From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E87F9C38142 for ; Fri, 27 Jan 2023 09:59:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232216AbjA0J7L (ORCPT ); Fri, 27 Jan 2023 04:59:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40656 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231743AbjA0J7K (ORCPT ); Fri, 27 Jan 2023 04:59:10 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1821C18B08 for ; Fri, 27 Jan 2023 01:59:09 -0800 (PST) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4P3Cc26mZvz6J7SM; Fri, 27 Jan 2023 17:54:58 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Fri, 27 Jan 2023 09:59:06 +0000 Date: Fri, 27 Jan 2023 09:59:06 +0000 From: Jonathan Cameron To: Alison Schofield CC: , Vishal Verma , "Ira Weiny" , Dan Williams , Subject: Re: [PATCH] cxl/pci: Set the device timestamp Message-ID: <20230127095906.000074ea@Huawei.com> In-Reply-To: References: <20230126180458.5145-1-Jonathan.Cameron@huawei.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml500002.china.huawei.com (7.191.160.78) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org On Thu, 26 Jan 2023 11:59:21 -0800 Alison Schofield wrote: > On Thu, Jan 26, 2023 at 06:04:58PM +0000, Jonathan Cameron wrote: > > CXL r3.0 section 8.2.9.4.2 "Set Timestamp" recommends that the host sets > > the timestamp after every Conventional or CXL Reset to ensure accurate > > timestamps. This should include on initial boot up. The time base that > > is being set is used by a device for the poison list overflow timestamp > > and all event timestamps. Note that the command is optional and if > > not supported and the device cannot return accurate timestamps it will > > fill the fields in with an appropriate marker (see the specification > > description of each timestamp). > > > > Signed-off-by: Jonathan Cameron > > > > --- > > > > Open question: Should we only do this if Linux has control of the > > error handling? In theory it should be safe anyway given the > > specification is clear that the timestamp base should always be the > > same - so subject to small errors we shouldn't cause any firmware first > > handling to get confused. > > > > drivers/cxl/core/mbox.c | 25 +++++++++++++++++++++++++ > > drivers/cxl/cxlmem.h | 7 +++++++ > > drivers/cxl/pci.c | 5 +++++ > > include/uapi/linux/cxl_mem.h | 1 + > > 4 files changed, 38 insertions(+) > > > > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c > > index b03fba212799..a7317bb142ed 100644 > > --- a/drivers/cxl/core/mbox.c > > +++ b/drivers/cxl/core/mbox.c > > @@ -65,6 +65,7 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = { > > CXL_CMD(GET_SCAN_MEDIA_CAPS, 0x10, 0x4, 0), > > CXL_CMD(SCAN_MEDIA, 0x11, 0, 0), > > CXL_CMD(GET_SCAN_MEDIA, 0, CXL_VARIABLE_PAYLOAD, 0), > > + CXL_CMD(SET_TIMESTAMP, 8, 0, 0), > > }; > > > > /* > > @@ -93,6 +94,7 @@ static u16 cxl_disabled_raw_commands[] = { > > CXL_MBOX_OP_SET_SHUTDOWN_STATE, > > CXL_MBOX_OP_SCAN_MEDIA, > > CXL_MBOX_OP_GET_SCAN_MEDIA, > > + CXL_MBOX_OP_SET_TIMESTAMP, > > }; > > > > /* > > @@ -857,6 +859,29 @@ int cxl_mem_create_range_info(struct cxl_dev_state *cxlds) > > } > > EXPORT_SYMBOL_NS_GPL(cxl_mem_create_range_info, CXL); > > > > +int cxl_set_timestamp(struct cxl_dev_state *cxlds, u64 ts) > > +{ > > + struct cxl_mbox_cmd mbox_cmd; > > + struct cxl_mbox_set_timestamp_in pi; > > + > > + /* > > + * Command is optional and functionality should not be affected if > > + * the