linux/include
Steven Rostedt (Google) 1e4c64b71c mm/memblock: Add "reserve_mem" to reserved named memory at boot up
In order to allow for requesting a memory region that can be used for
things like pstore on multiple machines where the memory layout is not the
same, add a new option to the kernel command line called "reserve_mem".

The format is:  reserve_mem=nn:align:name

Where it will find nn amount of memory at the given alignment of align.
The name field is to allow another subsystem to retrieve where the memory
was found. For example:

  reserve_mem=12M:4096:oops ramoops.mem_name=oops

Where ramoops.mem_name will tell ramoops that memory was reserved for it
via the reserve_mem option and it can find it by calling:

  if (reserve_mem_find_by_name("oops", &start, &size)) {
	// start holds the start address and size holds the size given

This is typically used for systems that do not wipe the RAM, and this
command line will try to reserve the same physical memory on soft reboots.
Note, it is not guaranteed to be the same location. For example, if KASLR
places the kernel at the location of where the RAM reservation was from a
previous boot, the new reservation will be at a different location.  Any
subsystem using this feature must add a way to verify that the contents of
the physical memory is from a previous boot, as there may be cases where
the memory will not be located at the same location.

Not all systems may work either. There could be bit flips if the reboot
goes through the BIOS. Using kexec to reboot the machine is likely to
have better results in such cases.

Link: https://lore.kernel.org/all/ZjJVnZUX3NZiGW6q@kernel.org/

Suggested-by: Mike Rapoport <rppt@kernel.org>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20240613155527.437020271@goodmis.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
2024-06-19 10:59:49 +03:00
..
acpi The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
asm-generic asm-generic cleanups for 6.10 2024-05-20 15:18:34 -07:00
clocksource
crypto This push fixes a bug in the new ecc P521 code as well as a buggy 2024-05-20 08:47:54 -07:00
drm Short summary of fixes pull: 2024-05-27 13:47:14 +10:00
dt-bindings - Core Frameworks 2024-05-22 10:49:54 -07:00
keys Hi, 2024-05-13 10:40:15 -07:00
kunit
kvm
linux mm/memblock: Add "reserve_mem" to reserved named memory at boot up 2024-06-19 10:59:49 +03:00
math-emu
media
memory
misc
net net: fix __dst_negative_advice() race 2024-05-29 17:34:49 -07:00
pcmcia
ras tracing/treewide: Remove second parameter of __assign_str() 2024-05-22 20:14:47 -04:00
rdma The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
rv
scsi SCSI misc on 20240514 2024-05-14 18:25:53 -07:00
soc I'm actually surprised this time. There aren't any new Qualcomm SoC clk 2024-05-18 12:48:37 -07:00
sound ALSA: pcm: fix typo in comment 2024-05-29 10:40:36 +02:00
target
trace block-6.10-20240523 2024-05-23 13:44:47 -07:00
uapi TTY fix for 6.10-rc2 2024-06-01 08:53:39 -07:00
ufs
vdso
video
xen