2e356d6de4
[ Upstream commit e184d42a6e085f95f5c4f1a4fbabebab2984cb68 ] Move the reserved regions to account for a decrease in DRAM when ECC is enabled. ECC takes 1/9th of memory. Running on HW with ECC off, u-boot prints: DRAM: already initialized, 1008 MiB (capacity:1024 MiB, VGA:16 MiB, ECC:off) And with ECC on, u-boot prints: DRAM: already initialized, 896 MiB (capacity:1024 MiB, VGA:16 MiB, ECC:on, ECC size:896 MiB) This implies that MCR54 is configured for ECC to be bounded at the bottom of a 16MiB VGA memory region: 1024MiB - 16MiB (VGA) = 1008MiB 1008MiB / 9 (for ECC) = 112MiB 1008MiB - 112MiB = 896MiB (available DRAM) The flash_memory region currently starts at offset 896MiB: 0xb8000000 (flash_memory offset) - 0x80000000 (base memory address) = 0x38000000 = 896MiB This is the end of the available DRAM with ECC enabled and therefore it needs to be moved. Since the flash_memory is 64MiB in size and needs to be 64MiB aligned, it can just be moved up by 64MiB and would sit right at the end of the available DRAM buffer. The ramoops region currently follows the flash_memory, but it can be moved to sit above flash_memory which would minimize the address-space fragmentation. Signed-off-by: Adriana Kobylak <anoo@us.ibm.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Link: https://lore.kernel.org/r/20220916195535.1020185-1-anoo@linux.ibm.com Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.