[v2,0/4] Introduce reserved heap

Message

Henry Wang Sept. 5, 2022, 7:26 a.m. UTC

The reserved heap, or statically configured heap, refers to parts
of RAM reserved in the beginning for heap. Like the static memory
allocation, such reserved heap regions are reserved by configuration
in the device tree using physical address ranges.

This feature is useful to run Xen on Arm MPU systems, where only a
finite number of memory protection regions are available. The limited
number of protection regions places requirement on planning the use of
MPU protection regions and one or more MPU protection regions needs to
be reserved only for heap.

The first patch introduces the reserved heap and the device tree parsing
code. The second patch enhances the error handling in processing the dts
chosen node. The third patch adds the implementation of the reserved heap
pages handling in boot and heap allocator for Arm. The fourth patch
renames xenheap_* to directmap_* for better readablity.

Changes from v1 to v2:
- Rename the device tree property to xen,static-heap to avoid confusion.
- Change of commit msg and doc wording, correct typo in commit msg.
- Add an empty line in make_memory_node() memory type check to improve
  readability.
- Use enum membank_type to make the memory type cleaner.
- New commits for make process_chosen_node() return int and rename
  xenheap_* to directmap_*.
- Move the global bool `reserved_heap` to bootinfo.
- Replace the open open-coding address ~0 by INVALID_PADDR.
- Do not use reverted logic in heap_pages calculation.
- Remove unused Arm32 reserved_heap_start variable.
- Decouple the arm32 reserved heap too small size check with region
  end check.
- Reuse the arm32 original xenheap finding logic with the new helper
  to make sure xenheap on arm32 is contiguous.

Henry Wang (4):
  docs, xen/arm: Introduce reserved heap memory
  xen/arm: bootfdt: Make process_chosen_node() return int
  xen/arm: Handle reserved heap pages in boot and heap allocator
  xen/arm: mm: Rename xenheap_* variable to directmap_*

 docs/misc/arm/device-tree/booting.txt |  45 ++++++++
 xen/arch/arm/bootfdt.c                |  54 +++++++---
 xen/arch/arm/domain_build.c           |   8 +-
 xen/arch/arm/include/asm/config.h     |   2 +-
 xen/arch/arm/include/asm/mm.h         |  22 ++--
 xen/arch/arm/include/asm/setup.h      |   8 +-
 xen/arch/arm/mm.c                     |  24 ++---
 xen/arch/arm/setup.c                  | 145 ++++++++++++++++++++------
 8 files changed, 238 insertions(+), 70 deletions(-)