linux/drivers/firmware/efi/x86_fake_mem.c

70 lines
1.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2019 Intel Corporation. All rights reserved. */
#include <linux/efi.h>
#include <asm/e820/api.h>
#include "fake_mem.h"
void __init efi_fake_memmap_early(void)
{
int i;
/*
* The late efi_fake_mem() call can handle all requests if
* EFI_MEMORY_SP support is disabled.
*/
if (!efi_soft_reserve_enabled())
return;
if (!efi_enabled(EFI_MEMMAP) || !nr_fake_mem)
return;
/*
* Given that efi_fake_memmap() needs to perform memblock
* allocations it needs to run after e820__memblock_setup().
* However, if efi_fake_mem specifies EFI_MEMORY_SP for a given
* address range that potentially needs to mark the memory as
* reserved prior to e820__memblock_setup(). Update e820
* directly if EFI_MEMORY_SP is specified for an
* EFI_CONVENTIONAL_MEMORY descriptor.
*/
for (i = 0; i < nr_fake_mem; i++) {
struct efi_mem_range *mem = &efi_fake_mems[i];
efi_memory_desc_t *md;
u64 m_start, m_end;
if ((mem->attribute & EFI_MEMORY_SP) == 0)
continue;
m_start = mem->range.start;
m_end = mem->range.end;
for_each_efi_memory_desc(md) {
u64 start, end;
if (md->type != EFI_CONVENTIONAL_MEMORY)
continue;
start = md->phys_addr;
end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1;
if (m_start <= end && m_end >= start)
/* fake range overlaps descriptor */;
else
continue;
/*
* Trim the boundary of the e820 update to the
* descriptor in case the fake range overlaps
* !EFI_CONVENTIONAL_MEMORY
*/
start = max(start, m_start);
end = min(end, m_end);
if (end <= start)
continue;
e820__range_update(start, end - start + 1, E820_TYPE_RAM,
E820_TYPE_SOFT_RESERVED);
e820__update_table(e820_table);
}
}
}