[RFC] ehea: kdump support using new shutdown hook

[Thomas Klein <osstklei@de.ibm.com>]

This patch adds kdump support using the new PPC crash shutdown hook to the
ehea driver. The driver now keeps a list of firmware handles which have to
be freed in case of a crash. The crash handler does the minimum required: it
frees the firmware resource handles plus broadcast/multicast registrations.

Please comment.

Shutdown hook patches:
  http://ozlabs.org/pipermail/linuxppc-dev/2007-December/048058.html
  http://ozlabs.org/pipermail/linuxppc-dev/2007-December/048059.html


Signed-off-by: Thomas Klein <tklein@de.ibm.com>

---
diff -Nurp -X dontdiff linux-2.6.24-rc5/drivers/net/ehea/ehea.h patched_kernel/drivers/net/ehea/ehea.h
--- linux-2.6.24-rc5/drivers/net/ehea/ehea.h	2007-12-11 04:48:43.000000000 +0100
+++ patched_kernel/drivers/net/ehea/ehea.h	2007-12-12 17:30:53.000000000 +0100
@@ -40,7 +40,7 @@
 #include <asm/io.h>
 
 #define DRV_NAME	"ehea"
-#define DRV_VERSION	"EHEA_0083"
+#define DRV_VERSION	"EHEA_0084"
 
 /* eHEA capability flags */
 #define DLPAR_PORT_ADD_REM 1
@@ -386,6 +386,7 @@ struct ehea_port_res {
 
 
 #define EHEA_MAX_PORTS 16
+#define EHEA_MAX_RES_HANDLES (100 * EHEA_MAX_PORTS + 10)
 struct ehea_adapter {
 	u64 handle;
 	struct of_device *ofdev;
@@ -397,6 +398,7 @@ struct ehea_adapter {
 	u64 max_mc_mac;            /* max number of multicast mac addresses */
 	int active_ports;
 	struct list_head list;
+	u64 res_handles[EHEA_MAX_RES_HANDLES];
 };
 
 
diff -Nurp -X dontdiff linux-2.6.24-rc5/drivers/net/ehea/ehea_main.c patched_kernel/drivers/net/ehea/ehea_main.c
--- linux-2.6.24-rc5/drivers/net/ehea/ehea_main.c	2007-12-11 04:48:43.000000000 +0100
+++ patched_kernel/drivers/net/ehea/ehea_main.c	2007-12-12 17:30:53.000000000 +0100
@@ -35,6 +35,7 @@
 #include <linux/if_ether.h>
 #include <linux/notifier.h>
 #include <linux/reboot.h>
+#include <asm-powerpc/kexec.h>
 
 #include <net/ip.h>
 
@@ -2256,6 +2257,33 @@ static int ehea_clean_all_portres(struct
 	return ret;
 }
 
+static void ehea_update_adapter_handles(struct ehea_adapter *adapter)
+{
+	int i, k;
+	int j = 0;
+
+	memset(adapter->res_handles, sizeof(adapter->res_handles), 0);
+
+	for (k = 0; k < EHEA_MAX_PORTS; k++) {
+		struct ehea_port *port = adapter->port[k];
+
+		if (!port || (port->state != EHEA_PORT_UP))
+			continue;
+
+		for(i = 0; i < port->num_def_qps + port->num_add_tx_qps; i++) {
+			struct ehea_port_res *pr = &port->port_res[i];
+
+			adapter->res_handles[j++] = pr->qp->fw_handle;
+			adapter->res_handles[j++] = pr->send_cq->fw_handle;
+			adapter->res_handles[j++] = pr->recv_cq->fw_handle;
+			adapter->res_handles[j++] = pr->eq->fw_handle;
+			adapter->res_handles[j++] = pr->send_mr.handle;
+			adapter->res_handles[j++] = pr->recv_mr.handle;
+		}
+		adapter->res_handles[j++] = port->qp_eq->fw_handle;
+	}
+}
+
 static void ehea_remove_adapter_mr(struct ehea_adapter *adapter)
 {
 	if (adapter->active_ports)
@@ -2318,6 +2346,7 @@ static int ehea_up(struct net_device *de
 
 	ret = 0;
 	port->state = EHEA_PORT_UP;
+	ehea_update_adapter_handles(port->adapter);
 	goto out;
 
 out_free_irqs:
@@ -2387,6 +2416,8 @@ static int ehea_down(struct net_device *
 		ehea_info("Failed freeing resources for %s. ret=%i",
 			  dev->name, ret);
 
