Re: [PATCH v5 07/10] PCI/RCEC: Add RCiEP's linked RCEC to AER/ERR
From: Sean V Kelley
Date: Tue Sep 22 2020 - 22:51:18 EST
On Mon, Sep 21, 2020 at 4:33 AM Jonathan Cameron
<Jonathan.Cameron@xxxxxxxxxx> wrote:
>
> On Fri, 18 Sep 2020 13:46:00 -0700
> Sean V Kelley <sean.v.kelley@xxxxxxxxx> wrote:
>
> > From: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>
> >
> > When attempting error recovery for an RCiEP associated with an RCEC device,
> > there needs to be a way to update the Root Error Status, the Uncorrectable
> > Error Status and the Uncorrectable Error Severity of the parent RCEC.
> > In some non-native cases in which there is no OS visible device
> > associated with the RCiEP, there is nothing to act upon as the firmware
> > is acting before the OS. So add handling for the linked 'rcec' in AER/ERR
> > while taking into account non-native cases.
> >
> > Co-developed-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx>
> > Signed-off-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx>
> > Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>
> I'll give this a test run later to check I'm not missing anything, but LGTM.
>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
>
> Thanks,
Appreciate it.
Thanks,
Sean
>
> > ---
> > drivers/pci/pcie/aer.c | 9 +++++----
> > drivers/pci/pcie/err.c | 38 ++++++++++++++++++++++++--------------
> > 2 files changed, 29 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> > index 65dff5f3457a..dccdba60b5d9 100644
> > --- a/drivers/pci/pcie/aer.c
> > +++ b/drivers/pci/pcie/aer.c
> > @@ -1358,17 +1358,18 @@ static int aer_probe(struct pcie_device *dev)
> > static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
> > {
> > int aer = dev->aer_cap;
> > + int rc = 0;
> > u32 reg32;
> > - int rc;
> > -
> >
> > /* Disable Root's interrupt in response to error messages */
> > pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, ®32);
> > reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
> > pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, reg32);
> >
> > - rc = pci_bus_error_reset(dev);
> > - pci_info(dev, "Root Port link has been reset\n");
> > + if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_EC) {
> > + rc = pci_bus_error_reset(dev);
> > + pci_info(dev, "Root Port link has been reset\n");
> > + }
> >
> > /* Clear Root Error Status */
> > pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, ®32);
> > diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
> > index 5380ecc41506..a61a2518163a 100644
> > --- a/drivers/pci/pcie/err.c
> > +++ b/drivers/pci/pcie/err.c
> > @@ -149,7 +149,8 @@ static int report_resume(struct pci_dev *dev, void *data)
> > /**
> > * pci_bridge_walk - walk bridges potentially AER affected
> > * @bridge bridge which may be an RCEC with associated RCiEPs,
> > - * an RCiEP associated with an RCEC, or a Port.
> > + * or a Port.
> > + * @dev an RCiEP lacking an associated RCEC.
> > * @cb callback to be called for each device found
> > * @userdata arbitrary pointer to be passed to callback.
> > *
> > @@ -160,13 +161,16 @@ static int report_resume(struct pci_dev *dev, void *data)
> > * If the device provided has no subordinate bus, call the provided
> > * callback on the device itself.
> > */
> > -static void pci_bridge_walk(struct pci_dev *bridge, int (*cb)(struct pci_dev *, void *),
> > +static void pci_bridge_walk(struct pci_dev *bridge, struct pci_dev *dev,
> > + int (*cb)(struct pci_dev *, void *),
> > void *userdata)
> > {
> > - if (bridge->subordinate)
> > + if (bridge && bridge->subordinate)
> > pci_walk_bus(bridge->subordinate, cb, userdata);
> > - else
> > + else if (bridge)
> > cb(bridge, userdata);
> > + else
> > + cb(dev, userdata);
> > }
> >
> > static pci_ers_result_t flr_on_rciep(struct pci_dev *dev)
> > @@ -196,16 +200,24 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
> > type = pci_pcie_type(dev);
> > if (type == PCI_EXP_TYPE_ROOT_PORT ||
> > type == PCI_EXP_TYPE_DOWNSTREAM ||
> > - type == PCI_EXP_TYPE_RC_EC ||
> > - type == PCI_EXP_TYPE_RC_END)
> > + type == PCI_EXP_TYPE_RC_EC)
> > bridge = dev;
> > + else if (type == PCI_EXP_TYPE_RC_END)
> > + bridge = dev->rcec;
> > else
> > bridge = pci_upstream_bridge(dev);
> >
> > pci_dbg(dev, "broadcast error_detected message\n");
> > if (state == pci_channel_io_frozen) {
> > - pci_bridge_walk(bridge, report_frozen_detected, &status);
> > + pci_bridge_walk(bridge, dev, report_frozen_detected, &status);
> > if (type == PCI_EXP_TYPE_RC_END) {
> > + /*
> > + * The callback only clears the Root Error Status
> > + * of the RCEC (see aer.c).
> > + */
> > + if (bridge)
> > + reset_subordinate_devices(bridge);
> > +
> > status = flr_on_rciep(dev);
> > if (status != PCI_ERS_RESULT_RECOVERED) {
> > pci_warn(dev, "function level reset failed\n");
> > @@ -219,13 +231,13 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
> > }
> > }
> > } else {
> > - pci_bridge_walk(bridge, report_normal_detected, &status);
> > + pci_bridge_walk(bridge, dev, report_normal_detected, &status);
> > }
> >
> > if (status == PCI_ERS_RESULT_CAN_RECOVER) {
> > status = PCI_ERS_RESULT_RECOVERED;
> > pci_dbg(dev, "broadcast mmio_enabled message\n");
> > - pci_bridge_walk(bridge, report_mmio_enabled, &status);
> > + pci_bridge_walk(bridge, dev, report_mmio_enabled, &status);
> > }
> >
> > if (status == PCI_ERS_RESULT_NEED_RESET) {
> > @@ -236,18 +248,16 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
> > */
> > status = PCI_ERS_RESULT_RECOVERED;
> > pci_dbg(dev, "broadcast slot_reset message\n");
> > - pci_bridge_walk(bridge, report_slot_reset, &status);
> > + pci_bridge_walk(bridge, dev, report_slot_reset, &status);
> > }
> >
> > if (status != PCI_ERS_RESULT_RECOVERED)
> > goto failed;
> >
> > pci_dbg(dev, "broadcast resume message\n");
> > - pci_bridge_walk(bridge, report_resume, &status);
> > + pci_bridge_walk(bridge, dev, report_resume, &status);
> >
> > - if (type == PCI_EXP_TYPE_ROOT_PORT ||
> > - type == PCI_EXP_TYPE_DOWNSTREAM ||
> > - type == PCI_EXP_TYPE_RC_EC) {
> > + if (bridge) {
> > if (pcie_aer_is_native(bridge))
> > pcie_clear_device_status(bridge);
> > pci_aer_clear_nonfatal_status(bridge);
>
>