From patchwork Thu May 23 12:58:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avri Altman X-Patchwork-Id: 798626 Received: from esa6.hgst.iphmx.com (esa6.hgst.iphmx.com [216.71.154.45]) (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 6ED598174C; Thu, 23 May 2024 12:58:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.71.154.45 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716469122; cv=none; b=rj3Z2ohpF+5N+wDSoxD01t0b0Cu/o4HCw69PFmlmh77r1buDJpBeDy7JwRU9x4cXJqJZq21aMyTZ4LKobCcZTLhnNYGtyGZAkyDrx4sv5Pe339HY7hkcbiz9jtfN5aAH6JNJBugccVZ1mvL+3my1boBcGQhDmZfnDdYF2LZHZzQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716469122; c=relaxed/simple; bh=oV2ZFplCblWKmN/I2j0dD142TAdaLRkSzUlqV4hF1yw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=UVHOGJYw4BNsK2XFMA4H0XmPITH1HGxtfspuebeeBo4cLmBNLEMmsI2YQ/RvNVvfKN+xecVxukP17FuHrXnRF511aLxPJIiozviBwOhJ572ad1z+gQQK8D4p3J9y8VDUEUILaY71KLG17YZwpkn45TxJ+cqEEvmVkegKP78y1zo= 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=Mkd3Bh4L; arc=none smtp.client-ip=216.71.154.45 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="Mkd3Bh4L" DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1716469120; x=1748005120; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=oV2ZFplCblWKmN/I2j0dD142TAdaLRkSzUlqV4hF1yw=; b=Mkd3Bh4L9L4QcsfG96chEZ1gX7gfq0IvK4RMLWJ+LIyw5nYlYkLoLByc oolW+pbEayY/91spqDHckmLYDZa9jStsW7Zs11uIlA13ZJOh6uwBEUiIK M4DJOecVD14nhMUxP3OlHG5ZN0sJ0oYl5QVJJwQkY0eSKD0EqaKLNFaaJ TfKzGqn3+3thnDgObg0NQNnDvALzg8Eymm+QzH4+kk1kCf3YjUh8NojIJ foDvKRxPjtYz/U54vEBQaKpQ86bJGV4IC6VlfklM2C1H4EPsgzK233XQc eNl/eVhFYeWLB0tE90vCqrFbI97KXFoyulhG1ToKOH6XVKqniUoTNrgd+ A==; X-CSE-ConnectionGUID: B1vBICsYTTuwkvbP7gcZhQ== X-CSE-MsgGUID: K+g1x1t8Rg+4LYSgjzX96w== X-IronPort-AV: E=Sophos;i="6.08,182,1712592000"; d="scan'208";a="17062539" Received: from uls-op-cesaip01.wdc.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 23 May 2024 20:58:39 +0800 IronPort-SDR: 664f3136_ZssmQlMpJAR0S2alNUERHDIT1Ml7xFl4ZRQpOX5+WaltTJS 0WIQvBy2mg1Myl1BL6ika/A38lJZM7LsO8ZFa7g== Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep01.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 23 May 2024 05:06:14 -0700 WDCIronportException: Internal Received: from bxygm33.ad.shared ([10.45.31.229]) by uls-op-cesaip02.wdc.com with ESMTP; 23 May 2024 05:58:38 -0700 From: Avri Altman To: "Martin K . Petersen" Cc: Bart Van Assche , Bean Huo , Peter Wang , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Avri Altman Subject: [PATCH v5 0/3] scsi: ufs: Allow RTT negotiation Date: Thu, 23 May 2024 15:58:23 +0300 Message-ID: <20240523125827.818-1-avri.altman@wdc.com> X-Mailer: git-send-email 2.42.0 Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The rtt-upiu packets precede any data-out upiu packets, thus synchronizing the data input to the device: this mostly applies to write operations, but there are other operations that requires rtt as well. There are several rules binding this rtt - data-out dialog, specifically There can be at most outstanding bMaxNumOfRTT such packets. This might have an effect on write performance (sequential write in particular), as each data-out upiu must wait for its rtt sibling. UFSHCI expects bMaxNumOfRTT to be min(bDeviceRTTCap, NORTT). However, as of today, there does not appear to be no-one who sets it: not the host controller nor the driver. It wasn't an issue up to now: bMaxNumOfRTT is set to 2 after manufacturing, and wasn't limiting the write performance. UFS4.0, and specifically gear 5 changes this, and requires the device to be more attentive. This doesn't come free - the device has to allocate more resources to that end, but the sequential write performance improvement is significant. Early measurements shows 25% gain when moving from rtt 2 to 9. Therefore, set bMaxNumOfRTT to be min(bDeviceRTTCap, NORTT) as UFSHCI expects. v4 -> v5: Quiesce the queues before writing bMaxNumOfRTT (Bart) Make bDeviceRTTCap available in ufshcd_device_params_init() (Bart) v3 -> v4: Allow bMaxNumOfRTT to be configured via sysfs (Bart) v2 -> v3: Allow platform vendors to take precedence having their own rtt negotiation mechanism (Peter) v1 -> v2: bMaxNumOfRTT is a Persistent attribute - do not override if it was written (Bean) Avri Altman (3): scsi: ufs: Allow RTT negotiation scsi: ufs: Allow platform vendors to set rtt scsi: ufs: sysfs: Make max_number_of_rtt read-write Documentation/ABI/testing/sysfs-driver-ufs | 14 +++-- drivers/ufs/core/ufs-sysfs.c | 72 +++++++++++++++++++++- drivers/ufs/core/ufshcd-priv.h | 12 ++++ drivers/ufs/core/ufshcd.c | 53 ++++++++++++---- include/ufs/ufs.h | 2 + include/ufs/ufshcd.h | 4 ++ include/ufs/ufshci.h | 1 + 7 files changed, 139 insertions(+), 19 deletions(-)