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 X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53F29C433DB for ; Thu, 18 Mar 2021 01:02:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 05A9564F10 for ; Thu, 18 Mar 2021 01:02:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229918AbhCRBBV (ORCPT ); Wed, 17 Mar 2021 21:01:21 -0400 Received: from a0.mail.mailgun.net ([198.61.254.59]:42334 "EHLO a0.mail.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229720AbhCRBAz (ORCPT ); Wed, 17 Mar 2021 21:00:55 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1616029255; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=cdXXKx/6cmpJ3k5zTd24Wab1Zl+Vk9yFNKDeZVbO238=; b=vINr4YwVgzaE90t7B4wZKjnRvdL3L39wNBbfmrsqhEY72dMPRN6ccuB5erjhfMnLy7iPXsg2 o0LK9bopvfkBoCgL1GrbNSjSDHK1RYC3KSChYzbL2PMBER858z3k0fuONZXnZcK83Rio79Od wFN1Cd4J4pZqSE+HSdlt//EitKQ= X-Mailgun-Sending-Ip: 198.61.254.59 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n04.prod.us-west-2.postgun.com with SMTP id 6052a63b3f267701a49f0d14 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Thu, 18 Mar 2021 01:00:43 GMT Sender: cang=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id F1BADC43468; Thu, 18 Mar 2021 01:00:42 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: cang) by smtp.codeaurora.org (Postfix) with ESMTPSA id 46873C433C6; Thu, 18 Mar 2021 01:00:41 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 18 Mar 2021 09:00:41 +0800 From: Can Guo To: Avri Altman Cc: "James E . J . Bottomley" , "Martin K . Petersen" , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, Bart Van Assche , yongmyung lee , Daejun Park , alim.akhtar@samsung.com, asutoshd@codeaurora.org, Zang Leigang , Avi Shchislowski , Bean Huo , stanley.chu@mediatek.com Subject: Re: [PATCH v5 06/10] scsi: ufshpb: Add hpb dev reset response In-Reply-To: References: <20210302132503.224670-1-avri.altman@wdc.com> <20210302132503.224670-7-avri.altman@wdc.com> <59a62fc17ec9229a8498e696eb0474be@codeaurora.org> <1d0e3c5441ecf14b6614ec0af0d30af6@codeaurora.org> <37d0a4f115ad5d08ab12a76e6cbe17a5@codeaurora.org> <4562e78aee9c5fbb7bbff65930fc81cd@codeaurora.org> Message-ID: <546d67b328afcd0d26dff41180288b63@codeaurora.org> X-Sender: cang@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-03-17 23:46, Avri Altman wrote: >> >> >> >> >> >> >> >> Just curious, directly doing below things inside ufshpb_rsp_upiu() >> >> >> >> does >> >> >> >> not >> >> >> >> seem a problem to me, does this really deserve a separate work? >> >> >> > I don't know, I never even consider of doing this. >> >> >> > The active region list may contain up to few thousands of regions - >> >> >> > It is not rare to see configurations that covers the entire device. >> >> >> > >> >> >> >> >> >> Yes, true, it can be a huge list. But what does the ops >> >> >> "HPB_RSP_DEV_RESET" >> >> >> really mean? The specs says "Device reset HPB Regions information", >> >> >> but >> >> >> I >> >> >> don't know what is really happening. Could you please elaborate? >> >> > It means that the device informs the host that the L2P cache is no >> >> > longer valid. >> >> > The spec doesn't say what to do in that case. >> >> >> >> Then it means that all the clean (without DIRTY flag set) HPB entries >> >> (ppns) >> >> in active rgns in host memory side may not be valid to the device >> >> anymore. >> >> Please correct me if I am wrong. >> >> >> >> > We thought that in host mode, it make sense to update all the active >> >> > regions. >> >> >> >> But current logic does not set the state of the sub-regions (in active >> >> regions) to >> >> INVALID, it only marks all active regions as UPDATE. >> >> >> >> Although one of subsequent read cmds shall put the sub-region back to >> >> activate_list, >> >> ufshpb_test_ppn_dirty() can still return false, thus these read cmds >> >> still think the >> >> ppns are valid and they shall move forward to send HPB Write Buffer >> >> (buffer id = 0x2, >> >> in case of HPB2.0) and HPB Read cmds. >> >> >> >> HPB Read cmds with invalid ppns will be treated as normal Read cmds by >> >> device as the >> >> specs says, but what would happen to HPB Write Buffer cmds (buffer id >> >> = >> >> 0x2, in case >> >> of HPB2.0) with invalid ppns? Can this be a real problem? >> > No need to control the ppn dirty / invalid state for this case. >> > The device send device reset so it is aware that all the L2P cache is >> > invalid. >> > Any HPB_READ is treated like normal READ10. >> > >> > Only once HPB-READ-BUFFER is completed, >> > the device will relate back to the physical address. >> >> What