Increase maximum number of Infiniband HCAs per system

PATCH Applied Alex Chiang 2 participants 21 messages Feb 2, 2010 – Feb 24, 2010 InfiniBand

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Alex Chiang

author

2010-02-02 19:07 UTC #0 lore raw

v2 cover Increase maximum number of Infiniband HCAs per system

This is v2 of a patch series that increases the maximum number of IB HCAs supported per system.

The original mail thread is here:

	http://lkml.org/lkml/2010/1/29/346

One note, I decided to "copy/paste" since factoring out the overflow code in the three drivers seemed like overkill. If so desired, I could factor those three separate functions into something provided by the core, but that seemed like more trouble than it was worth at the time.

As before, I still don't have access to a giant system, so what I did to test was to stick 4 cards into a small system, and then modify the limits with debug patches similar to this:

drivers/infiniband/core/ucm.c +1 -1

index 7bf0a82..8581e64 100644
@@ -102,7 +102,7 @@ struct ib_ucm_event {
 enum {
        IB_UCM_MAJOR = 231,
        IB_UCM_BASE_MINOR = 224,
-       IB_UCM_MAX_DEVICES = 32
+       IB_UCM_MAX_DEVICES = 2
 };

I tested all 3 drivers this way (uverbs, umad, ucm). I verified that we're not leaking device numbers on multiple modprobe/rmmod cycles, that there aren't any funny interactions when various combinations of the drivers are loaded.

I did not test the rest of the OFED stack. I did write some trivial programs to open the devices in /dev and close them again.

Here's an example of some of the testing:

	dl585g2:~ # modprobe ib_uverbs
	dl585g2:~ # modprobe ib_umad
	dl585g2:~ # modprobe ib_ucm
	dl585g2:~ # ls -l /dev/uverb*
	crw-rw---- 1 root root 231, 192 Feb  2 05:55 /dev/uverbs0
	crw-rw---- 1 root root 231, 193 Feb  2 05:55 /dev/uverbs1
	crw-rw---- 1 root root 249,   0 Feb  2 05:55 /dev/uverbs2
	crw-rw---- 1 root root 249,   1 Feb  2 05:55 /dev/uverbs3
	dl585g2:~ # ls -l /dev/umad*
	crw-rw---- 1 root root 231, 0 Feb  2 05:55 /dev/umad0
	crw-rw---- 1 root root 231, 1 Feb  2 05:55 /dev/umad1
	crw-rw---- 1 root root 231, 2 Feb  2 05:55 /dev/umad2
	crw-rw---- 1 root root 231, 3 Feb  2 05:55 /dev/umad3
	crw-rw---- 1 root root 248, 0 Feb  2 05:55 /dev/umad4
	crw-rw---- 1 root root 248, 1 Feb  2 05:55 /dev/umad5
	crw-rw---- 1 root root 248, 2 Feb  2 05:55 /dev/umad6
	crw-rw---- 1 root root 248, 3 Feb  2 05:55 /dev/umad7
	dl585g2:~ # ls -l /dev/issm*
	crw-rw---- 1 root root 231, 4 Feb  2 05:55 /dev/issm0
	crw-rw---- 1 root root 231, 5 Feb  2 05:55 /dev/issm1
	crw-rw---- 1 root root 231, 6 Feb  2 05:55 /dev/issm2
	crw-rw---- 1 root root 231, 7 Feb  2 05:55 /dev/issm3
	crw-rw---- 1 root root 248, 4 Feb  2 05:55 /dev/issm4
	crw-rw---- 1 root root 248, 5 Feb  2 05:55 /dev/issm5
	crw-rw---- 1 root root 248, 6 Feb  2 05:55 /dev/issm6
	crw-rw---- 1 root root 248, 7 Feb  2 05:55 /dev/issm7
	dl585g2:~ # ls -l /dev/ucm*
	crw-rw---- 1 root root 231, 224 Feb  2 05:55 /dev/ucm0
	crw-rw---- 1 root root 231, 225 Feb  2 05:55 /dev/ucm1
	crw-rw---- 1 root root 247,   0 Feb  2 05:55 /dev/ucm2
	crw-rw---- 1 root root 247,   1 Feb  2 05:55 /dev/ucm3

Note that the major and minor numbers are behaving rather sanely.

	dl585g2:~ # rmmod ib_ucm
	dl585g2:~ # rmmod ib_uverbs
	dl585g2:~ # rmmod ib_umad

Reset.

	dl585g2:~ # modprobe ib_ucm
	dl585g2:~ # ls -l /dev/ucm*
	crw-rw---- 1 root root 231, 224 Feb  2 05:57 /dev/ucm0
	crw-rw---- 1 root root 231, 225 Feb  2 05:57 /dev/ucm1
	crw-rw---- 1 root root 248,   0 Feb  2 05:57 /dev/ucm2
	crw-rw---- 1 root root 248,   1 Feb  2 05:57 /dev/ucm3

See that /dev/ucm* devices now have a different major number compared to last time(248 vs 247), since we loaded that driver first.

But wait, why is it 248 and not 249? Is there a leak somewhere?

	dl585g2:~ # ls -l /dev/uverb*
	crw-rw---- 1 root root 231, 192 Feb  2 05:57 /dev/uverbs0
	crw-rw---- 1 root root 231, 193 Feb  2 05:57 /dev/uverbs1
	crw-rw---- 1 root root 249,   0 Feb  2 05:57 /dev/uverbs2
	crw-rw---- 1 root root 249,   1 Feb  2 05:57 /dev/uverbs3
	dl585g2:~ # rmmod ib_uverbs
	ERROR: Module ib_uverbs is in use by ib_ucm

Ah, ib_ucm is dependent on ib_uverbs, so when we modprobed ib_ucm, in reality ib_uverbs got loaded first. See how it has a higher major number.

	dl585g2:~ # rmmod ib_ucm
	dl585g2:~ # rmmod ib_uverbs
	dl585g2:~ # modprobe ib_umad
	dl585g2:~ # ls -l /dev/umad*
	crw-rw---- 1 root root 231, 0 Feb  2 05:58 /dev/umad0
	crw-rw---- 1 root root 231, 1 Feb  2 05:58 /dev/umad1
	crw-rw---- 1 root root 231, 2 Feb  2 05:58 /dev/umad2
	crw-rw---- 1 root root 231, 3 Feb  2 05:58 /dev/umad3
	crw-rw---- 1 root root 249, 0 Feb  2 05:58 /dev/umad4
	crw-rw---- 1 root root 249, 1 Feb  2 05:58 /dev/umad5
	crw-rw---- 1 root root 249, 2 Feb  2 05:58 /dev/umad6
	crw-rw---- 1 root root 249, 3 Feb  2 05:58 /dev/umad7
	dl585g2:~ # ls -l /dev/issm*
	crw-rw---- 1 root root 231, 4 Feb  2 05:58 /dev/issm0
	crw-rw---- 1 root root 231, 5 Feb  2 05:58 /dev/issm1
	crw-rw---- 1 root root 231, 6 Feb  2 05:58 /dev/issm2
	crw-rw---- 1 root root 231, 7 Feb  2 05:58 /dev/issm3
	crw-rw---- 1 root root 249, 4 Feb  2 05:58 /dev/issm4
	crw-rw---- 1 root root 249, 5 Feb  2 05:58 /dev/issm5
	crw-rw---- 1 root root 249, 6 Feb  2 05:58 /dev/issm6
	crw-rw---- 1 root root 249, 7 Feb  2 05:58 /dev/issm7

Finally, after one more reset, we see ib_umad loaded first and obtaining the major number of 249.

v1 -> v2:
- update umad and ucm drivers too

---

Alex Chiang (18):
IB/uverbs: convert *cdev to cdev in struct ib_uverbs_device IB/uverbs: remove dev_table
IB/uverbs: use stack variable 'devnum' in ib_uverbs_add_one IB/uverbs: use stack variable 'base' in ib_uverbs_add_one IB/uverbs: increase maximum devices supported
IB/uverbs: pack struct ib_uverbs_event_file tighter IB/uverbs: whitespace cleanup
IB/umad: convert cdev pointers to embedded structs in struct ib_umad_port IB/umad: remove port_table[]
IB/umad: use stack variable 'devnum' in ib_umad_init_port IB/umad: use stack variable 'base' in ib_umad_init_port IB/umad: increase maximum devices supported
IB/umad: clean whitespace
IB/ucm: use stack variable 'devnum' in ib_ucm_add_one IB/ucm: use stack variable 'base' in ib_ucm_add_one
IB/ucm: increase maximum devices supported
IB/ucm: clean whitespace errors
IB/core: pack struct ib_device a little tighter

 drivers/infiniband/core/ucm.c         |   63 ++++++++++--
 drivers/infiniband/core/user_mad.c    |  173 +++++++++++++++++----------------
 drivers/infiniband/core/uverbs.h      |   11 +-
 drivers/infiniband/core/uverbs_main.c |  175 +++++++++++++++++++--------------
 include/rdma/ib_verbs.h               |    4 -
 5 files changed, 255 insertions(+), 171 deletions(-)

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Alex Chiang

author

2010-02-02 19:07 UTC #1 lore raw

PATCH v2 1/18 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 <[email protected]>

---

 drivers/infiniband/core/uverbs.h      |    7 ++++---
 drivers/infiniband/core/uverbs_main.c |   23 ++++++++++-------------
 2 files changed, 14 insertions(+), 16 deletions(-)

drivers/infiniband/core/uverbs.h +4 -3

index b3ea958..e695f65 100644
@@ -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 {

drivers/infiniband/core/uverbs_main.c +10 ~~-13~~

index 5f284ff..5da9a73 100644
@@ -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;

Alex Chiang

author

2010-02-02 19:07 UTC #2 lore raw

PATCH v2 2/18 IB/uverbs: remove dev_table

In reply to Alex Chiang

dev_table's raison d'etre was to associate an inode back to a struct ib_uverbs_device.

