[RFC PATCH 00/31] Make U-Boot memory reservations coherent
Sughosh Ganu
sughosh.ganu at linaro.org
Fri Jun 7 20:52:09 CEST 2024
The aim of this patch series is to fix the current state of
incoherence between modules when it comes to memory usage. The primary
issue that this series is trying to fix is that the EFI memory module
which is responsible for allocating and freeing memory, does not have
any visibility of the memory that is being used by the LMB
module. This is further complicated by the fact that the LMB
allocations are caller specific -- the LMB memory map is not global
nor persistent. This means that the memory "allocated" by the LMB
module might be relevant only for a given function. Hence one of the
requirements for making the memory usage visible across modules is to
make LMB allocations persistent and global, and then have means to
communicate the use of memory across modules.
The first set of patches in this series work on making the LMB memory
map persistent and global. This is being done keeping in mind the
usage of LMB memory by platforms where the same memory region can be
used to load multiple different images. What is not allowed is to
overwrite memory that has been allocated by the other module,
currently the EFI memory module. This is being achieved by introducing
a new flag, LMB_NOOVERWRITE, which represents memory which cannot be
re-requested once allocated.
The second set of patches are then introducing a notification
mechanism to indicate any changes to a respective module's memory
map. This way, any memory allocation/reservation by a module gets
notified to any interested listners, who then update their memory map
accordingly, thus keeping memory usage coherent.
Todo's
------
I have run these patches through CI, but the LMB unit tests need an
overhaul. I have currently marked these tests for manual run, as
running these would obviously tamper the LMB memory map, thus
affecting subsequent tests. The current set of LMB tests are written
with the assumption of local LMB memory maps. This needs to be
reworked.
Secondly, there needs to be a test written for testing the various
scenarios of memory being allocated and freed by different modules,
namely LMB and EFI. I have written a couple of commands for testing
the changes that I have made -- I have also included these temporary
commands to assist anyone who might want to test these changes. But I
will be working on adding a more comprehensive test.
Lastly, as the series touches common code, there is obviously an
increase in the size of the image, moreover since the LMB memory is
now persistent, and the variables do not reside on the stack. I want
to check if there can be ways of decreasing the size impact of the
changes.
Sughosh Ganu (31):
lmb: remove the unused lmb_is_reserved() function
lmb: staticize __lmb_alloc_base()
lmb: make the lmb reservations persistent
lmb: remove local instances of the lmb structure variable
lmb: pass a flag to image_setup_libfdt() for lmb reservations
lmb: reserve and add common memory regions post relocation
lmb: remove lmb_init_and_reserve_range() function
lmb: replcace the lmb_init_and_reserve() function
lmb: allow for resizing lmb regions
event: add events to notify memory map changes
lib: Kconfig: add a config symbol for getting memory map updates
add a function to check if an address is in RAM memory
efi_memory: notify of any changes to the EFI memory map
lmb: notify of any changes to the LMB memory map
efi_memory: add an event handler to update memory map
lmb: add an event handler to update memory map
lmb: remove call to efi_lmb_reserve()
sandbox: iommu: remove lmb allocation in the driver
zynq: lmb: do not add to lmb map before relocation
test: cedit: use allocated address for reading file
test: event: update the expected event dump output
test: lmb: run the LMB tests only on sandbox
test: lmb: initialise the lmb structure before tests
test: lmb: add a test case for checking overlapping region add
test: lmb: adjust the test case to handle overlapping regions
test: lmb: run lmb tests only manually
test: bdinfo: dump the global LMB memory map
cmd: bdinfo: only dump the current LMB memory
temp: mx6sabresd: bump up the size limit of the board
temp: cmd: efi_mem: add a command to test efi alloc/free
temp: cmd: efi: add a command to dump EFI memory map
arch/arc/lib/cache.c | 4 +-
arch/arm/lib/stack.c | 4 +-
arch/arm/mach-apple/board.c | 17 +-
arch/arm/mach-snapdragon/board.c | 17 +-
arch/arm/mach-stm32mp/dram_init.c | 8 +-
arch/arm/mach-stm32mp/stm32mp1/cpu.c | 6 +-
arch/m68k/lib/bootm.c | 7 +-
arch/microblaze/lib/bootm.c | 4 +-
arch/mips/lib/bootm.c | 11 +-
arch/nios2/lib/bootm.c | 4 +-
arch/powerpc/cpu/mpc85xx/mp.c | 4 +-
arch/powerpc/include/asm/mp.h | 4 +-
arch/powerpc/lib/bootm.c | 14 +-
arch/riscv/lib/bootm.c | 4 +-
arch/sandbox/cpu/cpu.c | 5 +
arch/sh/lib/bootm.c | 4 +-
arch/x86/lib/bootm.c | 4 +-
arch/xtensa/lib/bootm.c | 4 +-
board/xilinx/common/board.c | 33 --
boot/bootm.c | 26 +-
boot/bootm_os.c | 5 +-
boot/image-board.c | 34 +--
boot/image-fdt.c | 36 +--
cmd/Makefile | 2 +
cmd/bdinfo.c | 5 +-
cmd/booti.c | 2 +-
cmd/bootz.c | 2 +-
cmd/efi_map_dump.c | 28 ++
cmd/efi_memory.c | 155 ++++++++++
cmd/elf.c | 2 +-
cmd/load.c | 7 +-
common/board_r.c | 20 ++
common/event.c | 4 +
configs/mx6sabresd_defconfig | 2 +-
drivers/iommu/apple_dart.c | 8 +-
drivers/iommu/sandbox_iommu.c | 17 +-
fs/fs.c | 7 +-
include/efi_loader.h | 2 +
include/event.h | 28 ++
include/image.h | 27 +-
include/lmb.h | 96 +++---
lib/Kconfig | 10 +
lib/efi_loader/efi_dt_fixup.c | 2 +-
lib/efi_loader/efi_helper.c | 2 +-
lib/efi_loader/efi_memory.c | 127 +++++++-
lib/lmb.c | 442 ++++++++++++++++++---------
net/tftp.c | 5 +-
net/wget.c | 5 +-
test/boot/cedit.c | 5 +-
test/cmd/bdinfo.c | 22 +-
test/lib/Makefile | 2 +-
test/lib/lmb.c | 274 +++++++++--------
test/py/tests/test_event_dump.py | 2 +
53 files changed, 1001 insertions(+), 570 deletions(-)
create mode 100644 cmd/efi_map_dump.c
create mode 100644 cmd/efi_memory.c
--
2.34.1
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