[PATCH 0/2] ARM: remove TEXT_OFFSET override for Axxia

[Ard Biesheuvel]

Now that the minimum relative alignment of physical to linear virtual
addresses has been reduced to 2 MiB (from 16 MiB), simply rounding up
the lowest usable DRAM address is no longer as wasteful as before.

Combined with Geert's DT memory discovery patch [0], we can now also
cross reference the decompressor's intended load address against DT memory
reservations, and override it if it points into a reserved area.

By doing this, we remove the need for TEXT_OFFSET hacks that override the
placement of the decompressed kernel on all platforms to accommodate a
single platform that has decided to put reserved areas at the base of DRAM.

As a first step, apply this change to mach-axxia, which is the only platform
that increments TEXT_OFFSET by 3 MiB, and defines this memory reservation as
a /memreserve/ entry.

Future followup work could be done that takes the /reserved-memory node into
account as well, which would allow us to remove another set of TEXT_OFFSET
override hacks for a collection of Qualcomm platforms.

[0] https://lore.kernel.org/linux-arm-kernel/20210104130111.1269694-1-geert+renesas@glider.be/

Cc: Arnd Bergmann <arnd at arndb.de>
Cc: Linus Walleij <linus.walleij at linaro.org>
Cc: Russell King - ARM Linux <linux at armlinux.org.uk>
Cc: Geert Uytterhoeven <geert+renesas at glider.be>
Cc: Alexander Sverdlin <alexander.sverdlin at nokia.com>

Ard Biesheuvel (2):
  ARM: take memreserve FDT entries into account when discovering base of
    RAM
  ARM: axxia: remove TEXT_OFFSET override hack

 arch/arm/Makefile                             |  1 -
 arch/arm/boot/compressed/Makefile             |  2 ++
 .../arm/boot/compressed/fdt_check_mem_start.c | 35 ++++++++++++++++++-
 3 files changed, 36 insertions(+), 2 deletions(-)

-- 
2.17.1