From: Marc Zyngier <marc.zyngier@xxxxxxx>
commit 9405447ef79bc93101373e130f72e9e6cbf17dbb upstream.
As a PRFM instruction racing against a TTBR update can have undesirable
effects on TX2, NOP-out such PRFM on cores that are affected by
the TX2-219 erratum.
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/include/asm/cpucaps.h | 3 ++-
arch/arm64/kernel/cpu_errata.c | 5 +++++
arch/arm64/kernel/entry.S | 2 ++
3 files changed, 9 insertions(+), 1 deletion(-)
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -53,7 +53,8 @@
#define ARM64_HAS_DCPODP 43
#define ARM64_WORKAROUND_1463225 44
#define ARM64_WORKAROUND_CAVIUM_TX2_219_TVM 45
+#define ARM64_WORKAROUND_CAVIUM_TX2_219_PRFM 46
-#define ARM64_NCAPS 46
+#define ARM64_NCAPS 47
#endif /* __ASM_CPUCAPS_H */
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -851,6 +851,11 @@ const struct arm64_cpu_capabilities arm6
.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
.matches = has_cortex_a76_erratum_1463225,
},
+ {
+ .desc = "Cavium ThunderX2 erratum 219 (PRFM removal)",
+ .capability = ARM64_WORKAROUND_CAVIUM_TX2_219_PRFM,
+ ERRATA_MIDR_RANGE_LIST(tx2_family_cpus),
+ },
#endif
{
}
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -1070,7 +1070,9 @@ alternative_insn isb, nop, ARM64_WORKARO
#else
ldr x30, =vectors
#endif
+alternative_if_not ARM64_WORKAROUND_CAVIUM_TX2_219_PRFM
prfm plil1strm, [x30, #(1b - tramp_vectors)]
+alternative_else_nop_endif
msr vbar_el1, x30
add x30, x30, #(1b - tramp_vectors)
isb