However, now that we've converted ib_uverbs_device to contain an embedded cdev (instead of a *cdev), we can use the container_of() macro and cast back to the containing device.

There's no longer any need for dev_table, so get rid of it.

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/uverbs_main.c |   24 +++++-------------------
 1 files changed, 5 insertions(+), 19 deletions(-)

drivers/infiniband/core/uverbs_main.c +5 ~~-19~~

index 5da9a73..3f11292 100644
@@ -74,7 +74,6 @@ DEFINE_IDR(ib_uverbs_qp_idr);
 DEFINE_IDR(ib_uverbs_srq_idr);
 
 static DEFINE_SPINLOCK(map_lock);
-static struct ib_uverbs_device *dev_table[IB_UVERBS_MAX_DEVICES];
 static DECLARE_BITMAP(dev_map, IB_UVERBS_MAX_DEVICES);
 
 static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,

@@ -616,14 +615,12 @@ static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
 /*
  * ib_uverbs_open() does not need the BKL:
  *
- *  - dev_table[] accesses are protected by map_lock, the
- *    ib_uverbs_device structures are properly reference counted, and
+ *  - the ib_uverbs_device structures are properly reference counted and
  *    everything else is purely local to the file being created, so
  *    races against other open calls are not a problem;
  *  - there is no ioctl method to race against;
- *  - the device is added to dev_table[] as the last part of module
- *    initialization, the open method will either immediately run
- *    -ENXIO, or all required initialization will be done.
+ *  - the open method will either immediately run -ENXIO, or all
+ *    required initialization will be done.
  */
 static int ib_uverbs_open(struct inode *inode, struct file *filp)
 {

@@ -631,13 +628,10 @@ static int ib_uverbs_open(struct inode *inode, struct file *filp)
 	struct ib_uverbs_file *file;
 	int ret;
 
-	spin_lock(&map_lock);
-	dev = dev_table[iminor(inode) - IB_UVERBS_BASE_MINOR];
+	dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
 	if (dev)
 		kref_get(&dev->ref);
-	spin_unlock(&map_lock);
-
-	if (!dev)
+	else
 		return -ENXIO;
 
 	if (!try_module_get(dev->ib_dev->owner)) {

@@ -778,10 +772,6 @@ static void ib_uverbs_add_one(struct ib_device *device)
 	if (device_create_file(uverbs_dev->dev, &dev_attr_abi_version))
 		goto err_class;
 
-	spin_lock(&map_lock);
-	dev_table[uverbs_dev->devnum] = uverbs_dev;
-	spin_unlock(&map_lock);
-
 	ib_set_client_data(device, &uverbs_client, uverbs_dev);
 
 	return;

@@ -811,10 +801,6 @@ static void ib_uverbs_remove_one(struct ib_device *device)
 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
 	cdev_del(&uverbs_dev->cdev);
 
-	spin_lock(&map_lock);
-	dev_table[uverbs_dev->devnum] = NULL;
-	spin_unlock(&map_lock);
-
 	clear_bit(uverbs_dev->devnum, dev_map);
 
 	kref_put(&uverbs_dev->ref, ib_uverbs_release_dev);

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Alex Chiang

author

2010-02-02 19:07 UTC #3 lore raw

PATCH v2 3/18 IB/uverbs: use stack variable 'devnum' in ib_uverbs_add_one

In reply to Alex Chiang

This change is not useful by itself, but it sets us up for a future change that allows us to dynamically allocate device numbers in case we have more than IB_UVERBS_MAX_DEVICES in the system.

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/uverbs_main.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)

drivers/infiniband/core/uverbs_main.c +7 -5

index 3f11292..acae9ed 100644
@@ -730,6 +730,7 @@ static CLASS_ATTR(abi_version, S_IRUGO, show_abi_version, NULL);
 
 static void ib_uverbs_add_one(struct ib_device *device)
 {
+	int devnum;
 	struct ib_uverbs_device *uverbs_dev;
 
 	if (!device->alloc_ucontext)

@@ -743,12 +744,13 @@ static void ib_uverbs_add_one(struct ib_device *device)
 	init_completion(&uverbs_dev->comp);
 
 	spin_lock(&map_lock);
-	uverbs_dev->devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
-	if (uverbs_dev->devnum >= IB_UVERBS_MAX_DEVICES) {
+	devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
+	if (devnum >= IB_UVERBS_MAX_DEVICES) {
 		spin_unlock(&map_lock);
 		goto err;
 	}
-	set_bit(uverbs_dev->devnum, dev_map);
+	uverbs_dev->devnum = devnum;
+	set_bit(devnum, dev_map);
 	spin_unlock(&map_lock);
 
 	uverbs_dev->ib_dev           = device;

@@ -758,7 +760,7 @@ static void ib_uverbs_add_one(struct ib_device *device)
 	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))
+	if (cdev_add(&uverbs_dev->cdev, IB_UVERBS_BASE_DEV + devnum, 1))
 		goto err_cdev;
 
 	uverbs_dev->dev = device_create(uverbs_class, device->dma_device,

@@ -781,7 +783,7 @@ err_class:
 
 err_cdev:
 	cdev_del(&uverbs_dev->cdev);
-	clear_bit(uverbs_dev->devnum, dev_map);
+	clear_bit(devnum, dev_map);
 
 err:
 	kref_put(&uverbs_dev->ref, ib_uverbs_release_dev);

Alex Chiang

author

2010-02-02 19:08 UTC #4 lore raw

PATCH v2 4/18 IB/uverbs: use stack variable 'base' in ib_uverbs_add_one

In reply to Alex Chiang

This change is not useful by itself, but sets us up for a future change that allows us to support more than IB_UVERBS_MAX_DEVICES in a system.

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/uverbs_main.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

drivers/infiniband/core/uverbs_main.c +3 -1

index acae9ed..8c594cd 100644
@@ -731,6 +731,7 @@ static CLASS_ATTR(abi_version, S_IRUGO, show_abi_version, NULL);
 static void ib_uverbs_add_one(struct ib_device *device)
 {
 	int devnum;
+	dev_t base;
 	struct ib_uverbs_device *uverbs_dev;
 
 	if (!device->alloc_ucontext)

@@ -750,6 +751,7 @@ static void ib_uverbs_add_one(struct ib_device *device)
 		goto err;
 	}
 	uverbs_dev->devnum = devnum;
+	base = devnum + IB_UVERBS_BASE_DEV;
 	set_bit(devnum, dev_map);
 	spin_unlock(&map_lock);

@@ -760,7 +762,7 @@ static void ib_uverbs_add_one(struct ib_device *device)
 	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 + devnum, 1))
+	if (cdev_add(&uverbs_dev->cdev, base, 1))
 		goto err_cdev;
 
 	uverbs_dev->dev = device_create(uverbs_class, device->dma_device,

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Alex Chiang

author

2010-02-02 19:08 UTC #5 lore raw

PATCH v2 5/18 IB/uverbs: increase maximum devices supported

In reply to Alex Chiang

Some large systems may support more than IB_UVERBS_MAX_DEVICES (currently 32).

This change allows us to support more devices in a backwards-compatible manner. The first IB_UVERBS_MAX_DEVICES keep the same major/minor device numbers that they've always had.

If there are more than IB_UVERBS_MAX_DEVICES, we then dynamically request a new major device number (new minors start at 0).

This change increases the maximum number of HCAs to 64 (from 32).

