2 #define pr_fmt(fmt) "OF: " fmt
4 #include <linux/device.h>
6 #include <linux/ioport.h>
7 #include <linux/module.h>
8 #include <linux/of_address.h>
10 #include <linux/pci_regs.h>
11 #include <linux/sizes.h>
12 #include <linux/slab.h>
13 #include <linux/string.h>
15 /* Max address size we deal with */
16 #define OF_MAX_ADDR_CELLS 4
17 #define OF_CHECK_ADDR_COUNT(na) ((na) > 0 && (na) <= OF_MAX_ADDR_CELLS)
18 #define OF_CHECK_COUNTS(na, ns) (OF_CHECK_ADDR_COUNT(na) && (ns) > 0)
20 static struct of_bus
*of_match_bus(struct device_node
*np
);
21 static int __of_address_to_resource(struct device_node
*dev
,
22 const __be32
*addrp
, u64 size
, unsigned int flags
,
23 const char *name
, struct resource
*r
);
27 static void of_dump_addr(const char *s
, const __be32
*addr
, int na
)
31 pr_cont(" %08x", be32_to_cpu(*(addr
++)));
35 static void of_dump_addr(const char *s
, const __be32
*addr
, int na
) { }
38 /* Callbacks for bus specific translators */
41 const char *addresses
;
42 int (*match
)(struct device_node
*parent
);
43 void (*count_cells
)(struct device_node
*child
,
44 int *addrc
, int *sizec
);
45 u64 (*map
)(__be32
*addr
, const __be32
*range
,
46 int na
, int ns
, int pna
);
47 int (*translate
)(__be32
*addr
, u64 offset
, int na
);
48 unsigned int (*get_flags
)(const __be32
*addr
);
52 * Default translator (generic bus)
55 static void of_bus_default_count_cells(struct device_node
*dev
,
56 int *addrc
, int *sizec
)
59 *addrc
= of_n_addr_cells(dev
);
61 *sizec
= of_n_size_cells(dev
);
64 static u64
of_bus_default_map(__be32
*addr
, const __be32
*range
,
65 int na
, int ns
, int pna
)
69 cp
= of_read_number(range
, na
);
70 s
= of_read_number(range
+ na
+ pna
, ns
);
71 da
= of_read_number(addr
, na
);
73 pr_debug("default map, cp=%llx, s=%llx, da=%llx\n",
74 (unsigned long long)cp
, (unsigned long long)s
,
75 (unsigned long long)da
);
77 if (da
< cp
|| da
>= (cp
+ s
))
82 static int of_bus_default_translate(__be32
*addr
, u64 offset
, int na
)
84 u64 a
= of_read_number(addr
, na
);
85 memset(addr
, 0, na
* 4);
88 addr
[na
- 2] = cpu_to_be32(a
>> 32);
89 addr
[na
- 1] = cpu_to_be32(a
& 0xffffffffu
);
94 static unsigned int of_bus_default_get_flags(const __be32
*addr
)
96 return IORESOURCE_MEM
;
99 #ifdef CONFIG_OF_ADDRESS_PCI
101 * PCI bus specific translator
104 static int of_bus_pci_match(struct device_node
*np
)
107 * "pciex" is PCI Express
108 * "vci" is for the /chaos bridge on 1st-gen PCI powermacs
109 * "ht" is hypertransport
111 return !strcmp(np
->type
, "pci") || !strcmp(np
->type
, "pciex") ||
112 !strcmp(np
->type
, "vci") || !strcmp(np
->type
, "ht");
115 static void of_bus_pci_count_cells(struct device_node
*np
,
116 int *addrc
, int *sizec
)
124 static unsigned int of_bus_pci_get_flags(const __be32
*addr
)
126 unsigned int flags
= 0;
127 u32 w
= be32_to_cpup(addr
);
129 switch((w
>> 24) & 0x03) {
131 flags
|= IORESOURCE_IO
;
133 case 0x02: /* 32 bits */
134 case 0x03: /* 64 bits */
135 flags
|= IORESOURCE_MEM
;
139 flags
|= IORESOURCE_PREFETCH
;
143 static u64
of_bus_pci_map(__be32
*addr
, const __be32
*range
, int na
, int ns
,
149 af
= of_bus_pci_get_flags(addr
);
150 rf
= of_bus_pci_get_flags(range
);
152 /* Check address type match */
153 if ((af
^ rf
) & (IORESOURCE_MEM
| IORESOURCE_IO
))
156 /* Read address values, skipping high cell */
157 cp
= of_read_number(range
+ 1, na
- 1);
158 s
= of_read_number(range
+ na
+ pna
, ns
);
159 da
= of_read_number(addr
+ 1, na
- 1);
161 pr_debug("PCI map, cp=%llx, s=%llx, da=%llx\n",
162 (unsigned long long)cp
, (unsigned long long)s
,
