On Fri, 18 Sep 2020 13:45:59 -0700
Sean V Kelley <sean.v.kelley@xxxxxxxxx> wrote:
> A Root Complex Event Collector provides support for
> terminating error and PME messages from associated RCiEPs.
>
> Make use of the RCEC Endpoint Association Extended Capability
> to identify associated RCiEPs. Link the associated RCiEPs as
> the RCECs are enumerated.
>
> Co-developed-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>
> Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>
> Signed-off-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx>
A couple of minor things inline plus follow through on not
special casing the older versions of the capability.
Otherwise looks good to me.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> ---
> drivers/pci/pci.h | 2 +
> drivers/pci/pcie/portdrv_pci.c | 3 ++
> drivers/pci/pcie/rcec.c | 96 ++++++++++++++++++++++++++++++++++
> include/linux/pci.h | 1 +
> 4 files changed, 102 insertions(+)
>
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 7b547fc3679a..ddb5872466fb 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -474,9 +474,11 @@ static inline void pci_dpc_init(struct pci_dev *pdev) {}
> #ifdef CONFIG_PCIEPORTBUS
> void pci_rcec_init(struct pci_dev *dev);
> void pci_rcec_exit(struct pci_dev *dev);
> +void pcie_link_rcec(struct pci_dev *rcec);
> #else
> static inline void pci_rcec_init(struct pci_dev *dev) {}
> static inline void pci_rcec_exit(struct pci_dev *dev) {}
> +static inline void pcie_link_rcec(struct pci_dev *rcec) {}
> #endif
>
> #ifdef CONFIG_PCI_ATS
> diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c
> index 4d880679b9b1..dbeb0155c2c3 100644
> --- a/drivers/pci/pcie/portdrv_pci.c
> +++ b/drivers/pci/pcie/portdrv_pci.c
> @@ -110,6 +110,9 @@ static int pcie_portdrv_probe(struct pci_dev *dev,
> (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_EC)))
> return -ENODEV;
>
> + if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC)
> + pcie_link_rcec(dev);
> +
> status = pcie_port_device_register(dev);
> if (status)
> return status;
> diff --git a/drivers/pci/pcie/rcec.c b/drivers/pci/pcie/rcec.c
> index 519ae086ff41..5630480a6659 100644
> --- a/drivers/pci/pcie/rcec.c
> +++ b/drivers/pci/pcie/rcec.c
> @@ -17,6 +17,102 @@
>
> #include "../pci.h"
>
> +struct walk_rcec_data {
> + struct pci_dev *rcec;
> + int (*user_callback)(struct pci_dev *dev, void *data);
> + void *user_data;
> +};
> +
> +static bool rcec_assoc_rciep(struct pci_dev *rcec, struct pci_dev *rciep)
> +{
> + unsigned long bitmap = rcec->rcec_ext->bitmap;
> + unsigned int devn;
> +
> + /* An RCiEP found on bus in range */
Perhaps adjust the comment to say:
/* An RCiEP found on a different bus in range */
as the actual rcec bus can be in the range as I understand it.
> + if (rcec->bus->number != rciep->bus->number)
> + return true;
> +
> + /* Same bus, so check bitmap */
> + for_each_set_bit(devn, &bitmap, 32)
> + if (devn == rciep->devfn)
> + return true;
> +
> + return false;
> +}
> +
> +static int link_rcec_helper(struct pci_dev *dev, void *data)
> +{
> + struct walk_rcec_data *rcec_data = data;
> + struct pci_dev *rcec = rcec_data->rcec;
> +
> + if ((pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) && rcec_assoc_rciep(rcec, dev)) {
> + dev->rcec = rcec;
> + pci_dbg(dev, "PME & error events reported via %s\n", pci_name(rcec));
> + }
> +
> + return 0;
> +}
> +
> +void walk_rcec(int (*cb)(struct pci_dev *dev, void *data), void *userdata)
static, or declare it in a header if we are going to need it elsewhere
later in the series.
> +{
> + struct walk_rcec_data *rcec_data = userdata;
> + struct pci_dev *rcec = rcec_data->rcec;
> + u8 nextbusn, lastbusn;
> + struct pci_bus *bus;
> + unsigned int bnr;
> +
> + if (!rcec->rcec_cap)
> + return;
> +
> + /* Walk own bus for bitmap based association */
> + pci_walk_bus(rcec->bus, cb, rcec_data);
> +
> + /* Check whether RCEC BUSN register is present */
> + if (rcec->rcec_ext->ver < PCI_RCEC_BUSN_REG_VER)
> + return;
If you make earlier suggested change go fill in nextbusn = 0xFF
for the earlier versions of the capability can avoid special casing
here.
> +
> + nextbusn = rcec->rcec_ext->nextbusn;
> + lastbusn = rcec->rcec_ext->lastbusn;
> +
> + /* All RCiEP devices are on the same bus as the RCEC */
> + if (nextbusn == 0xff && lastbusn == 0x00)
> + return;
> +
> + for (bnr = nextbusn; bnr <= lastbusn; bnr++) {
> + /* No association indicated (PCIe 5.0-1, 7.9.10.3) */
> + if (bnr == rcec->bus->number)
> + continue;
> +
> + bus = pci_find_bus(pci_domain_nr(rcec->bus), bnr);
> + if (!bus)
> + continue;
> +
> + /* Find RCiEP devices on the given bus ranges */
> + pci_walk_bus(bus, cb, rcec_data);
> + }
> +}
> +
> +/**
> + * pcie_link_rcec - Link RCiEP devices associating with RCEC.
> + * @rcec RCEC whose RCiEP devices should be linked.
> + *
> + * Link the given RCEC to each RCiEP device found.
I'm a fusspot on blank lines. The one here doesn't add anything!
> + *
> + */
> +void pcie_link_rcec(struct pci_dev *rcec)
> +{
> + struct walk_rcec_data rcec_data;
> +
> + if (!rcec->rcec_cap)
> + return;
> +
> + rcec_data.rcec = rcec;
> + rcec_data.user_callback = NULL;
> + rcec_data.user_data = NULL;
> +
> + walk_rcec(link_rcec_helper, &rcec_data);
> +}
> +
> void pci_rcec_init(struct pci_dev *dev)
> {
> u32 rcec, hdr, busn;
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 5c5c4eb642b6..ad382a9484ea 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -330,6 +330,7 @@ struct pci_dev {
> #ifdef CONFIG_PCIEPORTBUS
> u16 rcec_cap; /* RCEC capability offset */
> struct rcec_ext *rcec_ext; /* RCEC cached assoc. endpoint extended capabilities */
> + struct pci_dev *rcec; /* Associated RCEC device */
> #endif
> u8 pcie_cap; /* PCIe capability offset */
> u8 msi_cap; /* MSI capability offset */
