On 07/06/18 01:29, Aneesh Kumar K.V wrote: > This patch steal system RAM and use that to emulate pmem device using the > e820 platform driver. > > This adds a new kernel command line 'pmemmap' which takes the format <size[KMG]> > to allocate memory early in the boot. This memory is later registered as > persistent memory range. > > Based on original patch from Oliver OHalloran <oliveroh@xxxxxxxxxxx> > > Not-Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> > --- > drivers/nvdimm/Kconfig | 13 ++++ > drivers/nvdimm/Makefile | 1 + > drivers/nvdimm/memblockpmem.c | 115 ++++++++++++++++++++++++++++++++++ > 3 files changed, 129 insertions(+) > create mode 100644 drivers/nvdimm/memblockpmem.c > > diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig > index 50d2a33de441..cbbbcbd4506b 100644 > --- a/drivers/nvdimm/Kconfig > +++ b/drivers/nvdimm/Kconfig > @@ -115,4 +115,17 @@ config OF_PMEM > config PMEM_PLATFORM_DEVICE > bool > > +config MEMBLOCK_PMEM > + bool "pmemmap= parameter support" > + default y > + depends on HAVE_MEMBLOCK > + select PMEM_PLATFORM_DEVICE > + help > + Add support for the pmemmap= kernel command line parameter. This is similar > + to the memmap= parameter available on ACPI platforms, but it uses generic > + kernel facilities (the memblock allocator) to reserve memory rather than adding > + to the e820 table. > + > + Select Y if unsure. > + > endif There's a high barrier for "default y", something like if the platform or device cannot boot without it, it can be "default y". I have doubts that this is OK. -- ~Randy