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/uverbs_main.c |   56 +++++++++++++++++++++++++++++----
 1 files changed, 50 insertions(+), 6 deletions(-)

drivers/infiniband/core/uverbs_main.c +50 -6

index 8c594cd..38b9085 100644
@@ -728,6 +728,34 @@ static ssize_t show_abi_version(struct class *class, char *buf)
 }
 static CLASS_ATTR(abi_version, S_IRUGO, show_abi_version, NULL);
 
+static dev_t oflo_maj;
+static DECLARE_BITMAP(oflo_map, IB_UVERBS_MAX_DEVICES);
+
+/*
+ * If we have more than IB_UVERBS_MAX_DEVICES, dynamically overflow by
+ * requesting a new major number and doubling the number of max devices we
+ * support. It's stupid, but simple.
+ */
+static int find_oflo_devnum(void)
+{
+	int ret;
+
+	if (!oflo_maj) {
+		ret = alloc_chrdev_region(&oflo_maj, 0, IB_UVERBS_MAX_DEVICES,
+					  "infiniband_verbs");
+		if (ret) {
+			printk(KERN_ERR "user_verbs: couldn't register dynamic device number\n");
+			return ret;
+		}
+	}
+
+	ret = find_first_zero_bit(oflo_map, IB_UVERBS_MAX_DEVICES);
+	if (ret >= IB_UVERBS_MAX_DEVICES)
+		return -1;
+
+	return ret;
+}
+
 static void ib_uverbs_add_one(struct ib_device *device)
 {
 	int devnum;

@@ -748,11 +776,19 @@ static void ib_uverbs_add_one(struct ib_device *device)
 	devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
 	if (devnum >= IB_UVERBS_MAX_DEVICES) {
 		spin_unlock(&map_lock);
-		goto err;
+		devnum = find_oflo_devnum();
+		if (devnum < 0)
+			goto err;
+
+		spin_lock(&map_lock);
+		uverbs_dev->devnum = devnum + IB_UVERBS_MAX_DEVICES;
+		base = devnum + oflo_maj;
+		set_bit(devnum, oflo_map);
+	} else {
+		uverbs_dev->devnum = devnum;
+		base = devnum + IB_UVERBS_BASE_DEV;
+		set_bit(devnum, dev_map);
 	}
-	uverbs_dev->devnum = devnum;
-	base = devnum + IB_UVERBS_BASE_DEV;
-	set_bit(devnum, dev_map);
 	spin_unlock(&map_lock);
 
 	uverbs_dev->ib_dev           = device;

@@ -785,7 +821,10 @@ err_class:
 
 err_cdev:
 	cdev_del(&uverbs_dev->cdev);
-	clear_bit(devnum, dev_map);
+	if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
+		clear_bit(devnum, dev_map);
+	else
+		clear_bit(devnum, oflo_map);
 
 err:
 	kref_put(&uverbs_dev->ref, ib_uverbs_release_dev);

@@ -805,7 +844,10 @@ static void ib_uverbs_remove_one(struct ib_device *device)
 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
 	cdev_del(&uverbs_dev->cdev);
 
-	clear_bit(uverbs_dev->devnum, dev_map);
+	if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
+		clear_bit(uverbs_dev->devnum, dev_map);
+	else
+		clear_bit(uverbs_dev->devnum - IB_UVERBS_MAX_DEVICES, oflo_map);
 
 	kref_put(&uverbs_dev->ref, ib_uverbs_release_dev);
 	wait_for_completion(&uverbs_dev->comp);

@@ -895,6 +937,8 @@ static void __exit ib_uverbs_cleanup(void)
 	unregister_filesystem(&uverbs_event_fs);
 	class_destroy(uverbs_class);
 	unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
+	if (oflo_maj)
+		unregister_chrdev_region(oflo_maj, IB_UVERBS_MAX_DEVICES);
 	idr_destroy(&ib_uverbs_pd_idr);
 	idr_destroy(&ib_uverbs_mr_idr);
 	idr_destroy(&ib_uverbs_mw_idr);

Alex Chiang

author

2010-02-02 19:08 UTC #6 lore raw

PATCH v2 6/18 IB/uverbs: pack struct ib_uverbs_event_file tighter

In reply to Alex Chiang

Eliminate some padding in the structure by rearranging the members.

sizeof(struct ib_uverbs_event_file) is now 72 bytes (from 80) and more members now fit in the first cacheline.

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/uverbs.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

drivers/infiniband/core/uverbs.h +2 -2

index e695f65..e54d9ac 100644
@@ -80,13 +80,13 @@ struct ib_uverbs_device {
 
 struct ib_uverbs_event_file {
 	struct kref				ref;
+	int					is_async;
 	struct ib_uverbs_file		       *uverbs_file;
 	spinlock_t				lock;
+	int					is_closed;
 	wait_queue_head_t			poll_wait;
 	struct fasync_struct		       *async_queue;
 	struct list_head			event_list;
-	int					is_async;
-	int					is_closed;
 };
 
 struct ib_uverbs_file {

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Alex Chiang

author

2010-02-02 19:08 UTC #7 lore raw

PATCH v2 7/18 IB/uverbs: whitespace cleanup

In reply to Alex Chiang

Clean up the errors as shown when 'let c_space_errors=1' is set in vim.

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/uverbs_main.c |   68 +++++++++++++++++----------------
 1 files changed, 34 insertions(+), 34 deletions(-)

drivers/infiniband/core/uverbs_main.c +34 ~~-34~~

index 38b9085..aff706e 100644
@@ -79,34 +79,34 @@ static DECLARE_BITMAP(dev_map, IB_UVERBS_MAX_DEVICES);
 static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
 				     const char __user *buf, int in_len,
 				     int out_len) = {
-	[IB_USER_VERBS_CMD_GET_CONTEXT]   	= ib_uverbs_get_context,
-	[IB_USER_VERBS_CMD_QUERY_DEVICE]  	= ib_uverbs_query_device,
-	[IB_USER_VERBS_CMD_QUERY_PORT]    	= ib_uverbs_query_port,
-	[IB_USER_VERBS_CMD_ALLOC_PD]      	= ib_uverbs_alloc_pd,
-	[IB_USER_VERBS_CMD_DEALLOC_PD]    	= ib_uverbs_dealloc_pd,
-	[IB_USER_VERBS_CMD_REG_MR]        	= ib_uverbs_reg_mr,
-	[IB_USER_VERBS_CMD_DEREG_MR]      	= ib_uverbs_dereg_mr,
+	[IB_USER_VERBS_CMD_GET_CONTEXT]		= ib_uverbs_get_context,
+	[IB_USER_VERBS_CMD_QUERY_DEVICE]	= ib_uverbs_query_device,
+	[IB_USER_VERBS_CMD_QUERY_PORT]		= ib_uverbs_query_port,
+	[IB_USER_VERBS_CMD_ALLOC_PD]		= ib_uverbs_alloc_pd,
+	[IB_USER_VERBS_CMD_DEALLOC_PD]		= ib_uverbs_dealloc_pd,
+	[IB_USER_VERBS_CMD_REG_MR]		= ib_uverbs_reg_mr,
+	[IB_USER_VERBS_CMD_DEREG_MR]		= ib_uverbs_dereg_mr,
 	[IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL] = ib_uverbs_create_comp_channel,
-	[IB_USER_VERBS_CMD_CREATE_CQ]     	= ib_uverbs_create_cq,
-	[IB_USER_VERBS_CMD_RESIZE_CQ]     	= ib_uverbs_resize_cq,
-	[IB_USER_VERBS_CMD_POLL_CQ]     	= ib_uverbs_poll_cq,
-	[IB_USER_VERBS_CMD_REQ_NOTIFY_CQ]     	= ib_uverbs_req_notify_cq,
-	[IB_USER_VERBS_CMD_DESTROY_CQ]    	= ib_uverbs_destroy_cq,
-	[IB_USER_VERBS_CMD_CREATE_QP]     	= ib_uverbs_create_qp,
-	[IB_USER_VERBS_CMD_QUERY_QP]     	= ib_uverbs_query_qp,
-	[IB_USER_VERBS_CMD_MODIFY_QP]     	= ib_uverbs_modify_qp,
-	[IB_USER_VERBS_CMD_DESTROY_QP]    	= ib_uverbs_destroy_qp,
-	[IB_USER_VERBS_CMD_POST_SEND]    	= ib_uverbs_post_send,
-	[IB_USER_VERBS_CMD_POST_RECV]    	= ib_uverbs_post_recv,
-	[IB_USER_VERBS_CMD_POST_SRQ_RECV]    	= ib_uverbs_post_srq_recv,
-	[IB_USER_VERBS_CMD_CREATE_AH]    	= ib_uverbs_create_ah,
-	[IB_USER_VERBS_CMD_DESTROY_AH]    	= ib_uverbs_destroy_ah,
-	[IB_USER_VERBS_CMD_ATTACH_MCAST]  	= ib_uverbs_attach_mcast,
-	[IB_USER_VERBS_CMD_DETACH_MCAST]  	= ib_uverbs_detach_mcast,
-	[IB_USER_VERBS_CMD_CREATE_SRQ]    	= ib_uverbs_create_srq,
-	[IB_USER_VERBS_CMD_MODIFY_SRQ]    	= ib_uverbs_modify_srq,
-	[IB_USER_VERBS_CMD_QUERY_SRQ]     	= ib_uverbs_query_srq,
-	[IB_USER_VERBS_CMD_DESTROY_SRQ]   	= ib_uverbs_destroy_srq,
+	[IB_USER_VERBS_CMD_CREATE_CQ]		= ib_uverbs_create_cq,
+	[IB_USER_VERBS_CMD_RESIZE_CQ]		= ib_uverbs_resize_cq,
+	[IB_USER_VERBS_CMD_POLL_CQ]		= ib_uverbs_poll_cq,
+	[IB_USER_VERBS_CMD_REQ_NOTIFY_CQ]	= ib_uverbs_req_notify_cq,
+	[IB_USER_VERBS_CMD_DESTROY_CQ]		= ib_uverbs_destroy_cq,
+	[IB_USER_VERBS_CMD_CREATE_QP]		= ib_uverbs_create_qp,
+	[IB_USER_VERBS_CMD_QUERY_QP]		= ib_uverbs_query_qp,
+	[IB_USER_VERBS_CMD_MODIFY_QP]		= ib_uverbs_modify_qp,
+	[IB_USER_VERBS_CMD_DESTROY_QP]		= ib_uverbs_destroy_qp,
+	[IB_USER_VERBS_CMD_POST_SEND]		= ib_uverbs_post_send,
+	[IB_USER_VERBS_CMD_POST_RECV]		= ib_uverbs_post_recv,
+	[IB_USER_VERBS_CMD_POST_SRQ_RECV]	= ib_uverbs_post_srq_recv,
+	[IB_USER_VERBS_CMD_CREATE_AH]		= ib_uverbs_create_ah,
+	[IB_USER_VERBS_CMD_DESTROY_AH]		= ib_uverbs_destroy_ah,
+	[IB_USER_VERBS_CMD_ATTACH_MCAST]	= ib_uverbs_attach_mcast,
+	[IB_USER_VERBS_CMD_DETACH_MCAST]	= ib_uverbs_detach_mcast,
+	[IB_USER_VERBS_CMD_CREATE_SRQ]		= ib_uverbs_create_srq,
+	[IB_USER_VERBS_CMD_MODIFY_SRQ]		= ib_uverbs_modify_srq,
+	[IB_USER_VERBS_CMD_QUERY_SRQ]		= ib_uverbs_query_srq,
+	[IB_USER_VERBS_CMD_DESTROY_SRQ]		= ib_uverbs_destroy_srq,
 };
 
