Subject: [patch 1/8] [PATCH] iucv: provide second per-cpu IUCV command parameter block

From: Ursula Braun <[email-masked]>
Date: Wed, 22 Apr 2009 11:26:20 +0200

From: Ursula Braun <[email-masked]>

Some of the IUCV commands can be invoked in interrupt context.
Those commands need a different per-cpu IUCV command parameter block,
otherwise they might overwrite an IUCV command parameter of a not yet
finished IUCV command invocation in process context.

Signed-off-by: Ursula Braun <[email-masked]>
---

 net/iucv/iucv.c |   41 +++++++++++++++++++++++++++++++----------
 1 file changed, 31 insertions(+), 10 deletions(-)

diff -urpN linux-2.6/net/iucv/iucv.c linux-2.6-patched/net/iucv/iucv.c
--- linux-2.6/net/iucv/iucv.c	2009-03-04 15:58:05.000000000 +0100
+++ linux-2.6-patched/net/iucv/iucv.c	2009-03-04 15:58:26.000000000 +0100
@@ -280,6 +280,7 @@ union iucv_param {
  * Anchor for per-cpu IUCV command parameter block.
  */
 static union iucv_param *iucv_param[NR_CPUS];
+static union iucv_param *iucv_param_irq[NR_CPUS];
 
 /**
  * iucv_call_b2f0
@@ -358,7 +359,7 @@ static void iucv_allow_cpu(void *data)
 	 *	0x10 - Flag to allow priority message completion interrupts
 	 *	0x08 - Flag to allow IUCV control interrupts
 	 */
-	parm = iucv_param[cpu];
+	parm = iucv_param_irq[cpu];
 	memset(parm, 0, sizeof(union iucv_param));
 	parm->set_mask.ipmask = 0xf8;
 	iucv_call_b2f0(IUCV_SETMASK, parm);
@@ -379,7 +380,7 @@ static void iucv_block_cpu(void *data)
 	union iucv_param *parm;
 
 	/* Disable all iucv interrupts. */
-	parm = iucv_param[cpu];
+	parm = iucv_param_irq[cpu];
 	memset(parm, 0, sizeof(union iucv_param));
 	iucv_call_b2f0(IUCV_SETMASK, parm);
 
@@ -403,7 +404,7 @@ static void iucv_declare_cpu(void *data)
 		return;
 
 	/* Declare interrupt buffer. */
-	parm = iucv_param[cpu];
+	parm = iucv_param_irq[cpu];
 	memset(parm, 0, sizeof(union iucv_param));
 	parm->db.ipbfadr1 = virt_to_phys(iucv_irq_data[cpu]);
 	rc = iucv_call_b2f0(IUCV_DECLARE_BUFFER, parm);
@@ -460,7 +461,7 @@ static void iucv_retrieve_cpu(void *data
 	iucv_block_cpu(NULL);
 
 	/* Retrieve interrupt buffer. */
-	parm = iucv_param[cpu];
+	parm = iucv_param_irq[cpu];
 	iucv_call_b2f0(IUCV_RETRIEVE_BUFFER, parm);
 
 	/* Clear indication that an iucv buffer exists for this cpu. */
@@ -574,11 +575,22 @@ static int __cpuinit iucv_cpu_notify(str
 			iucv_irq_data[cpu] = NULL;
 			return NOTIFY_BAD;
 		}
+		iucv_param_irq[cpu] = kmalloc_node(sizeof(union iucv_param),
+					GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
+		if (!iucv_param_irq[cpu]) {
+			kfree(iucv_param[cpu]);
+			iucv_param[cpu] = NULL;
+			kfree(iucv_irq_data[cpu]);
+			iucv_irq_data[cpu] = NULL;
+			return NOTIFY_BAD;
+		}
 		break;
 	case CPU_UP_CANCELED:
 	case CPU_UP_CANCELED_FROZEN:
 	case CPU_DEAD:
 	case CPU_DEAD_FROZEN:
+		kfree(iucv_param_irq[cpu]);
+		iucv_param_irq[cpu] = NULL;
 		kfree(iucv_param[cpu]);
 		iucv_param[cpu] = NULL;
 		kfree(iucv_irq_data[cpu]);
@@ -625,7 +637,7 @@ static int iucv_sever_pathid(u16 pathid,
 {
 	union iucv_param *parm;
 
-	parm = iucv_param[smp_processor_id()];
+	parm = iucv_param_irq[smp_processor_id()];
 	memset(parm, 0, sizeof(union iucv_param));
 	if (userdata)
 		memcpy(parm->ctrl.ipuser, userdata, sizeof(parm->ctrl.ipuser));
@@ -918,10 +930,8 @@ int iucv_path_sever(struct iucv_path *pa
 	if (iucv_active_cpu != smp_processor_id())
 		spin_lock_bh(&iucv_table_lock);
 	rc = iucv_sever_pathid(path->pathid, userdata);
-	if (!rc) {
-		iucv_path_table[path->pathid] = NULL;
-		list_del_init(&path->list);
-	}
+	iucv_path_table[path->pathid] = NULL;
+	list_del_init(&path->list);
 	if (iucv_active_cpu != smp_processor_id())
 		spin_unlock_bh(&iucv_table_lock);
 	preempt_enable();
@@ -1413,7 +1423,7 @@ static void iucv_path_severed(struct iuc
 	else {
 		iucv_sever_pathid(path->pathid, NULL);
 		iucv_path_table[path->pathid] = NULL;
-		list_del_init(&path->list);
+		list_del(&path->list);
 		iucv_path_free(path);
 	}
 }
@@ -1717,6 +1727,13 @@ static int __init iucv_init(void)
 			rc = -ENOMEM;
 			goto out_free;
 		}
+		iucv_param_irq[cpu] = kmalloc_node(sizeof(union iucv_param),
+				  GFP_KERNEL|GFP_DMA, cpu_to_node(cpu));
+		if (!iucv_param_irq[cpu]) {
+			rc = -ENOMEM;
+			goto out_free;
+		}
+
 	}
 	rc = register_hotcpu_notifier(&iucv_cpu_notifier);
 	if (rc)
@@ -1734,6 +1751,8 @@ out_cpu:
 	unregister_hotcpu_notifier(&iucv_cpu_notifier);
 out_free:
 	for_each_possible_cpu(cpu) {
+		kfree(iucv_param_irq[cpu]);
+		iucv_param_irq[cpu] = NULL;
 		kfree(iucv_param[cpu]);
 		iucv_param[cpu] = NULL;
 		kfree(iucv_irq_data[cpu]);
@@ -1764,6 +1783,8 @@ static void __exit iucv_exit(void)
 	spin_unlock_irq(&iucv_queue_lock);
 	unregister_hotcpu_notifier(&iucv_cpu_notifier);
 	for_each_possible_cpu(cpu) {
+		kfree(iucv_param_irq[cpu]);
+		iucv_param_irq[cpu] = NULL;
 		kfree(iucv_param[cpu]);
 		iucv_param[cpu] = NULL;
 		kfree(iucv_irq_data[cpu]);