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ARM: 8690/1: lpae: build TTB control register value from scratch in v7_ttb_setup 

Reading TTBCR in early boot stage might return the value of the previous
kernel's configuration, especially in case of kexec. For example, if
normal kernel (first kernel) had run on a configuration of PHYS_OFFSET <=
PAGE_OFFSET and crash kernel (second kernel) is running on a configuration
PHYS_OFFSET > PAGE_OFFSET, which can happen because it depends on the
reserved area for crash kernel, reading TTBCR and using the value to OR
other bit fields might be risky because it doesn't have a reset value for TTBCR.

Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Hoeun Ryu <hoeun.ryu@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This commit is contained in:
Hoeun Ryu 2017-08-07 06:49:19 +01:00 committed by Russell King
parent 1abd350237
commit f26fee5f11
1 changed files with 1 additions and 2 deletions
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3
arch/arm/mm/proc-v7-3level.S
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@ -129,8 +129,7 @@ ENDPROC(cpu_v7_set_pte_ext)
.macro v7_ttb_setup, zero, ttbr0l, ttbr0h, ttbr1, tmp
ldr \tmp, =swapper_pg_dir @ swapper_pg_dir virtual address
cmp \ttbr1, \tmp, lsr #12 @ PHYS_OFFSET > PAGE_OFFSET?
mrc p15, 0, \tmp, c2, c0, 2 @ TTB control egister
orr \tmp, \tmp, #TTB_EAE
mov \tmp, #TTB_EAE @ for TTB control egister
ALT_SMP(orr \tmp, \tmp, #TTB_FLAGS_SMP)
ALT_UP(orr \tmp, \tmp, #TTB_FLAGS_UP)
ALT_SMP(orr \tmp, \tmp, #TTB_FLAGS_SMP << 16)