From ce8c80c536dac9f325a051b30bf7730ee505eddc Mon Sep 17 00:00:00 2001
From: Catalin Marinas <catalin.marinas@arm.com>
Date: Mon, 19 Nov 2018 11:27:28 +0000
Subject: [PATCH] arm64: Add workaround for Cortex-A76 erratum 1286807
On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual address
for a cacheable mapping of a location is being accessed by a core while
another core is remapping the virtual address to a new physical page
using the recommended break-before-make sequence, then under very rare
circumstances TLBI+DSB completes before a read using the translation
being invalidated has been observed by other observers. The workaround
repeats the TLBI+DSB operation and is shared with the Qualcomm Falkor
erratum 1009
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
Documentation/arm64/silicon-errata.txt | 1 +
arch/arm64/Kconfig | 25 +++++++++++++++++++++++++
arch/arm64/include/asm/tlbflush.h | 4 ++--
arch/arm64/kernel/cpu_errata.c | 20 +++++++++++++++++---
4 files changed, 45 insertions(+), 5 deletions(-)
diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
index 76ccded8b74c0..8f95776211447 100644
--- a/Documentation/arm64/silicon-errata.txt
+++ b/Documentation/arm64/silicon-errata.txt
@@ -57,6 +57,7 @@ stable kernels.
| ARM | Cortex-A73 | #858921 | ARM64_ERRATUM_858921 |
| ARM | Cortex-A55 | #1024718 | ARM64_ERRATUM_1024718 |
| ARM | Cortex-A76 | #1188873 | ARM64_ERRATUM_1188873 |
+| ARM | Cortex-A76 | #1286807 | ARM64_ERRATUM_1286807 |
| ARM | MMU-500 | #841119,#826419 | N/A |
| | | | |
| Cavium | ThunderX ITS | #22375, #24313 | CAVIUM_ERRATUM_22375 |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 787d7850e0643..ea2ab0330e3a1 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -497,6 +497,24 @@ config ARM64_ERRATUM_1188873
If unsure, say Y.
+config ARM64_ERRATUM_1286807
+ bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation"
+ default y
+ select ARM64_WORKAROUND_REPEAT_TLBI
+ help
+ This option adds workaround for ARM Cortex-A76 erratum 1286807
+
+ On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual
+ address for a cacheable mapping of a location is being
+ accessed by a core while another core is remapping the virtual
+ address to a new physical page using the recommended
+ break-before-make sequence, then under very rare circumstances
+ TLBI+DSB completes before a read using the translation being
+ invalidated has been observed by other observers. The
+ workaround repeats the TLBI+DSB operation.
+
+ If unsure, say Y.
+
config CAVIUM_ERRATUM_22375
bool "Cavium erratum 22375, 24313"
default y
@@ -566,9 +584,16 @@ config QCOM_FALKOR_ERRATUM_1003
is unchanged. Work around the erratum by invalidating the walk cache
entries for the trampoline before entering the kernel proper.
+config ARM64_WORKAROUND_REPEAT_TLBI
+ bool
+ help
+ Enable the repeat TLBI workaround for Falkor erratum 1009 and
+ Cortex-A76 erratum 1286807.
+
config QCOM_FALKOR_ERRATUM_1009
bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
default y
+ select ARM64_WORKAROUND_REPEAT_TLBI
help
On Falkor v1, the CPU may prematurely complete a DSB following a
TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation
diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index c3c0387aee18f..5dfd23897dea9 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -41,14 +41,14 @@
ALTERNATIVE("nop\n nop", \
"dsb ish\n tlbi " #op, \
ARM64_WORKAROUND_REPEAT_TLBI, \
- CONFIG_QCOM_FALKOR_ERRATUM_1009) \
+ CONFIG_ARM64_WORKAROUND_REPEAT_TLBI) \
: : )
#define __TLBI_1(op, arg) asm ("tlbi " #op ", %0\n" \
ALTERNATIVE("nop\n nop", \
"dsb ish\n tlbi " #op ", %0", \
ARM64_WORKAROUND_REPEAT_TLBI, \
- CONFIG_QCOM_FALKOR_ERRATUM_1009) \
+ CONFIG_ARM64_WORKAROUND_REPEAT_TLBI) \
: : "r" (arg))
#define __TLBI_N(op, arg, n, ...) __TLBI_##n(op, arg)
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index a509e35132d22..6ad715d67df89 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -570,6 +570,20 @@ static const struct midr_range arm64_harden_el2_vectors[] = {
#endif
+#ifdef CONFIG_ARM64_WORKAROUND_REPEAT_TLBI
+
+static const struct midr_range arm64_repeat_tlbi_cpus[] = {
+#ifdef CONFIG_QCOM_FALKOR_ERRATUM_1009
+ MIDR_RANGE(MIDR_QCOM_FALKOR_V1, 0, 0, 0, 0),
+#endif
+#ifdef CONFIG_ARM64_ERRATUM_1286807
+ MIDR_RANGE(MIDR_CORTEX_A76, 0, 0, 3, 0),
+#endif
+ {},
+};
+
+#endif
+
const struct arm64_cpu_capabilities arm64_errata[] = {
#if defined(CONFIG_ARM64_ERRATUM_826319) || \
defined(CONFIG_ARM64_ERRATUM_827319) || \
@@ -695,11 +709,11 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
.matches = is_kryo_midr,
},
#endif
-#ifdef CONFIG_QCOM_FALKOR_ERRATUM_1009
+#ifdef CONFIG_ARM64_WORKAROUND_REPEAT_TLBI
{
- .desc = "Qualcomm Technologies Falkor erratum 1009",
+ .desc = "Qualcomm erratum 1009, ARM erratum 1286807",
.capability = ARM64_WORKAROUND_REPEAT_TLBI,
- ERRATA_MIDR_REV(MIDR_QCOM_FALKOR_V1, 0, 0),
+ ERRATA_MIDR_RANGE_LIST(arm64_repeat_tlbi_cpus),
},
#endif
#ifdef CONFIG_ARM64_ERRATUM_858921
--
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