| Message ID | 1528762867-16823-5-git-send-email-ray.jui@broadcom.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On 2018-06-12 05:51, Ray Jui wrote: > PAXC is an emulated PCIe root complex internally in various Broadcom > based SoCs. PAXC internally connects to the embedded network processor > within these SoCs, with the embedeed network processor exposed as an > endpoint device > > The number of physical functions from the embedded network processor > that can be accessed depend on the firmware configuration. > Unfortunately, due to an ASIC bug, unconfigured physical functions > cannot > be properly hidden from the root complex during enumerattion. As a > result, config write access to these unconfigured physical functions > during enumeration will cause a bus lock up on the embedded network > processor > > Fortunately, these unconfigured physical functions contain a very > specific, staled PCIe device ID 0x168e. By making use of this device > ID, > one is able to terminate the enumeration early in the vendor/device ID > config read > > Signed-off-by: Ray Jui <ray.jui@broadcom.com> > Reviewed-by: Scott Branden <scott.branden@broadcom.com> > --- > drivers/pci/host/pcie-iproc.c | 26 +++++++++++++++++++++++++- > drivers/pci/host/pcie-iproc.h | 5 +++++ > 2 files changed, 30 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/host/pcie-iproc.c > b/drivers/pci/host/pcie-iproc.c > index 0804aa2..59be1e0 100644 > --- a/drivers/pci/host/pcie-iproc.c > +++ b/drivers/pci/host/pcie-iproc.c > @@ -582,6 +582,25 @@ static int iproc_pcie_config_read(struct pci_bus > *bus, unsigned int devfn, > if (size <= 2) > *val = (data >> (8 * (where & 3))) & ((1 << (size * 8)) - 1); > > + /* > + * For PAXC and PAXCv2, the total number of PFs that one can > enumerate > + * depends on the firmware configuration. Unfortunately, due to an > ASIC > + * bug, unconfigured PFs cannot be properly hidden from the root > + * complex. As a result, write access to these PFs will cause bus > lock > + * up on the embedded processor > + * > + * Since all unconfigured PFs are left with an incorrect, staled > device > + * ID of 0x168e (PCI_DEVICE_ID_NX2_57810), we try to catch those > access > + * early here and reject them all > + */ > +#define DEVICE_ID_MASK 0xffff0000 > +#define DEVICE_ID_SHIFT 16 > + if (pcie->rej_unconfig_pf && > + (where & CFG_ADDR_REG_NUM_MASK) == PCI_VENDOR_ID) > + if ((*val & DEVICE_ID_MASK) == > + (PCI_DEVICE_ID_NX2_57810 << DEVICE_ID_SHIFT)) > + return PCIBIOS_FUNC_NOT_SUPPORTED; > + > return PCIBIOS_SUCCESSFUL; > } > > @@ -681,7 +700,7 @@ static int iproc_pcie_config_read32(struct pci_bus > *bus, unsigned int devfn, > struct iproc_pcie *pcie = iproc_data(bus); > > iproc_pcie_apb_err_disable(bus, true); > - if (pcie->type == IPROC_PCIE_PAXB_V2) > + if (pcie->iproc_cfg_read) > ret = iproc_pcie_config_read(bus, devfn, where, size, val); > else > ret = pci_generic_config_read32(bus, devfn, where, size, val); > @@ -1336,6 +1355,7 @@ static int iproc_pcie_rev_init(struct iproc_pcie > *pcie) > break; > case IPROC_PCIE_PAXB: > regs = iproc_pcie_reg_paxb; > + pcie->iproc_cfg_read = true; > pcie->has_apb_err_disable = true; > if (pcie->need_ob_cfg) { > pcie->ob_map = paxb_ob_map; > @@ -1358,10 +1378,14 @@ static int iproc_pcie_rev_init(struct > iproc_pcie *pcie) > case IPROC_PCIE_PAXC: > regs = iproc_pcie_reg_paxc; > pcie->ep_is_internal = true; > + pcie->iproc_cfg_read = true; > + pcie->rej_unconfig_pf = true; > break; > case IPROC_PCIE_PAXC_V2: > regs = iproc_pcie_reg_paxc_v2; > pcie->ep_is_internal = true; > + pcie->iproc_cfg_read = true; > + pcie->rej_unconfig_pf = true; > pcie->need_msi_steer = true; > break; > default: > diff --git a/drivers/pci/host/pcie-iproc.h > b/drivers/pci/host/pcie-iproc.h > index 9d5cfee..4f03ea5 100644 > --- a/drivers/pci/host/pcie-iproc.h > +++ b/drivers/pci/host/pcie-iproc.h > @@ -58,6 +58,9 @@ struct iproc_msi; > * @phy: optional PHY device that controls the Serdes > * @map_irq: function callback to map interrupts > * @ep_is_internal: indicates an internal