diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 5b9e4e79c3ae39640f808cc2f3f0f46d9f50347d..0c32283b3276cc26adca449ada1f9b474969ac7b 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -178,6 +178,8 @@ #define MSI_IRQ_NUM 32 +#define CFG_RD_CRS_VAL 0xffff0001 + struct advk_pcie { struct platform_device *pdev; void __iomem *base; @@ -473,7 +475,7 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie) advk_writel(pcie, reg, PCIE_CORE_CMD_STATUS_REG); } -static int advk_pcie_check_pio_status(struct advk_pcie *pcie, u32 *val) +static int advk_pcie_check_pio_status(struct advk_pcie *pcie, bool allow_crs, u32 *val) { struct device *dev = &pcie->pdev->dev; u32 reg; @@ -515,9 +517,30 @@ static int advk_pcie_check_pio_status(struct advk_pcie *pcie, u32 *val) strcomp_status = "UR"; break; case PIO_COMPLETION_STATUS_CRS: + if (allow_crs && val) { + /* PCIe r4.0, sec 2.3.2, says: + * If CRS Software Visibility is enabled: + * For a Configuration Read Request that includes both + * bytes of the Vendor ID field of a device Function's + * Configuration Space Header, the Root Complex must + * complete the Request to the host by returning a + * read-data value of 0001h for the Vendor ID field and + * all '1's for any additional bytes included in the + * request. + * + * So CRS in this case is not an error status. + */ + *val = CFG_RD_CRS_VAL; + strcomp_status = NULL; + break; + } /* PCIe r4.0, sec 2.3.2, says: * If CRS Software Visibility is not enabled, the Root Complex * must re-issue the Configuration Request as a new Request. + * If CRS Software Visibility is enabled: For a Configuration + * Write Request or for any other Configuration Read Request, + * the Root Complex must re-issue the Configuration Request as + * a new Request. * A Root Complex implementation may choose to limit the number * of Configuration Request/CRS Completion Status loops before * determining that something is wrong with the target of the @@ -586,6 +609,7 @@ advk_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge, case PCI_EXP_RTCTL: { u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG); *value = (val & PCIE_MSG_PM_PME_MASK) ? 0 : PCI_EXP_RTCTL_PMEIE; + *value |= PCI_EXP_RTCAP_CRSVIS << 16; return PCI_BRIDGE_EMUL_HANDLED; } @@ -667,6 +691,7 @@ static struct pci_bridge_emul_ops advk_pci_bridge_emul_ops = { static int advk_sw_pci_bridge_init(struct advk_pcie *pcie) { struct pci_bridge_emul *bridge = &pcie->bridge; + int ret; bridge->conf.vendor = cpu_to_le16(advk_readl(pcie, PCIE_CORE_DEV_ID_REG) & 0xffff); @@ -690,7 +715,15 @@ static int advk_sw_pci_bridge_init(struct advk_pcie *pcie) bridge->data = pcie; bridge->ops = &advk_pci_bridge_emul_ops; - return pci_bridge_emul_init(bridge, 0); + /* PCIe config space can be initialized after pci_bridge_emul_init() */ + ret = pci_bridge_emul_init(bridge, 0); + if (ret < 0) + return ret; + + /* Indicates supports for Completion Retry Status */ + bridge->pcie_conf.rootcap = cpu_to_le16(PCI_EXP_RTCAP_CRSVIS); + + return 0; } static bool advk_pcie_valid_device(struct advk_pcie *pcie, struct pci_bus *bus, @@ -742,6 +775,7 @@ static int advk_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where, int size, u32 *val) { struct advk_pcie *pcie = bus->sysdata; + bool allow_crs; u32 reg; int ret; @@ -754,7 +788,24 @@ static int advk_pcie_rd_conf(struct pci_bus *bus, u32 devfn, return pci_bridge_emul_conf_read(&pcie->bridge, where, size, val); + /* + * Completion Retry Status is possible to return only when reading all + * 4 bytes from PCI_VENDOR_ID and PCI_DEVICE_ID registers at once and + * CRSSVE flag on Root Bridge is enabled. + */ + allow_crs = (where == PCI_VENDOR_ID) && (size == 4) && + (le16_to_cpu(pcie->bridge.pcie_conf.rootctl) & + PCI_EXP_RTCTL_CRSSVE); + if (advk_pcie_pio_is_running(pcie)) { + /* + * If it is possible return Completion Retry Status so caller + * tries to issue the request again instead of failing. + */ + if (allow_crs) { + *val = CFG_RD_CRS_VAL; + return PCIBIOS_SUCCESSFUL; + } *val = 0xffffffff; return PCIBIOS_SET_FAILED; } @@ -782,12 +833,20 @@ static int advk_pcie_rd_conf(struct pci_bus *bus, u32 devfn, ret = advk_pcie_wait_pio(pcie); if (ret < 0) { + /* + * If it is possible return Completion Retry Status so caller + * tries to issue the request again instead of failing. + */ + if (allow_crs) { + *val = CFG_RD_CRS_VAL; + return PCIBIOS_SUCCESSFUL; + } *val = 0xffffffff; return PCIBIOS_SET_FAILED; } /* Check PIO status and get the read result */ - ret = advk_pcie_check_pio_status(pcie, val); + ret = advk_pcie_check_pio_status(pcie, allow_crs, val); if (ret < 0) { *val = 0xffffffff; return PCIBIOS_SET_FAILED; @@ -856,7 +915,7 @@ static int advk_pcie_wr_conf(struct pci_bus *bus, u32 devfn, if (ret < 0) return PCIBIOS_SET_FAILED; - ret = advk_pcie_check_pio_status(pcie, NULL); + ret = advk_pcie_check_pio_status(pcie, false, NULL); if (ret < 0) return PCIBIOS_SET_FAILED;