /* Each reserved range is an (address,size) pair, 2 cells each,
593 * totalling 4 cells per range. */
594 for (i = 0; i < len / (sizeof(*prop) * 4); i++) {
597 base = of_read_number(prop + (i * 4) + 0, 2);
598 size = of_read_number(prop + (i * 4) + 2, 2);
601 DBG("reserving: %llx -> %llx\n", base, size);
602 memblock_reserve(base, size);
607 static void __init early_reserve_mem(void)
611 reserve_map = (__be64 *)(((unsigned long)initial_boot_params) +
612 fdt_off_mem_rsvmap(initial_boot_params));
614 /* Look for the new "reserved-regions" property in the DT */
615 early_reserve_mem_dt();
617 #ifdef CONFIG_BLK_DEV_INITRD
618 /* Then reserve the initrd, if any */
619 if (initrd_start && (initrd_end > initrd_start)) {
620 memblock_reserve(_ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
621 _ALIGN_UP(initrd_end, PAGE_SIZE) -
622 _ALIGN_DOWN(initrd_start, PAGE_SIZE));
624 #endif /* CONFIG_BLK_DEV_INITRD */
628 * Handle the case where we might be booting from an old kexec
629 * image that setup the mem_rsvmap as pairs of 32-bit values
631 if (be64_to_cpup(reserve_map) > 0xffffffffull) {
632 u32 base_32, size_32;
633 __be32 *reserve_map_32 = (__be32 *)reserve_map;
635 DBG("Found old 32-bit reserve map\n");
638 base_32 = be32_to_cpup(reserve_map_32++);
639 size_32 = be32_to_cpup(reserve_map_32++);
642 DBG("reserving: %x -> %x\n", base_32, size_32);
643 memblock_reserve(base_32, size_32);
650 void __init early_init_devtree(void *params)
654 DBG(" -> early_init_devtree(%px)\n", params);
656 /* Too early to BUG_ON(), do it by hand */
657 if (!early_init_dt_verify(params))
658 panic("BUG: Failed verifying flat device tree, bad version?");
660 #ifdef CONFIG_PPC_RTAS
661 /* Some machines might need RTAS info for debugging, grab it now. */
662 of_scan_flat_dt(early_init_dt_scan_rtas, NULL);
665 #ifdef CONFIG_PPC_POWERNV
666 /* Some machines might need OPAL info for debugging, grab it now. */
667 of_scan_flat_dt(early_init_dt_scan_opal, NULL);
670 #ifdef CONFIG_FA_DUMP
671 /* scan tree to see if dump is active during last boot */
672 of_scan_flat_dt(early_init_dt_scan_fw_dump, NULL);
675 /* Retrieve various informations from the /chosen node of the
676 * device-tree, including the platform type, initrd location and
677 * size, TCE reserve, and more ...
679 of_scan_flat_dt(early_init_dt_scan_chosen_ppc, boot_command_line);
681 /* Scan memory nodes and rebuild MEMBLOCKs */
682 of_scan_flat_dt(early_init_dt_scan_root, NULL);
683 of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
687 /* make sure we've parsed cmdline for mem= before this */
689 first_memblock_size = min_t(u64, first_memblock_size, memory_limit);
690 setup_initial_memory_limit(memstart_addr, first_memblock_size);
691 /* Reserve MEMBLOCK regions used by kernel, initrd, dt, etc... */
692 memblock_reserve(PHYSICAL_START, __pa(klimit) - PHYSICAL_START);
693 /* If relocatable, reserve first 32k for interrupt vectors etc. */
694 if (PHYSICAL_START > MEMORY_START)
695 memblock_reserve(MEMORY_START, 0x8000);
696 reserve_kdump_trampoline();
697 #ifdef CONFIG_FA_DUMP
699 * If we fail to reserve memory for firmware-assisted dump then
700 * fallback to kexec based kdump.
702 if (fadump_reserve_mem() == 0)
704 reserve_crashkernel();
707 /* Ensure that total memory size is page-aligned. */
708 limit = ALIGN(memory_limit ?: memblock_phys_mem_size(), PAGE_SIZE);
709 memblock_enforce_memory_limit(limit);
711 memblock_allow_resize();
714 DBG("Phys. mem: %llx\n", (unsigned long long)memblock_phys_mem_size());
716 /* We may need to relocate the flat tree, do it now.
717 * FIXME .. and the initrd too? */
722 DBG("Scanning CPUs ...\n");
724 /* Retrieve CPU related informations from the flat tree
725 * (altivec support, boot CPU ID, ...)
727 of_scan_flat_dt(early_init_dt_scan_cpus, NULL);
728 if (boot_cpuid < 0) {
729 printk("Failed to identify boot CPU !\n");
733 #if defined(CONFIG_SMP) && defined(CONFIG_PPC64)
734 /* We'll later wait for secondaries to check in; there are
735 * NCPUS-1 non-boot CPUs :-)
737 spinning_secondaries = boot_cpu_count - 1;
740 mmu_early_init_devtree();
742 #ifdef CONFIG_PPC_POWERNV
743 /* Scan and build the list of machine check recoverable ranges */
744 of_scan_flat_dt(early_init_dt_scan_recoverable_ranges, NULL);
746 epapr_paravirt_early_init();
748 /* Now try to figure out if we are running on LPAR and so on */
749 pseries_probe_fw_features();
751 #ifdef CONFIG_PPC_PS3
752 /* Identify PS3 firmware */
753 if (of_flat_dt_is_compatible(of_get_flat_dt_root(), "sony,ps3"))
754 powerpc_firmware_features |= FW_FEATURE_PS3_POSSIBLE;
757 DBG(" <- early_init_devtree()\n");
760 #ifdef CONFIG_RELOCATABLE
762 * This function run before early_init_devtree, so we have to init
763 * initial_boot_params.
765 void __init early_get_first_memblock_info(void *params, phys_addr_t *size)
767 /* Setup flat device-tree pointer */
768 initial_boot_params = params;
771 * Scan the memory nodes and set add_mem_to_memblock to 0 to avoid
774 add_mem_to_memblock = 0;
775 of_scan_flat_dt(early_init_dt_scan_root, NULL);
776 of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
777 add_mem_to_memblock = 1;
780 *size = first_memblock_size;
786 * New implementation of the OF "find" APIs, return a refcounted
787 * object, call of_node_put() when done. The device tree and list
788 * are protected by a rw_lock.
790 * Note that property management will need some locking as well,
791 * this isn't dealt with yet.
796 * of_get_ibm_chip_id - Returns the IBM "chip-id" of a device
797 * @np: device node of the device
799 * This looks for a property "ibm,chip-id" in the node or any
800 * of its parents and returns its content, or -1 if it cannot
803 int of_get_ibm_chip_id(struct device_node *np)
810 * Skiboot may produce memory nodes that contain more than one
811 * cell in chip-id, we only read the first one here.
813 if (!of_property_read_u32(np, "ibm,chip-id", &chip_id)) {
818 np = of_get_next_parent(np);
822 EXPORT_SYMBOL(of_get_ibm_chip_id);
825 * cpu_to_chip_id - Return the cpus chip-id
826 * @cpu: The logical cpu number.
828 * Return the value of the ibm,chip-id property corresponding to the given
829 * logical cpu number. If the chip-id can not be found, returns -1.
831 int cpu_to_chip_id(int cpu)
833 struct device_node *np;
835 np = of_get_cpu_node(cpu, NULL);
840 return of_get_ibm_chip_id(np);
842 EXPORT_SYMBOL(cpu_to_chip_id);
844 bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
846 return (int)phys_id == get_hard_smp_processor_id(cpu);