emulated endpoint device is > connected > + * @iproc_cfg_read: indicates the iProc config read function should be > used > + * @rej_unconfig_pf: indicates the root complex needs to detect and > reject > + * enumeration against unconfigured physical functions emulated in the > ASIC > * @has_apb_err_disable: indicates the controller can be configured to > prevent > * unsupported request from being forwarded as an APB bus error > * @fix_paxc_cap: indicates the controller has corrupted capability > list in its > @@ -86,6 +89,8 @@ struct iproc_pcie { > struct phy *phy; > int (*map_irq)(const struct pci_dev *, u8, u8); > bool ep_is_internal; > + bool iproc_cfg_read; > + bool rej_unconfig_pf; > bool has_apb_err_disable; > bool fix_paxc_cap; Reviewed-by: Oza Pawandeep <poza@codeaurora.org>
diff --git a/drivers/pci/host/pcie-iproc.c b/drivers/pci/host/pcie-iproc.c index 0804aa2..59be1e0 100644 --- a/drivers/pci/host/pcie-iproc.c +++ b/drivers/pci/host/pcie-iproc.c @@ -582,6 +582,25 @@ static int iproc_pcie_config_read(struct pci_bus *bus, unsigned int devfn, if (size <= 2) *val = (data >> (8 * (where & 3))) & ((1 << (size * 8)) - 1); + /* + * For PAXC and PAXCv2, the total number of PFs that one can enumerate + * depends on the firmware configuration. Unfortunately, due to an ASIC + * bug, unconfigured PFs cannot be properly hidden from the root + * complex. As a result, write access to these PFs will cause bus lock + * up on the embedded processor + * + * Since all unconfigured PFs are left with an incorrect, staled device + * ID of 0x168e (PCI_DEVICE_ID_NX2_57810), we try to catch those access + * early here and reject them all + */ +#define DEVICE_ID_MASK 0xffff0000 +#define DEVICE_ID_SHIFT 16 + if (pcie->rej_unconfig_pf && + (where & CFG_ADDR_REG_NUM_MASK) == PCI_VENDOR_ID) + if ((*val & DEVICE_ID_MASK) == + (PCI_DEVICE_ID_NX2_57810 << DEVICE_ID_SHIFT)) + return PCIBIOS_FUNC_NOT_SUPPORTED; + return PCIBIOS_SUCCESSFUL; } @@ -681,7 +700,7 @@ static int iproc_pcie_config_read32(struct pci_bus *bus, unsigned int devfn, struct iproc_pcie *pcie = iproc_data(bus); iproc_pcie_apb_err_disable(bus, true); - if (pcie->type == IPROC_PCIE_PAXB_V2) + if (pcie->iproc_cfg_read) ret = iproc_pcie_config_read(bus, devfn, where, size, val); else ret = pci_generic_config_read32(bus, devfn, where, size, val); @@ -1336,6 +1355,7 @@ static int iproc_pcie_rev_init(struct iproc_pcie *pcie) break; case IPROC_PCIE_PAXB: regs = iproc_pcie_reg_paxb; + pcie->iproc_cfg_read = true; pcie->has_apb_err_disable = true; if (pcie->need_ob_cfg) { pcie->ob_map = paxb_ob_map; @@ -1358,10 +1378,14 @@ static int iproc_pcie_rev_init(struct iproc_pcie *pcie) case IPROC_PCIE_PAXC: regs = iproc_pcie_reg_paxc; pcie->ep_is_internal = true; + pcie->iproc_cfg_read = true; + pcie->rej_unconfig_pf = true; break; case IPROC_PCIE_PAXC_V2: regs = iproc_pcie_reg_paxc_v2; pcie->ep_is_internal = true; + pcie->iproc_cfg_read = true; + pcie->rej_unconfig_pf = true; pcie->need_msi_steer = true; break; default: diff --git a/drivers/pci/host/pcie-iproc.h b/drivers/pci/host/pcie-iproc.h index 9d5cfee..4f03ea5 100644 --- a/drivers/pci/host/pcie-iproc.h +++ b/drivers/pci/host/pcie-iproc.h @@ -58,6 +58,9 @@ struct iproc_msi; * @phy: optional PHY device that controls the Serdes * @map_irq: function callback to map interrupts * @ep_is_internal: indicates an internal emulated endpoint device is connected + * @iproc_cfg_read: indicates the iProc config read function should be used + * @rej_unconfig_pf: indicates the root complex needs to detect and reject + * enumeration against unconfigured physical functions emulated in the ASIC * @has_apb_err_disable: indicates the controller can be configured to prevent * unsupported request from being forwarded as an APB bus error * @fix_paxc_cap: indicates the controller has corrupted capability list in its @@ -86,6 +89,8 @@ struct iproc_pcie { struct phy *phy; int (*map_irq)(const struct pci_dev *, u8, u8); bool ep_is_internal; + bool iproc_cfg_read; + bool rej_unconfig_pf; bool has_apb_err_disable; bool fix_paxc_cap;