4 files changed, 148 insertions, 55 deletions

diff --git a/include/litmus/ftdev.h b/include/litmus/ftdev.h
index efb2a5c9a9b0..348387e9adf9 100644
--- a/include/litmus/ftdev.h
+++ b/include/litmus/ftdev.h
@@ -6,8 +6,6 @@
 #include <linux/mutex.h>
 #include <linux/cdev.h>
 
-#define MAX_FTDEV_MINORS NR_CPUS
-
 #define FTDEV_ENABLE_CMD        0
 #define FTDEV_DISABLE_CMD       1
 
@@ -32,11 +30,11 @@ struct ftdev_minor {
 };
 
 struct ftdev {
+        dev_t                   major;
         struct cdev             cdev;
         struct class*           class;
         const char*             name;
-        /* FIXME: don't waste memory, allocate dynamically */
-        struct ftdev_minor      minor[MAX_FTDEV_MINORS];
+        struct ftdev_minor*     minor;
         unsigned int            minor_cnt;
         ftdev_alloc_t           alloc;
         ftdev_free_t            free;
@@ -46,7 +44,9 @@ struct ftdev {
 struct ft_buffer* alloc_ft_buffer(unsigned int count, size_t size);
 void free_ft_buffer(struct ft_buffer* buf);
 
-void ftdev_init(struct ftdev* ftdev, struct module* owner, const char* name);
+int ftdev_init( struct ftdev* ftdev, struct module* owner,
+                const int minor_cnt, const char* name);
+void ftdev_exit(struct ftdev* ftdev);
 int register_ftdev(struct ftdev* ftdev);
 
 #endif
diff --git a/litmus/ftdev.c b/litmus/ftdev.c
index d68d05c6d7dc..4a4b2e3e56c2 100644
--- a/litmus/ftdev.c
+++ b/litmus/ftdev.c
@@ -310,80 +310,131 @@ struct file_operations ftdev_fops = {
         .read    = ftdev_read,
 };
 
-
-void ftdev_init(struct ftdev* ftdev, struct module* owner, const char* name)
+int ftdev_init( struct ftdev* ftdev, struct module* owner,
+                const int minor_cnt, const char* name)
 {
-        int i, error;
+        int i, err;
+
+        BUG_ON(minor_cnt < 1);
+
         cdev_init(&ftdev->cdev, &ftdev_fops);
         ftdev->name = name;
+        ftdev->minor_cnt = minor_cnt;
         ftdev->cdev.owner = owner;
         ftdev->cdev.ops = &ftdev_fops;
-        ftdev->minor_cnt  = 0;
-        for (i = 0; i < MAX_FTDEV_MINORS; i++) {
+        ftdev->alloc    = NULL;
+        ftdev->free     = NULL;
+        ftdev->can_open = NULL;
+
+        ftdev->minor = kcalloc(ftdev->minor_cnt, sizeof(*ftdev->minor),
+                        GFP_KERNEL);
+        if (!ftdev->minor) {
+                printk(KERN_WARNING "ftdev(%s): Could not allocate memory\n",
+                        ftdev->name);
+                err = -ENOMEM;
+                goto err_out;
+        }
+
+        for (i = 0; i < ftdev->minor_cnt; i++) {
                 mutex_init(&ftdev->minor[i].lock);
                 ftdev->minor[i].readers = 0;
                 ftdev->minor[i].buf     = NULL;
                 ftdev->minor[i].events  = NULL;
         }
-        ftdev->alloc    = NULL;
-        ftdev->free     = NULL;
-        ftdev->can_open = NULL;
 
         ftdev->class = class_create(owner, ftdev->name);
         if (IS_ERR(ftdev->class)) {
-                error = PTR_ERR(ftdev->class);
+                err = PTR_ERR(ftdev->class);
                 printk(KERN_WARNING "ftdev(%s): "
-                        "Could not create device class.\n",
-                        name);
+                        "Could not create device class.\n", ftdev->name);
+                goto err_dealloc;
         }
+
+        return 0;
+
+err_dealloc:
+        kfree(ftdev->minor);
+err_out:
+        return err;
+}
+
+/*
+ * Destroy minor devices up to, but not including, up_to.
+ */
+static void ftdev_device_destroy(struct ftdev* ftdev, unsigned int up_to)
+{
+        dev_t minor_cntr;
+
+        if (up_to < 1)
+                up_to = (ftdev->minor_cnt < 1) ? 0 : ftdev->minor_cnt;
+
+        for (minor_cntr = 0; minor_cntr < up_to; ++minor_cntr)
+                device_destroy(ftdev->class, MKDEV(ftdev->major, minor_cntr));
+}
+
+void ftdev_exit(struct ftdev* ftdev)
+{
+        printk("ftdev(%s): Exiting\n", ftdev->name);
+        ftdev_device_destroy(ftdev, -1);
+        cdev_del(&ftdev->cdev);
+        unregister_chrdev_region(MKDEV(ftdev->major, 0), ftdev->minor_cnt);
+        class_destroy(ftdev->class);
+        kfree(ftdev->minor);
 }
 
 int register_ftdev(struct ftdev* ftdev)
 {
         struct device **device;
-        dev_t   trace_dev;
-        int error = 0, major, i;
+        dev_t trace_dev_tmp, minor_cntr;
+        int err;
 
-        error = alloc_chrdev_region(&trace_dev, 0, ftdev->minor_cnt,
+        err = alloc_chrdev_region(&trace_dev_tmp, 0, ftdev->minor_cnt,
                         ftdev->name);
-        major = MAJOR(trace_dev);
-        if (error)
-        {
+        if (err) {
                 printk(KERN_WARNING "ftdev(%s): "
-                       "Could not register major/minor number %d/%u\n",
-                       ftdev->name, major, ftdev->minor_cnt);
-                goto out;
+                       "Could not allocate char. device region (%d minors)\n",
+                       ftdev->name, ftdev->minor_cnt);
+                goto err_out;
         }
-        error = cdev_add(&ftdev->cdev, trace_dev, ftdev->minor_cnt);
-        if (error) {
+
+        ftdev->major = MAJOR(trace_dev_tmp);
+
+        err = cdev_add(&ftdev->cdev, trace_dev_tmp, ftdev->minor_cnt);
+        if (err) {
                 printk(KERN_WARNING "ftdev(%s): "
-                       "Could not add cdev for major/minor = %d/%u.\n",
-                       ftdev->name, major, ftdev->minor_cnt);
-                goto out;
+                       "Could not add cdev for major %u with %u minor(s).\n",
+                       ftdev->name, ftdev->major, ftdev->minor_cnt);
+                goto err_unregister;
         }
 
-        /*
-         * create all the minor devices
-         */
-        for (i = 0; i < ftdev->minor_cnt; ++i)
+        /* create the minor device(s) */
+        for (minor_cntr = 0; minor_cntr < ftdev->minor_cnt; ++minor_cntr)
         {
-                trace_dev = MKDEV(major, i);
-                device = &(ftdev->minor[i].device);
+                trace_dev_tmp = MKDEV(ftdev->major, minor_cntr);
+                device = &ftdev->minor[minor_cntr].device;
 
-                *device = device_create(ftdev->class, NULL, trace_dev, NULL,
-                                "%s%d", ftdev->name, i);
+                *device = device_create(ftdev->class, NULL, trace_dev_tmp, NULL,
+                                "litmus/%s%d", ftdev->name, minor_cntr);
                 if (IS_ERR(*device)) {
-                        error = PTR_ERR(*device);
+                        err = PTR_ERR(*device);
                         printk(KERN_WARNING "ftdev(%s): "
                                 "Could not create device major/minor number "