drivers/edac: edac_device code tidying

For the file edac_device.c perform some coding style enhancements
Add some function header comments
Made for better readability commands

Signed-off-by: Douglas Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 54 insertions, 51 deletions

diff --git a/drivers/edac/edac_device.c b/drivers/edac/edac_device.c
index 258e146efcbd..3ccadda3e723 100644
--- a/drivers/edac/edac_device.c
+++ b/drivers/edac/edac_device.c
@@ -20,6 +20,7 @@
 #include <linux/highmem.h>
 #include <linux/timer.h>
 #include <linux/slab.h>
+#include <linux/jiffies.h>
 #include <linux/spinlock.h>
 #include <linux/list.h>
 #include <linux/sysdev.h>
@@ -31,20 +32,10 @@
 #include "edac_core.h"
 #include "edac_module.h"
 
-/* lock to memory controller's control array */
+/* lock to memory controller's control array 'edac_device_list' */
 static DECLARE_MUTEX(device_ctls_mutex);
 static struct list_head edac_device_list = LIST_HEAD_INIT(edac_device_list);
 
-static inline void lock_device_list(void)
-{
-        down(&device_ctls_mutex);
-}
-
-static inline void unlock_device_list(void)
-{
-        up(&device_ctls_mutex);
-}
-
 #ifdef CONFIG_EDAC_DEBUG
 static void edac_device_dump_device(struct edac_device_ctl_info *edac_dev)
 {
@@ -58,20 +49,25 @@ static void edac_device_dump_device(struct edac_device_ctl_info *edac_dev)
 #endif                          /* CONFIG_EDAC_DEBUG */
 
 /*
- * The alloc() and free() functions for the 'edac_device' control info
- * structure. A MC driver will allocate one of these for each edac_device
- * it is going to control/register with the EDAC CORE.
+ * edac_device_alloc_ctl_info()
+ *      Allocate a new edac device control info structure
+ *
+ *      The control structure is allocated in complete chunk
+ *      from the OS. It is in turn sub allocated to the
+ *      various objects that compose the struture
+ *
+ *      The structure has a 'nr_instance' array within itself.
+ *      Each instance represents a major component
+ *              Example:  L1 cache and L2 cache are 2 instance components
+ *
+ *      Within each instance is an array of 'nr_blocks' blockoffsets
  */
 struct edac_device_ctl_info *edac_device_alloc_ctl_info(
         unsigned sz_private,
-        char *edac_device_name,
-        unsigned nr_instances,
-        char *edac_block_name,
-        unsigned nr_blocks,
-        unsigned offset_value,
-        struct edac_attrib_spec
-        *attrib_spec,
-        unsigned nr_attribs)
+        char *edac_device_name, unsigned nr_instances,
+        char *edac_block_name, unsigned nr_blocks,
+        unsigned offset_value,          /* zero, 1, or other based offset */
+        struct edac_attrib_spec *attrib_spec, unsigned nr_attribs)
 {
         struct edac_device_ctl_info *dev_ctl;
         struct edac_device_instance *dev_inst, *inst;
@@ -90,7 +86,7 @@ struct edac_device_ctl_info *edac_device_alloc_ctl_info(
          * to be at least as stringent as what the compiler would
          * provide if we could simply hardcode everything into a single struct.
          */
-        dev_ctl = (struct edac_device_ctl_info *)0;
+        dev_ctl = (struct edac_device_ctl_info *)NULL;
 
         /* Calc the 'end' offset past the ctl_info structure */
         dev_inst = (struct edac_device_instance *)
@@ -114,7 +110,8 @@ struct edac_device_ctl_info *edac_device_alloc_ctl_info(
         total_size = ((unsigned long)pvt) + sz_private;
 
         /* Allocate the amount of memory for the set of control structures */
-        if ((dev_ctl = kmalloc(total_size, GFP_KERNEL)) == NULL)
+        dev_ctl = kzalloc(total_size, GFP_KERNEL);
+        if (dev_ctl == NULL)
                 return NULL;
 
         /* Adjust pointers so they point within the memory we just allocated
@@ -128,14 +125,12 @@ struct edac_device_ctl_info *edac_device_alloc_ctl_info(
                 (((char *)dev_ctl) + ((unsigned long)dev_attrib));
         pvt = sz_private ? (((char *)dev_ctl) + ((unsigned long)pvt)) : NULL;
 
-        memset(dev_ctl, 0, total_size); /* clear all fields */
         dev_ctl->nr_instances = nr_instances;
         dev_ctl->instances = dev_inst;
         dev_ctl->pvt_info = pvt;
 
