[PATCH 0/3] support reserving crashkernel above 4G on arm64 kdump

Chen Zhou chenzhou10 at huawei.com
Tue Apr 2 20:05:43 PDT 2019


When crashkernel is reserved above 4G in memory, kernel should reserve
some amount of low memory for swiotlb and some DMA buffers. So there may
be two crash kernel regions, one is below 4G, the other is above 4G.

Crash dump kernel reads more than one crash kernel regions via a dtb
property under node /chosen,
linux,usable-memory-range = <BASE1 SIZE1 [BASE2 SIZE2]>.

Besides, we need to modify kexec-tools:
  arm64: support more than one crash kernel regions

Chen Zhou (3):
  arm64: kdump: support reserving crashkernel above 4G
  arm64: kdump: support more than one crash kernel regions
  kdump: update Documentation about crashkernel on arm64

 Documentation/admin-guide/kernel-parameters.txt |   4 +-
 arch/arm64/kernel/setup.c                       |   3 +
 arch/arm64/mm/init.c                            | 108 ++++++++++++++++++++----
 include/linux/memblock.h                        |   1 +
 mm/memblock.c                                   |  40 +++++++++
 5 files changed, 139 insertions(+), 17 deletions(-)

-- 
2.7.4




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