1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Copyright IBM Corp. 2008, 2009
 4 *
 5 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
 6 */
 7
 8#include <linux/kernel.h>
 9#include <linux/memblock.h>
10#include <linux/init.h>
11#include <linux/debugfs.h>
12#include <linux/seq_file.h>
13#include <asm/ipl.h>
14#include <asm/sclp.h>
15#include <asm/setup.h>
16
17#define CHUNK_READ_WRITE 0
18#define CHUNK_READ_ONLY  1
19
20static inline void memblock_physmem_add(phys_addr_t start, phys_addr_t size)
21{
22	memblock_dbg("memblock_physmem_add: [%#016llx-%#016llx]\n",
23		     start, start + size - 1);
24	memblock_add_range(&memblock.memory, start, size, 0, 0);
25	memblock_add_range(&memblock.physmem, start, size, 0, 0);
26}
27
28void __init detect_memory_memblock(void)
29{
30	unsigned long memsize, rnmax, rzm, addr, size;
31	int type;
32
33	rzm = sclp.rzm;
34	rnmax = sclp.rnmax;
35	memsize = rzm * rnmax;
36	if (!rzm)
37		rzm = 1UL << 17;
38	max_physmem_end = memsize;
39	addr = 0;
40	/* keep memblock lists close to the kernel */
41	memblock_set_bottom_up(true);
42	do {
43		size = 0;
44		/* assume lowcore is writable */
45		type = addr ? tprot(addr) : CHUNK_READ_WRITE;
46		do {
47			size += rzm;
48			if (max_physmem_end && addr + size >= max_physmem_end)
49				break;
50		} while (type == tprot(addr + size));
51		if (type == CHUNK_READ_WRITE || type == CHUNK_READ_ONLY) {
52			if (max_physmem_end && (addr + size > max_physmem_end))
53				size = max_physmem_end - addr;
54			memblock_physmem_add(addr, size);
55		}
56		addr += size;
57	} while (addr < max_physmem_end);
58	memblock_set_bottom_up(false);
59	if (!max_physmem_end)
60		max_physmem_end = memblock_end_of_DRAM();
61	memblock_dump_all();
62}