xref: /openbmc/linux/arch/sparc/prom/memory.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0
2 /* memory.c: Prom routine for acquiring various bits of information
3  *           about RAM on the machine, both virtual and physical.
4  *
5  * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
6  * Copyright (C) 1997 Michael A. Griffith (grif@acm.org)
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/sort.h>
11 #include <linux/init.h>
12 
13 #include <asm/openprom.h>
14 #include <asm/oplib.h>
15 #include <asm/page.h>
16 
17 static int __init prom_meminit_v0(void)
18 {
19 	struct linux_mlist_v0 *p;
20 	int index;
21 
22 	index = 0;
23 	for (p = *(romvec->pv_v0mem.v0_available); p; p = p->theres_more) {
24 		sp_banks[index].base_addr = (unsigned long) p->start_adr;
25 		sp_banks[index].num_bytes = p->num_bytes;
26 		index++;
27 	}
28 
29 	return index;
30 }
31 
32 static int __init prom_meminit_v2(void)
33 {
34 	struct linux_prom_registers reg[64];
35 	phandle node;
36 	int size, num_ents, i;
37 
38 	node = prom_searchsiblings(prom_getchild(prom_root_node), "memory");
39 	size = prom_getproperty(node, "available", (char *) reg, sizeof(reg));
40 	num_ents = size / sizeof(struct linux_prom_registers);
41 
42 	for (i = 0; i < num_ents; i++) {
43 		sp_banks[i].base_addr = reg[i].phys_addr;
44 		sp_banks[i].num_bytes = reg[i].reg_size;
45 	}
46 
47 	return num_ents;
48 }
49 
50 static int sp_banks_cmp(const void *a, const void *b)
51 {
52 	const struct sparc_phys_banks *x = a, *y = b;
53 
54 	if (x->base_addr > y->base_addr)
55 		return 1;
56 	if (x->base_addr < y->base_addr)
57 		return -1;
58 	return 0;
59 }
60 
61 /* Initialize the memory lists based upon the prom version. */
62 void __init prom_meminit(void)
63 {
64 	int i, num_ents = 0;
65 
66 	switch (prom_vers) {
67 	case PROM_V0:
68 		num_ents = prom_meminit_v0();
69 		break;
70 
71 	case PROM_V2:
72 	case PROM_V3:
73 		num_ents = prom_meminit_v2();
74 		break;
75 
76 	default:
77 		break;
78 	}
79 	sort(sp_banks, num_ents, sizeof(struct sparc_phys_banks),
80 	     sp_banks_cmp, NULL);
81 
82 	/* Sentinel.  */
83 	sp_banks[num_ents].base_addr = 0xdeadbeef;
84 	sp_banks[num_ents].num_bytes = 0;
85 
86 	for (i = 0; i < num_ents; i++)
87 		sp_banks[i].num_bytes &= PAGE_MASK;
88 }
89