platform/x86/intel/vsec: Add intel_vsec_register

Add and export intel_vsec_register() to allow the registration of Intel
extended capabilities from other drivers. Add check to look for memory
conflicts before registering a new capability. Since the vsec provider
may not be a PCI device, add a parent field to
intel_vsec_platform_info() to allow specifying the parent device for
device managed cleanup.

Signed-off-by: Gayatri Kammela <gayatri.kammela@linux.intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20231129222132.2331261-8-david.e.box@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Author: Gayatri Kammela

drivers/platform/x86/intel/vsec.c

@@ -152,9 +152,15 @@ static int intel_vsec_add_dev(struct pci_dev *pdev, struct intel_vsec_header *he
 	struct intel_vsec_device __free(kfree) *intel_vsec_dev = NULL;
 	struct resource __free(kfree) *res = NULL;
 	struct resource *tmp;
+	struct device *parent;
 	unsigned long quirks = info->quirks;
 	int i;
 
+	if (info->parent)
+		parent = info->parent;
+	else
+		parent = &pdev->dev;
+
 	if (!intel_vsec_supported(header->id, info->caps))
 		return -EINVAL;
 
@@ -189,6 +195,12 @@ static int intel_vsec_add_dev(struct pci_dev *pdev, struct intel_vsec_header *he
 			     header->offset + i * (header->entry_size * sizeof(u32));
 		tmp->end = tmp->start + (header->entry_size * sizeof(u32)) - 1;
 		tmp->flags = IORESOURCE_MEM;
+
+		/* Check resource is not in use */
+		if (!request_mem_region(tmp->start, resource_size(tmp), ""))
+			return -EBUSY;
+
+		release_mem_region(tmp->start, resource_size(tmp));
 	}
 
 	intel_vsec_dev->pcidev = pdev;
@@ -205,7 +217,7 @@ static int intel_vsec_add_dev(struct pci_dev *pdev, struct intel_vsec_header *he
 	 * Pass the ownership of intel_vsec_dev and resource within it to
 	 * intel_vsec_add_aux()
 	 */
-	return intel_vsec_add_aux(pdev, &pdev->dev, no_free_ptr(intel_vsec_dev),
+	return intel_vsec_add_aux(pdev, parent, no_free_ptr(intel_vsec_dev),
 				  intel_vsec_name(header->id));
 }
 
@@ -323,6 +335,16 @@ static bool intel_vsec_walk_vsec(struct pci_dev *pdev,
 	return have_devices;
 }
 
+void intel_vsec_register(struct pci_dev *pdev,
+			 struct intel_vsec_platform_info *info)
+{
+	if (!pdev || !info)
+		return;
+
+	intel_vsec_walk_header(pdev, info);
+}
+EXPORT_SYMBOL_NS_GPL(intel_vsec_register, INTEL_VSEC);
+
 static int intel_vsec_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct intel_vsec_platform_info *info;

drivers/platform/x86/intel/vsec.h

@@ -69,6 +69,7 @@ enum intel_vsec_quirks {
 
 /* Platform specific data */
 struct intel_vsec_platform_info {
+	struct device *parent;
 	struct intel_vsec_header **headers;
 	unsigned long caps;
 	unsigned long quirks;
@@ -99,4 +100,7 @@ static inline struct intel_vsec_device *auxdev_to_ivdev(struct auxiliary_device
 {
 	return container_of(auxdev, struct intel_vsec_device, auxdev);
 }
+
+void intel_vsec_register(struct pci_dev *pdev,
+			 struct intel_vsec_platform_info *info);
 #endif