From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 0BEB7299920; Sat, 12 Sep 2026 10:24:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789208699; cv=none; b=fPVqPxB6ivy83FxXFQh7eDR6UnSSIGkmayS0STQYV4zL8rb55YOVGyIFOYD+06Md06/sVK2VxjWvwe9ovYenf2SQZyRwOjvTH90SQ0JPyZY6CgUHqjq5lxwEbCvRZkgY53yYTOtY6juUSTSgUeVB3sOzuGHdsYHzR4Y0RPcAIkQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789208699; c=relaxed/simple; bh=zdbcp714I8NPlaHVQp6UQfvZnkoAJAPS4XLlLfZlC6o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fv0XFt5xlJYBxEvJWkprj8LsJ6kiGO5PxxjDgGtxMLANdy+hZbg7V+Wt9McVH1KW4KkA2RfYz1EytyHq9DHHM91WRHZPAV+VOOUAspW9bFvBz68h29g7UY1Ivf+8rx9pDT0pxVAHVK2gG8K5fWzW+Uqx1jjoVBP+WoYtsX4Ozg0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1x7ekTwM; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="1x7ekTwM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 111781F000FF; Sat, 12 Sep 2026 10:24:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789208697; bh=3i18u2MMN8uvrm3LORJv96G2FqBtw58IZZZLNzL18ho=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=1x7ekTwMl7LLtyzwSwSzQK24ZWPvDFQ1hyhXZbKJHMig5k5C91TOBj+g1cO9shYTI W+aRRxsMGOnczRBjHIgLzAp76Ut8NA/6/TWQsTIShELWLkiYr002SuAdmvZTEz9TMb wOeMA023NXnfvhsMQB8Oo8TKZWTCHU2/fw6K/QSs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Konrad Dybcio , Yuvaraj Ranganathan , Bjorn Andersson , Sasha Levin Subject: [PATCH 6.18 0670/1518] firmware: qcom: scm: add trace events for the SMC call interface Date: Sat, 12 Sep 2026 08:47:19 +0200 Message-ID: <20260912065638.591710975@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065623.398859879@linuxfoundation.org> References: <20260912065623.398859879@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yuvaraj Ranganathan [ Upstream commit f6bb2daa4584229af155c2488b83151999315293 ] The SCM SMC call path is opaque at runtime. Stalls caused by firmware congestion, QCOM_SCM_WAITQ_SLEEP/RESUME cycles, and EBUSY retry loops are invisible without recompiling the kernel with temporary printk statements or attaching a hardware debugger. Add five TRACE_EVENTs covering the complete lifecycle of an SCM call: scm_smc_request Emit before each arm_smccc_smc_quirk() invocation. Records the SMC function ID, decoded service and command identifiers, argument count, and up to six register arguments in hex and decimal. Because the caller loops on QCOM_SCM_INTERRUPTED, this event fires once per physical SMC instruction including inte scm_smc_done Emit after the outer __scm_smc_do() returns, pairing each request with its final outcome. Records the SMC function ID, the kernel error code returned to the caller, and the four firmware result registers a0-a3. scm_waitq_sleep Emit when the firmware returns QCOM_SCM_WAITQ_SLEEP. Records the wait-queue context and the SMC call context handles required to issue the matching WAITQ_RESUME. scm_waitq_resume Emit just before constructing and sending the WAITQ_RESUME follow-up call. Records the SMC call context handle being resumed. scm_waitq_get_wq_ctx Emit after a successful WAITQ_GET_WQ_CTX fast-call. Records the returned wait-queue context, flags, and more_pending indicator. These events let ftrace and perf reconstruct the full sequence of firmware interactions, measure per-call and end-to-end latency, and attribute waitqueue stalls to specific service/command pairs without modifying driver source. Reviewed-by: Konrad Dybcio Signed-off-by: Yuvaraj Ranganathan Link: https://lore.kernel.org/r/20260522-scm-tracepoints-v2-1-e27cdbe0c585@oss.qualcomm.com Signed-off-by: Bjorn Andersson Stable-dep-of: 