RDMA/efa: Add shutdown notifier

Add driver function to stop the device and release any active IRQs as
preparation for shutdown. This should fix issues caused by unexpected AQ
interrupts when booting kernel using kexec and possible data integrity
issues when the system is being shutdown during traffic.

Link: https://lore.kernel.org/r/20240425171814.25216-1-mrgolin@amazon.com
Reviewed-by: Firas Jahjah <firasj@amazon.com>
Reviewed-by: Yonatan Nachum <ynachum@amazon.com>
Signed-off-by: Michael Margolin <mrgolin@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Author: mrgolin

drivers/infiniband/hw/efa/efa_main.c

@@ -671,11 +671,22 @@ static void efa_remove(struct pci_dev *pdev)
 	efa_remove_device(pdev);
 }
 
+static void efa_shutdown(struct pci_dev *pdev)
+{
+	struct efa_dev *dev = pci_get_drvdata(pdev);
+
+	efa_destroy_eqs(dev);
+	efa_com_dev_reset(&dev->edev, EFA_REGS_RESET_SHUTDOWN);
+	efa_free_irq(dev, &dev->admin_irq);
+	efa_disable_msix(dev);
+}
+
 static struct pci_driver efa_pci_driver = {
 	.name           = DRV_MODULE_NAME,
 	.id_table       = efa_pci_tbl,
 	.probe          = efa_probe,
 	.remove         = efa_remove,
+	.shutdown       = efa_shutdown,
 };
 
 module_pci_driver(efa_pci_driver);