+	ehea_update_adapter_handles(port->adapter);
+
 	return ret;
 }
 
@@ -3302,6 +3333,71 @@ static int __devexit ehea_remove(struct 
 	return 0;
 }
 
+void ehea_crash_deregister(void)
+{
+	struct ehea_adapter *adapter;
+	int i;
+	u64 hret;
+	u8 reg_type;
+
+	list_for_each_entry(adapter, &adapter_list, list) {
+		for (i = 0; i < EHEA_MAX_PORTS; i++) {
+			struct ehea_port *port = adapter->port[i];
+			if (port->state == EHEA_PORT_UP) {
+				struct ehea_mc_list *mc_entry = port->mc_list;
+				struct list_head *pos;
+				struct list_head *temp;
+
+				/* Undo multicast registrations */
+				list_for_each_safe(pos, temp,
+						   &(port->mc_list->list)) {
+					mc_entry = list_entry(pos,
+							    struct ehea_mc_list,
+							    list);
+					ehea_multicast_reg_helper(port,
+							      mc_entry->macaddr,
+							      H_DEREG_BCMC);
+				}
+
+				/* Undo broad registration */
+				reg_type = EHEA_BCMC_BROADCAST |
+					   EHEA_BCMC_UNTAGGED;
+				ehea_h_reg_dereg_bcmc(port->adapter->handle,
+						      port->logical_port_id,
+						      reg_type, port->mac_addr,
+						      0, H_DEREG_BCMC);
+
+				reg_type = EHEA_BCMC_BROADCAST |
+					   EHEA_BCMC_VLANID_ALL;
+				ehea_h_reg_dereg_bcmc(port->adapter->handle,
+						      port->logical_port_id,
+						      reg_type, port->mac_addr,
+						      0, H_DEREG_BCMC);
+			}
+		}
+		for (i = 0; i < EHEA_MAX_RES_HANDLES; i++) {
+			u64 handle = adapter->res_handles[i];
+			if (handle) {
+				hret = ehea_h_free_resource(adapter->handle,
+							    handle,
+							    FORCE_FREE);
+			}
+		}
+
+		if (adapter->neq) {
+			hret = ehea_h_free_resource(adapter->handle,
+						    adapter->neq->fw_handle,
+						    FORCE_FREE);
+		}
+
+		if (adapter->mr.handle) {
+			hret = ehea_h_free_resource(adapter->handle,
+						    adapter->mr.handle,
+						    FORCE_FREE);
+		}
+	}
+}
+
 static int ehea_reboot_notifier(struct notifier_block *nb,
 				unsigned long action, void *unused)
 {
@@ -3373,6 +3469,9 @@ int __init ehea_module_init(void)
 		goto out;
 
 	register_reboot_notifier(&ehea_reboot_nb);
+	ret = crash_shutdown_register(&ehea_crash_deregister);
+	if (ret)
+		ehea_info("failed registering crash handler");
 
 	ret = ibmebus_register_driver(&ehea_driver);
 	if (ret) {
@@ -3386,6 +3485,7 @@ int __init ehea_module_init(void)
 		ehea_error("failed to register capabilities attribute, ret=%d",
 			   ret);
 		unregister_reboot_notifier(&ehea_reboot_nb);
+		crash_shutdown_unregister(&ehea_crash_deregister);
 		ibmebus_unregister_driver(&ehea_driver);
 		goto out;
 	}
@@ -3396,10 +3496,15 @@ out:
 
 static void __exit ehea_module_exit(void)
 {
+	int ret;
+
 	flush_scheduled_work();
 	driver_remove_file(&ehea_driver.driver, &driver_attr_capabilities);
 	ibmebus_unregister_driver(&ehea_driver);
 	unregister_reboot_notifier(&ehea_reboot_nb);
+	ret = crash_shutdown_unregister(&ehea_crash_deregister);
+	if (ret)
+		ehea_info("failed unregistering crash handler");
 	ehea_destroy_busmap();
 }