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/module.h>
31 #include <linux/kexec.h>
32 #include <linux/debugfs.h>
33 #include <linux/irq.h>
39 #include <asm/processor.h>
42 #include <asm/kdump.h>
44 #include <asm/system.h>
46 #include <asm/pgtable.h>
48 #include <asm/iommu.h>
49 #include <asm/btext.h>
50 #include <asm/sections.h>
51 #include <asm/machdep.h>
52 #include <asm/pSeries_reconfig.h>
53 #include <asm/pci-bridge.h>
54 #include <asm/kexec.h>
57 #define DBG(fmt...) printk(KERN_ERR fmt)
63 static int __initdata dt_root_addr_cells;
64 static int __initdata dt_root_size_cells;
67 int __initdata iommu_is_off;
68 int __initdata iommu_force_on;
69 unsigned long tce_alloc_start, tce_alloc_end;
75 static struct boot_param_header *initial_boot_params __initdata;
77 struct boot_param_header *initial_boot_params;
80 static struct device_node *allnodes = NULL;
82 /* use when traversing tree through the allnext, child, sibling,
83 * or parent members of struct device_node.
85 static DEFINE_RWLOCK(devtree_lock);
87 /* export that to outside world */
88 struct device_node *of_chosen;
90 static inline char *find_flat_dt_string(u32 offset)
92 return ((char *)initial_boot_params) +
93 initial_boot_params->off_dt_strings + offset;
97 * This function is used to scan the flattened device-tree, it is
98 * used to extract the memory informations at boot before we can
101 int __init of_scan_flat_dt(int (*it)(unsigned long node,
102 const char *uname, int depth,
106 unsigned long p = ((unsigned long)initial_boot_params) +
107 initial_boot_params->off_dt_struct;
112 u32 tag = *((u32 *)p);
116 if (tag == OF_DT_END_NODE) {
120 if (tag == OF_DT_NOP)
122 if (tag == OF_DT_END)
124 if (tag == OF_DT_PROP) {
125 u32 sz = *((u32 *)p);
127 if (initial_boot_params->version < 0x10)
128 p = _ALIGN(p, sz >= 8 ? 8 : 4);
133 if (tag != OF_DT_BEGIN_NODE) {
134 printk(KERN_WARNING "Invalid tag %x scanning flattened"
135 " device tree !\n", tag);
140 p = _ALIGN(p + strlen(pathp) + 1, 4);
141 if ((*pathp) == '/') {
143 for (lp = NULL, np = pathp; *np; np++)
149 rc = it(p, pathp, depth, data);
157 unsigned long __init of_get_flat_dt_root(void)
159 unsigned long p = ((unsigned long)initial_boot_params) +
160 initial_boot_params->off_dt_struct;
162 while(*((u32 *)p) == OF_DT_NOP)
164 BUG_ON (*((u32 *)p) != OF_DT_BEGIN_NODE);
166 return _ALIGN(p + strlen((char *)p) + 1, 4);
170 * This function can be used within scan_flattened_dt callback to get
171 * access to properties
173 void* __init of_get_flat_dt_prop(unsigned long node, const char *name,
176 unsigned long p = node;
179 u32 tag = *((u32 *)p);
184 if (tag == OF_DT_NOP)
186 if (tag != OF_DT_PROP)
190 noff = *((u32 *)(p + 4));
192 if (initial_boot_params->version < 0x10)
193 p = _ALIGN(p, sz >= 8 ? 8 : 4);
195 nstr = find_flat_dt_string(noff);
197 printk(KERN_WARNING "Can't find property index"
201 if (strcmp(name, nstr) == 0) {
211 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
214 unsigned long cplen, l;
216 cp = of_get_flat_dt_prop(node, "compatible", &cplen);
220 if (strncasecmp(cp, compat, strlen(compat)) == 0)
230 static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
235 *mem = _ALIGN(*mem, align);
242 static unsigned long __init unflatten_dt_node(unsigned long mem,
244 struct device_node *dad,
245 struct device_node ***allnextpp,
246 unsigned long fpsize)
248 struct device_node *np;
249 struct property *pp, **prev_pp = NULL;
252 unsigned int l, allocl;
256 tag = *((u32 *)(*p));
257 if (tag != OF_DT_BEGIN_NODE) {
258 printk("Weird tag at start of node: %x\n", tag);
263 l = allocl = strlen(pathp) + 1;
264 *p = _ALIGN(*p + l, 4);
266 /* version 0x10 has a more compact unit name here instead of the full
267 * path. we accumulate the full path size using "fpsize", we'll rebuild
268 * it later. We detect this because the first character of the name is
271 if ((*pathp) != '/') {
274 /* root node: special case. fpsize accounts for path
275 * plus terminating zero. root node only has '/', so
276 * fpsize should be 2, but we want to avoid the first
277 * level nodes to have two '/' so we use fpsize 1 here
282 /* account for '/' and path size minus terminal 0
291 np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
292 __alignof__(struct device_node));
294 memset(np, 0, sizeof(*np));
295 np->full_name = ((char*)np) + sizeof(struct device_node);
297 char *p = np->full_name;
298 /* rebuild full path for new format */
299 if (dad && dad->parent) {
300 strcpy(p, dad->full_name);
302 if ((strlen(p) + l + 1) != allocl) {
