Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751252AbdFCOnn (ORCPT ); Sat, 3 Jun 2017 10:43:43 -0400 Received: from mail-pg0-f44.google.com ([74.125.83.44]:35395 "EHLO mail-pg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750765AbdFCOnl (ORCPT ); Sat, 3 Jun 2017 10:43:41 -0400 From: Leo Yan To: Mathieu Poirier , Will Deacon , Suzuki K Poulose , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Mike Leach , Chunyan Zhang Cc: Leo Yan Subject: [PATCH v1 3/4] coresight: tmc: hook panic callback for ETB/ETF Date: Sat, 3 Jun 2017 22:42:55 +0800 Message-Id: <1496500976-18362-4-git-send-email-leo.yan@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1496500976-18362-1-git-send-email-leo.yan@linaro.org> References: <1496500976-18362-1-git-send-email-leo.yan@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2393 Lines: 70 The panic dump functionality has been ready, this patch is to hook panic callback function for ETB/ETF. Because the driver data structure has allocated buffer when the session started, so simply save ETB/ETF trace data into the buffer when panic happens. Below is simple usage when we connect kdump to extract trace data: - During kernel panic, tmc driver prints out below log. Dump ETB buffer 0x2000@0xffff80003bd5a180 - After get kernel dump file 'vmcore', use below command to extract ETB/ETF trace data. crash vmlinux vmcore rd 0xffff80003bd5a180 0x2000 -r cs_etb_trace.bin - Generate perf formatted file, so can be analyzed by perf tool: python perf_cs_dump_wrapper.py -i cs_etb_trace.bin -o perf.data ./perf script -v -F cpu,event,ip,sym,symoff --kallsyms ksymbol -i perf.data -k vmlinux Signed-off-by: Leo Yan --- drivers/hwtracing/coresight/coresight-tmc-etf.c | 26 +++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index e3b9fb8..4cadbb1 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -476,6 +476,31 @@ static void tmc_update_etf_buffer(struct coresight_device *csdev, CS_LOCK(drvdata->base); } +static int tmc_panic_cb(struct coresight_device *csdev) +{ + struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + unsigned long flags; + + if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETB && + drvdata->config_type != TMC_CONFIG_TYPE_ETF)) + return -EINVAL; + + spin_lock_irqsave(&drvdata->spinlock, flags); + + CS_UNLOCK(drvdata->base); + + tmc_flush_and_stop(drvdata); + tmc_etb_dump_hw(drvdata); + + CS_LOCK(drvdata->base); + + dev_err(drvdata->dev, "Dump ETB buffer 0x%x@0x%p\n", + drvdata->len, drvdata->buf); + + spin_unlock_irqrestore(&drvdata->spinlock, flags); + return 0; +} + static const struct coresight_ops_sink tmc_etf_sink_ops = { .enable = tmc_enable_etf_sink, .disable = tmc_disable_etf_sink, @@ -484,6 +509,7 @@ static const struct coresight_ops_sink tmc_etf_sink_ops = { .set_buffer = tmc_set_etf_buffer, .reset_buffer = tmc_reset_etf_buffer, .update_buffer = tmc_update_etf_buffer, + .panic_cb = tmc_panic_cb, }; static const struct coresight_ops_link tmc_etf_link_ops = { -- 2.7.4