1 Device-tree bindings for persistent memory reg
2 ----------------------------------------------
3
4 Persistent memory refers to a class of memory
5
6 a) Usable as main system memory (i.e.
7 b) Retain their contents across power
8
9 Given b) it is best to think of persistent mem
10 storage device. To ensure data integrity the o
11 persistent regions separately to the normal me
12 binding provides a standardised interface for
13 memory regions exist inside the physical addre
14
15 Bindings for the region nodes:
16 -----------------------------
17
18 Required properties:
19 - compatible = "pmem-region"
20
21 - reg = <base, size>;
22 The reg property should specif
23 translatable to a system physi
24 range should be mappable as no
25 (i.e cacheable).
26
27 If the reg property contains m
28 each address range will be tre
29 in a separate device node. Hav
30 node implies no special relati
31
32 Optional properties:
33 - Any relevant NUMA associativity prop
34
35 - volatile; This property indicates th
36 backed by non-persistent memory. Thi
37 may skip the cache flushes required
38 persistent after a write.
39
40 If this property is absent then the
41 is backed by non-volatile memory.
42
43 Examples:
44 --------------------
45
46 /*
47 * This node specifies one 4KB region
48 * 0x5000 to 0x5fff that is backed by
49 */
50 pmem@5000 {
51 compatible = "pmem-region";
52 reg = <0x00005000 0x00001000>;
53 };
54
55 /*
56 * This node specifies two 4KB regions
57 * volatile (normal) memory.
58 */
59 pmem@6000 {
60 compatible = "pmem-region";
61 reg = < 0x00006000 0x00001000
62 0x00008000 0x00001000
63 volatile;
64 };
65
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