303 DBG("%s: p: %d, l: %d, a: %d\n",
304 pathp, (int)strlen(p), l, allocl);
312 memcpy(np->full_name, pathp, l);
313 prev_pp = &np->properties;
315 *allnextpp = &np->allnext;
318 /* we temporarily use the next field as `last_child'*/
322 dad->next->sibling = np;
325 kref_init(&np->kref);
331 tag = *((u32 *)(*p));
332 if (tag == OF_DT_NOP) {
336 if (tag != OF_DT_PROP)
340 noff = *((u32 *)((*p) + 4));
342 if (initial_boot_params->version < 0x10)
343 *p = _ALIGN(*p, sz >= 8 ? 8 : 4);
345 pname = find_flat_dt_string(noff);
347 printk("Can't find property name in list !\n");
350 if (strcmp(pname, "name") == 0)
352 l = strlen(pname) + 1;
353 pp = unflatten_dt_alloc(&mem, sizeof(struct property),
354 __alignof__(struct property));
356 if (strcmp(pname, "linux,phandle") == 0) {
357 np->node = *((u32 *)*p);
358 if (np->linux_phandle == 0)
359 np->linux_phandle = np->node;
361 if (strcmp(pname, "ibm,phandle") == 0)
362 np->linux_phandle = *((u32 *)*p);
365 pp->value = (void *)*p;
369 *p = _ALIGN((*p) + sz, 4);
371 /* with version 0x10 we may not have the name property, recreate
372 * it here from the unit name if absent
375 char *p = pathp, *ps = pathp, *pa = NULL;
388 pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
389 __alignof__(struct property));
393 pp->value = (unsigned char *)(pp + 1);
396 memcpy(pp->value, ps, sz - 1);
397 ((char *)pp->value)[sz - 1] = 0;
398 DBG("fixed up name for %s -> %s\n", pathp, pp->value);
403 np->name = get_property(np, "name", NULL);
404 np->type = get_property(np, "device_type", NULL);
411 while (tag == OF_DT_BEGIN_NODE) {
412 mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize);
413 tag = *((u32 *)(*p));
415 if (tag != OF_DT_END_NODE) {
416 printk("Weird tag at end of node: %x\n", tag);
423 static int __init early_parse_mem(char *p)
428 memory_limit = PAGE_ALIGN(memparse(p, &p));
429 DBG("memory limit = 0x%lx\n", memory_limit);
433 early_param("mem", early_parse_mem);
436 * The device tree may be allocated below our memory limit, or inside the
437 * crash kernel region for kdump. If so, move it out now.
439 static void move_device_tree(void)
441 unsigned long start, size;
444 DBG("-> move_device_tree\n");
446 start = __pa(initial_boot_params);
447 size = initial_boot_params->totalsize;
449 if ((memory_limit && (start + size) > memory_limit) ||
450 overlaps_crashkernel(start, size)) {
451 p = __va(lmb_alloc_base(size, PAGE_SIZE, lmb.rmo_size));
452 memcpy(p, initial_boot_params, size);
453 initial_boot_params = (struct boot_param_header *)p;
454 DBG("Moved device tree to 0x%p\n", p);
457 DBG("<- move_device_tree\n");
461 * unflattens the device-tree passed by the firmware, creating the
462 * tree of struct device_node. It also fills the "name" and "type"
463 * pointers of the nodes so the normal device-tree walking functions
464 * can be used (this used to be done by finish_device_tree)
466 void __init unflatten_device_tree(void)
468 unsigned long start, mem, size;
469 struct device_node **allnextp = &allnodes;
471 DBG(" -> unflatten_device_tree()\n");
473 /* First pass, scan for size */
474 start = ((unsigned long)initial_boot_params) +
475 initial_boot_params->off_dt_struct;
476 size = unflatten_dt_node(0, &start, NULL, NULL, 0);
477 size = (size | 3) + 1;
479 DBG(" size is %lx, allocating...\n", size);
481 /* Allocate memory for the expanded device tree */
482 mem = lmb_alloc(size + 4, __alignof__(struct device_node));
483 mem = (unsigned long) __va(mem);
485 ((u32 *)mem)[size / 4] = 0xdeadbeef;
487 DBG(" unflattening %lx...\n", mem);
489 /* Second pass, do actual unflattening */
490 start = ((unsigned long)initial_boot_params) +
491 initial_boot_params->off_dt_struct;
492 unflatten_dt_node(mem, &start, NULL, &allnextp, 0);
493 if (*((u32 *)start) != OF_DT_END)
494 printk(KERN_WARNING "Weird tag at end of tree: %08x\n", *((u32 *)start));
495 if (((u32 *)mem)[size / 4] != 0xdeadbeef)
496 printk(KERN_WARNING "End of tree marker overwritten: %08x\n",
497 ((u32 *)mem)[size / 4] );
500 /* Get pointer to OF "/chosen" node for use everywhere */
501 of_chosen = of_find_node_by_path("/chosen");
502 if (of_chosen == NULL)
503 of_chosen = of_find_node_by_path("/chosen@0");
505 DBG(" <- unflatten_device_tree()\n");
509 * ibm,pa-features is a per-cpu property that contains a string of
510 * attribute descriptors, each of which has a 2 byte header plus up
511 * to 254 bytes worth of processor attribute bits. First header
512 * byte specifies the number of bytes following the header.
