From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZonOmF8lwSMCLIl/TNCkR+oVrslIF8Qt/qop2gWZ2dPcBwfWOyvMfw4k4DDiufdmms3Nb5v ARC-Seal: i=1; a=rsa-sha256; t=1526458588; cv=none; d=google.com; s=arc-20160816; b=ujfkE7W15s6VsYqNV0GWaS++f83MJR7kd9Zv957zNep0BEPe/Ojzu/1q+IAt+bgNNn r0vRaWQvnK71S85OdUQy4eCLz9whXH3cIBZTrkw8AchkkR8HrY6+MZ2ZlJJauqAgBNDA dSO3vZwRqHcoZe/e4cD1OuamjymzSpixp7jRyySXpYawzd2rZuS276ShoBIG278qajLW Ym2btR/Yp+gu/2dtNSnxfWqgbPZfRzgBmk3xLlziTNFmC3Z713u49AVynd5HNSzljtQb fehGzv7kJe7RKQHm9IUAnJ3JgK8y8O2oRE2rhsviLXEwzvfFfi2dqfNQpTPpCOkm385W w+Kw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:message-id:references:in-reply-to:subject:cc:to:from :date:content-transfer-encoding:mime-version:dkim-signature :dkim-signature:arc-authentication-results; bh=ZTfZIBRXFN78ELzvgAKQwOE+1kC/FioOvWSlOhYqcwA=; b=oiEwnFID4cDQxmC/0f4lBhBvQ9/Zpya5Xnt6jH0slMFNhJCZuo2H4FsXHd7gyM/2Cd tLgLRI1O69nGJiLSprE7veR5HP1zrR3QruFXVOiWvTBMjd6+h9w92QD4Z5TvLSIuhAqk yaOXDMiZT7mDGtndOrQfdC8kw2P1XvQq6cfsjZjTgrb0dwCj3/eDTZgKUgfVo4UXN3O0 rPhOq1fqiTiXsUlR87Z7pXW4xvwAYoox4rGtnnWg7HbTWX7Lc5tbP2crTFOaaqm1IyXS AszJwOrJbUYOGxn8HW8yUQKlkdhiVy16pI6DBTLHM45nd9aoeqqFWStYlSyk9nkBRbWq 0JMA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@codeaurora.org header.s=default header.b=EqtyYIGv; dkim=pass header.i=@codeaurora.org header.s=default header.b=Is6NzsoL; spf=pass (google.com: domain of poza@codeaurora.org designates 198.145.29.96 as permitted sender) smtp.mailfrom=poza@codeaurora.org Authentication-Results: mx.google.com; dkim=pass header.i=@codeaurora.org header.s=default header.b=EqtyYIGv; dkim=pass header.i=@codeaurora.org header.s=default header.b=Is6NzsoL; spf=pass (google.com: domain of poza@codeaurora.org designates 198.145.29.96 as permitted sender) smtp.mailfrom=poza@codeaurora.org MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 16 May 2018 13:46:25 +0530 From: poza@codeaurora.org To: Bjorn Helgaas Cc: Bjorn Helgaas , Philippe Ombredanne , Thomas Gleixner , Greg Kroah-Hartman , Kate Stewart , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Dongdong Liu , Keith Busch , Wei Zhang , Sinan Kaya , Timur Tabi Subject: Re: [PATCH v16 8/9] PCI/DPC: Unify and plumb error handling into DPC In-Reply-To: <20180515235632.GB11156@bhelgaas-glaptop.roam.corp.google.com> References: <1526035408-31328-1-git-send-email-poza@codeaurora.org> <1526035408-31328-9-git-send-email-poza@codeaurora.org> <20180515235632.GB11156@bhelgaas-glaptop.roam.corp.google.com> Message-ID: <2ca65f6b38668cfcf553833409ee38e3@codeaurora.org> User-Agent: Roundcube Webmail/1.2.5 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1600164111312988494?= X-GMAIL-MSGID: =?utf-8?q?1600607840954159838?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 2018-05-16 05:26, Bjorn Helgaas wrote: > On Fri, May 11, 2018 at 05:22:08PM +0530, poza@codeaurora.org wrote: >> On 2018-05-11 16:13, Oza Pawandeep wrote: >> > DPC driver implements link_reset callback, and calls >> > pci_do_fatal_recovery(). >> > >> > Which follows standard path of ERR_FATAL recovery. >> > >> > Signed-off-by: Oza Pawandeep >> > >> > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h >> > index 5e8857a..6af7595 100644 >> > --- a/drivers/pci/pci.h >> > +++ b/drivers/pci/pci.h >> > @@ -354,7 +354,7 @@ static inline resource_size_t >> > pci_resource_alignment(struct pci_dev *dev, >> > void pci_enable_acs(struct pci_dev *dev); >> > >> > /* PCI error reporting and recovery */ >> > -void pcie_do_fatal_recovery(struct pci_dev *dev); >> > +void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service); >> > void pcie_do_nonfatal_recovery(struct pci_dev *dev); >> > >> > bool pcie_wait_for_link(struct pci_dev *pdev, bool active); >> > diff --git a/drivers/pci/pcie/aer/aerdrv_core.c >> > b/drivers/pci/pcie/aer/aerdrv_core.c >> > index fdfc474..36e622d 100644 >> > --- a/drivers/pci/pcie/aer/aerdrv_core.c >> > +++ b/drivers/pci/pcie/aer/aerdrv_core.c >> > @@ -254,7 +254,7 @@ static void handle_error_source(struct pcie_device >> > *aerdev, >> > } else if (info->severity == AER_NONFATAL) >> > pcie_do_nonfatal_recovery(dev); >> > else if (info->severity == AER_FATAL) >> > - pcie_do_fatal_recovery(dev); >> > + pcie_do_fatal_recovery(dev, PCIE_PORT_SERVICE_AER); >> > } >> > >> > #ifdef