966d23c7e68e ("firmware: qcom: scm: Fix NULL dereference in IRQ handler before __scm is published") Signed-off-by: Sasha Levin --- drivers/firmware/qcom/qcom_scm_trace.h | 143 +++++++++++++++++++++++++ 1 file changed, 143 insertions(+) create mode 100644 drivers/firmware/qcom/qcom_scm_trace.h diff --git a/drivers/firmware/qcom/qcom_scm_trace.h b/drivers/firmware/qcom/qcom_scm_trace.h new file mode 100644 index 0000000000000..6c911124fc56b --- /dev/null +++ b/drivers/firmware/qcom/qcom_scm_trace.h @@ -0,0 +1,143 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. + */ + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM qcom_scm + +#if !defined(_TRACE_SCM_SMC_INTERFACE_H) || defined(TRACE_HEADER_MULTI_READ) + +#define _TRACE_SCM_SMC_INTERFACE_H + +#include + +TRACE_EVENT(scm_smc_request, + + TP_PROTO(unsigned long a0, const struct arm_smccc_args *smc), + + TP_ARGS(a0, smc), + + TP_STRUCT__entry( + __field(u64, smc_id) + __field(u8, svc_id) + __field(u8, cmd_id) + __field(u8, args_cnt) + __dynamic_array(unsigned long, args, + min_t(u8, (smc->args[1] & 0xF), (u8)6)) + ), + + TP_fast_assign( + __entry->smc_id = a0; + __entry->svc_id = (smc->args[0] >> 8) & 0xFF; + __entry->cmd_id = smc->args[0] & 0xFF; + u8 n = min_t(u8, (smc->args[1] & 0xF), (u8)6); + + __entry->args_cnt = n; + + unsigned long *dst = __get_dynamic_array(args); + + for (int i = 0; i < n; i++) + dst[i] = smc->args[2 + i]; + ), + + TP_printk("smc_id:0x%08llx svc_id:0x%02x cmd_id:0x%02x args_cnt:%u args:%s", + __entry->smc_id, __entry->svc_id, __entry->cmd_id, __entry->args_cnt, + __print_dynamic_array(args, sizeof(unsigned long))) +); + +TRACE_EVENT(scm_waitq_sleep, + + TP_PROTO(u32 wq_ctx, u32 smc_ctx), + + TP_ARGS(wq_ctx, smc_ctx), + + TP_STRUCT__entry( + __field(u32, wq_ctx) + __field(u32, smc_call_ctx) + ), + + TP_fast_assign( + __entry->wq_ctx = wq_ctx; + __entry->smc_call_ctx = smc_ctx; + ), + + TP_printk("wq_ctx:%u, smc_call_ctx:%u", __entry->wq_ctx, __entry->smc_call_ctx) +); + +TRACE_EVENT(scm_waitq_resume, + + TP_PROTO(u32 smc_ctx), + + TP_ARGS(smc_ctx), + + TP_STRUCT__entry( + __field(u32, smc_call_ctx) + ), + + TP_fast_assign( + __entry->smc_call_ctx = smc_ctx; + ), + + TP_printk("smc_call_ctx:%u", __entry->smc_call_ctx) +); + +TRACE_EVENT(scm_waitq_get_wq_ctx, + + TP_PROTO(u32 wq_ctx, u32 flags, u32 pending), + + TP_ARGS(wq_ctx, flags, pending), + + TP_STRUCT__entry( + __field(u32, wq_ctx) + __field(u32, flags) + __field(u32, more_pending) + ), + + TP_fast_assign( + __entry->wq_ctx = wq_ctx; + __entry->flags = flags; + __entry->more_pending = pending; + ), + + TP_printk("wq_ctx:%u, flags:%u, more_pending:%u", + __entry->wq_ctx, __entry->flags, __entry->more_pending) +); + +TRACE_EVENT(scm_smc_done, + + TP_PROTO(int ret, u64 smc_id, struct arm_smccc_res *smc_res), + + TP_ARGS(ret, smc_id, smc_res), + + TP_STRUCT__entry( + __field(int, ret) + __field(u64, smc_id) + __field(unsigned long, res) + __field(unsigned long, res0) + __field(unsigned long, res1) + __field(unsigned long, res2) + ), + + TP_fast_assign( + __entry->ret = ret; + __entry->smc_id = smc_id; + __entry->res = smc_res->a0; + __entry->res0 = smc_res->a1; + __entry->res1 = smc_res->a2; + __entry->res2 = smc_res->a3; + ), + + TP_printk("smc_id:0x%08llx, ret:%d res_to_callee:0x%lx res0:0x%lx res1:0x%lx res2:0x%lx", + __entry->smc_id, __entry->ret, __entry->res, + __entry->res0, __entry->res1, __entry->res2) +); + +#endif /* _TRACE_SCM_SMC_INTERFACE_H */ + +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . +#define TRACE_INCLUDE_FILE qcom_scm_trace + +#include + -- 2.53.0