diff options
| author | Vladimir Murzin <vladimir.murzin@arm.com> | 2021-01-07 12:47:24 +0300 |
|---|---|---|
| committer | Russell King <rmk+kernel@armlinux.org.uk> | 2021-02-01 22:42:13 +0300 |
| commit | 2acb909750431030b65a0a2a17fd8afcbd813a84 (patch) | |
| tree | 3d1066b41d2b452e34db089f14a134968e1073d9 /arch/arm/boot/compressed | |
| parent | 0673cb38951215060d7993b43ad3c45cd413c2c3 (diff) | |
| download | linux-2acb909750431030b65a0a2a17fd8afcbd813a84.tar.xz | |
ARM: 9046/1: decompressor: Do not clear SCTLR.nTLSMD for ARMv7+ cores
It was observed that decompressor running on hardware implementing ARM v8.2
Load/Store Multiple Atomicity and Ordering Control (LSMAOC), say, as guest,
would stuck just after:
Uncompressing Linux... done, booting the kernel.
The reason is that it clears nTLSMD bit when disabling caches:
nTLSMD, bit [3]
When ARMv8.2-LSMAOC is implemented:
No Trap Load Multiple and Store Multiple to
Device-nGRE/Device-nGnRE/Device-nGnRnE memory.
0b0 All memory accesses by A32 and T32 Load Multiple and Store
Multiple at EL1 or EL0 that are marked at stage 1 as
Device-nGRE/Device-nGnRE/Device-nGnRnE memory are trapped and
generate a stage 1 Alignment fault.
0b1 All memory accesses by A32 and T32 Load Multiple and Store
Multiple at EL1 or EL0 that are marked at stage 1 as
Device-nGRE/Device-nGnRE/Device-nGnRnE memory are not trapped.
This bit is permitted to be cached in a TLB.
This field resets to 1.
Otherwise:
Reserved, RES1
So as effect we start getting traps we are not quite ready for.
Looking into history it seems that mask used for SCTLR clear came from
the similar code for ARMv4, where bit[3] is the enable/disable bit for
the write buffer. That not applicable to ARMv7 and onwards, so retire
that bit from the masks.
Fixes: 7d09e85448dfa78e3e58186c934449aaf6d49b50 ("[ARM] 4393/2: ARMv7: Add uncompressing code for the new CPU Id format")
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm/boot/compressed')
| -rw-r--r-- | arch/arm/boot/compressed/head.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 262b5b6e45d1..b1cb1972361b 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -1191,9 +1191,9 @@ __armv4_mmu_cache_off: __armv7_mmu_cache_off: mrc p15, 0, r0, c1, c0 #ifdef CONFIG_MMU - bic r0, r0, #0x000d + bic r0, r0, #0x0005 #else - bic r0, r0, #0x000c + bic r0, r0, #0x0004 #endif mcr p15, 0, r0, c1, c0 @ turn MMU and cache off mov r0, #0 |