kernel_optimize_test/Documentation/arm
Ard Biesheuvel 1eb7756902 ARM: 9012/1: move device tree mapping out of linear region
commit 7a1be318f5795cb66fa0dc86b3ace427fe68057f upstream

On ARM, setting up the linear region is tricky, given the constraints
around placement and alignment of the memblocks, and how the kernel
itself as well as the DT are placed in physical memory.

Let's simplify matters a bit, by moving the device tree mapping to the
top of the address space, right between the end of the vmalloc region
and the start of the the fixmap region, and create a read-only mapping
for it that is independent of the size of the linear region, and how it
is organized.

Since this region was formerly used as a guard region, which will now be
populated fully on LPAE builds by this read-only mapping (which will
still be able to function as a guard region for stray writes), bump the
start of the [underutilized] fixmap region by 512 KB as well, to ensure
that there is always a proper guard region here. Doing so still leaves
ample room for the fixmap space, even with NR_CPUS set to its maximum
value of 32.

Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-19 10:13:18 +02:00
..
keystone docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
nwfpe docs: add SPDX tags to new index files 2019-07-15 11:03:03 -03:00
omap docs: add SPDX tags to new index files 2019-07-15 11:03:03 -03:00
pxa docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
sa1100 Documentation/arm/sa1100/assabet: Fix 'make assabet_defconfig' command 2019-08-12 15:24:31 -06:00
samsung docs: add SPDX tags to new index files 2019-07-15 11:03:03 -03:00
samsung-s3c24xx Documentation/arm/samsung-s3c24xx: Remove stray U+FEFF character to fix title 2019-08-12 15:25:32 -06:00
spear docs: arm: fix a breakage with pdf output 2019-07-15 11:03:04 -03:00
sti docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
stm32 docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
sunxi docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
vfp docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
arm.rst ARM: 8996/1: Documentation/Clean up the description of mach-<class> 2020-07-28 10:52:12 +01:00
booting.rst docs: dt: convert booting-without-of.txt to ReST format 2020-06-26 11:33:26 -06:00
cluster-pm-race-avoidance.rst docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
firmware.rst docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
index.rst docs: add SPDX tags to new index files 2019-07-15 11:03:03 -03:00
interrupts.rst docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
ixp4xx.rst docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
kernel_mode_neon.rst docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
kernel_user_helpers.rst docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
marvel.rst docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
mem_alignment.rst docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
memory.rst ARM: 9012/1: move device tree mapping out of linear region 2021-05-19 10:13:18 +02:00
microchip.rst docs: dt: convert ABI.txt to ReST format 2020-05-04 17:09:52 -05:00
netwinder.rst docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
porting.rst docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
setup.rst docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
sunxi.rst documentation: arm: sunxi: add Allwinner H6 documents 2020-10-28 11:19:24 -06:00
swp_emulation.rst docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00
tcm.rst docs: arm: tcm: Fix a few typos 2020-02-19 02:42:21 -07:00
uefi.rst efi: efivars: limit availability to X86 builds 2020-09-29 19:40:57 +02:00
vlocks.rst docs: arm: convert docs to ReST and rename to *.rst 2019-07-15 09:20:24 -03:00