1// SPDX-License-Identifier: GPL-2.0
 2/* Copyright(c) 2019 Intel Corporation. All rights reserved. */
 3#include <linux/efi.h>
 4#include <asm/e820/api.h>
 5#include "fake_mem.h"
 6
 7void __init efi_fake_memmap_early(void)
 8{
 9	int i;
10
11	/*
12	 * The late efi_fake_mem() call can handle all requests if
13	 * EFI_MEMORY_SP support is disabled.
14	 */
15	if (!efi_soft_reserve_enabled())
16		return;
17
18	if (!efi_enabled(EFI_MEMMAP) || !nr_fake_mem)
19		return;
20
21	/*
22	 * Given that efi_fake_memmap() needs to perform memblock
23	 * allocations it needs to run after e820__memblock_setup().
24	 * However, if efi_fake_mem specifies EFI_MEMORY_SP for a given
25	 * address range that potentially needs to mark the memory as
26	 * reserved prior to e820__memblock_setup(). Update e820
27	 * directly if EFI_MEMORY_SP is specified for an
28	 * EFI_CONVENTIONAL_MEMORY descriptor.
29	 */
30	for (i = 0; i < nr_fake_mem; i++) {
31		struct efi_mem_range *mem = &efi_fake_mems[i];
32		efi_memory_desc_t *md;
33		u64 m_start, m_end;
34
35		if ((mem->attribute & EFI_MEMORY_SP) == 0)
36			continue;
37
38		m_start = mem->range.start;
39		m_end = mem->range.end;
40		for_each_efi_memory_desc(md) {
41			u64 start, end;
42
43			if (md->type != EFI_CONVENTIONAL_MEMORY)
44				continue;
45
46			start = md->phys_addr;
47			end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1;
48
49			if (m_start <= end && m_end >= start)
50				/* fake range overlaps descriptor */;
51			else
52				continue;
53
54			/*
55			 * Trim the boundary of the e820 update to the
56			 * descriptor in case the fake range overlaps
57			 * !EFI_CONVENTIONAL_MEMORY
58			 */
59			start = max(start, m_start);
60			end = min(end, m_end);
61
62			if (end <= start)
63				continue;
64			e820__range_update(start, end - start + 1, E820_TYPE_RAM,
65					E820_TYPE_SOFT_RESERVED);
66			e820__update_table(e820_table);
67		}
68	}
69}