about HPB-WRITE-BUFFER (buffer id = 0x2) cmds? > Same. > Oper 0x2 is a relative simple case. > The device is expected to manage some versioning framework not to be > "fooled" by erroneous ppn. > There are some more challenging races that the device should meet. > But I don't find the handling w.r.t this scenario on HPB2.0 specs - how would the device re-act/respond to HPB-WRITE-BUFFER cmds with invalid HPB entries? Could you please point me to relevant section/paragraph? Thanks, Can Guo. > Thanks, > Avri >> >> Thanks, >> Can Guo. >> >> > >> >> >> >> > >> >> > I think I will go with your suggestion. >> >> > Effectively, in host mode, since it is deactivating "cold" regions, >> >> > the lru list is kept relatively small, and contains only "hot" regions. >> >> >> >> hmm... I don't really have a idea on this, please go with whatever you >> >> and Daejun think is fine here. >> > I will take your advice and remove the worker. >> > >> > >> > Thanks, >> > Avri >> > >> >> >> >> Thanks, >> >> Can Guo. >> >> >> >> > >> >> > Thanks, >> >> > Avri >> >> > >> >> >> >> >> >> Thanks, >> >> >> Can Guo. >> >> >> >> >> >> > But yes, I can do that. >> >> >> > Better to get ack from Daejun first. >> >> >> > >> >> >> > Thanks, >> >> >> > Avri >> >> >> > >> >> >> >> >> >> >> >> Thanks, >> >> >> >> Can Guo. >> >> >> >> >> >> >> >> > +{ >> >> >> >> > + struct ufshpb_lu *hpb; >> >> >> >> > + struct victim_select_info *lru_info; >> >> >> >> > + struct ufshpb_region *rgn; >> >> >> >> > + unsigned long flags; >> >> >> >> > + >> >> >> >> > + hpb = container_of(work, struct ufshpb_lu, >> >> ufshpb_lun_reset_work); >> >> >> >> > + >> >> >> >> > + lru_info = &hpb->lru_info; >> >> >> >> > + >> >> >> >> > + spin_lock_irqsave(&hpb->rgn_state_lock, flags); >> >> >> >> > + >> >> >> >> > + list_for_each_entry(rgn, &lru_info->lh_lru_rgn, list_lru_rgn) >> >> >> >> > + set_bit(RGN_FLAG_UPDATE, &rgn->rgn_flags); >> >> >> >> > + >> >> >> >> > + spin_unlock_irqrestore(&hpb->rgn_state_lock, flags); >> >> >> >> > +} >> >> >> >> > + >> >> >> >> > static void ufshpb_normalization_work_handler(struct work_struct >> >> >> >> > *work) >> >> >> >> > { >> >> >> >> > struct ufshpb_lu *hpb; >> >> >> >> > @@ -1798,6 +1832,8 @@ static int ufshpb_alloc_region_tbl(struct >> >> >> >> > ufs_hba *hba, struct ufshpb_lu *hpb) >> >> >> >> > } else { >> >> >> >> > rgn->rgn_state = HPB_RGN_INACTIVE; >> >> >> >> > } >> >> >> >> > + >> >> >> >> > + rgn->rgn_flags = 0; >> >> >> >> > } >> >> >> >> > >> >> >> >> > return 0; >> >> >> >> > @@ -2012,9 +2048,12 @@ static int ufshpb_lu_hpb_init(struct >> >> ufs_hba >> >> >> >> > *hba, struct ufshpb_lu *hpb) >> >> >> >> > INIT_LIST_HEAD(&hpb->list_hpb_lu); >> >> >> >> > >> >> >> >> > INIT_WORK(&hpb->map_work, ufshpb_map_work_handler); >> >> >> >> > - if (hpb->is_hcm) >> >> >> >> > + if (hpb->is_hcm) { >> >> >> >> > INIT_WORK(&hpb->ufshpb_normalization_work, >> >> >> >> > ufshpb_normalization_work_handler); >> >> >> >> > + INIT_WORK(&hpb->ufshpb_lun_reset_work, >> >> >> >> > + ufshpb_reset_work_handler); >> >> >> >> > + } >> >> >> >> > >> >> >> >> > hpb->map_req_cache = >> kmem_cache_create("ufshpb_req_cache", >> >> >> >> > sizeof(struct ufshpb_req), 0, 0, NULL); >> >> >> >> > @@ -2114,8 +2153,10 @@ static void >> ufshpb_discard_rsp_lists(struct >> >> >> >> > ufshpb_lu *hpb) >> >> >> >> > >> >> >> >> > static void ufshpb_cancel_jobs(struct ufshpb_lu *hpb) >> >> >> >> > { >> >> >> >> > - if (hpb->is_hcm) >> >> >> >> > + if (hpb->is_hcm) { >> >> >> >> > + cancel_work_sync(&hpb->ufshpb_lun_reset_work); >> >> >> >> > cancel_work_sync(&hpb->ufshpb_normalization_work); >> >> >> >> > + } >> >> >> >> > cancel_work_sync(&hpb->map_work); >> >> >> >> > } >> >> >> >> > >> >> >> >> > diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h >> >> >> >> > index 84598a317897..37c1b0ea0c0a 100644 >> >> >> >> > --- a/drivers/scsi/ufs/ufshpb.h >> >> >> >> > +++ b/drivers/scsi/ufs/ufshpb.h >> >> >> >> > @@ -121,6 +121,7 @@ struct ufshpb_region { >> >> >> >> > struct list_head list_lru_rgn; >> >> >> >> > unsigned long rgn_flags; >> >> >> >> > #define RGN_FLAG_DIRTY 0 >> >> >> >> > +#define RGN_FLAG_UPDATE 1 >> >> >> >> > >> >> >> >> > /* region reads - for host mode */ >> >> >> >> > spinlock_t rgn_lock; >> >> >> >> > @@ -217,6 +218,7 @@ struct ufshpb_lu { >> >> >> >> > /* for selecting victim */ >> >> >> >> > struct victim_select_info lru_info; >> >> >> >> > struct work_struct ufshpb_normalization_work; >> >> >> >> > + struct work_struct ufshpb_lun_reset_work; >> >> >> >> > >> >> >> >> > /* pinned region information */ >> >> >> >> > u32 lu_pinned_start;