IB/uverbs: Convert *cdev to cdev in struct ib_uverbs_device

Instead of storing a pointer to a cdev, embed the entire struct cdev.

This change allows us to use the container_of() macro in
ib_uverbs_open() in a future patch.

This change increases the size of struct ib_uverbs_device to 168 bytes
across 3 cachelines from 80 bytes in 2 cachelines.  However, we
rearrange the members so that everything fits into the first cacheline
except for the struct cdev. Finally, we don't touch the cdev in any
fastpaths, so this change shouldn't negatively affect performance.

Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h
index b3ea9587dc808641e79481131c7119a71cb37431..e695f65328a38e53b45880e312abc584baeea791 100644 (file)
--- a/drivers/infiniband/core/uverbs.h
+++ b/drivers/infiniband/core/uverbs.h
@@ -41,6 +41,7 @@
 #include <linux/idr.h>
 #include <linux/mutex.h>
 #include <linux/completion.h>
+#include <linux/cdev.h>
 
 #include <rdma/ib_verbs.h>
 #include <rdma/ib_umem.h>
@@ -69,12 +70,12 @@
 
 struct ib_uverbs_device {
        struct kref                             ref;
+       int                                     num_comp_vectors;
        struct completion                       comp;
-       int                                     devnum;
-       struct cdev                            *cdev;
        struct device                          *dev;
        struct ib_device                       *ib_dev;
-       int                                     num_comp_vectors;
+       int                                     devnum;
+       struct cdev                             cdev;
 };
 
 struct ib_uverbs_event_file {

diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index 5f284ffd430e8b72dcdc493f91a1bd5430070973..5da9a734959a432bcd9dd54d472915eca7a96801 100644 (file)
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -43,7 +43,6 @@
 #include <linux/sched.h>
 #include <linux/file.h>
 #include <linux/mount.h>
-#include <linux/cdev.h>
 
 #include <asm/uaccess.h>
 
@@ -761,17 +760,15 @@ static void ib_uverbs_add_one(struct ib_device *device)
        uverbs_dev->ib_dev           = device;
        uverbs_dev->num_comp_vectors = device->num_comp_vectors;
 
-       uverbs_dev->cdev = cdev_alloc();
-       if (!uverbs_dev->cdev)
-               goto err;
-       uverbs_dev->cdev->owner = THIS_MODULE;
-       uverbs_dev->cdev->ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
-       kobject_set_name(&uverbs_dev->cdev->kobj, "uverbs%d", uverbs_dev->devnum);
-       if (cdev_add(uverbs_dev->cdev, IB_UVERBS_BASE_DEV + uverbs_dev->devnum, 1))
+       cdev_init(&uverbs_dev->cdev, NULL);
+       uverbs_dev->cdev.owner = THIS_MODULE;
+       uverbs_dev->cdev.ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
+       kobject_set_name(&uverbs_dev->cdev.kobj, "uverbs%d", uverbs_dev->devnum);
+       if (cdev_add(&uverbs_dev->cdev, IB_UVERBS_BASE_DEV + uverbs_dev->devnum, 1))
                goto err_cdev;
 
        uverbs_dev->dev = device_create(uverbs_class, device->dma_device,
-                                       uverbs_dev->cdev->dev, uverbs_dev,
+                                       uverbs_dev->cdev.dev, uverbs_dev,
                                        "uverbs%d", uverbs_dev->devnum);
        if (IS_ERR(uverbs_dev->dev))
                goto err_cdev;
@@ -790,10 +787,10 @@ static void ib_uverbs_add_one(struct ib_device *device)
        return;
 
 err_class:
-       device_destroy(uverbs_class, uverbs_dev->cdev->dev);
+       device_destroy(uverbs_class, uverbs_dev->cdev.dev);
 
 err_cdev:
-       cdev_del(uverbs_dev->cdev);
+       cdev_del(&uverbs_dev->cdev);
        clear_bit(uverbs_dev->devnum, dev_map);
 
 err:
@@ -811,8 +808,8 @@ static void ib_uverbs_remove_one(struct ib_device *device)
                return;
 
        dev_set_drvdata(uverbs_dev->dev, NULL);
-       device_destroy(uverbs_class, uverbs_dev->cdev->dev);
-       cdev_del(uverbs_dev->cdev);
+       device_destroy(uverbs_class, uverbs_dev->cdev.dev);
+       cdev_del(&uverbs_dev->cdev);
 
        spin_lock(&map_lock);
        dev_table[uverbs_dev->devnum] = NULL;