From nobody Mon Dec 1 22:03:47 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 8CCDA30C61B; Mon, 1 Dec 2025 11:22:56 +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=1764588178; cv=none; b=dpYtwRFdkwqOrLhVlO5mERlwD6raZNygbRmPmNEH/i+gmipAc5Gw7uM69C6iNeiLvlcYJHk+Jvb4wA7u9wVyT7dGSq6zG10O8gu6FiAQn+Vm4V4aI79AN9BhJu46ZpwEqlezPlee2R4blILAKwYUQIiv4u4lHrWAFJZScYqWgKw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764588178; c=relaxed/simple; bh=eJElq7gC/JnnPBEjj1BBHX13g7bjZ8CcdBXjEePLB/4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=FUAgs58C2otWx0H1mC+9bp7KsPVz3kpG8Ja8aDdDBU6mynIJTru1mP0W5h3XsfwdG4+zBICc77GrEjsEduvU+DXY9InA+gEQsCZS1kFVOm4C2BrYe2Yij7xHkETib2gsUEORKK/M7Eia4GbQCsfRpvPh7xdP6psA66FAAipPhYE= 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; 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 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 8F3091595; Mon, 1 Dec 2025 03:22:48 -0800 (PST) Received: from e132581.arm.com (e132581.arm.com [10.1.196.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6E8DC3F59E; Mon, 1 Dec 2025 03:22:53 -0800 (PST) From: Leo Yan Date: Mon, 01 Dec 2025 11:22:07 +0000 Subject: [PATCH 17/19] coresight: trbe: Enable circle mode for snapshot 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: quoted-printable Message-Id: <20251201-trbe_buffer_refactor_v1-1-v1-17-7da32b076b28@arm.com> References: <20251201-trbe_buffer_refactor_v1-1-v1-0-7da32b076b28@arm.com> In-Reply-To: <20251201-trbe_buffer_refactor_v1-1-v1-0-7da32b076b28@arm.com> To: Suzuki K Poulose , Mike Leach , James Clark , Anshuman Khandual , Yeoreum Yun , Will Deacon , Mark Rutland , Tamas Petz , Tamas Zsoldos , Arnaldo Carvalho de Melo , Namhyung Kim , Jiri Olsa , Ian Rogers , Adrian Hunter Cc: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Leo Yan X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1764588125; l=1408; i=leo.yan@arm.com; s=20250604; h=from:subject:message-id; bh=eJElq7gC/JnnPBEjj1BBHX13g7bjZ8CcdBXjEePLB/4=; b=HQEoNUUs9+ttxYbCdH0xtRa8oIkNFKPAR0kgNljjd84BooIOh8Sfb9YOFOnI16mZeSDc1ZOIV omtaVR/7aqGAU2xmRk+/cxq/XLmW1ei1HSb3CgzG5AArMTyPRhhjME1 X-Developer-Key: i=leo.yan@arm.com; a=ed25519; pk=k4BaDbvkCXzBFA7Nw184KHGP5thju8lKqJYIrOWxDhI= A snapshot session captures trace data only when userspace receives a signal and disables tracing. Before disabling, enable circle mode instead of fill mode to avoid unnecessary interrupt handling. Signed-off-by: Leo Yan --- drivers/hwtracing/coresight/coresight-trbe.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtraci= ng/coresight/coresight-trbe.c index 0551ea9b4f8286c156e3c9c7ac94e2ecd3b9dc3f..ee9993d518d2a41f0d709b7d069= 0b2dfe0bef2d9 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -635,6 +635,12 @@ static void set_trbe_limit_pointer_enabled(struct trbe= _buf *buf) trblimitr &=3D ~TRBLIMITR_EL1_TM_MASK; trblimitr &=3D ~TRBLIMITR_EL1_LIMIT_MASK; =20 + if (buf->snapshot) { + trblimitr |=3D FIELD_PREP(TRBLIMITR_EL1_FM_MASK, TRBLIMITR_EL1_FM_CBUF) | + FIELD_PREP(TRBLIMITR_EL1_TM_MASK, TRBLIMITR_EL1_TM_IGNR); + goto enable_trace_buf; + } + if (!buf->trbe_count || buf->trbe_write + buf->trbe_count =3D=3D buf->trbe_limit) { /* @@ -669,6 +675,7 @@ static void set_trbe_limit_pointer_enabled(struct trbe_= buf *buf) FIELD_PREP(TRBLIMITR_EL1_TM_MASK, TRBLIMITR_EL1_TM_STOP); } =20 +enable_trace_buf: trblimitr |=3D (addr & PAGE_MASK); set_trbe_enabled(buf->cpudata, trblimitr); } --=20 2.34.1