CONFIG_ACPI_APEI_PCIEAER >> > @@ -321,7 +321,7 @@ static void aer_recover_work_func(struct work_struct >> > *work) >> > if (entry.severity == AER_NONFATAL) >> > pcie_do_nonfatal_recovery(pdev); >> > else if (entry.severity == AER_FATAL) >> > - pcie_do_fatal_recovery(pdev); >> > + pcie_do_fatal_recovery(pdev, PCIE_PORT_SERVICE_AER); >> > pci_dev_put(pdev); >> > } >> > } >> > diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c >> > index 80ec384..5680c13 100644 >> > --- a/drivers/pci/pcie/dpc.c >> > +++ b/drivers/pci/pcie/dpc.c >> > @@ -73,29 +73,31 @@ static void dpc_wait_link_inactive(struct dpc_dev >> > *dpc) >> > pcie_wait_for_link(pdev, false); >> > } >> > >> > -static void dpc_work(struct work_struct *work) >> > +static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev) >> > { >> > - struct dpc_dev *dpc = container_of(work, struct dpc_dev, work); >> > - struct pci_dev *dev, *temp, *pdev = dpc->dev->port; >> > - struct pci_bus *parent = pdev->subordinate; >> > - u16 cap = dpc->cap_pos, ctl; >> > - >> > - pci_lock_rescan_remove(); >> > - list_for_each_entry_safe_reverse(dev, temp, &parent->devices, >> > - bus_list) { >> > - pci_dev_get(dev); >> > - pci_dev_set_disconnected(dev, NULL); >> > - if (pci_has_subordinate(dev)) >> > - pci_walk_bus(dev->subordinate, >> > - pci_dev_set_disconnected, NULL); >> > - pci_stop_and_remove_bus_device(dev); >> > - pci_dev_put(dev); >> > - } >> > - pci_unlock_rescan_remove(); >> > - >> > + struct dpc_dev *dpc; >> > + struct pcie_device *pciedev; >> > + struct device *devdpc; >> > + u16 cap, ctl; >> > + >> > + /* >> > + * DPC disables the Link automatically in hardware, so it has >> > + * already been reset by the time we get here. >> > + */ >> > + >> > + devdpc = pcie_port_find_device(pdev, PCIE_PORT_SERVICE_DPC); >> > + pciedev = to_pcie_device(devdpc); >> > + dpc = get_service_data(pciedev); >> > + cap = dpc->cap_pos; >> > + >> > + /* >> > + * Waiting until the link is inactive, then clearing DPC >> > + * trigger status to allow the port to leave DPC. >> > + */ >> > dpc_wait_link_inactive(dpc); >> > + >> > if (dpc->rp_extensions && dpc_wait_rp_inactive(dpc)) >> > - return; >> > + return PCI_ERS_RESULT_DISCONNECT; >> > if (dpc->rp_extensions && dpc->rp_pio_status) { >> > pci_write_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS, >> > dpc->rp_pio_status); >> > @@ -108,6 +110,17 @@ static void dpc_work(struct work_struct *work) >> > pci_read_config_word(pdev, cap + PCI_EXP_DPC_CTL, &ctl); >> > pci_write_config_word(pdev, cap + PCI_EXP_DPC_CTL, >> > ctl | PCI_EXP_DPC_CTL_INT_EN); >> > + >> > + return PCI_ERS_RESULT_RECOVERED; >> > +} >> > + >> > +static void dpc_work(struct work_struct *work) >> > +{ >> > + struct dpc_dev *dpc = container_of(work, struct dpc_dev, work); >> > + struct pci_dev *pdev = dpc->dev->port; >> > + >> > + /* From DPC point of view error is always FATAL. */ >> > + pcie_do_fatal_recovery(pdev, PCIE_PORT_SERVICE_DPC); >> > } >> > >> > static void dpc_process_rp_pio_error(struct dpc_dev *dpc) >> > @@ -288,6 +301,7 @@ static struct pcie_port_service_driver dpcdriver = { >> > .service = PCIE_PORT_SERVICE_DPC, >> > .probe = dpc_probe, >> > .remove = dpc_remove, >> > + .reset_link = dpc_reset_link, >> > }; >> > >> > static int __init dpc_service_init(void) >> > diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c >> > index 33a16b1..29ff148 100644 >> > --- a/drivers/pci/pcie/err.c >> > +++ b/drivers/pci/pcie/err.c >> > @@ -185,7 +185,7 @@ static pci_ers_result_t default_reset_link(struct >> > pci_dev *dev) >> > return PCI_ERS_RESULT_RECOVERED; >> > } >> > >> > -static pci_ers_result_t reset_link(struct pci_dev *dev) >> > +static pci_ers_result_t reset_link(struct pci_dev *dev, u32 service) >> > { >> > struct pci_dev *udev; >> > pci_ers_result_t status; >> > @@ -200,7 +200,7 @@ static pci_ers_result_t reset_link(struct pci_dev >> > *dev) >> > } >> > >> > /* Use the aer driver of the component firstly */ >> > - driver = pcie_port_find_service(udev, PCIE_PORT_SERVICE_AER); >> > + driver = pcie_port_find_service(udev, service); >> > >> > if (driver && driver->reset_link) { >> > status = driver->reset_link(udev); >> > @@ -287,7 +287,7 @@ static pci_ers_result_t >> > broadcast_error_message(struct pci_dev *dev, >> > * followed by re-enumeration of devices. >> > */ >> > >> > -void pcie_do_fatal_recovery(struct pci_dev *dev) >> > +void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service) >> > { >> > struct pci_dev *udev; >> > struct pci_bus *parent; >> > @@ -313,7 +313,7 @@ void pcie_do_fatal_recovery(struct pci_dev *dev) >> > pci_dev_put(pdev); >> > } >> > >> > - result = reset_link(udev); >> > + result = reset_link(udev, service); >> > >> > if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { >> > /* >> > diff --git a/include/linux/aer.h b/include/linux/aer.h >> > index 8f87bbe..0c506fe 100644 >> > --- a/include/linux/aer.h >> > +++ b/include/linux/aer.h >> > @@ -14,6 +14,7 @@ >> > #define AER_NONFATAL 0 >> > #define AER_FATAL 1 >> > #define AER_CORRECTABLE 2 >> > +#define DPC_FATAL 4 > > I think DPC_FATAL can be 3, since these values are not used as a bit > mask. > >> > struct pci_dev; >> >> >> Hi Bjorn, >> >> >> I have addressed all the comments, and I hope we are heading towards >> closure. >> >> I just figure that pcie_do_fatal_recovery (which is getting executed >> for >> DPC as well) >> >> if (result == PCI_ERS_RESULT_RECOVERED) { >> if (pcie_wait_for_link(udev, true)) >> pci_rescan_bus(udev->bus); >> pci_info(dev, "Device recovery successful\n"); >> } >> >> I have to correct it to >> >> if (service==AER && result == PCI_ERS_RESULT_RECOVERED) { >> if (pcie_wait_for_link(udev, true)) >> pci_rescan_bus(udev->bus); >> pci_info(dev, "Device recovery successful\n"); >> } > > This patch is mostly a restructuring of DPC and doesn't really change > its > behavior. DPC didn't previously call pcie_wait_for_link() or > pci_rescan_bus(), so I agree that adding the "service==AER" test will > help preserve the existing DPC behavior. > > However, the rescan should happen with DPC *somewhere* and we should > clarify where that is. Maybe for now we only need a comment about > where > that happens. Ideally, we could eventually converge this so the same > mechanism is used for AER and DPC, so we wouldn't need a test like > "service=AER". > >> rest of the things look okay to me. >> If you have any more comments, >> I can fix them with this one and hopefully v17 will be the final one. I am sorry I pasted the wrong snippet. following needs to be fixed in v17. from: if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { /* * If the error is reported by a bridge, we think this error * is related to the downstream link of the bridge, so we * do error recovery on all subordinates of the bridge instead * of the bridge and clear the error status of the bridge. */ pci_walk_bus(dev->subordinate, report_resume, &result_data); pci_cleanup_aer_uncorrect_error_status(dev); } to if (service==AER && dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { /* * If the error is reported by a bridge, we think this error * is related to the downstream link of the bridge, so we * do error recovery on all subordinates of the bridge instead * of the bridge and clear the error status of the bridge. */ pci_walk_bus(dev->subordinate, report_resume, &result_data); pci_cleanup_aer_uncorrect_error_status(dev); } this is only needed in case of AER. by the way I can not find pci/oza-v16 branch when I cloned git clone https://kernel.googlesource.com/pub/scm/linux/kernel/git/helgaas/pci Regards, Oza. >> >> >> PS: I am going though the code more, and we can have some follow up >> patches >> (probably some cleanup) >> for e.g. pcie_portdrv_slot_reset() checks >> if (dev->error_state == pci_channel_io_frozen) { >> dev->state_saved = true; >> pci_restore_state(dev); >> pcie_portdrv_restore_config(dev); >> pci_enable_pcie_error_reporting(dev); >> } >> >> >> but now since the ERR_FATAL path does not call pcie_portdrv_slot_reset >> the >> check is meaning less. >> >> besides driver's shut_down callbacks might want to handle >> pci_channel_io_frozen, but that something left to be discussed later. >> So, I am not touching dev->error_state anywhere as of now in ERR_FATAL >> case. >> >> Regards, >> Oza. >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >>