1 files changed, 80 insertions, 0 deletions
diff --git a/drivers/pci/msi/legacy.c b/drivers/pci/msi/legacy.c
new file mode 100644
index 000000000000..db761adef652
--- /dev/null
+++ b/drivers/pci/msi/legacy.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI Message Signaled Interrupt (MSI).
+ *
+ * Legacy architecture specific setup and teardown mechanism.
+ */
+#include "msi.h"
+
+/* Arch hooks */
+int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
+{
+	return -EINVAL;
+}
+
+void __weak arch_teardown_msi_irq(unsigned int irq)
+{
+}
+
+int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+	struct msi_desc *desc;
+	int ret;
+
+	/*
+	 * If an architecture wants to support multiple MSI, it needs to
+	 * override arch_setup_msi_irqs()
+	 */
+	if (type == PCI_CAP_ID_MSI && nvec > 1)
+		return 1;
+
+	msi_for_each_desc(desc, &dev->dev, MSI_DESC_NOTASSOCIATED) {
+		ret = arch_setup_msi_irq(dev, desc);
+		if (ret)
+			return ret < 0 ? ret : -ENOSPC;
+	}
+
+	return 0;
+}
+
+void __weak arch_teardown_msi_irqs(struct pci_dev *dev)
+{
+	struct msi_desc *desc;
+	int i;
+
+	msi_for_each_desc(desc, &dev->dev, MSI_DESC_ASSOCIATED) {
+		for (i = 0; i < desc->nvec_used; i++)
+			arch_teardown_msi_irq(desc->irq + i);
+	}
+}
+
+static int pci_msi_setup_check_result(struct pci_dev *dev, int type, int ret)
+{
+	struct msi_desc *desc;
+	int avail = 0;
+
+	if (type != PCI_CAP_ID_MSIX || ret >= 0)
+		return ret;
+
+	/* Scan the MSI descriptors for successfully allocated ones. */
+	msi_for_each_desc(desc, &dev->dev, MSI_DESC_ASSOCIATED)
+		avail++;
+
+	return avail ? avail : ret;
+}
+
+int pci_msi_legacy_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+	int ret = arch_setup_msi_irqs(dev, nvec, type);
+
+	ret = pci_msi_setup_check_result(dev, type, ret);
+	if (!ret)
+		ret = msi_device_populate_sysfs(&dev->dev);
+	return ret;
+}
+
+void pci_msi_legacy_teardown_msi_irqs(struct pci_dev *dev)
+{
+	msi_device_destroy_sysfs(&dev->dev);
+	arch_teardown_msi_irqs(dev);
+}