From ac0ba2100298a3e85d9a92924a959b80612144e6 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Tue, 25 Jan 2022 19:50:35 +0530 Subject: coresight: trbe: Work around the ignored system register writes TRBE implementations affected by Arm erratum #2064142 might fail to write into certain system registers after the TRBE has been disabled. Under some conditions after TRBE has been disabled, writes into certain TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1 and TRBTRG_EL1 will be ignored and not be effected. Work around this problem in the TRBE driver by executing TSB CSYNC and DSB just after the trace collection has stopped and before performing a system register write to one of the affected registers. This just updates the TRBE driver as required. Cc: Catalin Marinas Cc: Will Deacon Cc: Mathieu Poirier Cc: Suzuki Poulose Cc: coresight@lists.linaro.org Cc: linux-doc@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Suzuki K Poulose Signed-off-by: Anshuman Khandual Link: https://lore.kernel.org/r/1643120437-14352-6-git-send-email-anshuman.khandual@arm.com Signed-off-by: Mathieu Poirier Signed-off-by: Suzuki K Poulose --- arch/arm64/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm64/Kconfig') diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index cbcd42decb2a..93980bf31e2c 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -806,7 +806,7 @@ config ARM64_ERRATUM_2224489 config ARM64_ERRATUM_2064142 bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" - depends on COMPILE_TEST # Until the CoreSight TRBE driver changes are in + depends on CORESIGHT_TRBE default y help This option adds the workaround for ARM Cortex-A510 erratum 2064142. -- cgit v1.2.3 From f209e9fe5bd7614b30b050f2095e80b77b99c333 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Tue, 25 Jan 2022 19:50:36 +0530 Subject: coresight: trbe: Work around the invalid prohibited states TRBE implementations affected by Arm erratum #2038923 might get TRBE into an inconsistent view on whether trace is prohibited within the CPU. As a result, the trace buffer or trace buffer state might be corrupted. This happens after TRBE buffer has been enabled by setting TRBLIMITR_EL1.E, followed by just a single context synchronization event before execution changes from a context, in which trace is prohibited to one where it isn't, or vice versa. In these mentioned conditions, the view of whether trace is prohibited is inconsistent between parts of the CPU, and the trace buffer or the trace buffer state might be corrupted. Work around this problem in the TRBE driver by preventing an inconsistent view of whether the trace is prohibited or not based on TRBLIMITR_EL1.E by immediately following a change to TRBLIMITR_EL1.E with at least one ISB instruction before an ERET, or two ISB instructions if no ERET is to take place. This just updates the TRBE driver as required. Cc: Catalin Marinas Cc: Will Deacon Cc: Mathieu Poirier Cc: Suzuki Poulose Cc: coresight@lists.linaro.org Cc: linux-doc@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Suzuki K Poulose Signed-off-by: Anshuman Khandual Link: https://lore.kernel.org/r/1643120437-14352-7-git-send-email-anshuman.khandual@arm.com Signed-off-by: Mathieu Poirier Signed-off-by: Suzuki K Poulose --- arch/arm64/Kconfig | 2 +- drivers/hwtracing/coresight/coresight-trbe.c | 48 +++++++++++++++++++++------- 2 files changed, 37 insertions(+), 13 deletions(-) (limited to 'arch/arm64/Kconfig') diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 93980bf31e2c..8c7df3405de2 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -824,7 +824,7 @@ config ARM64_ERRATUM_2064142 