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| author | Ard Biesheuvel <ardb@kernel.org> | 2020-10-11 12:21:37 +0300 |
|---|---|---|
| committer | Russell King <rmk+kernel@armlinux.org.uk> | 2020-10-27 15:11:01 +0300 |
| commit | 7a1be318f5795cb66fa0dc86b3ace427fe68057f (patch) | |
| tree | a84f9c1b2418a33837d53dbc0ce3e242e401dcfc /arch/arm/mm/pv-fixup-asm.S | |
| parent | e9a2f8b599d0bc22a1b13e69527246ac39c697b4 (diff) | |
| download | linux-7a1be318f5795cb66fa0dc86b3ace427fe68057f.tar.xz | |
ARM: 9012/1: move device tree mapping out of linear region
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>
Diffstat (limited to 'arch/arm/mm/pv-fixup-asm.S')
| -rw-r--r-- | arch/arm/mm/pv-fixup-asm.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm/mm/pv-fixup-asm.S b/arch/arm/mm/pv-fixup-asm.S index 8eade0416739..5c5e1952000a 100644 --- a/arch/arm/mm/pv-fixup-asm.S +++ b/arch/arm/mm/pv-fixup-asm.S @@ -39,8 +39,8 @@ ENTRY(lpae_pgtables_remap_asm) /* Update level 2 entries for the boot data */ add r7, r2, #0x1000 - add r7, r7, r3, lsr #SECTION_SHIFT - L2_ORDER - bic r7, r7, #(1 << L2_ORDER) - 1 + movw r3, #FDT_FIXED_BASE >> (SECTION_SHIFT - L2_ORDER) + add r7, r7, r3 ldrd r4, r5, [r7] adds r4, r4, r0 adc r5, r5, r1 |