-        /* Name of this edac device, ensure null terminated */
-        snprintf(dev_ctl->name, sizeof(dev_ctl->name), "%s", edac_device_name);
-        dev_ctl->name[sizeof(dev_ctl->name) - 1] = '\0';
+        /* Name of this edac device */
+        snprintf(dev_ctl->name,sizeof(dev_ctl->name),"%s",edac_device_name);
 
         /* Initialize every Instance */
         for (instance = 0; instance < nr_instances; instance++) {
@@ -148,7 +143,6 @@ struct edac_device_ctl_info *edac_device_alloc_ctl_info(
                 /* name of this instance */
                 snprintf(inst->name, sizeof(inst->name),
                          "%s%u", edac_device_name, instance);
-                inst->name[sizeof(inst->name) - 1] = '\0';
 
                 /* Initialize every block in each instance */
                 for (block = 0; block < nr_blocks; block++) {
@@ -159,7 +153,6 @@ struct edac_device_ctl_info *edac_device_alloc_ctl_info(
                         blk->attribs = attrib_p;
                         snprintf(blk->name, sizeof(blk->name),
                                  "%s%d", edac_block_name, block+offset_value);
-                        blk->name[sizeof(blk->name) - 1] = '\0';
 
                         debugf1("%s() instance=%d block=%d name=%s\n",
                                 __func__, instance, block, blk->name);
@@ -186,7 +179,6 @@ struct edac_device_ctl_info *edac_device_alloc_ctl_info(
 
         return dev_ctl;
 }
-
 EXPORT_SYMBOL_GPL(edac_device_alloc_ctl_info);
 
 /*
@@ -198,12 +190,17 @@ void edac_device_free_ctl_info(struct edac_device_ctl_info *ctl_info)
 {
         kfree(ctl_info);
 }
-
 EXPORT_SYMBOL_GPL(edac_device_free_ctl_info);
 
 /*
  * find_edac_device_by_dev
  *      scans the edac_device list for a specific 'struct device *'
+ *
+ *      lock to be held prior to call:  device_ctls_mutex
+ *
+ *      Return:
+ *              pointer to control structure managing 'dev'
+ *              NULL if not found on list
  */
 static struct edac_device_ctl_info *find_edac_device_by_dev(struct device *dev)
 {
@@ -226,6 +223,9 @@ static struct edac_device_ctl_info *find_edac_device_by_dev(struct device *dev)
  * add_edac_dev_to_global_list
  *      Before calling this function, caller must
  *      assign a unique value to edac_dev->dev_idx.
+ *
+ *      lock to be held prior to call:  device_ctls_mutex
+ *
  *      Return:
  *              0 on success
  *              1 on failure.
@@ -238,7 +238,8 @@ static int add_edac_dev_to_global_list(struct edac_device_ctl_info *edac_dev)
         insert_before = &edac_device_list;
 
         /* Determine if already on the list */
-        if (unlikely((rover = find_edac_device_by_dev(edac_dev->dev)) != NULL))
+        rover = find_edac_device_by_dev(edac_dev->dev);
+        if (unlikely(rover != NULL))
                 goto fail0;
 
         /* Insert in ascending order by 'dev_idx', so find position */
@@ -274,6 +275,8 @@ fail1:
 
 /*
  * complete_edac_device_list_del
+ *
+ *      callback function when reference count is zero
  */
 static void complete_edac_device_list_del(struct rcu_head *head)
 {
@@ -286,6 +289,9 @@ static void complete_edac_device_list_del(struct rcu_head *head)
 
 /*
  * del_edac_device_from_global_list
+ *
+ *      remove the RCU, setup for a callback call, then wait for the
+ *      callback to occur
  */
 static void del_edac_device_from_global_list(struct edac_device_ctl_info
                                                 *edac_device)
@@ -325,8 +331,7 @@ struct edac_device_ctl_info *edac_device_find(int idx)
 
         return NULL;
 }
-
-EXPORT_SYMBOL(edac_device_find);
+EXPORT_SYMBOL_GPL(edac_device_find);
 
 /*
  * edac_device_workq_function
@@ -338,7 +343,7 @@ static void edac_device_workq_function(struct work_struct *work_req)
         struct edac_device_ctl_info *edac_dev = to_edac_device_ctl_work(d_work);
 
         //debugf0("%s() here and running\n", __func__);
-        lock_device_list();
+        down(&device_ctls_mutex);
 
         /* Only poll controllers that are running polled and have a check */
         if ((edac_dev->op_state == OP_RUNNING_POLL) &&
@@ -346,7 +351,7 @@ static void edac_device_workq_function(struct work_struct *work_req)
                         edac_dev->edac_check(edac_dev);
         }
 
