On Fri, 10 Dec 2021 14:55:32 +0800, Zhen Lei wrote: > From: Chen Zhou <chenzhou10@xxxxxxxxxx> > > When reserving crashkernel in high memory, some low memory is reserved > for crash dump kernel devices and never mapped by the first kernel. > This memory range is advertised to crash dump kernel via DT property > under /chosen, > linux,usable-memory-range = <BASE1 SIZE1 [BASE2 SIZE2]> > > We reused the DT property linux,usable-memory-range and made the low > memory region as the second range "BASE2 SIZE2", which keeps compatibility > with existing user-space and older kdump kernels. > > Crash dump kernel reads this property at boot time and call memblock_add() > to add the low memory region after memblock_cap_memory_range() has been > called. > > Signed-off-by: Chen Zhou <chenzhou10@xxxxxxxxxx> > Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx> > Tested-by: Dave Kleikamp <dave.kleikamp@xxxxxxxxxx> > --- > drivers/of/fdt.c | 33 +++++++++++++++++++++++---------- > 1 file changed, 23 insertions(+), 10 deletions(-) > Reviewed-by: Rob Herring <robh@xxxxxxxxxx>