From patchwork Mon Oct 21 12:03:09 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avri Altman X-Patchwork-Id: 13843997 Received: from esa2.hgst.iphmx.com (esa2.hgst.iphmx.com [68.232.143.124]) (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 6377C1E47A1; Mon, 21 Oct 2024 12:05:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=68.232.143.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729512331; cv=none; b=kCP9uLTB8l1jDW8Ha4lr2cr64Vm2oOWBuBkPAkCkQRSFwUHjIyb3byddLu3bT1Oxw30sgeLVpOlB8cjsly9aJEh74chgvN2AhsFnJXXEl4ZCc93XxCIgugBFWVlNIL/gw5FgQRbyrUXbur9LClRLyHPR1shvfuOtLu1u0nq2tR8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729512331; c=relaxed/simple; bh=LNsUbmG85GNCpHXIN0EE9pk1aZO5pmFOBVXwhrOrgn4=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=OAUS7Gu5K1wc+JAvRENkS9rSkcePwfsG6y7ar9hK0gPyKXOmLZDXrZbWloJxoTWZ3GgOexgEMcm0QErOw0sQY9m0bSX1C/kZlQBiAPVNaEuDbd97ShzZYA2ytLbc5Q27jNhbkFW6dpI8Fr+kKe2lydODbXY2rFLOdIWXlBHoGI8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=wdc.com; spf=pass smtp.mailfrom=wdc.com; dkim=pass (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b=jWS+NcXQ; arc=none smtp.client-ip=68.232.143.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=wdc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=wdc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b="jWS+NcXQ" DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1729512329; x=1761048329; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=LNsUbmG85GNCpHXIN0EE9pk1aZO5pmFOBVXwhrOrgn4=; b=jWS+NcXQp+xWRun5mm5t/vz84B5vRst0vQd4f/3mShUur83t/MO/k7G9 PQX5WoxeX7pjFFkl6nULzCjVG9J0387kEyjm/tjIcGrvh94o0oqc+jmFZ gJCKdgSUlnhinfUvRCsv1OHsCR8Ddl0TGDV9Zosl3It6yzao4E4rxYPQJ JPGbSmyvAudWEqYM2811bxYo5ycC+oAG9RnaFs/PqdGPPOTfJ69aq96K0 od63gfIkRQCYjLzGSmxffpHzoX1whuKUjIjglAkehxjFbldqNNH/EMP38 ny8Km47dW8K7vxAVFHXi/zNAVQHPqysNAKDHmO69KiEMULtggALq8VHxk w==; X-CSE-ConnectionGUID: uQs5uvWdQdq2rDiTzI/wNA== X-CSE-MsgGUID: PxGId1zkQzuscQIb4773PQ== X-IronPort-AV: E=Sophos;i="6.11,220,1725292800"; d="scan'208";a="29967095" Received: from h199-255-45-15.hgst.com (HELO uls-op-cesaep02.wdc.com) ([199.255.45.15]) by ob1.hgst.iphmx.com with ESMTP; 21 Oct 2024 20:05:28 +0800 IronPort-SDR: 6716351a_MzVUalNWPUUcDEqCDZRcbMFk/t+bAsQKwrExsGzXg4iFHKq pJdjQte/w3nn2HWtdt+hr3Gw10TrW8kRwMFiiaw== Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep02.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 21 Oct 2024 04:03:54 -0700 WDCIronportException: Internal Received: from avri-office.ad.shared (HELO avri-office.sdcorp.global.sandisk.com) ([10.45.31.142]) by uls-op-cesaip02.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 21 Oct 2024 05:05:27 -0700 From: Avri Altman To: "Martin K . Petersen" Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Bart Van Assche , Avri Altman Subject: [PATCH 0/4] Untie the host lock entanglement - part 1 Date: Mon, 21 Oct 2024 15:03:09 +0300 Message-Id: <20241021120313.493371-1-avri.altman@wdc.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 While trying to simplify the ufs core driver with the guard() macro [1], Bart made note of the abuse of the scsi host lock in the ufs driver. Indeed, the host lock is deeply entangled in various flows across the driver, as if it was some occasional default synchronization mean. Here is the first part of defusing it, replace some of its occurrences of host registers accesses, with a dedicated host register lock. Doing this in phases seems like a reasonable approach, given the myriad use. [1] https://lore.kernel.org/linux-scsi/0b031b8f-c07c-42ef-af93-7336439d3c37@acm.org/ Avri Altman (4): scsi: ufs: core: Introduce a new host register lock scsi: ufs: core: Use reg_lock to protect UTMRLCLR scsi: ufs: core: Use reg_lock to protect UTRLCLR scsi: ufs: core: Use reg_lock to protect HCE register drivers/ufs/core/ufshcd.c | 38 ++++++++++++++++++++++++-------------- include/ufs/ufshcd.h | 3 +++ 2 files changed, 27 insertions(+), 14 deletions(-)