513 * Second header byte is an "attribute-specifier" type, of which
514 * zero is the only currently-defined value.
515 * Implementation: Pass in the byte and bit offset for the feature
516 * that we are interested in. The function will return -1 if the
517 * pa-features property is missing, or a 1/0 to indicate if the feature
518 * is supported/not supported. Note that the bit numbers are
519 * big-endian to match the definition in PAPR.
521 static struct ibm_pa_feature {
522 unsigned long cpu_features; /* CPU_FTR_xxx bit */
523 unsigned int cpu_user_ftrs; /* PPC_FEATURE_xxx bit */
524 unsigned char pabyte; /* byte number in ibm,pa-features */
525 unsigned char pabit; /* bit number (big-endian) */
526 unsigned char invert; /* if 1, pa bit set => clear feature */
527 } ibm_pa_features[] __initdata = {
528 {0, PPC_FEATURE_HAS_MMU, 0, 0, 0},
529 {0, PPC_FEATURE_HAS_FPU, 0, 1, 0},
530 {CPU_FTR_SLB, 0, 0, 2, 0},
531 {CPU_FTR_CTRL, 0, 0, 3, 0},
532 {CPU_FTR_NOEXECUTE, 0, 0, 6, 0},
533 {CPU_FTR_NODSISRALIGN, 0, 1, 1, 1},
535 /* put this back once we know how to test if firmware does 64k IO */
536 {CPU_FTR_CI_LARGE_PAGE, 0, 1, 2, 0},
538 {CPU_FTR_REAL_LE, PPC_FEATURE_TRUE_LE, 5, 0, 0},
541 static void __init check_cpu_pa_features(unsigned long node)
543 unsigned char *pa_ftrs;
544 unsigned long len, tablelen, i, bit;
546 pa_ftrs = of_get_flat_dt_prop(node, "ibm,pa-features", &tablelen);
550 /* find descriptor with type == 0 */
554 len = 2 + pa_ftrs[0];
556 return; /* descriptor 0 not found */
563 /* loop over bits we know about */
564 for (i = 0; i < ARRAY_SIZE(ibm_pa_features); ++i) {
565 struct ibm_pa_feature *fp = &ibm_pa_features[i];
567 if (fp->pabyte >= pa_ftrs[0])
569 bit = (pa_ftrs[2 + fp->pabyte] >> (7 - fp->pabit)) & 1;
570 if (bit ^ fp->invert) {
571 cur_cpu_spec->cpu_features |= fp->cpu_features;
572 cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftrs;
574 cur_cpu_spec->cpu_features &= ~fp->cpu_features;
575 cur_cpu_spec->cpu_user_features &= ~fp->cpu_user_ftrs;
580 static int __init early_init_dt_scan_cpus(unsigned long node,
581 const char *uname, int depth,
584 static int logical_cpuid = 0;
585 char *type = of_get_flat_dt_prop(node, "device_type", NULL);
586 #ifdef CONFIG_ALTIVEC
594 /* We are scanning "cpu" nodes only */
595 if (type == NULL || strcmp(type, "cpu") != 0)
598 /* Get physical cpuid */
599 intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
601 nthreads = len / sizeof(int);
603 intserv = of_get_flat_dt_prop(node, "reg", NULL);
608 * Now see if any of these threads match our boot cpu.
609 * NOTE: This must match the parsing done in smp_setup_cpu_maps.
611 for (i = 0; i < nthreads; i++) {
613 * version 2 of the kexec param format adds the phys cpuid of
616 if (initial_boot_params && initial_boot_params->version >= 2) {
618 initial_boot_params->boot_cpuid_phys) {
624 * Check if it's the boot-cpu, set it's hw index now,
625 * unfortunately this format did not support booting
626 * off secondary threads.
