mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-03 17:40:04 +00:00
199c847176
Given that EFI_MEMORY_SP is platform BIOS policy decision for marking memory ranges as "reserved for a specific purpose" there will inevitably be scenarios where the BIOS omits the attribute in situations where it is desired. Unlike other attributes if the OS wants to reserve this memory from the kernel the reservation needs to happen early in init. So early, in fact, that it needs to happen before e820__memblock_setup() which is a pre-requisite for efi_fake_memmap() that wants to allocate memory for the updated table. Introduce an x86 specific efi_fake_memmap_early() that can search for attempts to set EFI_MEMORY_SP via efi_fake_mem and update the e820 table accordingly. The KASLR code that scans the command line looking for user-directed memory reservations also needs to be updated to consider "efi_fake_mem=nn@ss:0x40000" requests. Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
69 lines
1.7 KiB
C
69 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);
|
|
}
|
|
}
|
|
}
|