Merge tag 'dmaengine-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul...

[platform/kernel/linux-starfive.git] / drivers / pci / pci.c

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index f4c26e6..1027f18 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -693,6 +693,36 @@ u8 pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
 EXPORT_SYMBOL_GPL(pci_find_ht_capability);
 
 /**
+ * pci_find_vsec_capability - Find a vendor-specific extended capability
+ * @dev: PCI device to query
+ * @vendor: Vendor ID for which capability is defined
+ * @cap: Vendor-specific capability ID
+ *
+ * If @dev has Vendor ID @vendor, search for a VSEC capability with
+ * VSEC ID @cap. If found, return the capability offset in
+ * config space; otherwise return 0.
+ */
+u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap)
+{
+       u16 vsec = 0;
+       u32 header;
+
+       if (vendor != dev->vendor)
+               return 0;
+
+       while ((vsec = pci_find_next_ext_capability(dev, vsec,
+                                                    PCI_EXT_CAP_ID_VNDR))) {
+               if (pci_read_config_dword(dev, vsec + PCI_VNDR_HEADER,
+                                         &header) == PCIBIOS_SUCCESSFUL &&
+                   PCI_VNDR_HEADER_ID(header) == cap)
+                       return vsec;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(pci_find_vsec_capability);
+
+/**
  * pci_find_parent_resource - return resource region of parent bus of given
  *                           region
  * @dev: PCI device structure contains resources to be searched