163 (unsigned long long)da
);
165 if (da
< cp
|| da
>= (cp
+ s
))
170 static int of_bus_pci_translate(__be32
*addr
, u64 offset
, int na
)
172 return of_bus_default_translate(addr
+ 1, offset
, na
- 1);
174 #endif /* CONFIG_OF_ADDRESS_PCI */
177 const __be32
*of_get_pci_address(struct device_node
*dev
, int bar_no
, u64
*size
,
182 struct device_node
*parent
;
184 int onesize
, i
, na
, ns
;
186 /* Get parent & match bus type */
187 parent
= of_get_parent(dev
);
190 bus
= of_match_bus(parent
);
191 if (strcmp(bus
->name
, "pci")) {
195 bus
->count_cells(dev
, &na
, &ns
);
197 if (!OF_CHECK_ADDR_COUNT(na
))
200 /* Get "reg" or "assigned-addresses" property */
201 prop
= of_get_property(dev
, bus
->addresses
, &psize
);
207 for (i
= 0; psize
>= onesize
; psize
-= onesize
, prop
+= onesize
, i
++) {
208 u32 val
= be32_to_cpu(prop
[0]);
209 if ((val
& 0xff) == ((bar_no
* 4) + PCI_BASE_ADDRESS_0
)) {
211 *size
= of_read_number(prop
+ na
, ns
);
213 *flags
= bus
->get_flags(prop
);
219 EXPORT_SYMBOL(of_get_pci_address
);
221 int of_pci_address_to_resource(struct device_node
*dev
, int bar
,
228 addrp
= of_get_pci_address(dev
, bar
, &size
, &flags
);
231 return __of_address_to_resource(dev
, addrp
, size
, flags
, NULL
, r
);
233 EXPORT_SYMBOL_GPL(of_pci_address_to_resource
);
235 static int parser_init(struct of_pci_range_parser
*parser
,
236 struct device_node
*node
, const char *name
)
238 const int na
= 3, ns
= 2;
242 parser
->pna
= of_n_addr_cells(node
);
243 parser
->np
= parser
->pna
+ na
+ ns
;
245 parser
->range
= of_get_property(node
, name
, &rlen
);
246 if (parser
->range
== NULL
)
249 parser
->end
= parser
->range
+ rlen
/ sizeof(__be32
);
254 int of_pci_range_parser_init(struct of_pci_range_parser
*parser
,
255 struct device_node
*node
)
257 return parser_init(parser
, node
, "ranges");
259 EXPORT_SYMBOL_GPL(of_pci_range_parser_init
);
261 int of_pci_dma_range_parser_init(struct of_pci_range_parser
*parser
,
262 struct device_node
*node
)
264 return parser_init(parser
, node
, "dma-ranges");
266 EXPORT_SYMBOL_GPL(of_pci_dma_range_parser_init
);
268 struct of_pci_range
*of_pci_range_parser_one(struct of_pci_range_parser
*parser
,
269 struct of_pci_range
*range
)
271 const int na
= 3, ns
= 2;
276 if (!parser
->range
|| parser
->range
+ parser
->np
> parser
->end
)
279 range
->pci_space
= be32_to_cpup(parser
->range
);
280 range
->flags
= of_bus_pci_get_flags(parser
->range
);
281 range
->pci_addr
= of_read_number(parser
->range
+ 1, ns
);
282 range
->cpu_addr
= of_translate_address(parser
->node
,
284 range
->size
= of_read_number(parser
->range
+ parser
->pna
+ na
, ns
);
286 parser
->range
+= parser
->np
;
288 /* Now consume following elements while they are contiguous */
289 while (parser
->range
+ parser
->np
<= parser
->end
) {
291 u64 pci_addr
, cpu_addr
, size
;
293 flags
= of_bus_pci_get_flags(parser
->range
);
294 pci_addr
= of_read_number(parser
->range
+ 1, ns
);
295 cpu_addr
= of_translate_address(parser
->node
,
297 size
= of_read_number(parser
->range
+ parser
->pna
+ na
, ns
);
299 if (flags
!= range
->flags
)
301 if (pci_addr
!= range
->pci_addr
+ range
->size
||
302 cpu_addr
!= range
->cpu_addr
+ range
->size
)
306 parser
->range
+= parser
->np
;
311 EXPORT_SYMBOL_GPL(of_pci_range_parser_one
);
314 * of_pci_range_to_resource - Create a resource from an of_pci_range
315 * @range: the PCI range that describes the resource
316 * @np: device node where the range belongs to
317 * @res: pointer to a valid resource that will be updated to
318 * reflect the values contained in the range.
