Re: [PATCH v9 10/15] PCI/ERR: Limit AER resets in pcie_do_recovery()
On 16 Oct 2020, at 10:22, Bjorn Helgaas wrote: On Thu, Oct 15, 2020 at 05:11:08PM -0700, Sean V Kelley wrote: From: Sean V Kelley In some cases a bridge may not exist as the hardware controlling may be handled only by firmware and so is not visible to the OS. This scenario is also possible in future use cases involving non-native use of RCECs by firmware. Explicitly apply conditional logic around these resets by limiting them to Root Ports and Downstream Ports. Link: https://lore.kernel.org/r/20201002184735.1229220-8-seanvk@oregontracks.org Signed-off-by: Sean V Kelley Signed-off-by: Bjorn Helgaas Acked-by: Jonathan Cameron --- drivers/pci/pcie/err.c | 31 +-- 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c index 8b53aecdb43d..7883c9791562 100644 --- a/drivers/pci/pcie/err.c +++ b/drivers/pci/pcie/err.c @@ -148,13 +148,17 @@ static int report_resume(struct pci_dev *dev, void *data) /** * pci_walk_bridge - walk bridges potentially AER affected - * @bridge:bridge which may be a Port + * @bridge: bridge which may be a Port, an RCEC with associated RCiEPs, + * or an RCiEP associated with an RCEC * @cb:callback to be called for each device found * @userdata: arbitrary pointer to be passed to callback * * If the device provided is a bridge, walk the subordinate bus, including * any bridged devices on buses under this bus. Call the provided callback * on each device found. + * + * If the device provided has no subordinate bus, call the callback on the + * device itself. */ static void pci_walk_bridge(struct pci_dev *bridge, int (*cb)(struct pci_dev *, void *), @@ -162,6 +166,8 @@ static void pci_walk_bridge(struct pci_dev *bridge, { if (bridge->subordinate) pci_walk_bus(bridge->subordinate, cb, userdata); + else + cb(bridge, userdata); Looks like *this* is the patch where the "no subordinate bus" case becomes possible? If you agree, I can just move the test here, no need to repost. Agree, this is the patch that the check is needed as we are opening things up for walking RC_ECs and RC_ENDs as below. Sean } pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, @@ -174,10 +180,13 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, /* * Error recovery runs on all subordinates of the bridge. If the -* bridge detected the error, it is cleared at the end. +* bridge detected the error, it is cleared at the end. For RCiEPs +* we should reset just the RCiEP itself. */ if (type == PCI_EXP_TYPE_ROOT_PORT || - type == PCI_EXP_TYPE_DOWNSTREAM) + type == PCI_EXP_TYPE_DOWNSTREAM || + type == PCI_EXP_TYPE_RC_EC || + type == PCI_EXP_TYPE_RC_END) bridge = dev; else bridge = pci_upstream_bridge(dev); @@ -185,6 +194,12 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, pci_dbg(bridge, "broadcast error_detected message\n"); if (state == pci_channel_io_frozen) { pci_walk_bridge(bridge, report_frozen_detected, &status); + if (type == PCI_EXP_TYPE_RC_END) { + pci_warn(dev, "subordinate device reset not possible for RCiEP\n"); + status = PCI_ERS_RESULT_NONE; + goto failed; + } + status = reset_subordinates(bridge); if (status != PCI_ERS_RESULT_RECOVERED) { pci_warn(bridge, "subordinate device reset failed\n"); @@ -217,9 +232,13 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, pci_dbg(bridge, "broadcast resume message\n"); pci_walk_bridge(bridge, report_resume, &status); - if (pcie_aer_is_native(bridge)) - pcie_clear_device_status(bridge); - pci_aer_clear_nonfatal_status(bridge); + if (type == PCI_EXP_TYPE_ROOT_PORT || + type == PCI_EXP_TYPE_DOWNSTREAM || + type == PCI_EXP_TYPE_RC_EC) { + if (pcie_aer_is_native(bridge)) + pcie_clear_device_status(bridge); + pci_aer_clear_nonfatal_status(bridge); + } pci_info(bridge, "device recovery successful\n"); return status; -- 2.28.0
