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arm64: Add work around for Arm Cortex-A55 Erratum 1024718 

commit ece1397cbc upstream.

Some variants of the Arm Cortex-55 cores (r0p0, r0p1, r1p0) suffer
from an erratum 1024718, which causes incorrect updates when DBM/AP
bits in a page table entry is modified without a break-before-make
sequence. The work around is to skip enabling the hardware DBM feature
on the affected cores. The hardware Access Flag management features
is not affected. There are some other cores suffering from this
errata, which could be added to the midr_list to trigger the work
around.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: ckadabi@codeaurora.org
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pull/10/head
Suzuki K Poulose 2018-03-26 15:12:49 +01:00 committed by Greg Kroah-Hartman
parent ca0ecba3dd
commit 50ed0188af
5 changed files with 62 additions and 0 deletions
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1
Documentation/arm64/silicon-errata.txt
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@ -55,6 +55,7 @@ stable kernels.
| ARM | Cortex-A57 | #834220 | ARM64_ERRATUM_834220 |
| ARM | Cortex-A72 | #853709 | N/A |
| ARM | Cortex-A73 | #858921 | ARM64_ERRATUM_858921 |
| ARM | Cortex-A55 | #1024718 | ARM64_ERRATUM_1024718 |
| ARM | MMU-500 | #841119,#826419 | N/A |
| | | | |
| Cavium | ThunderX ITS | #22375, #24313 | CAVIUM_ERRATUM_22375 |

14
arch/arm64/Kconfig
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@ -443,6 +443,20 @@ config ARM64_ERRATUM_843419
If unsure, say Y.
config ARM64_ERRATUM_1024718
bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
default y
help
This option adds work around for Arm Cortex-A55 Erratum 1024718.
Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect
update of the hardware dirty bit when the DBM/AP bits are updated
without a break-before-make. The work around is to disable the usage
of hardware DBM locally on the affected cores. CPUs not affected by
erratum will continue to use the feature.
If unsure, say Y.
config CAVIUM_ERRATUM_22375
bool "Cavium erratum 22375, 24313"
default y

40
arch/arm64/include/asm/assembler.h
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@ -25,6 +25,7 @@
#include <asm/asm-offsets.h>
#include <asm/cpufeature.h>
#include <asm/cputype.h>
#include <asm/page.h>
#include <asm/pgtable-hwdef.h>
#include <asm/ptrace.h>
@ -495,4 +496,43 @@ alternative_endif
and \phys, \pte, #(((1 << (48 - PAGE_SHIFT)) - 1) << PAGE_SHIFT)
.endm
/*
* Check the MIDR_EL1 of the current CPU for a given model and a range of
* variant/revision. See asm/cputype.h for the macros used below.
*
* model: MIDR_CPU_MODEL of CPU
* rv_min: Minimum of MIDR_CPU_VAR_REV()
* rv_max: Maximum of MIDR_CPU_VAR_REV()
* res: Result register.
* tmp1, tmp2, tmp3: Temporary registers
*
* Corrupts: res, tmp1, tmp2, tmp3
* Returns: 0, if the CPU id doesn't match. Non-zero otherwise
*/
.macro cpu_midr_match model, rv_min, rv_max, res, tmp1, tmp2, tmp3
mrs \res, midr_el1
mov_q \tmp1, (MIDR_REVISION_MASK | MIDR_VARIANT_MASK)
mov_q \tmp2, MIDR_CPU_MODEL_MASK
and \tmp3, \res, \tmp2 // Extract model
and \tmp1, \res, \tmp1 // rev & variant
mov_q \tmp2, \model
cmp \tmp3, \tmp2
cset \res, eq
cbz \res, .Ldone\@ // Model matches ?
.if (\rv_min != 0) // Skip min check if rv_min == 0
mov_q \tmp3, \rv_min
cmp \tmp1, \tmp3
cset \res, ge
.endif // \rv_min != 0
/* Skip rv_max check if rv_min == rv_max && rv_min != 0 */
.if ((\rv_min != \rv_max) || \rv_min == 0)
mov_q \tmp2, \rv_max
cmp \tmp1, \tmp2
cset \tmp2, le
and \res, \res, \tmp2
.endif
.Ldone\@:
.endm
#endif /* __ASM_ASSEMBLER_H */

2
arch/arm64/include/asm/cputype.h
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@ -78,6 +78,7 @@
#define ARM_CPU_PART_AEM_V8 0xD0F
#define ARM_CPU_PART_FOUNDATION 0xD00
#define ARM_CPU_PART_CORTEX_A55 0xD05
#define ARM_CPU_PART_CORTEX_A57 0xD07
#define ARM_CPU_PART_CORTEX_A72 0xD08
#define ARM_CPU_PART_CORTEX_A53 0xD03
@ -98,6 +99,7 @@
#define QCOM_CPU_PART_KRYO 0x200
#define MIDR_CORTEX_A53 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A53)
#define MIDR_CORTEX_A55 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A55)
#define MIDR_CORTEX_A57 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A57)
#define MIDR_CORTEX_A72 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A72)
#define MIDR_CORTEX_A73 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A73)

5
arch/arm64/mm/proc.S
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@ -438,6 +438,11 @@ ENTRY(__cpu_setup)
cbz x9, 2f
cmp x9, #2
b.lt 1f
#ifdef CONFIG_ARM64_ERRATUM_1024718
/* Disable hardware DBM on Cortex-A55 r0p0, r0p1 & r1p0 */
cpu_midr_match MIDR_CORTEX_A55, MIDR_CPU_VAR_REV(0, 0), MIDR_CPU_VAR_REV(1, 0), x1, x2, x3, x4
cbnz x1, 1f
#endif
orr x10, x10, #TCR_HD // hardware Dirty flag update
1: orr x10, x10, #TCR_HA // hardware Access flag update
2: