IB/ipath: Set CPU affinity early

This change moves around port assignment so that it happens before any
memory is allocated.  This allows memory to be allocated on an appropriate
CPU, which improves performance for users of /dev/ipath.

Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 31 insertions, 8 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_file_ops.c b/drivers/infiniband/hw/ipath/ipath_file_ops.c
index 64221b937762..a9ddc6911f66 100644
--- a/drivers/infiniband/hw/ipath/ipath_file_ops.c
+++ b/drivers/infiniband/hw/ipath/ipath_file_ops.c
@@ -1701,18 +1701,17 @@ done:
 
 static int ipath_open(struct inode *in, struct file *fp)
 {
-	/* The real work is performed later in ipath_do_user_init() */
+	/* The real work is performed later in ipath_assign_port() */
 	fp->private_data = kzalloc(sizeof(struct ipath_filedata), GFP_KERNEL);
 	return fp->private_data ? 0 : -ENOMEM;
 }
 
-static int ipath_do_user_init(struct file *fp,
+
+/* Get port early, so can set affinity prior to memory allocation */
+static int ipath_assign_port(struct file *fp,
 			      const struct ipath_user_info *uinfo)
 {
 	int ret;
-	struct ipath_portdata *pd;
-	struct ipath_devdata *dd;
-	u32 head32;
 	int i_minor;
 	unsigned swminor;
 
@@ -1757,8 +1756,18 @@ static int ipath_do_user_init(struct file *fp,
 
 	mutex_unlock(&ipath_mutex);
 
-	if (ret)
-		goto done;
+done:
+	return ret;
+}
+
+
+static int ipath_do_user_init(struct file *fp,
+			      const struct ipath_user_info *uinfo)
+{
+	int ret;
+	struct ipath_portdata *pd;
+	struct ipath_devdata *dd;
+	u32 head32;
 
 	pd = port_fp(fp);
 	dd = pd->port_dd;
@@ -2035,6 +2044,8 @@ static ssize_t ipath_write(struct file *fp, const char __user *data,
 	consumed = sizeof(cmd.type);
 
 	switch (cmd.type) {
+	case IPATH_CMD_ASSIGN_PORT:
+	case __IPATH_CMD_USER_INIT:
 	case IPATH_CMD_USER_INIT:
 		copy = sizeof(cmd.cmd.user_info);
 		dest = &cmd.cmd.user_info;
@@ -2083,12 +2094,24 @@ static ssize_t ipath_write(struct file *fp, const char __user *data,
 
 	consumed += copy;
 	pd = port_fp(fp);
-	if (!pd && cmd.type != IPATH_CMD_USER_INIT) {
+	if (!pd && cmd.type != __IPATH_CMD_USER_INIT &&
+		cmd.type != IPATH_CMD_ASSIGN_PORT) {
 		ret = -EINVAL;
 		goto bail;
 	}
 
 	switch (cmd.type) {
+	case IPATH_CMD_ASSIGN_PORT:
+		ret = ipath_assign_port(fp, &cmd.cmd.user_info);
+		if (ret)
+			goto bail;
+		break;
+	case __IPATH_CMD_USER_INIT:
+		/* backwards compatibility, get port first */
+		ret = ipath_assign_port(fp, &cmd.cmd.user_info);
+		if (ret)
+			goto bail;
+		/* and fall through to current version. */
 	case IPATH_CMD_USER_INIT:
 		ret = ipath_do_user_init(fp, &cmd.cmd.user_info);
 		if (ret)