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>

2 files changed, 35 insertions, 10 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_common.h b/drivers/infiniband/hw/ipath/ipath_common.h
index a9b109a353bc..54139d398181 100644
--- a/drivers/infiniband/hw/ipath/ipath_common.h
+++ b/drivers/infiniband/hw/ipath/ipath_common.h
@@ -412,15 +412,17 @@ struct ipath_user_info {
 
 #define IPATH_CMD_MIN           16
 
-#define IPATH_CMD_USER_INIT     16      /* set up userspace */
+#define __IPATH_CMD_USER_INIT   16      /* old set up userspace (for old user code) */
 #define IPATH_CMD_PORT_INFO     17      /* find out what resources we got */
 #define IPATH_CMD_RECV_CTRL     18      /* control receipt of packets */
 #define IPATH_CMD_TID_UPDATE    19      /* update expected TID entries */
 #define IPATH_CMD_TID_FREE      20      /* free expected TID entries */
 #define IPATH_CMD_SET_PART_KEY  21      /* add partition key */
 #define IPATH_CMD_SLAVE_INFO    22      /* return info on slave processes */
+#define IPATH_CMD_ASSIGN_PORT   23      /* allocate HCA and port */
+#define IPATH_CMD_USER_INIT     24      /* set up userspace */
 
-#define IPATH_CMD_MAX           22
+#define IPATH_CMD_MAX           24
 
 struct ipath_port_info {
         __u32 num_active;       /* number of active units */
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)