config ARM64_ERRATUM_2038923 bool "Cortex-A510: 2038923: workaround TRBE corruption with enable" - depends on COMPILE_TEST # Until the CoreSight TRBE driver changes are in + depends on CORESIGHT_TRBE default y help This option adds the workaround for ARM Cortex-A510 erratum 2038923. diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 4ef944971d8e..6254ba598df2 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -92,11 +92,13 @@ struct trbe_buf { #define TRBE_WORKAROUND_OVERWRITE_FILL_MODE 0 #define TRBE_WORKAROUND_WRITE_OUT_OF_RANGE 1 #define TRBE_NEEDS_DRAIN_AFTER_DISABLE 2 +#define TRBE_NEEDS_CTXT_SYNC_AFTER_ENABLE 3 static int trbe_errata_cpucaps[] = { [TRBE_WORKAROUND_OVERWRITE_FILL_MODE] = ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE, [TRBE_WORKAROUND_WRITE_OUT_OF_RANGE] = ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE, [TRBE_NEEDS_DRAIN_AFTER_DISABLE] = ARM64_WORKAROUND_2064142, + [TRBE_NEEDS_CTXT_SYNC_AFTER_ENABLE] = ARM64_WORKAROUND_2038923, -1, /* Sentinel, must be the last entry */ }; @@ -179,6 +181,17 @@ static inline bool trbe_needs_drain_after_disable(struct trbe_cpudata *cpudata) return trbe_has_erratum(cpudata, TRBE_NEEDS_DRAIN_AFTER_DISABLE); } +static inline bool trbe_needs_ctxt_sync_after_enable(struct trbe_cpudata *cpudata) +{ + /* + * Errata affected TRBE implementation will need an additional + * context synchronization in order to prevent an inconsistent + * TRBE prohibited region view on the CPU which could possibly + * corrupt the TRBE buffer or the TRBE state. + */ + return trbe_has_erratum(cpudata, TRBE_NEEDS_CTXT_SYNC_AFTER_ENABLE); +} + static int trbe_alloc_node(struct perf_event *event) { if (event->cpu == -1) @@ -192,6 +205,22 @@ static inline void trbe_drain_buffer(void) dsb(nsh); } +static inline void set_trbe_enabled(struct trbe_cpudata *cpudata, u64 trblimitr) +{ + /* + * Enable the TRBE without clearing LIMITPTR which + * might be required for fetching the buffer limits. + */ + trblimitr |= TRBLIMITR_ENABLE; + write_sysreg_s(trblimitr, SYS_TRBLIMITR_EL1); + + /* Synchronize the TRBE enable event */ + isb(); + + if (trbe_needs_ctxt_sync_after_enable(cpudata)) + isb(); +} + static inline void set_trbe_disabled(struct trbe_cpudata *cpudata) { u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1); @@ -555,9 +584,10 @@ static void clr_trbe_status(void) write_sysreg_s(trbsr, SYS_TRBSR_EL1); } -static void set_trbe_limit_pointer_enabled(unsigned long addr) +static void set_trbe_limit_pointer_enabled(struct trbe_buf *buf) { u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1); + unsigned long addr = buf->trbe_limit; WARN_ON(!IS_ALIGNED(addr, (1UL << TRBLIMITR_LIMIT_SHIFT))); WARN_ON(!IS_ALIGNED(addr, PAGE_SIZE)); @@ -585,12 +615,7 @@ static void set_trbe_limit_pointer_enabled(unsigned long addr) trblimitr |= (TRBE_TRIG_MODE_IGNORE & TRBLIMITR_TRIG_MODE_MASK) << TRBLIMITR_TRIG_MODE_SHIFT; trblimitr |= (addr & PAGE_MASK); - - trblimitr |= TRBLIMITR_ENABLE; - write_sysreg_s(trblimitr, SYS_TRBLIMITR_EL1); - - /* Synchronize the TRBE enable event */ - isb(); + set_trbe_enabled(buf->cpudata, trblimitr); } static void trbe_enable_hw(struct trbe_buf *buf) @@ -608,7 +633,7 @@ static void trbe_enable_hw(struct trbe_buf *buf) * till now before enabling the TRBE. */ isb(); - set_trbe_limit_pointer_enabled(buf->trbe_limit); + set_trbe_limit_pointer_enabled(buf); } static enum trbe_fault_action trbe_get_fault_act(struct perf_output_handle *handle, @@ -1013,16 +1038,15 @@ static int arm_trbe_disable(struct coresight_device *csdev) static void trbe_handle_spurious(struct perf_output_handle *handle) { - u64 limitr = read_sysreg_s(SYS_TRBLIMITR_EL1); + struct trbe_buf *buf = etm_perf_sink_config(handle); + u64 trblimitr = read_sysreg_s(SYS_TRBLIMITR_EL1); /* * If the IRQ was spurious, simply re-enable the TRBE * back without modifying the buffer parameters to * retain the trace collected so far. */ - limitr |= TRBLIMITR_ENABLE; - write_sysreg_s(limitr, SYS_TRBLIMITR_EL1); - isb(); + set_trbe_enabled(buf->cpudata, trblimitr); } static int trbe_handle_overflow(struct perf_output_handle *handle) -- cgit v1.2.3 From 3a828845ae35626c2c8de4c46f5c602c25bd122d Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Tue, 25 Jan 2022 19:50:37 +0530 Subject: coresight: trbe: Work around the trace data corruption TRBE implementations affected by Arm erratum #1902691 might corrupt trace data or deadlock, when it's being written into the memory. Workaround this problem in the driver, by preventing TRBE initialization on affected cpus. The firmware must have disabled the access to TRBE for the kernel on such implementations. This will cover the kernel for any firmware that doesn't do this already. This just updates the TRBE driver as required. Cc: Catalin Marinas Cc: Will Deacon Cc: Mathieu Poirier Cc: Suzuki Poulose Cc: coresight@lists.linaro.org Cc: linux-doc@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Suzuki K Poulose Signed-off-by: Anshuman Khandual Link: https://lore.kernel.org/r/1643120437-14352-8-git-send-email-anshuman.khandual@arm.com Signed-off-by: Mathieu Poirier Signed-off-by: Suzuki K Poulose --- arch/arm64/Kconfig | 2 +- drivers/hwtracing/coresight/coresight-trbe.c | 12 ++++++++++++ 2 files changed, 13 insertions(+), 1 deletion(-) (limited to 'arch/arm64/Kconfig') diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 8c7df3405de2..390f0b1d0144 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -847,7 +847,7 @@ config ARM64_ERRATUM_2038923 config ARM64_ERRATUM_1902691 bool "Cortex-A510: 1902691: workaround TRBE trace corruption" - depends on COMPILE_TEST # Until the CoreSight TRBE driver changes are in + depends on CORESIGHT_TRBE default y help This option adds the workaround for ARM Cortex-A510 erratum 1902691. diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 6254ba598df2..75b608bc400b 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -93,12 +93,14 @@ struct trbe_buf { #define TRBE_WORKAROUND_WRITE_OUT_OF_RANGE 1 #define TRBE_NEEDS_DRAIN_AFTER_DISABLE 2 #define TRBE_NEEDS_CTXT_SYNC_AFTER_ENABLE 3 +#define TRBE_IS_BROKEN 4 static int trbe_errata_cpucaps[] = { [TRBE_WORKAROUND_OVERWRITE_FILL_MODE] = ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE, [TRBE_WORKAROUND_WRITE_OUT_OF_RANGE] = ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANGE, [TRBE_NEEDS_DRAIN_AFTER_DISABLE] = ARM64_WORKAROUND_2064142, [TRBE_NEEDS_CTXT_SYNC_AFTER_ENABLE] = ARM64_WORKAROUND_2038923, + [TRBE_IS_BROKEN] = ARM64_WORKAROUND_1902691, -1, /* Sentinel, must be the last entry */ }; @@ -192,6 +194,11 @@ static inline bool trbe_needs_ctxt_sync_after_enable(struct trbe_cpudata *cpudat return trbe_has_erratum(cpudata, TRBE_NEEDS_CTXT_SYNC_AFTER_ENABLE); } +static inline bool trbe_is_broken(struct trbe_cpudata *cpudata) +{ + return trbe_has_erratum(cpudata, TRBE_IS_BROKEN); +} + static int trbe_alloc_node(struct perf_event *event) { if (event->cpu == -1) @@ -1288,6 +1295,11 @@ static void arm_trbe_probe_cpu(void *info) */ trbe_check_errata(cpudata); + if (trbe_is_broken(cpudata)) { + pr_err("Disabling TRBE on cpu%d due to erratum\n", cpu); + goto cpu_clear; + } + /* * If the TRBE is affected by erratum TRBE_WORKAROUND_OVERWRITE_FILL_MODE, * we must always program the TBRPTR_EL1, 256bytes from a page -- cgit v1.2.3