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-rw-r--r--drivers/pci/pci.c39
-rw-r--r--include/linux/pci.h2
2 files changed, 40 insertions, 1 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 225cec964f25..13605261a881 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4980,6 +4980,44 @@ static int pci_reset_bus_function(struct pci_dev *dev, bool probe)
return pci_parent_bus_reset(dev, probe);
}
+static int cxl_reset_bus_function(struct pci_dev *dev, bool probe)
+{
+ struct pci_dev *bridge;
+ u16 dvsec, reg, val;
+ int rc;
+
+ bridge = pci_upstream_bridge(dev);
+ if (!bridge)
+ return -ENOTTY;
+
+ dvsec = cxl_port_dvsec(bridge);
+ if (!dvsec)
+ return -ENOTTY;
+
+ if (probe)
+ return 0;
+
+ rc = pci_read_config_word(bridge, dvsec + PCI_DVSEC_CXL_PORT_CTL, &reg);
+ if (rc)
+ return -ENOTTY;
+
+ if (reg & PCI_DVSEC_CXL_PORT_CTL_UNMASK_SBR) {
+ val = reg;
+ } else {
+ val = reg | PCI_DVSEC_CXL_PORT_CTL_UNMASK_SBR;
+ pci_write_config_word(bridge, dvsec + PCI_DVSEC_CXL_PORT_CTL,
+ val);
+ }
+
+ rc = pci_reset_bus_function(dev, probe);
+
+ if (reg != val)
+ pci_write_config_word(bridge, dvsec + PCI_DVSEC_CXL_PORT_CTL,
+ reg);
+
+ return rc;
+}
+
void pci_dev_lock(struct pci_dev *dev)
{
/* block PM suspend, driver probe, etc. */
@@ -5064,6 +5102,7 @@ static const struct pci_reset_fn_method pci_reset_fn_methods[] = {
{ pci_af_flr, .name = "af_flr" },
{ pci_pm_reset, .name = "pm" },
{ pci_reset_bus_function, .name = "bus" },
+ { cxl_reset_bus_function, .name = "cxl_bus" },
};
static ssize_t reset_method_show(struct device *dev,
diff --git a/include/linux/pci.h b/include/linux/pci.h
index e4e7b175af54..b06c1c0ec9bd 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -51,7 +51,7 @@
PCI_STATUS_PARITY)
/* Number of reset methods used in pci_reset_fn_methods array in pci.c */
-#define PCI_NUM_RESET_METHODS 7
+#define PCI_NUM_RESET_METHODS 8
#define PCI_RESET_PROBE true
#define PCI_RESET_DO_RESET false