platform/x86/intel/vsec: Restore BAR fallback for header walk

The base_addr refactor changed intel_vsec_walk_header() to pass
info->base_addr as the discovery-table base address. For the PCI VSEC
driver this info comes from driver_data, but exported callers may provide
their own static headers and leave base_addr unset.

For xe, this made the discovery-table base address zero instead of the BAR
selected by header->tbir, preventing PMT endpoints from being created.

Restore the previous behavior for the header-walk path by falling back to
pci_resource_start(pdev, header->tbir) when base_addr is not specified.
Keep explicit base_addr override behavior unchanged.

This preserves the refactor structure while fixing the functional
regression in manual-header users.

Fixes: 904b333fc51c ("platform/x86/intel/vsec: Refactor base_addr handling")
Assisted-by: Claude:claude-sonnet-4-6
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Link: https://patch.msgid.link/20260529183150.129744-1-david.e.box@linux.intel.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/drivers/platform/x86/intel/vsec.c b/drivers/platform/x86/intel/vsec.c
index 1657834fd275972b37190d15fb9af4cb63975bd2..3ae4557b32b478dab273618fe169e700813a185e 100644 (file)
--- a/drivers/platform/x86/intel/vsec.c
+++ b/drivers/platform/x86/intel/vsec.c
@@ -482,10 +482,25 @@ static int intel_vsec_walk_header(struct device *dev,
                                  const struct intel_vsec_platform_info *info)
 {
        struct intel_vsec_header **header = info->headers;
+       u64 base_addr;
        int ret;
 
        for ( ; *header; header++) {
-               ret = intel_vsec_register_device(dev, *header, info, info->base_addr);
+               if (info->base_addr) {
+                       base_addr = info->base_addr;
+               } else {
+                       struct pci_dev *pdev;
+
+                       if (!dev_is_pci(dev)) {
+                               dev_err(dev, "non-PCI device without a base address\n");
+                               return -EINVAL;
+                       }
+
+                       pdev = to_pci_dev(dev);
+                       base_addr = pci_resource_start(pdev, (*header)->tbir);
+               }
+
+               ret = intel_vsec_register_device(dev, *header, info, base_addr);
                if (ret)
                        return ret;
        }