command is not available. > > + */ > > + if (!test_bit(CXL_MEM_COMMAND_ID_SET_TIMESTAMP, cxlds->enabled_cmds)) > > + return 0; > > Jonathan, > > Would it be more efficient to call ktime_get_real_ns() right here, > rather than pass in the call from cxl_pci_probe()? Dave raised that as well. Makes sense for now. I was wildly conjecturing that we might want clock skew tweaking sometime in the future if the timestamps ever matter for much beyond error records. Thanks, Jonathan > > Alison > > + > > + pi.timestamp = ts; > > + mbox_cmd = (struct cxl_mbox_cmd) { > > + .opcode = CXL_MBOX_OP_SET_TIMESTAMP, > > + .size_in = sizeof(pi), > > + .payload_in = &pi, > > + }; > > + > > + return cxl_internal_send_cmd(cxlds, &mbox_cmd); > > +} > > +EXPORT_SYMBOL_NS_GPL(cxl_set_timestamp, CXL); > > + > > struct cxl_dev_state *cxl_dev_state_create(struct device *dev) > > { > > struct cxl_dev_state *cxlds; > > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h > > index ab138004f644..0ca7a35de893 100644 > > --- a/drivers/cxl/cxlmem.h > > +++ b/drivers/cxl/cxlmem.h > > @@ -274,6 +274,7 @@ enum cxl_opcode { > > CXL_MBOX_OP_RAW = CXL_MBOX_OP_INVALID, > > CXL_MBOX_OP_GET_FW_INFO = 0x0200, > > CXL_MBOX_OP_ACTIVATE_FW = 0x0202, > > + CXL_MBOX_OP_SET_TIMESTAMP = 0x0301, > > CXL_MBOX_OP_GET_SUPPORTED_LOGS = 0x0400, > > CXL_MBOX_OP_GET_LOG = 0x0401, > > CXL_MBOX_OP_IDENTIFY = 0x4000, > > @@ -372,6 +373,11 @@ struct cxl_mbox_set_partition_info { > > > > #define CXL_SET_PARTITION_IMMEDIATE_FLAG BIT(0) > > > > +/* Set Timestamp CXL 3.0 Spec 8.2.9.4.2 */ > > +struct cxl_mbox_set_timestamp_in { > > + __le64 timestamp; > > +} __packed; > > + > > /** > > * struct cxl_mem_command - Driver representation of a memory device command > > * @info: Command information as it exists for the UAPI > > @@ -441,6 +447,7 @@ int cxl_mem_create_range_info(struct cxl_dev_state *cxlds); > > struct cxl_dev_state *cxl_dev_state_create(struct device *dev); > > void set_exclusive_cxl_commands(struct cxl_dev_state *cxlds, unsigned long *cmds); > > void clear_exclusive_cxl_commands(struct cxl_dev_state *cxlds, unsigned long *cmds); > > +int cxl_set_timestamp(struct cxl_dev_state *cxlds, u64 ts); > > #ifdef CONFIG_CXL_SUSPEND > > void cxl_mem_active_inc(void); > > void cxl_mem_active_dec(void); > > diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c > > index 2bbebbc7e032..30a2b231d970 100644 > > --- a/drivers/cxl/pci.c > > +++ b/drivers/cxl/pci.c > > @@ -2,6 +2,7 @@ > > /* Copyright(c) 2020 Intel Corporation. All rights reserved. */ > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -482,6 +483,10 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > if (rc) > > return rc; > > > > + rc = cxl_set_timestamp(cxlds, ktime_get_real_ns()); > > + if (rc) > > + return rc; > > + > > rc = cxl_dev_state_identify(cxlds); > > if (rc) > > return rc; > > diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h > > index c71021a2a9ed..333301037b74 100644 > > --- a/include/uapi/linux/cxl_mem.h > > +++ b/include/uapi/linux/cxl_mem.h > > @@ -41,6 +41,7 @@ > > ___C(GET_SCAN_MEDIA_CAPS, "Get Scan Media Capabilities"), \ > > ___C(SCAN_MEDIA, "Scan Media"), \ > > ___C(GET_SCAN_MEDIA, "Get Scan Media Results"), \ > > + ___C(SET_TIMESTAMP, "Set Device Timestamp"), \ > > ___C(MAX, "invalid / last command") > > > > #define ___C(a, b) CXL_MEM_COMMAND_ID_##a > > > > base-commit: 172738bbccdb4ef76bdd72fc72a315c741c39161 > > -- > > 2.37.2 > >