From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 55BC2174CA for ; Wed, 9 Aug 2023 10:58:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE03AC433C8; Wed, 9 Aug 2023 10:58:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691578686; bh=8+RgxHCLeUqDggBgbPEY7BoHgJO0zbcympNvSzdNxtI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=codruxTWXJHE9jw9e/UzY6/bIWdDATlokP0cnMRkqo6NxEBbFIHzggyJBBHOT/5CU YWN9bCM8LTe3SSE8DvdUg4JVaPT+uB13427PEugJi0O9hk6JCZhPyR7h0izK55tlZI HGAodVHLwQN/4GlmKBgYY1c2DMQbCR/Bz1tukwNE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Will Deacon , Catalin Marinas , Mathieu Poirier , Mike Leach , Mark Rutland , Anshuman Khandual , Marc Zyngier , Suzuki K Poulose , Easwar Hariharan Subject: [PATCH 5.15 04/92] arm64: errata: Add workaround for TSB flush failures Date: Wed, 9 Aug 2023 12:40:40 +0200 Message-ID: <20230809103633.677416983@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103633.485906560@linuxfoundation.org> References: <20230809103633.485906560@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Suzuki K Poulose commit fa82d0b4b833790ac4572377fb777dcea24a9d69 upstream Arm Neoverse-N2 (#2067961) and Cortex-A710 (#2054223) suffers from errata, where a TSB (trace synchronization barrier) fails to flush the trace data completely, when executed from a trace prohibited region. In Linux we always execute it after we have moved the PE to trace prohibited region. So, we can apply the workaround every time a TSB is executed. The work around is to issue two TSB consecutively. NOTE: This errata is defined as LOCAL_CPU_ERRATUM, implying that a late CPU could be blocked from booting if it is the first CPU that requires the workaround. This is because we do not allow setting a cpu_hwcaps after the SMP boot. The other alternative is to use "this_cpu_has_cap()" instead of the faster system wide check, which may be a bit of an overhead, given we may have to do this in nvhe KVM host before a guest entry. Cc: Will Deacon Cc: Catalin Marinas Cc: Mathieu Poirier Cc: Mike Leach Cc: Mark Rutland Cc: Anshuman Khandual Cc: Marc Zyngier Acked-by: Catalin Marinas Reviewed-by: Mathieu Poirier Reviewed-by: Anshuman Khandual Signed-off-by: Suzuki K Poulose Link: https://lore.kernel.org/r/20211019163153.3692640-4-suzuki.poulose@arm.com Signed-off-by: Will Deacon Signed-off-by: Easwar Hariharan Signed-off-by: Greg Kroah-Hartman --- Documentation/arm64/silicon-errata.rst | 4 ++++ arch/arm64/Kconfig | 33 +++++++++++++++++++++++++++++++++ arch/arm64/include/asm/barrier.h | 16 +++++++++++++++- arch/arm64/kernel/cpu_errata.c | 19 +++++++++++++++++++ arch/arm64/tools/cpucaps | 1 + 5 files changed, 72 insertions(+), 1 deletion(-) --- a/Documentation/arm64/silicon-errata.rst +++ b/Documentation/arm64/silicon-errata.rst @@ -104,6 +104,8 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-A710 | #2119858 | ARM64_ERRATUM_2119858 | +----------------+-----------------+-----------------+-----------------------------+ +| ARM | Cortex-A710 | #2054223 | ARM64_ERRATUM_2054223 | ++----------------+-----------------+-----------------+-----------------------------+ | ARM | Neoverse-N1 | #1188873,1418040| ARM64_ERRATUM_1418040 | +----------------+-----------------+-----------------+-----------------------------+ | ARM | Neoverse-N1 | #1349291 | N/A | @@ -112,6 +114,8 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | ARM | Neoverse-N2 | #2139208 | ARM64_ERRATUM_2139208 | +----------------+-----------------+-----------------+-----------------------------+ +| ARM | Neoverse-N2 | #2067961 | ARM64_ERRATUM_2067961 | ++----------------+-----------------+-----------------+-----------------------------+ | ARM | MMU-500 | #841119,826419 | N/A | +----------------+-----------------+-----------------+-----------------------------+ +----------------+-----------------+-----------------+-----------------------------+ --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -774,6 +774,39 @@ config ARM64_ERRATUM_2139208 If unsure, say Y. +config ARM64_WORKAROUND_TSB_FLUSH_FAILURE + bool + +config ARM64_ERRATUM_2054223 + bool "Cortex-A710: 2054223: workaround TSB instruction failing to flush trace" + default y + select ARM64_WORKAROUND_TSB_FLUSH_FAILURE + help + Enable workaround for ARM Cortex-A710 erratum 2054223 + + Affected cores may fail to flush the trace data on a TSB instruction, when + the PE is in trace prohibited state. This will cause losing a few bytes + of the trace cached. + + Workaround is to issue two TSB consecutively on affected cores. + + If unsure, say Y. + +config ARM64_ERRATUM_2067961 + bool "Neoverse-N2: 2067961: workaround TSB instruction failing to flush trace" + default y + select ARM64_WORKAROUND_TSB_FLUSH_FAILURE + help + Enable workaround for ARM Neoverse-N2 erratum 2067961 + + Affected cores may fail to flush the trace data on a TSB instruction, when + the PE is in trace prohibited state. This will cause losing a few bytes + of the trace cached. + + Workaround is to issue two TSB consecutively on affected cores. + + If unsure, say Y. + config CAVIUM_ERRATUM_22375 bool "Cavium erratum 22375, 24313" default y --- a/arch/arm64/include/asm/barrier.h +++ b/arch/arm64/include/asm/barrier.h @@ -23,7 +23,7 @@ #define dsb(opt) asm volatile("dsb " #opt : : : "memory") #define psb_csync() asm volatile("hint #17" : : : "memory") -#define tsb_csync() asm volatile("hint #18" : : : "memory") +#define __tsb_csync() asm volatile("hint #18" : : : "memory") #define csdb() asm volatile("hint #20" : : : "memory") #ifdef CONFIG_ARM64_PSEUDO_NMI @@ -46,6 +46,20 @@ #define dma_rmb() dmb(oshld) #define dma_wmb() dmb(oshst) + +#define tsb_csync() \ + do { \ + /* \ + * CPUs affected by Arm Erratum 2054223 or 2067961 needs \ + * another TSB to ensure the trace is flushed. The barriers \ + * don't have to be strictly back to back, as long as the \ + * CPU is in trace prohibited state. \ + */ \ + if (cpus_have_final_cap(ARM64_WORKAROUND_TSB_FLUSH_FAILURE)) \ + __tsb_csync(); \ + __tsb_csync(); \ + } while (0) + /* * Generate a mask for array_index__nospec() that is ~0UL when 0 <= idx < sz * and 0 otherwise. --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -375,6 +375,18 @@ static const struct midr_range trbe_over }; #endif /* CONFIG_ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE */ +#ifdef CONFIG_ARM64_WORKAROUND_TSB_FLUSH_FAILURE +static const struct midr_range tsb_flush_fail_cpus[] = { +#ifdef CONFIG_ARM64_ERRATUM_2067961 + MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2), +#endif +#ifdef CONFIG_ARM64_ERRATUM_2054223 + MIDR_ALL_VERSIONS(MIDR_CORTEX_A710), +#endif + {}, +}; +#endif /* CONFIG_ARM64_WORKAROUND_TSB_FLUSH_FAILURE */ + const struct arm64_cpu_capabilities arm64_errata[] = { #ifdef CONFIG_ARM64_WORKAROUND_CLEAN_CACHE { @@ -607,6 +619,13 @@ const struct arm64_cpu_capabilities arm6 CAP_MIDR_RANGE_LIST(trbe_overwrite_fill_mode_cpus), }, #endif +#ifdef CONFIG_ARM64_WORKAROUND_TSB_FLUSH_FAILURE + { + .desc = "ARM erratum 2067961 or 2054223", + .capability = ARM64_WORKAROUND_TSB_FLUSH_FAILURE, + ERRATA_MIDR_RANGE_LIST(tsb_flush_fail_cpus), + }, +#endif { } }; --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -57,6 +57,7 @@ WORKAROUND_1542419 WORKAROUND_1742098 WORKAROUND_2457168 WORKAROUND_TRBE_OVERWRITE_FILL_MODE +WORKAROUND_TSB_FLUSH_FAILURE WORKAROUND_CAVIUM_23154 WORKAROUND_CAVIUM_27456 WORKAROUND_CAVIUM_30115