Re: [PATCH v9 10/15] PCI/ERR: Limit AER resets in pcie_do_recovery()
On Thu, Oct 15, 2020 at 05:11:08PM -0700, Sean V Kelley wrote: > From: Sean V Kelley > > In some cases a bridge may not exist as the hardware controlling may be > handled only by firmware and so is not visible to the OS. This scenario is > also possible in future use cases involving non-native use of RCECs by > firmware. > > Explicitly apply conditional logic around these resets by limiting them to > Root Ports and Downstream Ports. > > Link: > https://lore.kernel.org/r/20201002184735.1229220-8-seanvk@oregontracks.org > Signed-off-by: Sean V Kelley > Signed-off-by: Bjorn Helgaas > Acked-by: Jonathan Cameron > --- > drivers/pci/pcie/err.c | 31 +-- > 1 file changed, 25 insertions(+), 6 deletions(-) > > diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c > index 8b53aecdb43d..7883c9791562 100644 > --- a/drivers/pci/pcie/err.c > +++ b/drivers/pci/pcie/err.c > @@ -148,13 +148,17 @@ static int report_resume(struct pci_dev *dev, void > *data) > > /** > * pci_walk_bridge - walk bridges potentially AER affected > - * @bridge: bridge which may be a Port > + * @bridge: bridge which may be a Port, an RCEC with associated RCiEPs, > + * or an RCiEP associated with an RCEC > * @cb: callback to be called for each device found > * @userdata:arbitrary pointer to be passed to callback > * > * If the device provided is a bridge, walk the subordinate bus, including > * any bridged devices on buses under this bus. Call the provided callback > * on each device found. > + * > + * If the device provided has no subordinate bus, call the callback on the > + * device itself. > */ > static void pci_walk_bridge(struct pci_dev *bridge, > int (*cb)(struct pci_dev *, void *), > @@ -162,6 +166,8 @@ static void pci_walk_bridge(struct pci_dev *bridge, > { > if (bridge->subordinate) > pci_walk_bus(bridge->subordinate, cb, userdata); > + else > + cb(bridge, userdata); Looks like *this* is the patch where the "no subordinate bus" case becomes possible? If you agree, I can just move the test here, no need to repost. > } > > pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, > @@ -174,10 +180,13 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, > > /* >* Error recovery runs on all subordinates of the bridge. If the > - * bridge detected the error, it is cleared at the end. > + * bridge detected the error, it is cleared at the end. For RCiEPs > + * we should reset just the RCiEP itself. >*/ > if (type == PCI_EXP_TYPE_ROOT_PORT || > - type == PCI_EXP_TYPE_DOWNSTREAM) > + type == PCI_EXP_TYPE_DOWNSTREAM || > + type == PCI_EXP_TYPE_RC_EC || > + type == PCI_EXP_TYPE_RC_END) > bridge = dev; > else > bridge = pci_upstream_bridge(dev); > @@ -185,6 +194,12 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, > pci_dbg(bridge, "broadcast error_detected message\n"); > if (state == pci_channel_io_frozen) { > pci_walk_bridge(bridge, report_frozen_detected, &status); > + if (type == PCI_EXP_TYPE_RC_END) { > + pci_warn(dev, "subordinate device reset not possible > for RCiEP\n"); > + status = PCI_ERS_RESULT_NONE; > + goto failed; > + } > + > status = reset_subordinates(bridge); > if (status != PCI_ERS_RESULT_RECOVERED) { > pci_warn(bridge, "subordinate device reset failed\n"); > @@ -217,9 +232,13 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, > pci_dbg(bridge, "broadcast resume message\n"); > pci_walk_bridge(bridge, report_resume, &status); > > - if (pcie_aer_is_native(bridge)) > - pcie_clear_device_status(bridge); > - pci_aer_clear_nonfatal_status(bridge); > + if (type == PCI_EXP_TYPE_ROOT_PORT || > + type == PCI_EXP_TYPE_DOWNSTREAM || > + type == PCI_EXP_TYPE_RC_EC) { > + if (pcie_aer_is_native(bridge)) > + pcie_clear_device_status(bridge); > + pci_aer_clear_nonfatal_status(bridge); > + } > pci_info(bridge, "device recovery successful\n"); > return status; > > -- > 2.28.0 >
