On Tue, 8 Oct 2024 17:16:54 -0500
Terry Bowman <terry.bowman@xxxxxxx> wrote:
The CXL drivers do not contain error handlers for CXL PCIe portA few comments inline.
device protocol errors. These are needed in order to handle and log
RAS protocol errors.
Add CXL PCIe port protocol error handlers to the CXL driver.
Provide access to RAS registers for the specific CXL PCIe port types:
root port, upstream switch port, and downstream switch port.
Also, register and unregister the CXL PCIe port error handlers with
the AER service driver using register_cxl_port_err_hndlrs() and
unregister_cxl_port_err_hndlrs(). Invoke the registration from
cxl_pci_driver_init() and the unregistration from cxl_pci_driver_exit().
[1] CXL3.1 - 12.2.2 CXL Root Ports, Downstream Switch Ports, and
Upstream Switch Ports
Signed-off-by: Terry Bowman <terry.bowman@xxxxxxx>
Jonathan
---Why would this happen? Seems an odd check to have so maybe a comment.
drivers/cxl/core/pci.c | 83 ++++++++++++++++++++++++++++++++++++++++++
drivers/cxl/cxl.h | 5 +++
drivers/cxl/pci.c | 8 ++++
3 files changed, 96 insertions(+)
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index c3c82c051d73..7e3770f7a955 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -815,6 +815,89 @@ static void cxl_disable_rch_root_ints(struct cxl_dport *dport)
}
}
+static int match_uport(struct device *dev, const void *data)
+{
+ struct device *uport_dev = (struct device *)data;
+ struct cxl_port *port;
+
+ if (!is_cxl_port(dev))
+ return 0;
+
+ port = to_cxl_port(dev);
+
+ return port->uport_dev == uport_dev;
+}
+
+static void __iomem *cxl_pci_port_ras(struct pci_dev *pdev)
+{
+ void __iomem *ras_base;
+ struct cxl_port *port;
+
+ if (!pdev)
+ return NULL;
+Can in theory fail>> + ras_base = dport ? dport->regs.ras : NULL;
+ if ((pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT) ||
+ (pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM)) {
+ struct cxl_dport *dport;
+
+ port = find_cxl_port(&pdev->dev, &dport);
+ put_device(&port->dev);If it fails this is a null pointer dereference.
+ return ras_base;
+ } else if (pci_pcie_type(pdev) == PCI_EXP_TYPE_UPSTREAM) {
+ struct device *port_dev __free(put_device);
Should be combined with the next line. We want it to be hard for anyone
to put code in between!
+
+ port_dev = bus_find_device(&cxl_bus_type, NULL, &pdev->dev, match_uport);
+ if (!port_dev)
+ return NULL;
+
+ port = to_cxl_port(port_dev);
+ if (!port)
+ return NULL;
+
+ ras_base = port ? port->uport_regs.ras : NULL;
Given check above, port exists. Remove one of the two
checks.
+ return ras_base;
+ }
+
+ return NULL;
+}