[PATCH v6 00/12] EFI Specific Purpose Memory Support

From: Dan Williams
Date: Wed Oct 09 2019 - 19:18:56 EST


Changes since v5 [1]:

- Move efi=nosoftreserve infrastructure to a common location. (Ard)

- Define a common efi_soft_reserve_enabled() helper for efi
stub code and runtime core efi. (Ard)

- Add ARM support for honoring soft reservations (Ard)

- Rename x86-fake_mem.c to x86_fake_mem.c. (Ard)

- Rebase on v5.4-rc2

[1]: http://lkml.kernel.org/r/156712993795.1616117.3781864460118989466.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

---
Merge notes:

Hi Ingo,

I'm targeting you since you piped on v5, and tip.git in general since
the deepest changes are in x86 init code. The entanglements between
tip.git and acpi.git that v5 hit have been resolved with what went
upstream during the 5.4 merge window. This all still needs an ack from
Ard to make sure he's on board with all the current changes, or
otherwise spots some more fixups. The ARM changes have only been compile
tested (0day-robot). The x86 changes, as mentioned below, have been boot
tested with efi_fake_mem= on a QEMU config that produces an HMAT.

---

The EFI 2.8 Specification [2] introduces the EFI_MEMORY_SP ("specific
purpose") memory attribute. This attribute bit replaces the deprecated
ACPI HMAT "reservation hint" that was introduced in ACPI 6.2 and removed
in ACPI 6.3.

Given the increasing diversity of memory types that might be advertised
to the operating system, there is a need for platform firmware to hint
which memory ranges are free for the OS to use as general purpose memory
and which ranges are intended for application specific usage. For
example, an application with prior knowledge of the platform may expect
to be able to exclusively allocate a precious / limited pool of high
bandwidth memory. Alternatively, for the general purpose case, the
operating system may want to make the memory available on a best effort
basis as a unique numa-node with performance properties by the new
CONFIG_HMEM_REPORTING [3] facility.

In support of optionally allowing either application-exclusive and
core-kernel-mm managed access to differentiated memory, claim
EFI_MEMORY_SP ranges for exposure as "soft reserved" and assigned to a
device-dax instance by default. Such instances can be directly owned /
mapped by a platform-topology-aware application. Alternatively, with the
new kmem facility [4], the administrator has the option to instead
designate that those memory ranges be hot-added to the core-kernel-mm as
a unique memory numa-node. In short, allow for the decision about what
software agent manages soft-reserved memory to be made at runtime.

The patches build on the new HMAT+HMEM_REPORTING facilities merged
for v5.2-rc1. The implementation is tested with qemu emulation of HMAT
[5] plus the efi_fake_mem facility for applying the EFI_MEMORY_SP
attribute. Specific details on reproducing the test configuration are in
patch 12.

[2]: https://uefi.org/sites/default/files/resources/UEFI_Spec_2_8_final.pdf
[3]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e1cf33aafb84
[4]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c221c0b0308f
[5]: http://patchwork.ozlabs.org/cover/1096737/

---

Dan Williams (12):
acpi/numa: Establish a new drivers/acpi/numa/ directory
efi: Enumerate EFI_MEMORY_SP
x86/efi: Push EFI_MEMMAP check into leaf routines
efi: Common enable/disable infrastructure for EFI soft reservation
x86/efi: EFI soft reservation to E820 enumeration
arm/efi: EFI soft reservation to memblock
x86/efi: Add efi_fake_mem support for EFI_MEMORY_SP
lib: Uplevel the pmem "region" ida to a global allocator
dax: Fix alloc_dax_region() compile warning
device-dax: Add a driver for "hmem" devices
acpi/numa/hmat: Register HMAT at device_initcall level
acpi/numa/hmat: Register "soft reserved" memory as an "hmem" device


Documentation/admin-guide/kernel-parameters.txt | 19 +++
arch/arm64/mm/mmu.c | 2
arch/x86/boot/compressed/eboot.c | 6 +
arch/x86/boot/compressed/kaslr.c | 46 +++++++-
arch/x86/include/asm/e820/types.h | 8 +
arch/x86/include/asm/efi.h | 17 +++
arch/x86/kernel/e820.c | 12 ++
arch/x86/kernel/setup.c | 18 +--
arch/x86/platform/efi/efi.c | 53 ++++++++-
arch/x86/platform/efi/quirks.c | 3 +
drivers/acpi/Kconfig | 9 --
drivers/acpi/Makefile | 3 -
drivers/acpi/hmat/Makefile | 2
drivers/acpi/numa/Kconfig | 7 +
drivers/acpi/numa/Makefile | 3 +
drivers/acpi/numa/hmat.c | 138 +++++++++++++++++++++--
drivers/acpi/numa/srat.c | 0
drivers/dax/Kconfig | 27 ++++-
drivers/dax/Makefile | 2
drivers/dax/bus.c | 2
drivers/dax/bus.h | 2
drivers/dax/dax-private.h | 2
drivers/dax/hmem.c | 56 +++++++++
drivers/firmware/efi/Kconfig | 21 ++++
drivers/firmware/efi/Makefile | 5 +
drivers/firmware/efi/arm-init.c | 9 ++
drivers/firmware/efi/arm-runtime.c | 24 ++++
drivers/firmware/efi/efi.c | 14 ++
drivers/firmware/efi/esrt.c | 3 +
drivers/firmware/efi/fake_mem.c | 26 ++--
drivers/firmware/efi/fake_mem.h | 10 ++
drivers/firmware/efi/libstub/arm32-stub.c | 5 +
drivers/firmware/efi/libstub/efi-stub-helper.c | 19 +++
drivers/firmware/efi/libstub/random.c | 4 +
drivers/firmware/efi/x86_fake_mem.c | 69 ++++++++++++
drivers/nvdimm/Kconfig | 1
drivers/nvdimm/core.c | 1
drivers/nvdimm/nd-core.h | 1
drivers/nvdimm/region_devs.c | 13 +-
include/linux/efi.h | 10 ++
include/linux/ioport.h | 1
include/linux/memregion.h | 23 ++++
lib/Kconfig | 3 +
lib/Makefile | 1
lib/memregion.c | 18 +++
45 files changed, 627 insertions(+), 91 deletions(-)
delete mode 100644 drivers/acpi/hmat/Makefile
rename drivers/acpi/{hmat/Kconfig => numa/Kconfig} (75%)
create mode 100644 drivers/acpi/numa/Makefile
rename drivers/acpi/{hmat/hmat.c => numa/hmat.c} (85%)
rename drivers/acpi/{numa.c => numa/srat.c} (100%)
create mode 100644 drivers/dax/hmem.c
create mode 100644 drivers/firmware/efi/fake_mem.h
create mode 100644 drivers/firmware/efi/x86_fake_mem.c
create mode 100644 include/linux/memregion.h
create mode 100644 lib/memregion.c