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path: root/drivers/pci/host/pci-xgene.c
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Diffstat (limited to 'drivers/pci/host/pci-xgene.c')
-rw-r--r--drivers/pci/host/pci-xgene.c66
1 files changed, 62 insertions, 4 deletions
diff --git a/drivers/pci/host/pci-xgene.c b/drivers/pci/host/pci-xgene.c
index ee082c036..a9dfb70d6 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)
@@ -130,9 +137,7 @@ static bool xgene_pcie_hide_rc_bars(struct pci_bus *bus, int offset)
static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
int offset)
{
- struct xgene_pcie_port *port = bus->sysdata;
-
- if ((pci_is_root_bus(bus) && devfn != 0) || !port->link_up ||
+ if ((pci_is_root_bus(bus) && devfn != 0) ||
xgene_pcie_hide_rc_bars(bus, offset))
return NULL;
@@ -140,9 +145,37 @@ static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
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,
};
@@ -468,6 +501,23 @@ static int xgene_pcie_setup(struct xgene_pcie_port *port,
return 0;
}
+static int xgene_pcie_msi_enable(struct pci_bus *bus)
+{
+ struct device_node *msi_node;
+
+ msi_node = of_parse_phandle(bus->dev.of_node,
+ "msi-parent", 0);
+ if (!msi_node)
+ return -ENODEV;
+
+ bus->msi = of_pci_find_msi_chip_by_node(msi_node);
+ if (!bus->msi)
+ return -ENODEV;
+
+ bus->msi->dev = &bus->dev;
+ return 0;
+}
+
static int xgene_pcie_probe_bridge(struct platform_device *pdev)
{
struct device_node *dn = pdev->dev.of_node;
@@ -483,6 +533,10 @@ 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;
@@ -504,6 +558,10 @@ static int xgene_pcie_probe_bridge(struct platform_device *pdev)
if (!bus)
return -ENOMEM;
+ if (IS_ENABLED(CONFIG_PCI_MSI))
+ if (xgene_pcie_msi_enable(bus))
+ dev_info(port->dev, "failed to enable MSI\n");
+
pci_scan_child_bus(bus);
pci_assign_unassigned_bus_resources(bus);
pci_bus_add_devices(bus);