Re: [PATCH v4 02/10] memblock: Add variables for usable memory limitation
From: Rob Herring <robh@kernel.org>
Date: 2021-07-14 13:51:09
Also in:
kexec, linux-arm-kernel, linux-mm, linux-renesas-soc, linux-riscv, lkml
On Wed, Jul 14, 2021 at 02:50:12PM +0200, Geert Uytterhoeven wrote:
Add two global variables (cap_mem_addr and cap_mem_size) for storing a
base address and size, describing a limited region in which memory may
be considered available for use by the kernel. If enabled, memory
outside of this range is not available for use.
These variables can by filled by firmware-specific code, and used in
calls to memblock_cap_memory_range() by architecture-specific code.
An example user is the parser of the "linux,usable-memory-range"
property in the DT "/chosen" node.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
This is similar to how the initial ramdisk (phys_initrd_{start,size})
and ELF core headers (elfcorehdr_{addr,size})) are handled.
Does there exist a suitable place in the common memblock code to call
"memblock_cap_memory_range(cap_mem_addr, cap_mem_size)", or does this
have to be done in architecture-specific code?Can't you just call it from early_init_dt_scan_usablemem? If the property is present, you want to call it. If the property is not present, nothing happens. Rob