320 * Returns EINVAL if the range cannot be converted to resource.
322 * Note that if the range is an IO range, the resource will be converted
323 * using pci_address_to_pio() which can fail if it is called too early or
324 * if the range cannot be matched to any host bridge IO space (our case here).
325 * To guard against that we try to register the IO range first.
326 * If that fails we know that pci_address_to_pio() will do too.
328 int of_pci_range_to_resource(struct of_pci_range
*range
,
329 struct device_node
*np
, struct resource
*res
)
332 res
->flags
= range
->flags
;
333 res
->parent
= res
->child
= res
->sibling
= NULL
;
334 res
->name
= np
->full_name
;
336 if (res
->flags
& IORESOURCE_IO
) {
338 err
= pci_register_io_range(range
->cpu_addr
, range
->size
);
341 port
= pci_address_to_pio(range
->cpu_addr
);
342 if (port
== (unsigned long)-1) {
348 if ((sizeof(resource_size_t
) < 8) &&
349 upper_32_bits(range
->cpu_addr
)) {
354 res
->start
= range
->cpu_addr
;
356 res
->end
= res
->start
+ range
->size
- 1;
360 res
->start
= (resource_size_t
)OF_BAD_ADDR
;
361 res
->end
= (resource_size_t
)OF_BAD_ADDR
;
364 #endif /* CONFIG_PCI */
367 * ISA bus specific translator
370 static int of_bus_isa_match(struct device_node
*np
)
372 return !strcmp(np
->name
, "isa");
375 static void of_bus_isa_count_cells(struct device_node
*child
,
376 int *addrc
, int *sizec
)
384 static u64
of_bus_isa_map(__be32
*addr
, const __be32
*range
, int na
, int ns
,
389 /* Check address type match */
390 if ((addr
[0] ^ range
[0]) & cpu_to_be32(1))
393 /* Read address values, skipping high cell */
394 cp
= of_read_number(range
+ 1, na
- 1);
395 s
= of_read_number(range
+ na
+ pna
, ns
);
396 da
= of_read_number(addr
+ 1, na
- 1);
398 pr_debug("ISA map, cp=%llx, s=%llx, da=%llx\n",
399 (unsigned long long)cp
, (unsigned long long)s
,
400 (unsigned long long)da
);
402 if (da
< cp
|| da
>= (cp
+ s
))
407 static int of_bus_isa_translate(__be32
*addr
, u64 offset
, int na
)
409 return of_bus_default_translate(addr
+ 1, offset
, na
- 1);
412 static unsigned int of_bus_isa_get_flags(const __be32
*addr
)
414 unsigned int flags
= 0;
415 u32 w
= be32_to_cpup(addr
);
418 flags
|= IORESOURCE_IO
;
420 flags
|= IORESOURCE_MEM
;
425 * Array of bus specific translators
428 static struct of_bus of_busses
[] = {
429 #ifdef CONFIG_OF_ADDRESS_PCI
433 .addresses
= "assigned-addresses",
434 .match
= of_bus_pci_match
,
435 .count_cells
= of_bus_pci_count_cells
,
436 .map
= of_bus_pci_map
,
437 .translate
= of_bus_pci_translate
,
438 .get_flags
= of_bus_pci_get_flags
,
440 #endif /* CONFIG_OF_ADDRESS_PCI */
445 .match
= of_bus_isa_match
,
446 .count_cells
= of_bus_isa_count_cells
,
447 .map
= of_bus_isa_map
,
448 .translate
= of_bus_isa_translate
,
449 .get_flags
= of_bus_isa_get_flags
,
456 .count_cells
= of_bus_default_count_cells
,
457 .map
= of_bus_default_map
,
458 .translate
= of_bus_default_translate
,
459 .get_flags
= of_bus_default_get_flags
,
463 static struct of_bus
*of_match_bus(struct device_node
*np
)
467 for (i
= 0; i
< ARRAY_SIZE(of_busses
); i
++)
468 if (!of_busses
[i
].match
|| of_busses
[i
].match(np
))
469 return &of_busses
[i
];
474 static int of_empty_ranges_quirk(struct device_node
*np
)
476 if (IS_ENABLED(CONFIG_PPC
)) {
477 /* To save cycles, we cache the result for global "Mac" setting */
478 static int quirk_state
= -1;
480 /* PA-SEMI sdc DT bug */