628 if (of_get_flat_dt_prop(node,
629 "linux,boot-cpu", NULL) != NULL) {
636 /* logical cpu id is always 0 on UP kernels */
642 DBG("boot cpu: logical %d physical %d\n", logical_cpuid,
644 boot_cpuid = logical_cpuid;
645 set_hard_smp_processor_id(boot_cpuid, intserv[i]);
648 #ifdef CONFIG_ALTIVEC
649 /* Check if we have a VMX and eventually update CPU features */
650 prop = (u32 *)of_get_flat_dt_prop(node, "ibm,vmx", NULL);
651 if (prop && (*prop) > 0) {
652 cur_cpu_spec->cpu_features |= CPU_FTR_ALTIVEC;
653 cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_ALTIVEC;
656 /* Same goes for Apple's "altivec" property */
657 prop = (u32 *)of_get_flat_dt_prop(node, "altivec", NULL);
659 cur_cpu_spec->cpu_features |= CPU_FTR_ALTIVEC;
660 cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_ALTIVEC;
662 #endif /* CONFIG_ALTIVEC */
664 check_cpu_pa_features(node);
666 #ifdef CONFIG_PPC_PSERIES
668 cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
670 cur_cpu_spec->cpu_features &= ~CPU_FTR_SMT;
676 static int __init early_init_dt_scan_chosen(unsigned long node,
677 const char *uname, int depth, void *data)
679 unsigned long *lprop;
683 DBG("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
686 (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
690 /* check if iommu is forced on or off */
691 if (of_get_flat_dt_prop(node, "linux,iommu-off", NULL) != NULL)
693 if (of_get_flat_dt_prop(node, "linux,iommu-force-on", NULL) != NULL)
697 /* mem=x on the command line is the preferred mechanism */
698 lprop = of_get_flat_dt_prop(node, "linux,memory-limit", NULL);
700 memory_limit = *lprop;
703 lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-start", NULL);
705 tce_alloc_start = *lprop;
706 lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-end", NULL);
708 tce_alloc_end = *lprop;
712 lprop = (u64*)of_get_flat_dt_prop(node, "linux,crashkernel-base", NULL);
714 crashk_res.start = *lprop;
716 lprop = (u64*)of_get_flat_dt_prop(node, "linux,crashkernel-size", NULL);
718 crashk_res.end = crashk_res.start + *lprop - 1;
721 /* Retreive command line */
722 p = of_get_flat_dt_prop(node, "bootargs", &l);
723 if (p != NULL && l > 0)
724 strlcpy(cmd_line, p, min((int)l, COMMAND_LINE_SIZE));
726 #ifdef CONFIG_CMDLINE
727 if (p == NULL || l == 0 || (l == 1 && (*p) == 0))
728 strlcpy(cmd_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
729 #endif /* CONFIG_CMDLINE */
731 DBG("Command line is: %s\n", cmd_line);
737 static int __init early_init_dt_scan_root(unsigned long node,
738 const char *uname, int depth, void *data)
745 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
746 dt_root_size_cells = (prop == NULL) ? 1 : *prop;
747 DBG("dt_root_size_cells = %x\n", dt_root_size_cells);
749 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
750 dt_root_addr_cells = (prop == NULL) ? 2 : *prop;
751 DBG("dt_root_addr_cells = %x\n", dt_root_addr_cells);
757 static unsigned long __init dt_mem_next_cell(int s, cell_t **cellp)
762 return of_read_ulong(p, s);
766 static int __init early_init_dt_scan_memory(unsigned long node,
767 const char *uname, int depth, void *data)
769 char *type = of_get_flat_dt_prop(node, "device_type", NULL);
773 /* We are scanning "memory" nodes only */
776 * The longtrail doesn't have a device_type on the
777 * /memory node, so look for the node called /memory@0.
779 if (depth != 1 || strcmp(uname, "memory@0") != 0)
781 } else if (strcmp(type, "memory") != 0)
784 reg = (cell_t *)of_get_flat_dt_prop(node, "linux,usable-memory", &l);
786 reg = (cell_t *)of_get_flat_dt_prop(node, "reg", &l);
790 endp = reg + (l / sizeof(cell_t));
792 DBG("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
793 uname, l, reg[0], reg[1], reg[2], reg[3]);
795 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
796 unsigned long base, size;
798 base = dt_mem_next_cell(dt_root_addr_cells, ®);
799 size = dt_mem_next_cell(dt_root_size_cells, ®);
803 DBG(" - %lx , %lx\n", base, size);
806 if (base >= 0x80000000ul)
808 if ((base + size) > 0x80000000ul)
809 size = 0x80000000ul - base;
817 static void __init early_reserve_mem(void)
821 unsigned long self_base;
822 unsigned long self_size;
824 reserve_map = (u64 *)(((unsigned long)initial_boot_params) +
825 initial_boot_params->off_mem_rsvmap);
827 /* before we do anything, lets reserve the dt blob */
828 self_base = __pa((unsigned long)initial_boot_params);
829 self_size = initial_boot_params->totalsize;
830 lmb_reserve(self_base, self_size);
834 * Handle the case where we might be booting from an old kexec
835 * image that setup the mem_rsvmap as pairs of 32-bit values
837 if (*reserve_map > 0xffffffffull) {
838 u32 base_32, size_32;
839 u32 *reserve_map_32 = (u32 *)reserve_map;
842 base_32 = *(reserve_map_32++);
843 size_32 = *(reserve_map_32++);
846 /* skip if the reservation is for the blob */
847 if (base_32 == self_base && size_32 == self_size)
849 DBG("reserving: %x -> %x\n", base_32, size_32);
850 lmb_reserve(base_32, size_32);
856 base = *(reserve_map++);
857 size = *(reserve_map++);
860 /* skip if the reservation is for the blob */
861 if (base == self_base && size == self_size)
863 DBG("reserving: %llx -> %llx\n", base, size);
864 lmb_reserve(base, size);
868 DBG("memory reserved, lmbs :\n");
873 void __init early_init_devtree(void *params)
875 DBG(" -> early_init_devtree()\n");
877 /* Setup flat device-tree pointer */
878 initial_boot_params = params;
880 #ifdef CONFIG_PPC_RTAS
881 /* Some machines might need RTAS info for debugging, grab it now. */
882 of_scan_flat_dt(early_init_dt_scan_rtas, NULL);
885 /* Retrieve various informations from the /chosen node of the
886 * device-tree, including the platform type, initrd location and
887 * size, TCE reserve, and more ...
