From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4970C40F73F for ; Fri, 16 Oct 2026 21:11:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792185120; cv=none; b=saJhVOpJoKnlgfqKLCvNoiYYuzJvLK+ebkOapHrBzm9g7ik2ndLwAiDe0c9ZQ4XzCJ9XiYBK8+YsEW3LELu3iSnKXvGfvmAowFR9H3QbOwbR2XD/PNM9TrD36gmuTsX4XRBy5GGoZmpIK+L4yAehK2Ke+Tk59obci6QwH6QlHyE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792185120; c=relaxed/simple; bh=3eeTClUfocUZWHT/67yaJ2MlrOnRG0Wjv8VqvYPEKQs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=b3wFhjF3wJEtrlwXtmLBloWiyoheWEg+xqH/F592p4YtAB+gTHtGrPc71T3QbnStknCtQwkZUZ63zvIMZekzmo5avck9/ENHewe1aknvTuynQ08oaQp7wErC/AaANRkUgA3P64lByN4tS/fCFQPNFKR+kdz6jbMRJIZD81PEQ4E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=j1wasMrj; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="j1wasMrj" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7EF5614BF; Fri, 16 Oct 2026 14:11:54 -0700 (PDT) Received: from e132581.arm.com (unknown [10.2.196.114]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3D7323F673; Fri, 16 Oct 2026 14:11:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1792185117; bh=3eeTClUfocUZWHT/67yaJ2MlrOnRG0Wjv8VqvYPEKQs=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=j1wasMrjmpXuViu89ewWFNCnrvUOGTLWtNpzPjeEECvR2uZtgNlZMMWLq3vgYXMLG DphB/vsUyamx2xtMeT6rNAWuXMmq4J4Bo0As+IUph6ZR7rhnq8MJRlanQd1rbK41CL K1+qlQRUxXU7KpsMkligbxMUWZ5uRVwTZuUxWzfE= From: Leo Yan Date: Fri, 16 Oct 2026 22:11:40 +0100 Subject: [PATCH v2 02/11] coresight: trbe: Refactor next buffer computation Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261016-trbe_buffer_refactor_v2-v2-2-383ac26382fa@arm.com> References: <20261016-trbe_buffer_refactor_v2-v2-0-383ac26382fa@arm.com> In-Reply-To: <20261016-trbe_buffer_refactor_v2-v2-0-383ac26382fa@arm.com> To: Suzuki K Poulose , Mike Leach , James Clark , Alexander Shishkin , Anshuman Khandual , Tamas Petz , Tamas Zsoldos , Suyash Mahar , Amir Ayupov Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, coresight@lists.linaro.org, Leo Yan X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1792185112; l=4015; i=leo.yan@arm.com; s=20250604; h=from:subject:message-id; bh=3eeTClUfocUZWHT/67yaJ2MlrOnRG0Wjv8VqvYPEKQs=; b=qJma/s4qsSVeQF1tTghsgxCQmV0xbfgJ2ZeeeGQA0vmvpyDILmDOdpkSZKtC18/djfnZD3+AM EYEve7xDRzmC3OnyFJ4QapACNrAt1d3DJcdAO3giB3e4ZclP5rsRyYt X-Developer-Key: i=leo.yan@arm.com; a=ed25519; pk=k4BaDbvkCXzBFA7Nw184KHGP5thju8lKqJYIrOWxDhI= compute_trbe_buffer_limit() only returned the next TRBE limit pointer, leaving __arm_trbe_enable() to derive the remaining buffer state and detect the -ENOSPC case. Replace it with trbe_compute_next(), which computes the next TRBE buffer state as one operation. Let the snapshot and normal paths set buf->trbe_limit directly and return 0 or an errno, then update trbe_write and trbe_hw_base after a successful limit calculation. The normal path now reports -ENOSPC directly when no writable area is available. This refactoring is for future extensions, such as calculating additional values (e.g., the trigger count). No functional changes are intended. Signed-off-by: Leo Yan --- drivers/hwtracing/coresight/coresight-trbe.c | 44 +++++++++++++++++----------- 1 file changed, 27 insertions(+), 17 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index ada4794c51f3eb9142cd62f4209affe308142d1b..09ed9bcf4a70479169094697dcc3d445629cfaae 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -349,7 +349,7 @@ static void trbe_pad_buf(struct perf_output_handle *handle, int len) perf_aux_output_skip(handle, len); } -static unsigned long trbe_snapshot_offset(struct perf_output_handle *handle) +static int trbe_snapshot_offset(struct perf_output_handle *handle) { struct trbe_buf *buf = etm_perf_sink_config(handle); @@ -358,7 +358,8 @@ static unsigned long trbe_snapshot_offset(struct perf_output_handle *handle) * the decoder to reset in case of an overflow or corruption. * So we can use the entire buffer for the snapshot mode. */ - return buf->nr_pages * PAGE_SIZE; + buf->trbe_limit = buf->trbe_base + buf->nr_pages * PAGE_SIZE; + return 0; } static u64 trbe_min_trace_buf_size(struct perf_output_handle *handle) @@ -527,7 +528,7 @@ static unsigned long __trbe_normal_offset(struct perf_output_handle *handle) return 0; } -static unsigned long trbe_normal_offset(struct perf_output_handle *handle) +static int trbe_normal_offset(struct perf_output_handle *handle) { struct trbe_buf *buf = etm_perf_sink_config(handle); u64 limit = __trbe_normal_offset(handle); @@ -546,19 +547,34 @@ static unsigned long trbe_normal_offset(struct perf_output_handle *handle) limit = __trbe_normal_offset(handle); head = PERF_IDX2OFF(handle->head, buf); } - return limit; + + if (!limit) + return -ENOSPC; + + buf->trbe_limit = buf->trbe_base + limit; + return 0; } -static unsigned long compute_trbe_buffer_limit(struct perf_output_handle *handle) +static int trbe_compute_next(struct perf_output_handle *handle) { struct trbe_buf *buf = etm_perf_sink_config(handle); - unsigned long offset; + int ret; + + perf_aux_output_flag(handle, PERF_AUX_FLAG_CORESIGHT_FORMAT_RAW); if (buf->snapshot) - offset = trbe_snapshot_offset(handle); + ret = trbe_snapshot_offset(handle); else - offset = trbe_normal_offset(handle); - return buf->trbe_base + offset; + ret = trbe_normal_offset(handle); + + if (ret) + return ret; + + buf->trbe_write = buf->trbe_base + PERF_IDX2OFF(handle->head, buf); + + /* Set the base of the TRBE to the buffer base */ + buf->trbe_hw_base = buf->trbe_base; + return 0; } static void clr_trbe_status(void) @@ -1022,15 +1038,9 @@ static int __arm_trbe_enable(struct trbe_buf *buf, { int ret = 0; - perf_aux_output_flag(handle, PERF_AUX_FLAG_CORESIGHT_FORMAT_RAW); - buf->trbe_limit = compute_trbe_buffer_limit(handle); - buf->trbe_write = buf->trbe_base + PERF_IDX2OFF(handle->head, buf); - if (buf->trbe_limit == buf->trbe_base) { - ret = -ENOSPC; + ret = trbe_compute_next(handle); + if (ret) goto err; - } - /* Set the base of the TRBE to the buffer base */ - buf->trbe_hw_base = buf->trbe_base; ret = trbe_apply_work_around_before_enable(buf); if (ret) -- 2.34.1