| Message ID | 017c1ec8e3f43f86a947eaddb30c9389e0b1053b.1434154377.git.dhdang@apm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
Hi, On Fri, Jun 12, 2015 at 5:35 PM, Duc Dang <dhdang@apm.com> wrote: > X-Gene v1 PCIe controller has a bug in Configuration Request Retry > Status (CRS) logic: > When CPU tries to read Vendor ID and Device ID of not-existed > remote device, the controller returns 0xFFFF0001 instead of > 0xFFFFFFFF; this will add significant delay in boot time as > pci_bus_read_dev_vendor_id will wait for 60 seconds before > giving up. > > So for X-Gene v1 PCIe controllers, disable CRS capability > advertisement by clearing CRS Software Visibility bit before > returning the Root Capability value to the callers. This is done > by implementing X-Gene PCIe specific xgene_pcie_config_read32 for > CFG read accesses to replace the generic default pci_generic_config_read32 > function. > > v2 changes: > Use pci_generic_config_read32 to implement xgene_pcie_config_read32 > > Signed-off-by: Duc Dang <dhdang@apm.com> > Tested-by: Ian Campbell <ian.campbell@citrix.com> > Tested-by: Marcin Juszkiewicz <mjuszkiewicz@redhat.com> Acked-by: Tanmay Inamdar <tinamdar@apm.com > --- > drivers/pci/host/pci-xgene.c | 43 ++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 42 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/host/pci-xgene.c b/drivers/pci/host/pci-xgene.c > index e6c8864..7e3cf28 100644 > --- a/drivers/pci/host/pci-xgene.c > +++ b/drivers/pci/host/pci-xgene.c > @@ -59,6 +59,12 @@ > #define SZ_1T (SZ_1G*1024ULL) > #define PIPE_PHY_RATE_RD(src) ((0xc000 & (u32)(src)) >> 0xe) > > +#define ROOT_CAP_AND_CTRL 0x5C > + > +/* PCIe IP version */ > +#define XGENE_PCIE_IP_VER_UNKN 0 > +#define XGENE_PCIE_IP_VER_1 1 > + > struct xgene_pcie_port { > struct device_node *node; > struct device *dev; > @@ -67,6 +73,7 @@ struct xgene_pcie_port { > void __iomem *cfg_base; > unsigned long cfg_addr; > bool link_up; > + u32 version; > }; > > static inline u32 pcie_bar_low_val(u32 addr, u32 flags) > @@ -140,9 +147,39 @@ static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn, > return xgene_pcie_get_cfg_base(bus) + offset; > } > > +int xgene_pcie_config_read32(struct pci_bus *bus, unsigned int devfn, > + int where, int size, u32 *val) > +{ > + struct xgene_pcie_port *port = bus->sysdata; > + > + if (pci_generic_config_read32(bus, devfn, where & ~0x3, 4, val) != > + PCIBIOS_SUCCESSFUL) > + return PCIBIOS_DEVICE_NOT_FOUND; > + /* > + * X-Gene v1 PCIe controller has a bug in Configuration Request > + * Retry Status (CRS) logic: > + * When CPU tries to read Vendor ID and Device ID of not-existed > + * remote device, the controller returns 0xFFFF0001 instead of > + * 0xFFFFFFFF; this will add significant delay in boot time as > + * pci_bus_read_dev_vendor_id will wait for 60 seconds before > + * giving up. > + * So for X-Gene v1 PCIe controllers, disable CRS capability > + * advertisement by clearing CRS Software Visibility bit before > + * returning the Root Capability value to the callers. > + */ > + if (pci_is_root_bus(bus) && (port->version == XGENE_PCIE_IP_VER_1) && > + ((where & ~0x3) == ROOT_CAP_AND_CTRL)) > + *val &= ~(PCI_EXP_RTCAP_CRSVIS << 16); > + > + if (size <= 2) > + *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1); > + > + return PCIBIOS_SUCCESSFUL; > +} > + > static struct pci_ops xgene_pcie_ops = { > .map_bus = xgene_pcie_map_bus, > - .read = pci_generic_config_read32, > + .read = xgene_pcie_config_read32, > .write = pci_generic_config_write32, > }; > > @@ -500,6 +537,10 @@ static int xgene_pcie_probe_bridge(struct platform_device *pdev) > port->node = of_node_get(pdev->dev.of_node); > port->dev = &pdev->dev; > > + port->version = XGENE_PCIE_IP_VER_UNKN; > + if (of_device_is_compatible(port->node, "apm,xgene-pcie")) > + port->version = XGENE_PCIE_IP_VER_1; > + > ret = xgene_pcie_map_reg(port, pdev); > if (ret) > return ret; > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pci/host/pci-xgene.c b/drivers/pci/host/pci-xgene.c index e6c8864..7e3cf28 100644 --- a/drivers/pci/host/pci-xgene.c +++ b/drivers/pci/host/pci-xgene.c @@ -59,6 +59,12 @@ #define SZ_1T (SZ_1G*1024ULL) #define PIPE_PHY_RATE_RD(src) ((0xc000 & (u32)(src)) >> 0xe) +#define ROOT_CAP_AND_CTRL 0x5C + +/* PCIe IP version */ +#define XGENE_PCIE_IP_VER_UNKN 0 +#define XGENE_PCIE_IP_VER_1 1 + struct xgene_pcie_port { struct device_node *node; struct device *dev; @@ -67,6 +73,7 @@ struct xgene_pcie_port { void __iomem *cfg_base; unsigned long cfg_addr; bool link_up; + u32 version; }; static inline u32 pcie_bar_low_val(u32 addr, u32 flags) @@ -140,9 +147,39 @@ static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn, return xgene_pcie_get_cfg_base(bus) + offset; } +int xgene_pcie_config_read32(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 *val) +{ + struct xgene_pcie_port *port = bus->sysdata; + + if (pci_generic_config_read32(bus, devfn, where & ~0x3, 4, val) != + PCIBIOS_SUCCESSFUL) + return PCIBIOS_DEVICE_NOT_FOUND; + /* + * X-Gene v1 PCIe controller has a bug in Configuration Request + * Retry Status (CRS) logic: + * When CPU tries to read Vendor ID and Device ID of not-existed + * remote device, the controller returns 0xFFFF0001 instead of + * 0xFFFFFFFF; this will add significant delay in boot time as + * pci_bus_read_dev_vendor_id will wait for 60 seconds before + * giving up. + * So for X-Gene v1 PCIe controllers, disable CRS capability + * advertisement by clearing CRS Software Visibility bit before + * returning the Root Capability value to the callers. + */ + if (pci_is_root_bus(bus) && (port->version == XGENE_PCIE_IP_VER_1) && + ((where & ~0x3) == ROOT_CAP_AND_CTRL)) + *val &= ~(PCI_EXP_RTCAP_CRSVIS << 16); + + if (size <= 2) + *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1); + + return PCIBIOS_SUCCESSFUL; +} + static struct pci_ops xgene_pcie_ops = { .map_bus = xgene_pcie_map_bus, - .read = pci_generic_config_read32, + .read = xgene_pcie_config_read32, .write = pci_generic_config_write32, }; @@ -500,6 +537,10 @@ static int xgene_pcie_probe_bridge(struct platform_device *pdev) port->node = of_node_get(pdev->dev.of_node); port->dev = &pdev->dev; + port->version = XGENE_PCIE_IP_VER_UNKN; + if (of_device_is_compatible(port->node, "apm,xgene-pcie")) + port->version = XGENE_PCIE_IP_VER_1; + ret = xgene_pcie_map_reg(port, pdev); if (ret) return ret;
X-Gene v1 PCIe controller has a bug in Configuration Request Retry Status (CRS) logic: When CPU tries to read Vendor ID and Device ID of not-existed remote device, the controller returns 0xFFFF0001 instead of 0xFFFFFFFF; this will add significant delay in boot time as pci_bus_read_dev_vendor_id will wait for 60 seconds before giving up. So for X-Gene v1 PCIe controllers, disable CRS capability advertisement by clearing CRS Software Visibility bit before returning the Root Capability value to the callers. This is done by implementing X-Gene PCIe specific xgene_pcie_config_read32 for CFG read accesses to replace the generic default pci_generic_config_read32 function. v2 changes: Use pci_generic_config_read32 to implement xgene_pcie_config_read32 Signed-off-by: Duc Dang <dhdang@apm.com> Tested-by: Ian Campbell <ian.campbell@citrix.com> Tested-by: Marcin Juszkiewicz <mjuszkiewicz@redhat.com> --- drivers/pci/host/pci-xgene.c | 43 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-)