889 of_scan_flat_dt(early_init_dt_scan_chosen, NULL);
891 /* Scan memory nodes and rebuild LMBs */
893 of_scan_flat_dt(early_init_dt_scan_root, NULL);
894 of_scan_flat_dt(early_init_dt_scan_memory, NULL);
896 /* Save command line for /proc/cmdline and then parse parameters */
897 strlcpy(saved_command_line, cmd_line, COMMAND_LINE_SIZE);
900 /* Reserve LMB regions used by kernel, initrd, dt, etc... */
901 lmb_reserve(PHYSICAL_START, __pa(klimit) - PHYSICAL_START);
902 reserve_kdump_trampoline();
903 reserve_crashkernel();
906 lmb_enforce_memory_limit(memory_limit);
909 DBG("Phys. mem: %lx\n", lmb_phys_mem_size());
911 /* We may need to relocate the flat tree, do it now.
912 * FIXME .. and the initrd too? */
915 DBG("Scanning CPUs ...\n");
917 /* Retreive CPU related informations from the flat tree
918 * (altivec support, boot CPU ID, ...)
920 of_scan_flat_dt(early_init_dt_scan_cpus, NULL);
922 DBG(" <- early_init_devtree()\n");
928 prom_n_addr_cells(struct device_node* np)
934 ip = get_property(np, "#address-cells", NULL);
937 } while (np->parent);
938 /* No #address-cells property for the root node, default to 1 */
941 EXPORT_SYMBOL(prom_n_addr_cells);
944 prom_n_size_cells(struct device_node* np)
950 ip = get_property(np, "#size-cells", NULL);
953 } while (np->parent);
954 /* No #size-cells property for the root node, default to 1 */
957 EXPORT_SYMBOL(prom_n_size_cells);
960 * Construct and return a list of the device_nodes with a given name.
962 struct device_node *find_devices(const char *name)
964 struct device_node *head, **prevp, *np;
967 for (np = allnodes; np != 0; np = np->allnext) {
968 if (np->name != 0 && strcasecmp(np->name, name) == 0) {
976 EXPORT_SYMBOL(find_devices);
979 * Construct and return a list of the device_nodes with a given type.
981 struct device_node *find_type_devices(const char *type)
983 struct device_node *head, **prevp, *np;
986 for (np = allnodes; np != 0; np = np->allnext) {
987 if (np->type != 0 && strcasecmp(np->type, type) == 0) {
995 EXPORT_SYMBOL(find_type_devices);
998 * Returns all nodes linked together
1000 struct device_node *find_all_nodes(void)
1002 struct device_node *head, **prevp, *np;
1005 for (np = allnodes; np != 0; np = np->allnext) {
1012 EXPORT_SYMBOL(find_all_nodes);
1014 /** Checks if the given "compat" string matches one of the strings in
1015 * the device's "compatible" property
1017 int device_is_compatible(const struct device_node *device, const char *compat)
1022 cp = get_property(device, "compatible", &cplen);
1026 if (strncasecmp(cp, compat, strlen(compat)) == 0)
1035 EXPORT_SYMBOL(device_is_compatible);
1039 * Indicates whether the root node has a given value in its
1040 * compatible property.
1042 int machine_is_compatible(const char *compat)
1044 struct device_node *root;
1047 root = of_find_node_by_path("/");
1049 rc = device_is_compatible(root, compat);
1054 EXPORT_SYMBOL(machine_is_compatible);
1057 * Construct and return a list of the device_nodes with a given type
1058 * and compatible property.