 static struct vfsmount *uverbs_event_mnt;

@@ -368,7 +368,7 @@ static int ib_uverbs_event_close(struct inode *inode, struct file *filp)
 
 static const struct file_operations uverbs_event_fops = {
 	.owner	 = THIS_MODULE,
-	.read 	 = ib_uverbs_event_read,
+	.read	 = ib_uverbs_event_read,
 	.poll    = ib_uverbs_event_poll,
 	.release = ib_uverbs_event_close,
 	.fasync  = ib_uverbs_event_fasync

@@ -678,17 +678,17 @@ static int ib_uverbs_close(struct inode *inode, struct file *filp)
 }
 
 static const struct file_operations uverbs_fops = {
-	.owner 	 = THIS_MODULE,
-	.write 	 = ib_uverbs_write,
-	.open 	 = ib_uverbs_open,
+	.owner	 = THIS_MODULE,
+	.write	 = ib_uverbs_write,
+	.open	 = ib_uverbs_open,
 	.release = ib_uverbs_close
 };
 
 static const struct file_operations uverbs_mmap_fops = {
-	.owner 	 = THIS_MODULE,
-	.write 	 = ib_uverbs_write,
+	.owner	 = THIS_MODULE,
+	.write	 = ib_uverbs_write,
 	.mmap    = ib_uverbs_mmap,
-	.open 	 = ib_uverbs_open,
+	.open	 = ib_uverbs_open,
 	.release = ib_uverbs_close
 };

--
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Alex Chiang

author

2010-02-02 19:08 UTC #8 lore raw

PATCH v2 8/18 IB/umad: convert cdev pointers to embedded structs in struct ib_umad_port

In reply to Alex Chiang

Instead of storing pointers to cdev and sm_cdev, embed the full structures instead.

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

This change increases the size of struct ib_umad_port to 320 bytes from 128.

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/user_mad.c |   46 ++++++++++++++++--------------------
 1 files changed, 20 insertions(+), 26 deletions(-)

drivers/infiniband/core/user_mad.c +20 ~~-26~~

index 7de0296..40440ef 100644
@@ -87,10 +87,10 @@ enum {
  */
 
 struct ib_umad_port {
-	struct cdev           *cdev;
+	struct cdev           cdev;
 	struct device	      *dev;
 
-	struct cdev           *sm_cdev;
+	struct cdev           sm_cdev;
 	struct device	      *sm_dev;
 	struct semaphore       sm_sem;

@@ -1008,17 +1008,14 @@ static int ib_umad_init_port(struct ib_device *device, int port_num,
 	mutex_init(&port->file_mutex);
 	INIT_LIST_HEAD(&port->file_list);
 
-	port->cdev = cdev_alloc();
-	if (!port->cdev)
-		return -1;
-	port->cdev->owner = THIS_MODULE;
-	port->cdev->ops   = &umad_fops;
-	kobject_set_name(&port->cdev->kobj, "umad%d", port->dev_num);
-	if (cdev_add(port->cdev, base_dev + port->dev_num, 1))
+	cdev_init(&port->cdev, &umad_fops);
+	port->cdev.owner = THIS_MODULE;
+	kobject_set_name(&port->cdev.kobj, "umad%d", port->dev_num);
+	if (cdev_add(&port->cdev, base_dev + port->dev_num, 1))
 		goto err_cdev;
 
 	port->dev = device_create(umad_class, device->dma_device,
-				  port->cdev->dev, port,
+				  port->cdev.dev, port,
 				  "umad%d", port->dev_num);
 	if (IS_ERR(port->dev))
 		goto err_cdev;

@@ -1028,17 +1025,14 @@ static int ib_umad_init_port(struct ib_device *device, int port_num,
 	if (device_create_file(port->dev, &dev_attr_port))
 		goto err_dev;
 
-	port->sm_cdev = cdev_alloc();
-	if (!port->sm_cdev)
-		goto err_dev;
-	port->sm_cdev->owner = THIS_MODULE;
-	port->sm_cdev->ops   = &umad_sm_fops;
-	kobject_set_name(&port->sm_cdev->kobj, "issm%d", port->dev_num);
-	if (cdev_add(port->sm_cdev, base_dev + port->dev_num + IB_UMAD_MAX_PORTS, 1))
+	cdev_init(&port->sm_cdev, &umad_sm_fops);
+	port->sm_cdev.owner = THIS_MODULE;
+	kobject_set_name(&port->sm_cdev.kobj, "issm%d", port->dev_num);
+	if (cdev_add(&port->sm_cdev, base_dev + port->dev_num + IB_UMAD_MAX_PORTS, 1))
 		goto err_sm_cdev;
 
 	port->sm_dev = device_create(umad_class, device->dma_device,
-				     port->sm_cdev->dev, port,
+				     port->sm_cdev.dev, port,
 				     "issm%d", port->dev_num);
 	if (IS_ERR(port->sm_dev))
 		goto err_sm_cdev;

@@ -1055,16 +1049,16 @@ static int ib_umad_init_port(struct ib_device *device, int port_num,
 	return 0;
 
 err_sm_dev:
-	device_destroy(umad_class, port->sm_cdev->dev);
+	device_destroy(umad_class, port->sm_cdev.dev);
 
 err_sm_cdev:
-	cdev_del(port->sm_cdev);
+	cdev_del(&port->sm_cdev);
 
 err_dev:
-	device_destroy(umad_class, port->cdev->dev);
+	device_destroy(umad_class, port->cdev.dev);
 
 err_cdev:
-	cdev_del(port->cdev);
+	cdev_del(&port->cdev);
 	clear_bit(port->dev_num, dev_map);
 
 	return -1;

@@ -1079,11 +1073,11 @@ static void ib_umad_kill_port(struct ib_umad_port *port)
 	dev_set_drvdata(port->dev,    NULL);
 	dev_set_drvdata(port->sm_dev, NULL);
 
-	device_destroy(umad_class, port->cdev->dev);
-	device_destroy(umad_class, port->sm_cdev->dev);
+	device_destroy(umad_class, port->cdev.dev);
+	device_destroy(umad_class, port->sm_cdev.dev);
 
-	cdev_del(port->cdev);
-	cdev_del(port->sm_cdev);
+	cdev_del(&port->cdev);
+	cdev_del(&port->sm_cdev);
 
 	spin_lock(&port_lock);
 	umad_port[port->dev_num] = NULL;

Alex Chiang

author

2010-02-02 19:08 UTC #9 lore raw

PATCH v2 9/18 IB/umad: remove port_table[]

In reply to Alex Chiang

We no longer need this data structure, as it was used to associate an inode back to a struct ib_umad_port during ->open().

But now that we're embedding a struct cdev in struct ib_umad_port, we can use the container_of() macro to go from the inode back to the device instead.

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/user_mad.c |   45 +++++++-----------------------------
 1 files changed, 9 insertions(+), 36 deletions(-)

drivers/infiniband/core/user_mad.c +9 ~~-36~~

index 40440ef..46c8879 100644
@@ -65,12 +65,9 @@ enum {
 };
 
 /*
- * Our lifetime rules for these structs are the following: each time a
- * device special file is opened, we look up the corresponding struct
- * ib_umad_port by minor in the umad_port[] table while holding the
- * port_lock.  If this lookup succeeds, we take a reference on the
- * ib_umad_port's struct ib_umad_device while still holding the
- * port_lock; if the lookup fails, we fail the open().  We drop these
+ * Our lifetime rules for these structs are the following:
+ * device special file is opened, we take a reference on the
+ * ib_umad_port's struct ib_umad_device. We drop these
  * references in the corresponding close().
  *
  * In addition to references coming from open character devices, there

@@ -78,12 +75,7 @@ enum {
  * module's reference taken when allocating the ib_umad_device in
  * ib_umad_add_one().
  *
- * When destroying an ib_umad_device, we clear all of its
- * ib_umad_ports from umad_port[] while holding port_lock before
- * dropping the module's reference to the ib_umad_device.  This is
- * always safe because any open() calls will either succeed and obtain
- * a reference before we clear the umad_port[] entries, or fail after
- * we clear the umad_port[] entries.
+ * When destroying an ib_umad_device, we drop the module's reference.
  */
 
 struct ib_umad_port {

@@ -136,7 +128,6 @@ static struct class *umad_class;
 static const dev_t base_dev = MKDEV(IB_UMAD_MAJOR, IB_UMAD_MINOR_BASE);
 
 static DEFINE_SPINLOCK(port_lock);
-static struct ib_umad_port *umad_port[IB_UMAD_MAX_PORTS];
 static DECLARE_BITMAP(dev_map, IB_UMAD_MAX_PORTS);
 
 static void ib_umad_add_one(struct ib_device *device);

@@ -779,15 +770,11 @@ static long ib_umad_compat_ioctl(struct file *filp, unsigned int cmd,
 /*
  * ib_umad_open() does not need the BKL:
  *
- *  - umad_port[] accesses are protected by port_lock, the
- *    ib_umad_port structures are properly reference counted, and
+ *  - the ib_umad_port structures are properly reference counted, and
  *    everything else is purely local to the file being created, so
  *    races against other open calls are not a problem;
  *  - the ioctl method does not affect any global state outside of the
  *    file structure being operated on;
- *  - the port is added to umad_port[] as the last part of module
- *    initialization so the open method will either immediately run
- *    -ENXIO, or all required initialization will be done.
  */
 static int ib_umad_open(struct inode *inode, struct file *filp)
 {

@@ -795,13 +782,10 @@ static int ib_umad_open(struct inode *inode, struct file *filp)
 	struct ib_umad_file *file;
 	int ret = 0;
 
-	spin_lock(&port_lock);
-	port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE];
+	port = container_of(inode->i_cdev, struct ib_umad_port, cdev);
 	if (port)
 		kref_get(&port->umad_dev->ref);
-	spin_unlock(&port_lock);
-
-	if (!port)
+	else
 		return -ENXIO;
 
 	mutex_lock(&port->file_mutex);

@@ -892,13 +876,10 @@ static int ib_umad_sm_open(struct inode *inode, struct file *filp)
 	};
 	int ret;
 
-	spin_lock(&port_lock);
-	port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE - IB_UMAD_MAX_PORTS];
+	port = container_of(inode->i_cdev, struct ib_umad_port, sm_cdev);
 	if (port)
 		kref_get(&port->umad_dev->ref);
-	spin_unlock(&port_lock);
-
-	if (!port)
+	else
 		return -ENXIO;
 
 	if (filp->f_flags & O_NONBLOCK) {

@@ -1042,10 +1023,6 @@ static int ib_umad_init_port(struct ib_device *device, int port_num,
 	if (device_create_file(port->sm_dev, &dev_attr_port))
 		goto err_sm_dev;
 
-	spin_lock(&port_lock);
-	umad_port[port->dev_num] = port;
-	spin_unlock(&port_lock);
-
 	return 0;
 
 err_sm_dev:

@@ -1079,10 +1056,6 @@ static void ib_umad_kill_port(struct ib_umad_port *port)
 	cdev_del(&port->cdev);
 	cdev_del(&port->sm_cdev);
 
-	spin_lock(&port_lock);
-	umad_port[port->dev_num] = NULL;
-	spin_unlock(&port_lock);
-
 	mutex_lock(&port->file_mutex);
 
 	port->ib_dev = NULL;

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Alex Chiang

author

2010-02-02 19:08 UTC #10 lore raw

PATCH v2 10/18 IB/umad: use stack variable 'devnum' in ib_umad_init_port

In reply to Alex Chiang

This change is not useful by itself, but sets us up for a future change that allows us to dynamically allocate device numbers in case we have more than IB_UMAD_MAX_PORTS in the system.

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/user_mad.c |   15 +++++++++------
 1 files changed, 9 insertions(+), 6 deletions(-)

drivers/infiniband/core/user_mad.c +9 -6

index 46c8879..df403ec 100644
@@ -974,13 +974,16 @@ static CLASS_ATTR(abi_version, S_IRUGO, show_abi_version, NULL);
 static int ib_umad_init_port(struct ib_device *device, int port_num,
 			     struct ib_umad_port *port)
 {
+	int devnum;
+
 	spin_lock(&port_lock);
-	port->dev_num = find_first_zero_bit(dev_map, IB_UMAD_MAX_PORTS);
-	if (port->dev_num >= IB_UMAD_MAX_PORTS) {
+	devnum = find_first_zero_bit(dev_map, IB_UMAD_MAX_PORTS);
+	if (devnum >= IB_UMAD_MAX_PORTS) {
 		spin_unlock(&port_lock);
 		return -1;
 	}
-	set_bit(port->dev_num, dev_map);
+	port->dev_num = devnum;
+	set_bit(devnum, dev_map);
 	spin_unlock(&port_lock);
 
 	port->ib_dev   = device;

@@ -992,7 +995,7 @@ static int ib_umad_init_port(struct ib_device *device, int port_num,
 	cdev_init(&port->cdev, &umad_fops);
 	port->cdev.owner = THIS_MODULE;
 	kobject_set_name(&port->cdev.kobj, "umad%d", port->dev_num);
-	if (cdev_add(&port->cdev, base_dev + port->dev_num, 1))
+	if (cdev_add(&port->cdev, base_dev + devnum, 1))
 		goto err_cdev;
 
 	port->dev = device_create(umad_class, device->dma_device,

@@ -1009,7 +1012,7 @@ static int ib_umad_init_port(struct ib_device *device, int port_num,
 	cdev_init(&port->sm_cdev, &umad_sm_fops);
 	port->sm_cdev.owner = THIS_MODULE;
 	kobject_set_name(&port->sm_cdev.kobj, "issm%d", port->dev_num);
-	if (cdev_add(&port->sm_cdev, base_dev + port->dev_num + IB_UMAD_MAX_PORTS, 1))
+	if (cdev_add(&port->sm_cdev, base_dev + devnum + IB_UMAD_MAX_PORTS, 1))
 		goto err_sm_cdev;
 
 	port->sm_dev = device_create(umad_class, device->dma_device,

@@ -1036,7 +1039,7 @@ err_dev:
 
 err_cdev:
 	cdev_del(&port->cdev);
-	clear_bit(port->dev_num, dev_map);
+	clear_bit(devnum, dev_map);
 
 	return -1;
 }

Alex Chiang

author

2010-02-02 19:08 UTC #11 lore raw

PATCH v2 11/18 IB/umad: use stack variable 'base' in ib_umad_init_port

In reply to Alex Chiang

This change is not useful by itself, but sets us up for a future change that allows us to support more than IB_UMAD_MAX_PORTS in a system.

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/user_mad.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

drivers/infiniband/core/user_mad.c +5 -2

index df403ec..5a66bd0 100644
@@ -975,6 +975,7 @@ static int ib_umad_init_port(struct ib_device *device, int port_num,
 			     struct ib_umad_port *port)
 {
 	int devnum;
+	dev_t base;
 
 	spin_lock(&port_lock);
 	devnum = find_first_zero_bit(dev_map, IB_UMAD_MAX_PORTS);

@@ -983,6 +984,7 @@ static int ib_umad_init_port(struct ib_device *device, int port_num,
 		return -1;
 	}
 	port->dev_num = devnum;
+	base = devnum + base_dev;
 	set_bit(devnum, dev_map);
 	spin_unlock(&port_lock);

@@ -995,7 +997,7 @@ static int ib_umad_init_port(struct ib_device *device, int port_num,
 	cdev_init(&port->cdev, &umad_fops);
 	port->cdev.owner = THIS_MODULE;
 	kobject_set_name(&port->cdev.kobj, "umad%d", port->dev_num);
-	if (cdev_add(&port->cdev, base_dev + devnum, 1))
+	if (cdev_add(&port->cdev, base, 1))
 		goto err_cdev;
 
 	port->dev = device_create(umad_class, device->dma_device,

@@ -1009,10 +1011,11 @@ static int ib_umad_init_port(struct ib_device *device, int port_num,
 	if (device_create_file(port->dev, &dev_attr_port))
 		goto err_dev;
 
+	base += IB_UMAD_MAX_PORTS;
 	cdev_init(&port->sm_cdev, &umad_sm_fops);
 	port->sm_cdev.owner = THIS_MODULE;
 	kobject_set_name(&port->sm_cdev.kobj, "issm%d", port->dev_num);
-	if (cdev_add(&port->sm_cdev, base_dev + devnum + IB_UMAD_MAX_PORTS, 1))
+	if (cdev_add(&port->sm_cdev, base, 1))
 		goto err_sm_cdev;
 
 	port->sm_dev = device_create(umad_class, device->dma_device,

Alex Chiang

author

2010-02-02 19:08 UTC #12 lore raw

PATCH v2 12/18 IB/umad: increase maximum devices supported

In reply to Alex Chiang

Some large systems may support more than IB_UMAD_MAX_PORTS (currently 64).