481 if (of_device_is_compatible(np
, "1682m-sdc"))
484 /* Make quirk cached */
487 of_machine_is_compatible("Power Macintosh") ||
488 of_machine_is_compatible("MacRISC");
494 static int of_translate_one(struct device_node
*parent
, struct of_bus
*bus
,
495 struct of_bus
*pbus
, __be32
*addr
,
496 int na
, int ns
, int pna
, const char *rprop
)
498 const __be32
*ranges
;
501 u64 offset
= OF_BAD_ADDR
;
504 * Normally, an absence of a "ranges" property means we are
505 * crossing a non-translatable boundary, and thus the addresses
506 * below the current cannot be converted to CPU physical ones.
507 * Unfortunately, while this is very clear in the spec, it's not
508 * what Apple understood, and they do have things like /uni-n or
509 * /ht nodes with no "ranges" property and a lot of perfectly
510 * useable mapped devices below them. Thus we treat the absence of
511 * "ranges" as equivalent to an empty "ranges" property which means
512 * a 1:1 translation at that level. It's up to the caller not to try
513 * to translate addresses that aren't supposed to be translated in
514 * the first place. --BenH.
516 * As far as we know, this damage only exists on Apple machines, so
517 * This code is only enabled on powerpc. --gcl
519 ranges
= of_get_property(parent
, rprop
, &rlen
);
520 if (ranges
== NULL
&& !of_empty_ranges_quirk(parent
)) {
521 pr_debug("no ranges; cannot translate\n");
524 if (ranges
== NULL
|| rlen
== 0) {
525 offset
= of_read_number(addr
, na
);
526 memset(addr
, 0, pna
* 4);
527 pr_debug("empty ranges; 1:1 translation\n");
531 pr_debug("walking ranges...\n");
533 /* Now walk through the ranges */
535 rone
= na
+ pna
+ ns
;
536 for (; rlen
>= rone
; rlen
-= rone
, ranges
+= rone
) {
537 offset
= bus
->map(addr
, ranges
, na
, ns
, pna
);
538 if (offset
!= OF_BAD_ADDR
)
541 if (offset
== OF_BAD_ADDR
) {
542 pr_debug("not found !\n");
545 memcpy(addr
, ranges
+ na
, 4 * pna
);
548 of_dump_addr("parent translation for:", addr
, pna
);
549 pr_debug("with offset: %llx\n", (unsigned long long)offset
);
551 /* Translate it into parent bus space */
552 return pbus
->translate(addr
, offset
, pna
);
556 * Translate an address from the device-tree into a CPU physical address,
557 * this walks up the tree and applies the various bus mappings on the
560 * Note: We consider that crossing any level with #size-cells == 0 to mean
561 * that translation is impossible (that is we are not dealing with a value
562 * that can be mapped to a cpu physical address). This is not really specified
563 * that way, but this is traditionally the way IBM at least do things
565 static u64
__of_translate_address(struct device_node
*dev
,
566 const __be32
*in_addr
, const char *rprop
)
568 struct device_node
*parent
= NULL
;
569 struct of_bus
*bus
, *pbus
;
570 __be32 addr
[OF_MAX_ADDR_CELLS
];
571 int na
, ns
, pna
, pns
;
572 u64 result
= OF_BAD_ADDR
;
574 pr_debug("** translation for device %pOF **\n", dev
);
576 /* Increase refcount at current level */
579 /* Get parent & match bus type */
580 parent
= of_get_parent(dev
);
583 bus
= of_match_bus(parent
);
585 /* Count address cells & copy address locally */
586 bus
->count_cells(dev
, &na
, &ns
);
587 if (!OF_CHECK_COUNTS(na
, ns
)) {
588 pr_debug("Bad cell count for %pOF\n", dev
);
591 memcpy(addr
, in_addr
, na
* 4);
593 pr_debug("bus is %s (na=%d, ns=%d) on %pOF\n",
594 bus
->name
, na
, ns
, parent
);