[PATCH v9 10/15] PCI/ERR: Limit AER resets in pcie_do_recovery()
From: Sean V Kelley In some cases a bridge may not exist as the hardware controlling may be handled only by firmware and so is not visible to the OS. This scenario is also possible in future use cases involving non-native use of RCECs by firmware. Explicitly apply conditional logic around these resets by limiting them to Root Ports and Downstream Ports. Link: https://lore.kernel.org/r/20201002184735.1229220-8-seanvk@oregontracks.org Signed-off-by: Sean V Kelley Signed-off-by: Bjorn Helgaas Acked-by: Jonathan Cameron --- drivers/pci/pcie/err.c | 31 +-- 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c index 8b53aecdb43d..7883c9791562 100644 --- a/drivers/pci/pcie/err.c +++ b/drivers/pci/pcie/err.c @@ -148,13 +148,17 @@ static int report_resume(struct pci_dev *dev, void *data) /** * pci_walk_bridge - walk bridges potentially AER affected - * @bridge:bridge which may be a Port + * @bridge:bridge which may be a Port, an RCEC with associated RCiEPs, + * or an RCiEP associated with an RCEC * @cb:callback to be called for each device found * @userdata: arbitrary pointer to be passed to callback * * If the device provided is a bridge, walk the subordinate bus, including * any bridged devices on buses under this bus. Call the provided callback * on each device found. + * + * If the device provided has no subordinate bus, call the callback on the + * device itself. */ static void pci_walk_bridge(struct pci_dev *bridge, int (*cb)(struct pci_dev *, void *), @@ -162,6 +166,8 @@ static void pci_walk_bridge(struct pci_dev *bridge, { if (bridge->subordinate) pci_walk_bus(bridge->subordinate, cb, userdata); + else + cb(bridge, userdata); } pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, @@ -174,10 +180,13 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, /* * Error recovery runs on all subordinates of the bridge. If the -* bridge detected the error, it is cleared at the end. +* bridge detected the error, it is cleared at the end. For RCiEPs +* we should reset just the RCiEP itself. */ if (type == PCI_EXP_TYPE_ROOT_PORT || - type == PCI_EXP_TYPE_DOWNSTREAM) + type == PCI_EXP_TYPE_DOWNSTREAM || + type == PCI_EXP_TYPE_RC_EC || + type == PCI_EXP_TYPE_RC_END) bridge = dev; else bridge = pci_upstream_bridge(dev); @@ -185,6 +194,12 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, pci_dbg(bridge, "broadcast error_detected message\n"); if (state == pci_channel_io_frozen) { pci_walk_bridge(bridge, report_frozen_detected, &status); + if (type == PCI_EXP_TYPE_RC_END) { + pci_warn(dev, "subordinate device reset not possible for RCiEP\n"); + status = PCI_ERS_RESULT_NONE; + goto failed; + } + status = reset_subordinates(bridge); if (status != PCI_ERS_RESULT_RECOVERED) { pci_warn(bridge, "subordinate device reset failed\n"); @@ -217,9 +232,13 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, pci_dbg(bridge, "broadcast resume message\n"); pci_walk_bridge(bridge, report_resume, &status); - if (pcie_aer_is_native(bridge)) - pcie_clear_device_status(bridge); - pci_aer_clear_nonfatal_status(bridge); + if (type == PCI_EXP_TYPE_ROOT_PORT || + type == PCI_EXP_TYPE_DOWNSTREAM || + type == PCI_EXP_TYPE_RC_EC) { + if (pcie_aer_is_native(bridge)) + pcie_clear_device_status(bridge); + pci_aer_clear_nonfatal_status(bridge); + } pci_info(bridge, "device recovery successful\n"); return status; -- 2.28.0