First attempt of making the MIPS subsystem utilizing the memblock early memory allocator was done by me a few years ago. I created a patchset with 21 patches [1]. It turned out to be too complicated and I decided to resend a reworked patchset with smaller number of changes [2]. I did this and after a small review process a v2 patchset was also posted. Then my spare time was over and I couldn't proceed with the patchset support and resubmission.
In a year Mike Rapoport took charge in this task and posted a small patch which essentially did the bootmem allocator removal from MIPS subsystem [3]. A single small patch did in general the whole thing my huge patchsetes were intended for in the first place (though it lacked a few fixes). Mike even went further and completely removed the bootmem allocator from kernel code, so all the subsystems would need to use the only one early memory allocator. This significantly simplified the platforms code as well as removed a deprecated subsystem with duplicated functionality. Million credits to Mike for this. Getting back to the MIPS subsystem and it memblock allocator usage. Even though the patch suggested by Mike [3] fixed most of the problems caused by enabling the memblock allocator usage, some of them have been left uncovered by it. First of all the PFNs calculation algorithm hasn't been fully refactored. A reserved memory declaration loop has been left untouched though it was clearly over-complicated for the new initialization procedure. Secondly the MIPS platform code reserved the whole space below kernel start address, which doesn't seem right since kernel can be located much higher than memory space really starts. Thirdly CMA if it is enabled reserves memory regions by means of memblock in the first place. So the bootmem-init code doesn't need to do it again. Fifthly at early platform initialization stage non of bootmem-left methods can be called since there is no memory pages mapping at that moment, so __nosave* region must be reserved by means of memblock allocator. Finally aside from memblock allocator introduction my early patchsets included a series of useful alterations like "nomap" property implementation for "reserved-memory" dts-nodes, memblock_dump_all() method call after early memory allocator initialization for debugging, low-memory test procedure, kernel memory mapping printout at boot-time, and so on. So all of these fixes and alterations are introduced in this new patchset. Please review. Hope this time I'll be more responsive and finish this series up until it is merged. [1] https://lkml.org/lkml/2016/12/18/195 [2] https://lkml.org/lkml/2018/1/17/1201 [3] https://lkml.org/lkml/2018/9/10/302 NOTE I added a few "Reviewed-by: Matt Redfearn <matt.redfe...@mips.com>" since some patches of this series have been picked up from my earlier patchsets, which Matt's already reviewed. I didn't add the tag for patches, which were either new or partially ported. Changelog v2 - Discard forcible selection of OF_RESERVED_MEM config - Reword 'mips: Dump memblock regions for debugging' commit message since memblock debug printout is activated by memblock=debug kernel parameter - Rebase onto mips-next - Keep patches from 8 to 12 as the rest of them have already been merged Serge Semin (5): mips: Dump memblock regions for debugging mips: Perform early low memory test mips: Print the kernel virtual mem layout on debugging mips: Make sure dt memory regions are valid mips: Manually call fdt_init_reserved_mem() method arch/mips/kernel/prom.c | 14 +++++++++++- arch/mips/kernel/setup.c | 7 ++++++ arch/mips/mm/init.c | 49 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 69 insertions(+), 1 deletion(-) -- 2.21.0