-        unlock_device_list();
+        up(&device_ctls_mutex);
 
         /* Reschedule */
         queue_delayed_work(edac_workqueue, &edac_dev->work, edac_dev->delay);
@@ -363,7 +368,7 @@ void edac_device_workq_setup(struct edac_device_ctl_info *edac_dev,
         debugf0("%s()\n", __func__);
 
         edac_dev->poll_msec = msec;
-        edac_calc_delay(edac_dev);      /* Calc delay jiffies */
+        edac_dev->delay = msecs_to_jiffies(msec);       /* Calc delay jiffies */
 
         INIT_DELAYED_WORK(&edac_dev->work, edac_device_workq_function);
         queue_delayed_work(edac_workqueue, &edac_dev->work, edac_dev->delay);
@@ -391,7 +396,7 @@ void edac_device_workq_teardown(struct edac_device_ctl_info *edac_dev)
 void edac_device_reset_delay_period(struct edac_device_ctl_info *edac_dev,
                                         unsigned long value)
 {
-        lock_device_list();
+        down(&device_ctls_mutex);
 
         /* cancel the current workq request */
         edac_device_workq_teardown(edac_dev);
@@ -399,7 +404,7 @@ void edac_device_reset_delay_period(struct edac_device_ctl_info *edac_dev,
         /* restart the workq request, with new delay value */
         edac_device_workq_setup(edac_dev, value);
 
-        unlock_device_list();
+        up(&device_ctls_mutex);
 }
 
 /**
@@ -423,7 +428,7 @@ int edac_device_add_device(struct edac_device_ctl_info *edac_dev, int edac_idx)
         if (edac_debug_level >= 3)
                 edac_device_dump_device(edac_dev);
 #endif
-        lock_device_list();
+        down(&device_ctls_mutex);
 
         if (add_edac_dev_to_global_list(edac_dev))
                 goto fail0;
@@ -461,7 +466,7 @@ int edac_device_add_device(struct edac_device_ctl_info *edac_dev, int edac_idx)
                                 dev_name(edac_dev),
                                 edac_op_state_toString(edac_dev->op_state));
 
-        unlock_device_list();
+        up(&device_ctls_mutex);
         return 0;
 
 fail1:
@@ -469,10 +474,9 @@ fail1:
         del_edac_device_from_global_list(edac_dev);
 
 fail0:
-        unlock_device_list();
+        up(&device_ctls_mutex);
         return 1;
 }
-
 EXPORT_SYMBOL_GPL(edac_device_add_device);
 
 /**
@@ -494,10 +498,12 @@ struct edac_device_ctl_info *edac_device_del_device(struct device *dev)
 
         debugf0("MC: %s()\n", __func__);
 
-        lock_device_list();
+        down(&device_ctls_mutex);
 
-        if ((edac_dev = find_edac_device_by_dev(dev)) == NULL) {
-                unlock_device_list();
+        /* Find the structure on the list, if not there, then leave */
+        edac_dev = find_edac_device_by_dev(dev);
+        if (edac_dev == NULL) {
+                up(&device_ctls_mutex);
                 return NULL;
         }
 
@@ -513,7 +519,7 @@ struct edac_device_ctl_info *edac_device_del_device(struct device *dev)
         /* deregister from global list */
         del_edac_device_from_global_list(edac_dev);
 
-        unlock_device_list();
+        up(&device_ctls_mutex);
 
         edac_printk(KERN_INFO, EDAC_MC,
                 "Removed device %d for %s %s: DEV %s\n",
@@ -522,7 +528,6 @@ struct edac_device_ctl_info *edac_device_del_device(struct device *dev)
 
         return edac_dev;
 }
-
 EXPORT_SYMBOL_GPL(edac_device_del_device);
 
 static inline int edac_device_get_log_ce(struct edac_device_ctl_info *edac_dev)
@@ -585,7 +590,6 @@ void edac_device_handle_ce(struct edac_device_ctl_info *edac_dev,
                                 edac_dev->ctl_name, instance->name,
                                 block ? block->name : "N/A", msg);
 }
-
 EXPORT_SYMBOL_GPL(edac_device_handle_ce);
 
 /*
@@ -637,5 +641,4 @@ void edac_device_handle_ue(struct edac_device_ctl_info *edac_dev,
                         edac_dev->ctl_name, instance->name,
                         block ? block->name : "N/A", msg);
 }
-
 EXPORT_SYMBOL_GPL(edac_device_handle_ue);