From: Peng Liu liupeng256@huawei.com
hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I56F4Z CVE: NA
--------------------------------
For arm64, the exactmap has to remove all memblock and then add the user assigned range of memblock. EFI initializes memblock too late so removing all memblock after it will cause panic. Hence, the exactmap can be just used in dt boot mode, add this limitation to Documentation/admin-guide/kernel-parameters.txt.
Signed-off-by: Peng Liu liupeng256@huawei.com Reviewed-by: Kefeng Wang wangkefeng.wang@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- Documentation/admin-guide/kernel-parameters.txt | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index f648dbd7d902..2702a1369c58 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2820,6 +2820,8 @@
memmap=exactmap [KNL,X86,ARM64] Enable setting of an exact E820 and ARM64 memory map, as specified by the user. + For ARM64, this setting is limited to dt boot mode as + exact mapping must be done after initializing memblock. Such memmap=exactmap lines can be constructed based on BIOS output or other requirements. See the memmap=nn@ss option description.