1060 struct device_node *find_compatible_devices(const char *type,
1063 struct device_node *head, **prevp, *np;
1066 for (np = allnodes; np != 0; np = np->allnext) {
1068 && !(np->type != 0 && strcasecmp(np->type, type) == 0))
1070 if (device_is_compatible(np, compat)) {
1078 EXPORT_SYMBOL(find_compatible_devices);
1081 * Find the device_node with a given full_name.
1083 struct device_node *find_path_device(const char *path)
1085 struct device_node *np;
1087 for (np = allnodes; np != 0; np = np->allnext)
1088 if (np->full_name != 0 && strcasecmp(np->full_name, path) == 0)
1092 EXPORT_SYMBOL(find_path_device);
1096 * New implementation of the OF "find" APIs, return a refcounted
1097 * object, call of_node_put() when done. The device tree and list
1098 * are protected by a rw_lock.
1100 * Note that property management will need some locking as well,
1101 * this isn't dealt with yet.
1106 * of_find_node_by_name - Find a node by its "name" property
1107 * @from: The node to start searching from or NULL, the node
1108 * you pass will not be searched, only the next one
1109 * will; typically, you pass what the previous call
1110 * returned. of_node_put() will be called on it
1111 * @name: The name string to match against
1113 * Returns a node pointer with refcount incremented, use
1114 * of_node_put() on it when done.
1116 struct device_node *of_find_node_by_name(struct device_node *from,
1119 struct device_node *np;
1121 read_lock(&devtree_lock);
1122 np = from ? from->allnext : allnodes;
1123 for (; np != NULL; np = np->allnext)
1124 if (np->name != NULL && strcasecmp(np->name, name) == 0
1129 read_unlock(&devtree_lock);
1132 EXPORT_SYMBOL(of_find_node_by_name);
1135 * of_find_node_by_type - Find a node by its "device_type" property
1136 * @from: The node to start searching from or NULL, the node
1137 * you pass will not be searched, only the next one
1138 * will; typically, you pass what the previous call
1139 * returned. of_node_put() will be called on it
1140 * @name: The type string to match against
1142 * Returns a node pointer with refcount incremented, use
1143 * of_node_put() on it when done.
1145 struct device_node *of_find_node_by_type(struct device_node *from,
1148 struct device_node *np;
1150 read_lock(&devtree_lock);
1151 np = from ? from->allnext : allnodes;
1152 for (; np != 0; np = np->allnext)
1153 if (np->type != 0 && strcasecmp(np->type, type) == 0
1158 read_unlock(&devtree_lock);
1161 EXPORT_SYMBOL(of_find_node_by_type);
1164 * of_find_compatible_node - Find a node based on type and one of the
1165 * tokens in its "compatible" property
1166 * @from: The node to start searching from or NULL, the node
1167 * you pass will not be searched, only the next one
1168 * will; typically, you pass what the previous call
1169 * returned. of_node_put() will be called on it
1170 * @type: The type string to match "device_type" or NULL to ignore
1171 * @compatible: The string to match to one of the tokens in the device
1172 * "compatible" list.
1174 * Returns a node pointer with refcount incremented, use
1175 * of_node_put() on it when done.
1177 struct device_node *of_find_compatible_node(struct device_node *from,
1178 const char *type, const char *compatible)
1180 struct device_node *np;
1182 read_lock(&devtree_lock);
1183 np = from ? from->allnext : allnodes;
1184 for (; np != 0; np = np->allnext) {
1186 && !(np->type != 0 && strcasecmp(np->type, type) == 0))
1188 if (device_is_compatible(np, compatible) && of_node_get(np))
1193 read_unlock(&devtree_lock);
1196 EXPORT_SYMBOL(of_find_compatible_node);
1199 * of_find_node_by_path - Find a node matching a full OF path
1200 * @path: The full path to match
1202 * Returns a node pointer with refcount incremented, use
1203 * of_node_put() on it when done.
1205 struct device_node *of_find_node_by_path(const char *path)
1207 struct device_node *np = allnodes;
1209 read_lock(&devtree_lock);
1210 for (; np != 0; np = np->allnext) {
1211 if (np->full_name != 0 && strcasecmp(np->full_name, path) == 0
1215 read_unlock(&devtree_lock);
1218 EXPORT_SYMBOL(of_find_node_by_path);
1221 * of_find_node_by_phandle - Find a node given a phandle
1222 * @handle: phandle of the node to find
1224 * Returns a node pointer with refcount incremented, use
1225 * of_node_put() on it when done.
1227 struct device_node *of_find_node_by_phandle(phandle handle)
1229 struct device_node *np;
1231 read_lock(&devtree_lock);
1232 for (np = allnodes; np != 0; np = np->allnext)
1233 if (np->linux_phandle == handle)
1237 read_unlock(&devtree_lock);
1240 EXPORT_SYMBOL(of_find_node_by_phandle);
1243 * of_find_all_nodes - Get next node in global list
1244 * @prev: Previous node or NULL to start iteration
1245 * of_node_put() will be called on it
1247 * Returns a node pointer with refcount incremented, use
1248 * of_node_put() on it when done.
