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Paul Burton authored
Malta boards can have more than 256MB DDR available, but we have previously only made use of up to 256MB (ie. the DDR accessible via kseg0) by default, without the user manually specifying mem= kernel parameters. This patch causes all available DDR, as reported by the bootloader via the ememsize or memsize environment variables or optionally on the command line, to be used when possible without the user needing to manually provide the memory ranges. Malta now has 2 subtly different memory maps which have to be taken into account when setting this up. The original memory map (referred to by the code as v1) has up to 2GB of DDR aliased in both the upper & lower halves of the 32 bit physical address space, with a 256MB I/O region obscuring 0x10000000-0x1fffffff only in the lower alias. The revised v2 memory map is flat with up to 4GB DDR starting from 0x0, and the I/O region obscures 256MB of DDR which becomes inacessible. The memory map in use is indicated by a register provided by the rocit2 system controller, which is checked in order to set up the kernels memory ranges accordingly. Signed-off-by:
Paul Burton <paul.burton@imgtec.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14273/Signed-off-by:
Ralf Baechle <ralf@linux-mips.org>
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