drivers/misc/sgi-xp/xpc_uv.c: SGI XPC fails to load when cpu 0 is out of IRQ resources

On many of our larger systems, CPU 0 has had all of its IRQ resources
consumed before XPC loads.  Worst cases on machines with multiple 10
GigE cards and multiple IB cards have depleted the entire first socket
of IRQs.

This patch makes selecting the node upon which IRQs are allocated (as
well as all the other GRU Message Queue structures) specifiable as a
module load param and has a default behavior of searching all nodes/cpus
for an available resources.

[akpm@linux-foundation.org: fix build: include cpu.h and module.h]
Signed-off-by: Robin Holt <holt@sgi.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/misc/sgi-xp/xpc_uv.c

@@ -18,6 +18,8 @@
 #include <linux/interrupt.h>
 #include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/cpu.h>
+#include <linux/module.h>
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <asm/uv/uv_hub.h>
@@ -59,6 +61,8 @@ static struct xpc_heartbeat_uv *xpc_heartbeat_uv;
 					 XPC_NOTIFY_MSG_SIZE_UV)
 #define XPC_NOTIFY_IRQ_NAME		"xpc_notify"
 
+static int xpc_mq_node = -1;
+
 static struct xpc_gru_mq_uv *xpc_activate_mq_uv;
 static struct xpc_gru_mq_uv *xpc_notify_mq_uv;
 
@@ -109,11 +113,8 @@ xpc_get_gru_mq_irq_uv(struct xpc_gru_mq_uv *mq, int cpu, char *irq_name)
 #if defined CONFIG_X86_64
 	mq->irq = uv_setup_irq(irq_name, cpu, mq->mmr_blade, mq->mmr_offset,
 			UV_AFFINITY_CPU);
-	if (mq->irq < 0) {
-		dev_err(xpc_part, "uv_setup_irq() returned error=%d\n",
-			-mq->irq);
+	if (mq->irq < 0)
 		return mq->irq;
-	}
 
 	mq->mmr_value = uv_read_global_mmr64(mmr_pnode, mq->mmr_offset);
 
@@ -238,7 +239,8 @@ xpc_create_gru_mq_uv(unsigned int mq_size, int cpu, char *irq_name,
 	mq->mmr_blade = uv_cpu_to_blade_id(cpu);
 
 	nid = cpu_to_node(cpu);
-	page = alloc_pages_exact_node(nid, GFP_KERNEL | __GFP_ZERO | GFP_THISNODE,
+	page = alloc_pages_exact_node(nid,
+				      GFP_KERNEL | __GFP_ZERO | GFP_THISNODE,
 				      pg_order);
 	if (page == NULL) {
 		dev_err(xpc_part, "xpc_create_gru_mq_uv() failed to alloc %d "
@@ -1731,37 +1733,81 @@ static struct xpc_arch_operations xpc_arch_ops_uv = {
 	.notify_senders_of_disconnect = xpc_notify_senders_of_disconnect_uv,
 };
 
-int
-xpc_init_uv(void)
+static int
+xpc_init_mq_node(int nid)
 {
-	xpc_arch_ops = xpc_arch_ops_uv;
+	int cpu;
 
-	if (sizeof(struct xpc_notify_mq_msghdr_uv) > XPC_MSG_HDR_MAX_SIZE) {
-		dev_err(xpc_part, "xpc_notify_mq_msghdr_uv is larger than %d\n",
-			XPC_MSG_HDR_MAX_SIZE);
-		return -E2BIG;
-	}
+	get_online_cpus();
 
-	xpc_activate_mq_uv = xpc_create_gru_mq_uv(XPC_ACTIVATE_MQ_SIZE_UV, 0,
+	for_each_cpu(cpu, cpumask_of_node(nid)) {
+		xpc_activate_mq_uv =
+			xpc_create_gru_mq_uv(XPC_ACTIVATE_MQ_SIZE_UV, nid,
 					     XPC_ACTIVATE_IRQ_NAME,
 					     xpc_handle_activate_IRQ_uv);
-	if (IS_ERR(xpc_activate_mq_uv))
+		if (!IS_ERR(xpc_activate_mq_uv))
+			break;
+	}
+	if (IS_ERR(xpc_activate_mq_uv)) {
+		put_online_cpus();
 		return PTR_ERR(xpc_activate_mq_uv);
+	}
 
-	xpc_notify_mq_uv = xpc_create_gru_mq_uv(XPC_NOTIFY_MQ_SIZE_UV, 0,
+	for_each_cpu(cpu, cpumask_of_node(nid)) {
+		xpc_notify_mq_uv =
+			xpc_create_gru_mq_uv(XPC_NOTIFY_MQ_SIZE_UV, nid,
 					     XPC_NOTIFY_IRQ_NAME,
 					     xpc_handle_notify_IRQ_uv);
+		if (!IS_ERR(xpc_notify_mq_uv))
+			break;
+	}
 	if (IS_ERR(xpc_notify_mq_uv)) {
 		xpc_destroy_gru_mq_uv(xpc_activate_mq_uv);
+		put_online_cpus();
 		return PTR_ERR(xpc_notify_mq_uv);
 	}
 
+	put_online_cpus();
 	return 0;
 }
 
+int
+xpc_init_uv(void)
+{
+	int nid;
+	int ret = 0;
+
+	xpc_arch_ops = xpc_arch_ops_uv;
+
+	if (sizeof(struct xpc_notify_mq_msghdr_uv) > XPC_MSG_HDR_MAX_SIZE) {
+		dev_err(xpc_part, "xpc_notify_mq_msghdr_uv is larger than %d\n",
+			XPC_MSG_HDR_MAX_SIZE);
+		return -E2BIG;
+	}
+
+	if (xpc_mq_node < 0)
+		for_each_online_node(nid) {
+			ret = xpc_init_mq_node(nid);
+
+			if (!ret)
+				break;
+		}
+	else
+		ret = xpc_init_mq_node(xpc_mq_node);
+
+	if (ret < 0)
+		dev_err(xpc_part, "xpc_init_mq_node() returned error=%d\n",
+			-ret);
+
+	return ret;
+}
+
 void
 xpc_exit_uv(void)
 {
 	xpc_destroy_gru_mq_uv(xpc_notify_mq_uv);
 	xpc_destroy_gru_mq_uv(xpc_activate_mq_uv);
 }
+
+module_param(xpc_mq_node, int, 0);
+MODULE_PARM_DESC(xpc_mq_node, "Node number on which to allocate message queues.");