1250 struct device_node *of_find_all_nodes(struct device_node *prev)
1252 struct device_node *np;
1254 read_lock(&devtree_lock);
1255 np = prev ? prev->allnext : allnodes;
1256 for (; np != 0; np = np->allnext)
1257 if (of_node_get(np))
1261 read_unlock(&devtree_lock);
1264 EXPORT_SYMBOL(of_find_all_nodes);
1267 * of_get_parent - Get a node's parent if any
1268 * @node: Node to get parent
1270 * Returns a node pointer with refcount incremented, use
1271 * of_node_put() on it when done.
1273 struct device_node *of_get_parent(const struct device_node *node)
1275 struct device_node *np;
1280 read_lock(&devtree_lock);
1281 np = of_node_get(node->parent);
1282 read_unlock(&devtree_lock);
1285 EXPORT_SYMBOL(of_get_parent);
1288 * of_get_next_child - Iterate a node childs
1289 * @node: parent node
1290 * @prev: previous child of the parent node, or NULL to get first
1292 * Returns a node pointer with refcount incremented, use
1293 * of_node_put() on it when done.
1295 struct device_node *of_get_next_child(const struct device_node *node,
1296 struct device_node *prev)
1298 struct device_node *next;
1300 read_lock(&devtree_lock);
1301 next = prev ? prev->sibling : node->child;
1302 for (; next != 0; next = next->sibling)
1303 if (of_node_get(next))
1307 read_unlock(&devtree_lock);
1310 EXPORT_SYMBOL(of_get_next_child);
1313 * of_node_get - Increment refcount of a node
1314 * @node: Node to inc refcount, NULL is supported to
1315 * simplify writing of callers
1319 struct device_node *of_node_get(struct device_node *node)
1322 kref_get(&node->kref);
1325 EXPORT_SYMBOL(of_node_get);
1327 static inline struct device_node * kref_to_device_node(struct kref *kref)
1329 return container_of(kref, struct device_node, kref);
1333 * of_node_release - release a dynamically allocated node
1334 * @kref: kref element of the node to be released
1336 * In of_node_put() this function is passed to kref_put()
1337 * as the destructor.
1339 static void of_node_release(struct kref *kref)
1341 struct device_node *node = kref_to_device_node(kref);
1342 struct property *prop = node->properties;
1344 if (!OF_IS_DYNAMIC(node))
1347 struct property *next = prop->next;
1354 prop = node->deadprops;
1355 node->deadprops = NULL;
1358 kfree(node->full_name);
1364 * of_node_put - Decrement refcount of a node
1365 * @node: Node to dec refcount, NULL is supported to
1366 * simplify writing of callers
1369 void of_node_put(struct device_node *node)
1372 kref_put(&node->kref, of_node_release);
1374 EXPORT_SYMBOL(of_node_put);
1377 * Plug a device node into the tree and global list.
1379 void of_attach_node(struct device_node *np)
1381 write_lock(&devtree_lock);
1382 np->sibling = np->parent->child;
1383 np->allnext = allnodes;
1384 np->parent->child = np;
1386 write_unlock(&devtree_lock);
1390 * "Unplug" a node from the device tree. The caller must hold
1391 * a reference to the node. The memory associated with the node
1392 * is not freed until its refcount goes to zero.
1394 void of_detach_node(const struct device_node *np)
1396 struct device_node *parent;
1398 write_lock(&devtree_lock);
1400 parent = np->parent;
1403 allnodes = np->allnext;
1405 struct device_node *prev;
1406 for (prev = allnodes;
1407 prev->allnext != np;
1408 prev = prev->allnext)
1410 prev->allnext = np->allnext;
1413 if (parent->child == np)
1414 parent->child = np->sibling;
1416 struct device_node *prevsib;
1417 for (prevsib = np->parent->child;
1418 prevsib->sibling != np;
1419 prevsib = prevsib->sibling)
1421 prevsib->sibling = np->sibling;
1424 write_unlock(&devtree_lock);
1427 #ifdef CONFIG_PPC_PSERIES
1429 * Fix up the uninitialized fields in a new device node:
1430 * name, type and pci-specific fields
1433 static int of_finish_dynamic_node(struct device_node *node)
1435 struct device_node *parent = of_get_parent(node);
1437 const phandle *ibm_phandle;
1439 node->name = get_property(node, "name", NULL);
1440 node->type = get_property(node, "device_type", NULL);
1447 /* We don't support that function on PowerMac, at least
1450 if (machine_is(powermac))
1453 /* fix up new node's linux_phandle field */
1454 if ((ibm_phandle = get_property(node, "ibm,phandle", NULL)))
1455 node->linux_phandle = *ibm_phandle;
1458 of_node_put(parent);
1462 static int prom_reconfig_notifier(struct notifier_block *nb,
1463 unsigned long action, void *node)
1468 case PSERIES_RECONFIG_ADD:
1469 err = of_finish_dynamic_node(node);
1471 printk(KERN_ERR "finish_node returned %d\n", err);
1482 static struct notifier_block prom_reconfig_nb = {
1483 .notifier_call = prom_reconfig_notifier,
1484 .priority = 10, /* This one needs to run first */
1487 static int __init prom_reconfig_setup(void)
1489 return pSeries_reconfig_notifier_register(&prom_reconfig_nb);
1491 __initcall(prom_reconfig_setup);
1494 struct property *of_find_property(const struct device_node *np,
1498 struct property *pp;
1500 read_lock(&devtree_lock);
1501 for (pp = np->properties; pp != 0; pp = pp->next)
1502 if (strcmp(pp->name, name) == 0) {
1507 read_unlock(&devtree_lock);
1513 * Find a property with a given name for a given node
1514 * and return the value.