595 of_dump_addr("translating address:", addr
, na
);
599 /* Switch to parent bus */
602 parent
= of_get_parent(dev
);
604 /* If root, we have finished */
605 if (parent
== NULL
) {
606 pr_debug("reached root node\n");
607 result
= of_read_number(addr
, na
);
611 /* Get new parent bus and counts */
612 pbus
= of_match_bus(parent
);
613 pbus
->count_cells(dev
, &pna
, &pns
);
614 if (!OF_CHECK_COUNTS(pna
, pns
)) {
615 pr_err("Bad cell count for %pOF\n", dev
);
619 pr_debug("parent bus is %s (na=%d, ns=%d) on %pOF\n",
620 pbus
->name
, pna
, pns
, parent
);
622 /* Apply bus translation */
623 if (of_translate_one(dev
, bus
, pbus
, addr
, na
, ns
, pna
, rprop
))
626 /* Complete the move up one level */
631 of_dump_addr("one level translation:", addr
, na
);
640 u64
of_translate_address(struct device_node
*dev
, const __be32
*in_addr
)
642 return __of_translate_address(dev
, in_addr
, "ranges");
644 EXPORT_SYMBOL(of_translate_address
);
646 u64
of_translate_dma_address(struct device_node
*dev
, const __be32
*in_addr
)
648 return __of_translate_address(dev
, in_addr
, "dma-ranges");
650 EXPORT_SYMBOL(of_translate_dma_address
);
652 const __be32
*of_get_address(struct device_node
*dev
, int index
, u64
*size
,
657 struct device_node
*parent
;
659 int onesize
, i
, na
, ns
;
661 /* Get parent & match bus type */
662 parent
= of_get_parent(dev
);
665 bus
= of_match_bus(parent
);
666 bus
->count_cells(dev
, &na
, &ns
);
668 if (!OF_CHECK_ADDR_COUNT(na
))
671 /* Get "reg" or "assigned-addresses" property */
672 prop
= of_get_property(dev
, bus
->addresses
, &psize
);
678 for (i
= 0; psize
>= onesize
; psize
-= onesize
, prop
+= onesize
, i
++)
681 *size
= of_read_number(prop
+ na
, ns
);
683 *flags
= bus
->get_flags(prop
);
688 EXPORT_SYMBOL(of_get_address
);
690 static int __of_address_to_resource(struct device_node
*dev
,
691 const __be32
*addrp
, u64 size
, unsigned int flags
,
692 const char *name
, struct resource
*r
)
696 if ((flags
& (IORESOURCE_IO
| IORESOURCE_MEM
)) == 0)
698 taddr
= of_translate_address(dev
, addrp
);
699 if (taddr
== OF_BAD_ADDR
)
701 memset(r
, 0, sizeof(struct resource
));
702 if (flags
& IORESOURCE_IO
) {
704 port
= pci_address_to_pio(taddr
);
705 if (port
== (unsigned long)-1)
708 r
->end
= port
+ size
- 1;
711 r
->end
= taddr
+ size
- 1;
714 r
->name
= name
? name
: dev
->full_name
;
720 * of_address_to_resource - Translate device tree address and return as resource
722 * Note that if your address is a PIO address, the conversion will fail if
723 * the physical address can't be internally converted to an IO token with
724 * pci_address_to_pio(), that is because it's either called too early or it
725 * can't be matched to any host bridge IO space
727 int of_address_to_resource(struct device_node
*dev
, int index
,
733 const char *name
= NULL
;
735 addrp
= of_get_address(dev
, index
, &size
, &flags
);
739 /* Get optional "reg-names" property to add a name to a resource */
740 of_property_read_string_index(dev
, "reg-names", index
, &name
);
742 return __of_address_to_resource(dev
, addrp
, size
, flags
, name
, r
);
744 EXPORT_SYMBOL_GPL(of_address_to_resource
);
746 struct device_node
*of_find_matching_node_by_address(struct device_node
*from
,
747 const struct of_device_id
*matches
,
750 struct device_node
*dn
= of_find_matching_node(from
, matches
);
754 if (!of_address_to_resource(dn
, 0, &res
) &&
755 res
