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-rw-r--r--drivers/pci/ats.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index 5b78f3b1b918..420cd0a578d0 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -368,6 +368,36 @@ int pci_pasid_features(struct pci_dev *pdev)
}
EXPORT_SYMBOL_GPL(pci_pasid_features);
+/**
+ * pci_prg_resp_pasid_required - Return PRG Response PASID Required bit
+ * status.
+ * @pdev: PCI device structure
+ *
+ * Returns 1 if PASID is required in PRG Response Message, 0 otherwise.
+ *
+ * Even though the PRG response PASID status is read from PRI Status
+ * Register, since this API will mainly be used by PASID users, this
+ * function is defined within #ifdef CONFIG_PCI_PASID instead of
+ * CONFIG_PCI_PRI.
+ */
+int pci_prg_resp_pasid_required(struct pci_dev *pdev)
+{
+ u16 status;
+ int pos;
+
+ pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
+ if (!pos)
+ return 0;
+
+ pci_read_config_word(pdev, pos + PCI_PRI_STATUS, &status);
+
+ if (status & PCI_PRI_STATUS_PASID)
+ return 1;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pci_prg_resp_pasid_required);
+
#define PASID_NUMBER_SHIFT 8
#define PASID_NUMBER_MASK (0x1f << PASID_NUMBER_SHIFT)
/**