PCI: xgene: Disable Configuration Request Retry Status for v1 silicon

#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;

	void __iomem		*cfg_base;

	unsigned long		cfg_addr;

	bool			link_up;

	u32			version;

};

static inline u32 pcie_bar_low_val(u32 addr, u32 flags)

	return xgene_pcie_get_cfg_base(bus) + offset;

}

static 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;

	/*

	 * The v1 controller has a bug in its Configuration Request

	 * Retry Status (CRS) logic: when CRS is enabled and we read the

	 * Vendor and Device ID of a non-existent device, the controller

	 * fabricates return data of 0xFFFF0001 ("device exists but is not

	 * ready") instead of 0xFFFFFFFF ("device does not exist").  This

	 * causes the PCI core to retry the read until it times out.

	 * Avoid this by not claiming to support CRS.

	 */

	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,

};

	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;