From: Leo Yan <leo.yan@linaro.org> To: Arnaldo Carvalho de Melo <acme@kernel.org>, Peter Zijlstra <peterz@infradead.org>, Adrian Hunter <adrian.hunter@intel.com>, Ingo Molnar <mingo@redhat.com>, Mark Rutland <mark.rutland@arm.com>, Alexander Shishkin <alexander.shishkin@linux.intel.com>, Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>, Will Deacon <will@kernel.org>, Russell King <linux@armlinux.org.uk>, Catalin Marinas <catalin.marinas@arm.com>, Mathieu Poirier <mathieu.poirier@linaro.org>, Suzuki K Poulose <suzuki.poulose@arm.com>, Mike Leach <mike.leach@linaro.org>, John Garry <john.garry@huawei.com>, Andi Kleen <ak@linux.intel.com>, Riccardo Mancini <rickyman7@gmail.com>, Jin Yao <yao.jin@linux.intel.com>, Li Huafei <lihuafei1@huawei.com>, coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Leo Yan <leo.yan@linaro.org> Subject: [PATCH v1 3/3] perf auxtrace arm: Support compat_auxtrace_mmap__{read_head|write_tail} Date: Mon, 9 Aug 2021 19:27:27 +0800 [thread overview] Message-ID: <20210809112727.596876-4-leo.yan@linaro.org> (raw) In-Reply-To: <20210809112727.596876-1-leo.yan@linaro.org> When the tool runs with compat mode on Arm platform, the kernel is in 64-bit mode and user space is in 32-bit mode; the user space can use instructions "ldrd" and "strd" for 64-bit value atomicity. This patch adds compat_auxtrace_mmap__{read_head|write_tail} for arm building, it uses "ldrd" and "strd" instructions to ensure accessing atomicity for aux head and tail. The file arch/arm/util/auxtrace.c is built for arm and arm64 building, these two functions are not needed for arm64, so check the compiler macro "__arm__" to only include them for arm building. Signed-off-by: Leo Yan <leo.yan@linaro.org> --- tools/perf/arch/arm/util/auxtrace.c | 32 +++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/tools/perf/arch/arm/util/auxtrace.c b/tools/perf/arch/arm/util/auxtrace.c index b187bddbd01a..c7c7ec0812d5 100644 --- a/tools/perf/arch/arm/util/auxtrace.c +++ b/tools/perf/arch/arm/util/auxtrace.c @@ -107,3 +107,35 @@ struct auxtrace_record *err = 0; return NULL; } + +#if defined(__arm__) +u64 compat_auxtrace_mmap__read_head(struct auxtrace_mmap *mm) +{ + struct perf_event_mmap_page *pc = mm->userpg; + u64 result; + + __asm__ __volatile__( +" ldrd %0, %H0, [%1]" + : "=&r" (result) + : "r" (&pc->aux_head), "Qo" (pc->aux_head) + ); + + return result; +} + +int compat_auxtrace_mmap__write_tail(struct auxtrace_mmap *mm, u64 tail) +{ + struct perf_event_mmap_page *pc = mm->userpg; + + /* Ensure all reads are done before we write the tail out */ + smp_mb(); + + __asm__ __volatile__( +" strd %2, %H2, [%1]" + : "=Qo" (pc->aux_tail) + : "r" (&pc->aux_tail), "r" (tail) + ); + + return 0; +} +#endif -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: Leo Yan <leo.yan@linaro.org> To: Arnaldo Carvalho de Melo <acme@kernel.org>, Peter Zijlstra <peterz@infradead.org>, Adrian Hunter <adrian.hunter@intel.com>, Ingo Molnar <mingo@redhat.com>, Mark Rutland <mark.rutland@arm.com>, Alexander Shishkin <alexander.shishkin@linux.intel.com>, Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>, Will Deacon <will@kernel.org>, Russell King <linux@armlinux.org.uk>, Catalin Marinas <catalin.marinas@arm.com>, Mathieu Poirier <mathieu.poirier@linaro.org>, Suzuki K Poulose <suzuki.poulose@arm.com>, Mike Leach <mike.leach@linaro.org>, John Garry <john.garry@huawei.com>, Andi Kleen <ak@linux.intel.com>, Riccardo Mancini <rickyman7@gmail.com>, Jin Yao <yao.jin@linux.intel.com>, Li Huafei <lihuafei1@huawei.com>, coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Leo Yan <leo.yan@linaro.org> Subject: [PATCH v1 3/3] perf auxtrace arm: Support compat_auxtrace_mmap__{read_head|write_tail} Date: Mon, 9 Aug 2021 19:27:27 +0800 [thread overview] Message-ID: <20210809112727.596876-4-leo.yan@linaro.org> (raw) In-Reply-To: <20210809112727.596876-1-leo.yan@linaro.org> When the tool runs with compat mode on Arm platform, the kernel is in 64-bit mode and user space is in 32-bit mode; the user space can use instructions "ldrd" and "strd" for 64-bit value atomicity. This patch adds compat_auxtrace_mmap__{read_head|write_tail} for arm building, it uses "ldrd" and "strd" instructions to ensure accessing atomicity for aux head and tail. The file arch/arm/util/auxtrace.c is built for arm and arm64 building, these two functions are not needed for arm64, so check the compiler macro "__arm__" to only include them for arm building. Signed-off-by: Leo Yan <leo.yan@linaro.org> --- tools/perf/arch/arm/util/auxtrace.c | 32 +++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/tools/perf/arch/arm/util/auxtrace.c b/tools/perf/arch/arm/util/auxtrace.c index b187bddbd01a..c7c7ec0812d5 100644 --- a/tools/perf/arch/arm/util/auxtrace.c +++ b/tools/perf/arch/arm/util/auxtrace.c @@ -107,3 +107,35 @@ struct auxtrace_record *err = 0; return NULL; } + +#if defined(__arm__) +u64 compat_auxtrace_mmap__read_head(struct auxtrace_mmap *mm) +{ + struct perf_event_mmap_page *pc = mm->userpg; + u64 result; + + __asm__ __volatile__( +" ldrd %0, %H0, [%1]" + : "=&r" (result) + : "r" (&pc->aux_head), "Qo" (pc->aux_head) + ); + + return result; +} + +int compat_auxtrace_mmap__write_tail(struct auxtrace_mmap *mm, u64 tail) +{ + struct perf_event_mmap_page *pc = mm->userpg; + + /* Ensure all reads are done before we write the tail out */ + smp_mb(); + + __asm__ __volatile__( +" strd %2, %H2, [%1]" + : "=Qo" (pc->aux_tail) + : "r" (&pc->aux_tail), "r" (tail) + ); + + return 0; +} +#endif -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-08-09 11:27 UTC|newest] Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-09 11:27 [PATCH v1 0/3] perf: Support compat mode for AUX ring buffer Leo Yan 2021-08-09 11:27 ` Leo Yan 2021-08-09 11:27 ` [PATCH v1 1/3] perf env: Track kernel 64-bit mode in environment Leo Yan 2021-08-09 11:27 ` Leo Yan 2021-08-09 20:11 ` Arnaldo Carvalho de Melo 2021-08-09 20:11 ` Arnaldo Carvalho de Melo 2021-08-09 11:27 ` [PATCH v1 2/3] perf auxtrace: Add compat_auxtrace_mmap__{read_head|write_tail} Leo Yan 2021-08-09 11:27 ` Leo Yan 2021-08-09 20:12 ` Arnaldo Carvalho de Melo 2021-08-09 20:12 ` Arnaldo Carvalho de Melo 2021-08-12 9:23 ` Adrian Hunter 2021-08-12 9:23 ` Adrian Hunter 2021-08-13 16:22 ` James Clark 2021-08-13 16:22 ` James Clark 2021-08-23 9:51 ` Leo Yan 2021-08-23 9:51 ` Leo Yan 2021-08-23 10:57 ` James Clark 2021-08-23 10:57 ` James Clark 2021-08-23 12:13 ` Leo Yan 2021-08-23 12:13 ` Leo Yan 2021-08-23 16:00 ` James Clark 2021-08-23 16:00 ` James Clark 2021-08-24 2:13 ` Leo Yan 2021-08-24 2:13 ` Leo Yan 2021-08-09 11:27 ` Leo Yan [this message] 2021-08-09 11:27 ` [PATCH v1 3/3] perf auxtrace arm: Support compat_auxtrace_mmap__{read_head|write_tail} Leo Yan 2021-08-23 12:23 ` James Clark 2021-08-23 12:23 ` James Clark 2021-08-23 13:30 ` Leo Yan 2021-08-23 13:30 ` Leo Yan 2021-08-23 13:39 ` Russell King (Oracle) 2021-08-23 13:39 ` Russell King (Oracle) 2021-08-23 14:54 ` Leo Yan 2021-08-23 14:54 ` Leo Yan
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