Hi Greg,

For v5.19, I can cherry-pick this patch directly from commit 39fdb65f52e9 ("arm64: errata: Add Cortex-A510 to the repeat tlbi list") to linux-5.19.y without conflicts. For v5.15, below is my working backport based on linux-5.15.y.

Please let me know if anything can be refined or needs to be changed. Thanks for your help and review! ---- From d4722275e4d7b686dc79363159e141b71f62f7d4 Mon Sep 17 00:00:00 2001 From: James Morse james.morse@arm.com Date: Mon, 4 Jul 2022 16:57:32 +0100 Subject: [PATCH] arm64: errata: Add Cortex-A510 to the repeat tlbi list

Cortex-A510 is affected by an erratum where in rare circumstances the CPUs may not handle a race between a break-before-make sequence on one CPU, and another CPU accessing the same page. This could allow a store to a page that has been unmapped.

Work around this by adding the affected CPUs to the list that needs TLB sequences to be done twice.

Signed-off-by: James Morse james.morse@arm.com Link: https://lore.kernel.org/r/20220704155732.21216-1-james.morse@arm.com Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Lucas Wei lucaswei@google.com --- Documentation/arm64/silicon-errata.rst | 2 ++ arch/arm64/Kconfig | 17 +++++++++++++++++ arch/arm64/kernel/cpu_errata.c | 8 +++++++- 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst index 7c1750bcc5bd..46644736e583 100644 --- a/Documentation/arm64/silicon-errata.rst +++ b/Documentation/arm64/silicon-errata.rst @@ -92,6 +92,8 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-A77 | #1508412 | ARM64_ERRATUM_1508412 | +----------------+-----------------+-----------------+-----------------------------+ +| ARM | Cortex-A510 | #2441009 | ARM64_ERRATUM_2441009 | ++----------------+-----------------+-----------------+-----------------------------+ | ARM | Neoverse-N1 | #1188873,1418040| ARM64_ERRATUM_1418040 | +----------------+-----------------+-----------------+-----------------------------+ | ARM | Neoverse-N1 | #1349291 | N/A | diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 69e7e293f72e..9d80c783142f 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -666,6 +666,23 @@ config ARM64_ERRATUM_1508412

If unsure, say Y.

+config ARM64_ERRATUM_2441009 + bool "Cortex-A510: Completion of affected memory accesses might not be guaranteed by completion of a TLBI" + default y + select ARM64_WORKAROUND_REPEAT_TLBI + help + This option adds a workaround for ARM Cortex-A510 erratum #2441009. + + Under very rare circumstances, affected Cortex-A510 CPUs + may not handle a race between a break-before-make sequence on one + CPU, and another CPU accessing the same page. This could allow a + store to a page that has been unmapped. + + Work around this by adding the affected CPUs to the list that needs + TLB sequences to be done twice. + + If unsure, say Y. + config CAVIUM_ERRATUM_22375 bool "Cavium erratum 22375, 24313" default y diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index c67c19d70159..e1be45fc7f5b 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -211,6 +211,12 @@ static const struct arm64_cpu_capabilities arm64_repeat_tlbi_list[] = { /* Kryo4xx Gold (rcpe to rfpe) => (r0p0 to r3p0) */ ERRATA_MIDR_RANGE(MIDR_QCOM_KRYO_4XX_GOLD, 0xc, 0xe, 0xf, 0xe), }, +#endif +#ifdef CONFIG_ARM64_ERRATUM_2441009 + { + /* Cortex-A510 r0p0 -> r1p1. Fixed in r1p2 */ + ERRATA_MIDR_RANGE(MIDR_CORTEX_A510, 0, 0, 1, 1), + }, #endif {}, }; @@ -427,7 +433,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = { #endif #ifdef CONFIG_ARM64_WORKAROUND_REPEAT_TLBI { - .desc = "Qualcomm erratum 1009, or ARM erratum 1286807", + .desc = "Qualcomm erratum 1009, or ARM erratum 1286807, 2441009", .capability = ARM64_WORKAROUND_REPEAT_TLBI, .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, .matches = cpucap_multi_entry_cap_matches, --

On Tue, Aug 30, 2022 at 1:57 PM Greg KH gregkh@linuxfoundation.org wrote:

On Tue, Aug 30, 2022 at 10:31:35AM +0800, Lucas Wei wrote:

...

Dear Linux stable kernel maintainers,

I would like to apply the below patch into kernel v5.15-stable.

• subject:arm64: errata: Add Cortex-A510 to the repeat tlbi list
• Upstream Commit ID: 39fdb65f52e9a53d32a6ba719f96669fd300ae78
• Targeted LTS release: v5.15

This patch is an errata of #2441009. Since v5.15 is still in its LTS lifecycle, I think it fits the rule of "New device IDs and quirks are also accepted" and I want to request to apply this patch to kernel v5.15.

You also need it in 5.19.y, right? And you never want someone to upgrade from an older kernel to a newer one and have a regression.

This commit does not cleanly cherry-pick, I need a working backport in order to apply it. As I'm sure you already have a working and tested backport of it (otherwise you wouldn't have asked for it), can you please send it to us so that it can be applied?

Same for 5.19.y too.

thanks,

greg k-h