This change allows us to support more ports in a backwards-compatible manner. The first IB_UMAD_MAX_PORTS keep the same major/minor device numbers they've always had.

If there are more than IB_UMAD_MAX_PORTS, we then dynamically request a new major device number (new minors start at 0).

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/user_mad.c |   50 ++++++++++++++++++++++++++++++++----
 1 files changed, 44 insertions(+), 6 deletions(-)

drivers/infiniband/core/user_mad.c +44 -6

index 5a66bd0..7fc1e51 100644
@@ -971,6 +971,28 @@ static ssize_t show_abi_version(struct class *class, char *buf)
 }
 static CLASS_ATTR(abi_version, S_IRUGO, show_abi_version, NULL);
 
+static dev_t oflo_maj;
+static DECLARE_BITMAP(oflo_map, IB_UMAD_MAX_PORTS);
+static int find_oflo_devnum(void)
+{
+	int ret;
+
+	if (!oflo_maj) {
+		ret = alloc_chrdev_region(&oflo_maj, 0, IB_UMAD_MAX_PORTS * 2,
+					  "infiniband_mad");
+		if (ret) {
+			printk(KERN_ERR "user_mad: couldn't register dynamic device number\n");
+			return ret;
+		}
+	}
+
+	ret = find_first_zero_bit(oflo_map, IB_UMAD_MAX_PORTS);
+	if (ret >= IB_UMAD_MAX_PORTS)
+		return -1;
+
+	return ret;
+}
+
 static int ib_umad_init_port(struct ib_device *device, int port_num,
 			     struct ib_umad_port *port)
 {

@@ -981,11 +1003,19 @@ static int ib_umad_init_port(struct ib_device *device, int port_num,
 	devnum = find_first_zero_bit(dev_map, IB_UMAD_MAX_PORTS);
 	if (devnum >= IB_UMAD_MAX_PORTS) {
 		spin_unlock(&port_lock);
-		return -1;
+		devnum = find_oflo_devnum();
+		if (devnum < 0)
+			return -1;
+
+		spin_lock(&port_lock);
+		port->dev_num = devnum + IB_UMAD_MAX_PORTS;
+		base = devnum + oflo_maj;
+		set_bit(devnum, oflo_map);
+	} else {
+		port->dev_num = devnum;
+		base = devnum + base_dev;
+		set_bit(devnum, dev_map);
 	}
-	port->dev_num = devnum;
-	base = devnum + base_dev;
-	set_bit(devnum, dev_map);
 	spin_unlock(&port_lock);
 
 	port->ib_dev   = device;

@@ -1042,7 +1072,10 @@ err_dev:
 
 err_cdev:
 	cdev_del(&port->cdev);
-	clear_bit(devnum, dev_map);
+	if (port->dev_num < IB_UMAD_MAX_PORTS)
+		clear_bit(devnum, dev_map);
+	else
+		clear_bit(devnum, oflo_map);
 
 	return -1;
 }

@@ -1079,7 +1112,10 @@ static void ib_umad_kill_port(struct ib_umad_port *port)
 
 	mutex_unlock(&port->file_mutex);
 
-	clear_bit(port->dev_num, dev_map);
+	if (port->dev_num < IB_UMAD_MAX_PORTS)
+		clear_bit(port->dev_num, dev_map);
+	else
+		clear_bit(port->dev_num - IB_UMAD_MAX_PORTS, oflo_map);
 }
 
 static void ib_umad_add_one(struct ib_device *device)

@@ -1187,6 +1223,8 @@ static void __exit ib_umad_cleanup(void)
 	ib_unregister_client(&umad_client);
 	class_destroy(umad_class);
 	unregister_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2);
+	if (oflo_maj)
+		unregister_chrdev_region(oflo_maj, IB_UMAD_MAX_PORTS * 2);
 }
 
 module_init(ib_umad_init);

Alex Chiang

author

2010-02-02 19:08 UTC #13 lore raw

PATCH v2 13/18 IB/umad: clean whitespace

In reply to Alex Chiang

Clean errors as shown when 'let c_space_errors=1' is set in vim.

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/user_mad.c |   26 +++++++++++++-------------
 1 files changed, 13 insertions(+), 13 deletions(-)

drivers/infiniband/core/user_mad.c +13 ~~-13~~

index 7fc1e51..3595bd5 100644
@@ -487,8 +487,8 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
 		ah_attr.ah_flags = IB_AH_GRH;
 		memcpy(ah_attr.grh.dgid.raw, packet->mad.hdr.gid, 16);
 		ah_attr.grh.sgid_index	   = packet->mad.hdr.gid_index;
-		ah_attr.grh.flow_label 	   = be32_to_cpu(packet->mad.hdr.flow_label);
-		ah_attr.grh.hop_limit  	   = packet->mad.hdr.hop_limit;
+		ah_attr.grh.flow_label	   = be32_to_cpu(packet->mad.hdr.flow_label);
+		ah_attr.grh.hop_limit	   = packet->mad.hdr.hop_limit;
 		ah_attr.grh.traffic_class  = packet->mad.hdr.traffic_class;
 	}

@@ -519,9 +519,9 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
 		goto err_ah;
 	}
 
-	packet->msg->ah 	= ah;
+	packet->msg->ah		= ah;
 	packet->msg->timeout_ms = packet->mad.hdr.timeout_ms;
-	packet->msg->retries 	= packet->mad.hdr.retries;
+	packet->msg->retries	= packet->mad.hdr.retries;
 	packet->msg->context[0] = packet;
 
 	/* Copy MAD header.  Any RMPP header is already in place. */

@@ -856,16 +856,16 @@ static int ib_umad_close(struct inode *inode, struct file *filp)
 }
 
 static const struct file_operations umad_fops = {
-	.owner 	 	= THIS_MODULE,
-	.read 	 	= ib_umad_read,
-	.write 	 	= ib_umad_write,
-	.poll 	 	= ib_umad_poll,
+	.owner		= THIS_MODULE,
+	.read		= ib_umad_read,
+	.write		= ib_umad_write,
+	.poll		= ib_umad_poll,
 	.unlocked_ioctl = ib_umad_ioctl,
 #ifdef CONFIG_COMPAT
-	.compat_ioctl 	= ib_umad_compat_ioctl,
+	.compat_ioctl	= ib_umad_compat_ioctl,
 #endif
-	.open 	 	= ib_umad_open,
-	.release 	= ib_umad_close
+	.open		= ib_umad_open,
+	.release	= ib_umad_close
 };
 
 static int ib_umad_sm_open(struct inode *inode, struct file *filp)

@@ -930,8 +930,8 @@ static int ib_umad_sm_close(struct inode *inode, struct file *filp)
 }
 
 static const struct file_operations umad_sm_fops = {
-	.owner 	 = THIS_MODULE,
-	.open 	 = ib_umad_sm_open,
+	.owner	 = THIS_MODULE,
+	.open	 = ib_umad_sm_open,
 	.release = ib_umad_sm_close
 };

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Alex Chiang

author

2010-02-02 19:08 UTC #14 lore raw

PATCH v2 14/18 IB/ucm: use stack variable 'devnum' in ib_ucm_add_one

In reply to Alex Chiang

This change is not useful by itself, but sets us up for a future change that allows us to dynamically allocate device numbers in case we have more than IB_UCM_MAX_DEVICES in the system.

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/ucm.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)

drivers/infiniband/core/ucm.c +7 -5

index f504c9b..7ff3300 100644
@@ -1239,6 +1239,7 @@ static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
 
 static void ib_ucm_add_one(struct ib_device *device)
 {
+	int devnum;
 	struct ib_ucm_device *ucm_dev;
 
 	if (!device->alloc_ucontext ||

@@ -1251,16 +1252,17 @@ static void ib_ucm_add_one(struct ib_device *device)
 
 	ucm_dev->ib_dev = device;
 
-	ucm_dev->devnum = find_first_zero_bit(dev_map, IB_UCM_MAX_DEVICES);
-	if (ucm_dev->devnum >= IB_UCM_MAX_DEVICES)
+	devnum = find_first_zero_bit(dev_map, IB_UCM_MAX_DEVICES);
+	if (devnum >= IB_UCM_MAX_DEVICES)
 		goto err;
 
-	set_bit(ucm_dev->devnum, dev_map);
+	ucm_dev->devnum = devnum;
+	set_bit(devnum, dev_map);
 
 	cdev_init(&ucm_dev->cdev, &ucm_fops);
 	ucm_dev->cdev.owner = THIS_MODULE;
 	kobject_set_name(&ucm_dev->cdev.kobj, "ucm%d", ucm_dev->devnum);
-	if (cdev_add(&ucm_dev->cdev, IB_UCM_BASE_DEV + ucm_dev->devnum, 1))
+	if (cdev_add(&ucm_dev->cdev, IB_UCM_BASE_DEV + devnum, 1))
 		goto err;
 
 	ucm_dev->dev.class = &cm_class;

@@ -1281,7 +1283,7 @@ err_dev:
 	device_unregister(&ucm_dev->dev);
 err_cdev:
 	cdev_del(&ucm_dev->cdev);
-	clear_bit(ucm_dev->devnum, dev_map);
+	clear_bit(devnum, dev_map);
 err:
 	kfree(ucm_dev);
 	return;

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Alex Chiang

author

2010-02-02 19:09 UTC #15 lore raw

PATCH v2 15/18 IB/ucm: use stack variable 'base' in ib_ucm_add_one

In reply to Alex Chiang

This change is not useful by itself, but sets us up for a future change that allows us to support more than IB_UCM_MAX_DEVICES.

