From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lf1-f46.google.com (mail-lf1-f46.google.com [209.85.167.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 297FD19C575 for ; Wed, 20 Nov 2024 11:13:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.46 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732101238; cv=none; b=SSi7B9/thXngbFAxeQXJt1IuWyfpFpBWvN+4u3uTDpmhcZCCkQIhhGj47rpUONvdMp6e/8zI/DejyTWyI/3PaW4ZCta1noj41+8FMXVIZazh3A2whZyGdMzLQlTEfIuOfLRKRGM2vPOPAlKYR7qy/hS283dQufc/Y0DBtikIZj8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732101238; c=relaxed/simple; bh=2R7MrlSbXdsIoKmQ8B225gvAC/SXbSoY+2vtlQPNGnw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=d8hDJGQICXjylPt8msVfMjDxCbOS0MzP7Ifz+TnC6OKmNzoe6Bl8d8YPc9lRXMqQ1C/SQ8rHRQI1HqcBgozrQTbjGIteIvjb43dUGv12gnx1K9/Ro6Ct19lmSvkYcn8chN//KsQss3pp5kite/su/3qrPYQIcnUYu6/nWsi5/6M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org; spf=pass smtp.mailfrom=linaro.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b=Xh6euSmW; arc=none smtp.client-ip=209.85.167.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="Xh6euSmW" Received: by mail-lf1-f46.google.com with SMTP id 2adb3069b0e04-53d9ff92edaso7373388e87.1 for ; Wed, 20 Nov 2024 03:13:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1732101235; x=1732706035; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=MSBDmYSFXuA2s69SSkdK3qaRDlUBpjefVOog6k4GCqA=; b=Xh6euSmWSI183aFHWmbJUcgYbM7Z4O1/VFPWRSHd8I1nkw3etu3zRfaJ2RchUv7p1/ m+QoQF9GilXji8STASehIi4MlaijBwdVrp99EiVv3xG804YAbKob7YH8bcX6G3V/33DX je8TVUVDamfu1ouKGm6Lm9iTNhl9oidfrVKHJLwHXjq/QxOb9blKdd58E2pzF5cqdjiV LzrVy9Xav5Nu7+tadoxM6AzXe1OMfYrQWt1pVquVt3PDR6oRbKrHJnQWR4bEdvh2dlR8 0REDI7bohd3lUIi9FnayMGAQKgRjdEdAGjw+3qeESX+19wTqcmEdWobXbtjBGJ3B5N+A m4Kg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1732101235; x=1732706035; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=MSBDmYSFXuA2s69SSkdK3qaRDlUBpjefVOog6k4GCqA=; b=pV2i/+UgvlwGVD2QL2AHRKDBBmkbDwUNXuZoujCoIv18zJnnTJcCpeZF471jSmjmYa Mg7JSzOZqJBUuM4LXre4Oi/RzLekuC/a8atm9SzOK8iJomQKZ1fe0BEOe5lnZL0jRLo1 KheJbg4Nuc5MxIgTb0J5m98s8j1DETch3S3tUZVXJWTOdQsYXQcs3zn848xztXz+W0JS jYeHSbHiC05IV5SYw8JxMB0OiVRsKK8zhjicNlfGhOlBaTpz0A8iTCJGYOGxNog1w15Y GSgPRyOY3YnV4nL2e+hKAus1ggNurnLJ4dxMq7OHG522/9wrAzLZlkb1RKguwSgfhfg6 gaSg== X-Forwarded-Encrypted: i=1; AJvYcCUEkxc3/VDV0BSnS6n21v2M3Pc8hFU5sYwoV3KpYi2br/k8rY8mC9sH+fmfj3WD8Zg1PA63MaAySOmAEUw=@vger.kernel.org X-Gm-Message-State: AOJu0YxJ3Rx5Fe+J9DSia2Yi5glbHzK+c1nUB57YiJMyyCdjcJ7nGCgv aKuiP/XK5hFEuaEqN4ZlCqdtMcHkSTIJH23Gwv1W+VfdTUFjJ4WoIUMhi51YIe8= X-Google-Smtp-Source: AGHT+IGYdVlXPyYW57Sact665A1h86qBYlsDUr8EZ6uXwnZYrcEpnGp/EwmAPkJR1t4j3+9iwpyGLg== X-Received: by 2002:a05:6512:b0d:b0:539:e3d8:fa33 with SMTP id 2adb3069b0e04-53dc13742c2mr907280e87.54.1732101235338; Wed, 20 Nov 2024 03:13:55 -0800 (PST) Received: from eriador.lumag.spb.ru (2001-14ba-a0c3-3a00--b8c.rev.dnainternet.fi. [2001:14ba:a0c3:3a00::b8c]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-53dbd3edcd5sm597600e87.44.2024.11.20.03.13.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 20 Nov 2024 03:13:53 -0800 (PST) Date: Wed, 20 Nov 2024 13:13:51 +0200 From: Dmitry Baryshkov To: Krzysztof Kozlowski Cc: Bjorn Andersson , Konrad Dybcio , Mukesh Ojha , Stephan Gerhold , Bartosz Golaszewski , Kuldeep Singh , Elliot Berman , Andrew Halaney , Avaneesh Kumar Dwivedi , Andy Gross , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH 0/6] firmware: qcom: scm: Fixes for concurrency Message-ID: References: <20241119-qcom-scm-missing-barriers-and-all-sort-of-srap-v1-0-7056127007a7@linaro.org> 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=us-ascii Content-Disposition: inline In-Reply-To: <20241119-qcom-scm-missing-barriers-and-all-sort-of-srap-v1-0-7056127007a7@linaro.org> On Tue, Nov 19, 2024 at 07:33:16PM +0100, Krzysztof Kozlowski wrote: > SCM driver looks messy in terms of handling concurrency of probe. The > driver exports interface which is guarded by global '__scm' variable > but: > 1. Lacks proper read barrier (commit adding write barriers mixed up > READ_ONCE with a read barrier). > 2. Lacks barriers or checks for '__scm' in multiple places. > 3. Lacks probe error cleanup. > > I fixed here few visible things, but this was not tested extensively. I > tried only SM8450. > > ARM32 and SC8280xp/X1E platforms would be useful for testing as well. ARM32 devices are present in the lab. > > All the issues here are non-urgent, IOW, they were here for some time > (v6.10-rc1 and earlier). > > Best regards, > Krzysztof > > --- > Krzysztof Kozlowski (6): > firmware: qcom: scm: Fix missing read barrier in qcom_scm_is_available() > firmware: qcom: scm: Fix missing read barrier in qcom_scm_get_tzmem_pool() > firmware: qcom: scm: Handle various probe ordering for qcom_scm_assign_mem() > [RFC/RFT] firmware: qcom: scm: Cleanup global '__scm' on probe failures > firmware: qcom: scm: smc: Handle missing SCM device > firmware: qcom: scm: smc: Narrow 'mempool' variable scope > > drivers/firmware/qcom/qcom_scm-smc.c | 6 +++- > drivers/firmware/qcom/qcom_scm.c | 55 +++++++++++++++++++++++++----------- > 2 files changed, 44 insertions(+), 17 deletions(-) > --- > base-commit: 414c97c966b69e4a6ea7b32970fa166b2f9b9ef0 > change-id: 20241119-qcom-scm-missing-barriers-and-all-sort-of-srap-a25d59074882 > > Best regards, > -- > Krzysztof Kozlowski > -- With best wishes Dmitry