[PATCH v3 5/5] arm64: Work around Falkor erratum 1009

Christopher Covington
2017-01-11T14:41:50Z

During a TLB invalidate sequence targeting the inner shareable
domain, Falkor may prematurely complete the DSB before all loads
and stores using the old translation are observed; instruction
fetches are not subject to the conditions of this erratum.

Signed-off-by: Christopher Covington <cov@codeaurora.org>
---
Documentation/arm64/silicon-errata.txt | 1 +
arch/arm64/Kconfig | 10 ++++++++++
arch/arm64/include/asm/cpucaps.h | 3 ++-
arch/arm64/include/asm/tlbflush.h | 5 ++++-
arch/arm64/kernel/cpu_errata.c | 7 +++++++
5 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
index 7151aed..98bef2a 100644
--- a/Documentation/arm64/silicon-errata.txt
+++ b/Documentation/arm64/silicon-errata.txt
@@ -64,3 +64,4 @@ stable kernels.
| | | | |
| Freescale/NXP | LS2080A/LS1043A | A-008585 | FSL_ERRATUM_A008585 |
| Qualcomm | Falkor v1 | E1003 | QCOM_FALKOR_ERRATUM_1003 |
+| Qualcomm | Falkor v1 | E1009 | QCOM_FALKOR_ERRATUM_1009 |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 2a80ac9..d13e903 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -490,6 +490,16 @@ config QCOM_FALKOR_ERRATUM_1003

If unsure, say Y.

+config QCOM_FALKOR_ERRATUM_1009
+ bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
+ default y
+ help
+ Falkor CPU may prematurely complete a DSB following a TLBI xxIS
+ invalidate maintenance operations. Repeat the TLBI operation one
+ more time to fix the issue.
+
+ If unsure, say Y.
+
endmenu

diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index 5aaf7ee..55bcd02 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -36,7 +36,8 @@
#define ARM64_MISMATCHED_CACHE_LINE_SIZE 15
#define ARM64_HAS_NO_FPSIMD 16
#define ARM64_WORKAROUND_QCOM_FALKOR_E1003 17
+#define ARM64_WORKAROUND_REPEAT_TLBI 18

-#define ARM64_NCAPS 18
+#define ARM64_NCAPS 19

#endif /* __ASM_CPUCAPS_H */
diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index f28813c..7313cd3 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -85,7 +85,10 @@
asm (__TLBI_INSTR(op, ##__VA_ARGS__) \
__TLBI_IO(op, ##__VA_ARGS__)); \
asm volatile ( as "\ndsb " #attr "\n" \
- : : : "memory"); } while (0)
+ ALTERNATIVE("nop" "\nnop" "\n", \
+ __TLBI_INSTR(op, ##__VA_ARGS__) "\ndsb " #attr "\n", \
+ ARM64_WORKAROUND_REPEAT_TLBI) \
+ __TLBI_IO(op, ##__VA_ARGS__) : "memory"); } while (0)

#define __tlbi_dsb(...) __tlbi_asm_dsb("", ##__VA_ARGS__)

diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 787b542..e644364 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -137,6 +137,13 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
MIDR_RANGE(MIDR_QCOM_FALKOR_V1, 0x00, 0x00),
},
#endif
+#ifdef CONFIG_QCOM_FALKOR_ERRATUM_1009
+ {
+ .desc = "Qualcomm Falkor erratum 1009",
+ .capability = ARM64_WORKAROUND_REPEAT_TLBI,
+ MIDR_RANGE(MIDR_QCOM_FALKOR_V1, 0x00, 0x00),
+ },
+#endif
{
}
};
--
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Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora
Forum, a Linux Foundation Collaborative Project.