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/ucm.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

drivers/infiniband/core/ucm.c +3 -1

index 7ff3300..06c50d8 100644
@@ -1240,6 +1240,7 @@ static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
 static void ib_ucm_add_one(struct ib_device *device)
 {
 	int devnum;
+	dev_t base;
 	struct ib_ucm_device *ucm_dev;
 
 	if (!device->alloc_ucontext ||

@@ -1257,12 +1258,13 @@ static void ib_ucm_add_one(struct ib_device *device)
 		goto err;
 
 	ucm_dev->devnum = devnum;
+	base = devnum + IB_UCM_BASE_DEV;
 	set_bit(devnum, dev_map);
 
 	cdev_init(&ucm_dev->cdev, &ucm_fops);
 	ucm_dev->cdev.owner = THIS_MODULE;
 	kobject_set_name(&ucm_dev->cdev.kobj, "ucm%d", ucm_dev->devnum);
-	if (cdev_add(&ucm_dev->cdev, IB_UCM_BASE_DEV + devnum, 1))
+	if (cdev_add(&ucm_dev->cdev, base, 1))
 		goto err;
 
 	ucm_dev->dev.class = &cm_class;

Alex Chiang

author

2010-02-02 19:09 UTC #16 lore raw

PATCH v2 16/18 IB/ucm: increase maximum devices supported

In reply to Alex Chiang

Some large systems may support more than IB_UCM_MAX_DEVICES (currently 32).

This change allows us to support more devices in a backwards-compatible manner. the first IB_UCM_MAX_DEVICES keep the same major/minor device numbers they've always had.

If there are more than IB_UCM_MAX_DEVICES, then we dynamically request a new major device number (new minors start at 0).

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/ucm.c |   53 +++++++++++++++++++++++++++++++++++------
 1 files changed, 45 insertions(+), 8 deletions(-)

drivers/infiniband/core/ucm.c +45 -8

index 06c50d8..1203ca4 100644
@@ -1215,7 +1215,10 @@ static void ib_ucm_release_dev(struct device *dev)
 
 	ucm_dev = container_of(dev, struct ib_ucm_device, dev);
 	cdev_del(&ucm_dev->cdev);
-	clear_bit(ucm_dev->devnum, dev_map);
+	if (ucm_dev->devnum < IB_UCM_MAX_DEVICES)
+		clear_bit(ucm_dev->devnum, dev_map);
+	else
+		clear_bit(ucm_dev->devnum - IB_UCM_MAX_DEVICES, dev_map);
 	kfree(ucm_dev);
 }

@@ -1237,6 +1240,28 @@ static ssize_t show_ibdev(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
 
+static dev_t oflo_maj;
+static DECLARE_BITMAP(oflo_map, IB_UCM_MAX_DEVICES);
+static int find_oflo_devnum(void)
+{
+	int ret;
+
+	if (!oflo_maj) {
+		ret = alloc_chrdev_region(&oflo_maj, 0, IB_UCM_MAX_DEVICES,
+					  "infiniband_cm");
+		if (ret) {
+			printk(KERN_ERR "ucm: couldn't register dynamic device number\n");
+			return ret;
+		}
+	}
+
+	ret = find_first_zero_bit(oflo_map, IB_UCM_MAX_DEVICES);
+	if (ret >= IB_UCM_MAX_DEVICES)
+		return -1;
+
+	return ret;
+}
+
 static void ib_ucm_add_one(struct ib_device *device)
 {
 	int devnum;

@@ -1254,12 +1279,19 @@ static void ib_ucm_add_one(struct ib_device *device)
 	ucm_dev->ib_dev = device;
 
 	devnum = find_first_zero_bit(dev_map, IB_UCM_MAX_DEVICES);
-	if (devnum >= IB_UCM_MAX_DEVICES)
-		goto err;
-
-	ucm_dev->devnum = devnum;
-	base = devnum + IB_UCM_BASE_DEV;
-	set_bit(devnum, dev_map);
+	if (devnum >= IB_UCM_MAX_DEVICES) {
+		devnum = find_oflo_devnum();
+		if (devnum < 0)
+			goto err;
+
+		ucm_dev->devnum = devnum + IB_UCM_MAX_DEVICES;
+		base = devnum + oflo_maj;
+		set_bit(devnum, oflo_map);
+	} else {
+		ucm_dev->devnum = devnum;
+		base = devnum + IB_UCM_BASE_DEV;
+		set_bit(devnum, dev_map);
+	}
 
 	cdev_init(&ucm_dev->cdev, &ucm_fops);
 	ucm_dev->cdev.owner = THIS_MODULE;

@@ -1285,7 +1317,10 @@ err_dev:
 	device_unregister(&ucm_dev->dev);
 err_cdev:
 	cdev_del(&ucm_dev->cdev);
-	clear_bit(devnum, dev_map);
+	if (ucm_dev->devnum < IB_UCM_MAX_DEVICES)
+		clear_bit(devnum, dev_map);
+	else
+		clear_bit(devnum, oflo_map);
 err:
 	kfree(ucm_dev);
 	return;

@@ -1344,6 +1379,8 @@ static void __exit ib_ucm_cleanup(void)
 	ib_unregister_client(&ucm_client);
 	class_remove_file(&cm_class, &class_attr_abi_version);
 	unregister_chrdev_region(IB_UCM_BASE_DEV, IB_UCM_MAX_DEVICES);
+	if (oflo_maj)
+		unregister_chrdev_region(oflo_maj, IB_UCM_MAX_DEVICES);
 	idr_destroy(&ctx_id_table);
 }

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Alex Chiang

author

2010-02-02 19:09 UTC #17 lore raw

PATCH v2 17/18 IB/ucm: clean whitespace errors

In reply to Alex Chiang

As shown when 'let c_space_errors=1' is set in vim.

Signed-off-by Alex Chiang <[email protected]>

---

 drivers/infiniband/core/ucm.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

drivers/infiniband/core/ucm.c +3 -3

index 1203ca4..7bf0a82 100644
@@ -1223,10 +1223,10 @@ static void ib_ucm_release_dev(struct device *dev)
 }
 
 static const struct file_operations ucm_fops = {
-	.owner 	 = THIS_MODULE,
-	.open 	 = ib_ucm_open,
+	.owner	 = THIS_MODULE,
+	.open	 = ib_ucm_open,
 	.release = ib_ucm_close,
-	.write 	 = ib_ucm_write,
+	.write	 = ib_ucm_write,
 	.poll    = ib_ucm_poll,
 };

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Alex Chiang

author

2010-02-02 19:09 UTC #18 lore raw

PATCH v2 18/18 IB/core: pack struct ib_device a little tighter

In reply to Alex Chiang

A small change to reduce the size of ib_device to 1112 bytes (from 1128).

Signed-off-by Alex Chiang <[email protected]>

---

 include/rdma/ib_verbs.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

include/rdma/ib_verbs.h +2 -2

index 09509ed..a585e0f 100644
@@ -984,9 +984,9 @@ struct ib_device {
 	struct list_head              event_handler_list;
 	spinlock_t                    event_handler_lock;
 
+	spinlock_t                    client_data_lock;
 	struct list_head              core_list;
 	struct list_head              client_data_list;
-	spinlock_t                    client_data_lock;
 
 	struct ib_cache               cache;
 	int                          *pkey_tbl_len;

@@ -1144,8 +1144,8 @@ struct ib_device {
 		IB_DEV_UNREGISTERED
 	}                            reg_state;
 
-	u64			     uverbs_cmd_mask;
 	int			     uverbs_abi_ver;
+	u64			     uverbs_cmd_mask;
 
 	char			     node_desc[64];
 	__be64			     node_guid;

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Roland Dreier

Applied

2010-02-24 18:24 UTC #19 lore raw

Re: [PATCH v2 18/18] IB/core: pack struct ib_device a little tighter

Applied all 18, thanks a lot Alex. You really made the review easy by splitting this up nicely...

- R.