.start
== base_address
)
758 dn
= of_find_matching_node(dn
, matches
);
766 * of_iomap - Maps the memory mapped IO for a given device_node
767 * @device: the device whose io range will be mapped
768 * @index: index of the io range
770 * Returns a pointer to the mapped memory
772 void __iomem
*of_iomap(struct device_node
*np
, int index
)
776 if (of_address_to_resource(np
, index
, &res
))
779 return ioremap(res
.start
, resource_size(&res
));
781 EXPORT_SYMBOL(of_iomap
);
784 * of_io_request_and_map - Requests a resource and maps the memory mapped IO
785 * for a given device_node
786 * @device: the device whose io range will be mapped
787 * @index: index of the io range
788 * @name: name of the resource
790 * Returns a pointer to the requested and mapped memory or an ERR_PTR() encoded
791 * error code on failure. Usage example:
793 * base = of_io_request_and_map(node, 0, "foo");
795 * return PTR_ERR(base);
797 void __iomem
*of_io_request_and_map(struct device_node
*np
, int index
,
803 if (of_address_to_resource(np
, index
, &res
))
804 return IOMEM_ERR_PTR(-EINVAL
);
806 if (!request_mem_region(res
.start
, resource_size(&res
), name
))
807 return IOMEM_ERR_PTR(-EBUSY
);
809 mem
= ioremap(res
.start
, resource_size(&res
));
811 release_mem_region(res
.start
, resource_size(&res
));
812 return IOMEM_ERR_PTR(-ENOMEM
);
817 EXPORT_SYMBOL(of_io_request_and_map
);
820 * of_dma_get_range - Get DMA range info
821 * @np: device node to get DMA range info
822 * @dma_addr: pointer to store initial DMA address of DMA range
823 * @paddr: pointer to store initial CPU address of DMA range
824 * @size: pointer to store size of DMA range
826 * Look in bottom up direction for the first "dma-ranges" property
829 * DMA addr (dma_addr) : naddr cells
830 * CPU addr (phys_addr_t) : pna cells
833 * It returns -ENODEV if "dma-ranges" property was not found
834 * for this device in DT.
836 int of_dma_get_range(struct device_node
*np
, u64
*dma_addr
, u64
*paddr
, u64
*size
)
838 struct device_node
*node
= of_node_get(np
);
839 const __be32
*ranges
= NULL
;
840 int len
, naddr
, nsize
, pna
;
848 naddr
= of_n_addr_cells(node
);
849 nsize
= of_n_size_cells(node
);
850 node
= of_get_next_parent(node
);
854 ranges
= of_get_property(node
, "dma-ranges", &len
);
856 /* Ignore empty ranges, they imply no translation required */
857 if (ranges
&& len
> 0)
861 * At least empty ranges has to be defined for parent node if
869 pr_debug("no dma-ranges found for node(%pOF)\n", np
);
876 pna
= of_n_addr_cells(node
);
878 /* dma-ranges format:
879 * DMA addr : naddr cells
880 * CPU addr : pna cells
883 dmaaddr
= of_read_number(ranges
, naddr
);
884 *paddr
= of_translate_dma_address(np
, ranges
);
885 if (*paddr
== OF_BAD_ADDR
) {
886 pr_err("translation of DMA address(%pad) to CPU address failed node(%pOF)\n",
893 *size
= of_read_number(ranges
+ naddr
+ pna
, nsize
);
895 pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
896 *dma_addr
, *paddr
, *size
);
903 EXPORT_SYMBOL_GPL(of_dma_get_range
);
906 * of_dma_is_coherent - Check if device is coherent
909 * It returns true if "dma-coherent" property was found
910 * for this device in DT.
912 bool of_dma_is_coherent(struct device_node
*np
)
914 struct device_node
*node
= of_node_get(np
);
917 if (of_property_read_bool(node
, "dma-coherent")) {
921 node
= of_get_next_parent(node
);
926 EXPORT_SYMBOL_GPL(of_dma_is_coherent
);