1516 const void *get_property(const struct device_node *np, const char *name,
1519 struct property *pp = of_find_property(np,name,lenp);
1520 return pp ? pp->value : NULL;
1522 EXPORT_SYMBOL(get_property);
1525 * Add a property to a node
1527 int prom_add_property(struct device_node* np, struct property* prop)
1529 struct property **next;
1532 write_lock(&devtree_lock);
1533 next = &np->properties;
1535 if (strcmp(prop->name, (*next)->name) == 0) {
1536 /* duplicate ! don't insert it */
1537 write_unlock(&devtree_lock);
1540 next = &(*next)->next;
1543 write_unlock(&devtree_lock);
1545 #ifdef CONFIG_PROC_DEVICETREE
1546 /* try to add to proc as well if it was initialized */
1548 proc_device_tree_add_prop(np->pde, prop);
1549 #endif /* CONFIG_PROC_DEVICETREE */
1555 * Remove a property from a node. Note that we don't actually
1556 * remove it, since we have given out who-knows-how-many pointers
1557 * to the data using get-property. Instead we just move the property
1558 * to the "dead properties" list, so it won't be found any more.
1560 int prom_remove_property(struct device_node *np, struct property *prop)
1562 struct property **next;
1565 write_lock(&devtree_lock);
1566 next = &np->properties;
1568 if (*next == prop) {
1569 /* found the node */
1571 prop->next = np->deadprops;
1572 np->deadprops = prop;
1576 next = &(*next)->next;
1578 write_unlock(&devtree_lock);
1583 #ifdef CONFIG_PROC_DEVICETREE
1584 /* try to remove the proc node as well */
1586 proc_device_tree_remove_prop(np->pde, prop);
1587 #endif /* CONFIG_PROC_DEVICETREE */
1593 * Update a property in a node. Note that we don't actually
1594 * remove it, since we have given out who-knows-how-many pointers
1595 * to the data using get-property. Instead we just move the property
1596 * to the "dead properties" list, and add the new property to the
1599 int prom_update_property(struct device_node *np,
1600 struct property *newprop,
1601 struct property *oldprop)
1603 struct property **next;
1606 write_lock(&devtree_lock);
1607 next = &np->properties;
1609 if (*next == oldprop) {
1610 /* found the node */
1611 newprop->next = oldprop->next;
1613 oldprop->next = np->deadprops;
1614 np->deadprops = oldprop;
1618 next = &(*next)->next;
1620 write_unlock(&devtree_lock);
1625 #ifdef CONFIG_PROC_DEVICETREE
1626 /* try to add to proc as well if it was initialized */
1628 proc_device_tree_update_prop(np->pde, newprop, oldprop);
1629 #endif /* CONFIG_PROC_DEVICETREE */
1635 /* Find the device node for a given logical cpu number, also returns the cpu
1636 * local thread number (index in ibm,interrupt-server#s) if relevant and
1637 * asked for (non NULL)
1639 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
1642 struct device_node *np;
1644 hardid = get_hard_smp_processor_id(cpu);
1646 for_each_node_by_type(np, "cpu") {
1648 unsigned int plen, t;
1650 /* Check for ibm,ppc-interrupt-server#s. If it doesn't exist
1651 * fallback to "reg" property and assume no threads
1653 intserv = get_property(np, "ibm,ppc-interrupt-server#s",
1655 if (intserv == NULL) {
1656 const u32 *reg = get_property(np, "reg", NULL);
1659 if (*reg == hardid) {
1665 plen /= sizeof(u32);
1666 for (t = 0; t < plen; t++) {
1667 if (hardid == intserv[t]) {
1679 static struct debugfs_blob_wrapper flat_dt_blob;
1681 static int __init export_flat_device_tree(void)
1685 d = debugfs_create_dir("powerpc", NULL);
1689 flat_dt_blob.data = initial_boot_params;
1690 flat_dt_blob.size = initial_boot_params->totalsize;
1692 d = debugfs_create_blob("flat-device-tree", S_IFREG | S_IRUSR,
1699 __initcall(export_flat_device_tree);