Signature · 7 lines

Roland Dreier  <[email protected]>
For corporate legal information go to:
http://www.cisco.com/web/about/doing_business/legal/cri/index.html
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Alex Chiang

author

2010-02-08 21:30 UTC #20 lore raw

In reply to Alex Chiang

Hi Roland,

Any thoughts on this patch series?

Thanks,
/ac

* Alex Chiang <[email protected]>:

Quoted 165 lines

This is v2 of a patch series that increases the maximum number of IB HCAs supported per system.
The original mail thread is here:
	http://lkml.org/lkml/2010/1/29/346
One note, I decided to "copy/paste" since factoring out the overflow code in the three drivers seemed like overkill. If so desired, I could factor those three separate functions into something provided by the core, but that seemed like more trouble than it was worth at the time.
As before, I still don't have access to a giant system, so what I did to test was to stick 4 cards into a small system, and then modify the limits with debug patches similar to this:
drivers/infiniband/core/ucm.c +1 -1
index 7bf0a82..8581e64 100644
@@ -102,7 +102,7 @@ struct ib_ucm_event {
 enum {
        IB_UCM_MAJOR = 231,
        IB_UCM_BASE_MINOR = 224,
-       IB_UCM_MAX_DEVICES = 32
+       IB_UCM_MAX_DEVICES = 2
 };
 
 
I tested all 3 drivers this way (uverbs, umad, ucm). I verified that we're not leaking device numbers on multiple modprobe/rmmod cycles, that there aren't any funny interactions when various combinations of the drivers are loaded.
I did not test the rest of the OFED stack. I did write some trivial programs to open the devices in /dev and close them again.
Here's an example of some of the testing:
	dl585g2:~ # modprobe ib_uverbs
	dl585g2:~ # modprobe ib_umad
	dl585g2:~ # modprobe ib_ucm
	dl585g2:~ # ls -l /dev/uverb*
	crw-rw---- 1 root root 231, 192 Feb  2 05:55 /dev/uverbs0
	crw-rw---- 1 root root 231, 193 Feb  2 05:55 /dev/uverbs1
	crw-rw---- 1 root root 249,   0 Feb  2 05:55 /dev/uverbs2
	crw-rw---- 1 root root 249,   1 Feb  2 05:55 /dev/uverbs3
	dl585g2:~ # ls -l /dev/umad*
	crw-rw---- 1 root root 231, 0 Feb  2 05:55 /dev/umad0
	crw-rw---- 1 root root 231, 1 Feb  2 05:55 /dev/umad1
	crw-rw---- 1 root root 231, 2 Feb  2 05:55 /dev/umad2
	crw-rw---- 1 root root 231, 3 Feb  2 05:55 /dev/umad3
	crw-rw---- 1 root root 248, 0 Feb  2 05:55 /dev/umad4
	crw-rw---- 1 root root 248, 1 Feb  2 05:55 /dev/umad5
	crw-rw---- 1 root root 248, 2 Feb  2 05:55 /dev/umad6
	crw-rw---- 1 root root 248, 3 Feb  2 05:55 /dev/umad7
	dl585g2:~ # ls -l /dev/issm*
	crw-rw---- 1 root root 231, 4 Feb  2 05:55 /dev/issm0
	crw-rw---- 1 root root 231, 5 Feb  2 05:55 /dev/issm1
	crw-rw---- 1 root root 231, 6 Feb  2 05:55 /dev/issm2
	crw-rw---- 1 root root 231, 7 Feb  2 05:55 /dev/issm3
	crw-rw---- 1 root root 248, 4 Feb  2 05:55 /dev/issm4
	crw-rw---- 1 root root 248, 5 Feb  2 05:55 /dev/issm5
	crw-rw---- 1 root root 248, 6 Feb  2 05:55 /dev/issm6
	crw-rw---- 1 root root 248, 7 Feb  2 05:55 /dev/issm7
	dl585g2:~ # ls -l /dev/ucm*
	crw-rw---- 1 root root 231, 224 Feb  2 05:55 /dev/ucm0
	crw-rw---- 1 root root 231, 225 Feb  2 05:55 /dev/ucm1
	crw-rw---- 1 root root 247,   0 Feb  2 05:55 /dev/ucm2
	crw-rw---- 1 root root 247,   1 Feb  2 05:55 /dev/ucm3
Note that the major and minor numbers are behaving rather sanely.
	dl585g2:~ # rmmod ib_ucm
	dl585g2:~ # rmmod ib_uverbs
	dl585g2:~ # rmmod ib_umad
Reset.
	dl585g2:~ # modprobe ib_ucm
	dl585g2:~ # ls -l /dev/ucm*
	crw-rw---- 1 root root 231, 224 Feb  2 05:57 /dev/ucm0
	crw-rw---- 1 root root 231, 225 Feb  2 05:57 /dev/ucm1
	crw-rw---- 1 root root 248,   0 Feb  2 05:57 /dev/ucm2
	crw-rw---- 1 root root 248,   1 Feb  2 05:57 /dev/ucm3
See that /dev/ucm* devices now have a different major number compared to last time(248 vs 247), since we loaded that driver first.
But wait, why is it 248 and not 249? Is there a leak somewhere?
	dl585g2:~ # ls -l /dev/uverb*
	crw-rw---- 1 root root 231, 192 Feb  2 05:57 /dev/uverbs0
	crw-rw---- 1 root root 231, 193 Feb  2 05:57 /dev/uverbs1
	crw-rw---- 1 root root 249,   0 Feb  2 05:57 /dev/uverbs2
	crw-rw---- 1 root root 249,   1 Feb  2 05:57 /dev/uverbs3
	dl585g2:~ # rmmod ib_uverbs
	ERROR: Module ib_uverbs is in use by ib_ucm
Ah, ib_ucm is dependent on ib_uverbs, so when we modprobed ib_ucm, in reality ib_uverbs got loaded first. See how it has a higher major number.
	dl585g2:~ # rmmod ib_ucm
	dl585g2:~ # rmmod ib_uverbs
	dl585g2:~ # modprobe ib_umad
	dl585g2:~ # ls -l /dev/umad*
	crw-rw---- 1 root root 231, 0 Feb  2 05:58 /dev/umad0
	crw-rw---- 1 root root 231, 1 Feb  2 05:58 /dev/umad1
	crw-rw---- 1 root root 231, 2 Feb  2 05:58 /dev/umad2
	crw-rw---- 1 root root 231, 3 Feb  2 05:58 /dev/umad3
	crw-rw---- 1 root root 249, 0 Feb  2 05:58 /dev/umad4
	crw-rw---- 1 root root 249, 1 Feb  2 05:58 /dev/umad5
	crw-rw---- 1 root root 249, 2 Feb  2 05:58 /dev/umad6
	crw-rw---- 1 root root 249, 3 Feb  2 05:58 /dev/umad7
	dl585g2:~ # ls -l /dev/issm*
	crw-rw---- 1 root root 231, 4 Feb  2 05:58 /dev/issm0
	crw-rw---- 1 root root 231, 5 Feb  2 05:58 /dev/issm1
	crw-rw---- 1 root root 231, 6 Feb  2 05:58 /dev/issm2
	crw-rw---- 1 root root 231, 7 Feb  2 05:58 /dev/issm3
	crw-rw---- 1 root root 249, 4 Feb  2 05:58 /dev/issm4
	crw-rw---- 1 root root 249, 5 Feb  2 05:58 /dev/issm5
	crw-rw---- 1 root root 249, 6 Feb  2 05:58 /dev/issm6
	crw-rw---- 1 root root 249, 7 Feb  2 05:58 /dev/issm7
Finally, after one more reset, we see ib_umad loaded first and obtaining the major number of 249.
v1 -> v2:
- update umad and ucm drivers too
---
Alex Chiang (18):
IB/uverbs: convert *cdev to cdev in struct ib_uverbs_device IB/uverbs: remove dev_table
IB/uverbs: use stack variable 'devnum' in ib_uverbs_add_one IB/uverbs: use stack variable 'base' in ib_uverbs_add_one IB/uverbs: increase maximum devices supported
IB/uverbs: pack struct ib_uverbs_event_file tighter IB/uverbs: whitespace cleanup
IB/umad: convert cdev pointers to embedded structs in struct ib_umad_port IB/umad: remove port_table[]
IB/umad: use stack variable 'devnum' in ib_umad_init_port IB/umad: use stack variable 'base' in ib_umad_init_port IB/umad: increase maximum devices supported
IB/umad: clean whitespace
IB/ucm: use stack variable 'devnum' in ib_ucm_add_one IB/ucm: use stack variable 'base' in ib_ucm_add_one
IB/ucm: increase maximum devices supported
IB/ucm: clean whitespace errors
IB/core: pack struct ib_device a little tighter
 drivers/infiniband/core/ucm.c         |   63 ++++++++++--
 drivers/infiniband/core/user_mad.c    |  173 +++++++++++++++++----------------
 drivers/infiniband/core/uverbs.h      |   11 +-
 drivers/infiniband/core/uverbs_main.c |  175 +++++++++++++++++++--------------
 include/rdma/ib_verbs.h               |    4 -
 5 files changed, 255 insertions(+), 171 deletions(-)
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