uwb: improved MAS allocator and reservation conflict handling

Greatly enhance the MAS allocator:
  - Handle row and column reservations.
  - Permit all the available MAS to be allocated.
  - Follows the WiMedia rules on MAS selection.

Take appropriate action when reservation conflicts are detected.
  - Correctly identify which reservation wins the conflict.
  - Protect alien BP reservations.
  - If an owned reservation loses, resize/move it.
  - Follow the backoff procedure before requesting additional MAS.

When reservations are terminated, move the remaining reservations (if
necessary) so they keep following the MAS allocation rules.

Signed-off-by: Stefano Panella <stefano.panella@csr.com>
Signed-off-by: David Vrabel <david.vrabel@csr.com>

1 files changed, 26 insertions, 23 deletions

diff --git a/drivers/uwb/uwb-debug.c b/drivers/uwb/uwb-debug.c
index a6debb9baf38..89b2e6a7214c 100644
--- a/drivers/uwb/uwb-debug.c
+++ b/drivers/uwb/uwb-debug.c
@@ -82,29 +82,21 @@ struct uwb_dbg {
         struct dentry *reservations_f;
         struct dentry *accept_f;
         struct dentry *drp_avail_f;
+        spinlock_t list_lock;
 };
 
 static struct dentry *root_dir;
 
 static void uwb_dbg_rsv_cb(struct uwb_rsv *rsv)
 {
-        struct uwb_rc *rc = rsv->rc;
-        struct device *dev = &rc->uwb_dev.dev;
-        struct uwb_dev_addr devaddr;
-        char owner[UWB_ADDR_STRSIZE], target[UWB_ADDR_STRSIZE];
-
-        uwb_dev_addr_print(owner, sizeof(owner), &rsv->owner->dev_addr);
-        if (rsv->target.type == UWB_RSV_TARGET_DEV)
-                devaddr = rsv->target.dev->dev_addr;
-        else
-                devaddr = rsv->target.devaddr;
-        uwb_dev_addr_print(target, sizeof(target), &devaddr);
+        struct uwb_dbg *dbg = rsv->pal_priv;
 
-        dev_dbg(dev, "debug: rsv %s -> %s: %s\n",
-                owner, target, uwb_rsv_state_str(rsv->state));
+        uwb_rsv_dump("debug", rsv);
 
         if (rsv->state == UWB_RSV_STATE_NONE) {
+                spin_lock(&dbg->list_lock);
                 list_del(&rsv->pal_node);
+                spin_unlock(&dbg->list_lock);
                 uwb_rsv_destroy(rsv);
         }
 }
@@ -128,20 +120,21 @@ static int cmd_rsv_establish(struct uwb_rc *rc,
                 return -ENOMEM;
         }
 
-        rsv->owner       = &rc->uwb_dev;
-        rsv->target.type = UWB_RSV_TARGET_DEV;
-        rsv->target.dev  = target;
-        rsv->type        = cmd->type;
-        rsv->max_mas     = cmd->max_mas;
-        rsv->min_mas     = cmd->min_mas;
-        rsv->sparsity    = cmd->sparsity;
+        rsv->target.type  = UWB_RSV_TARGET_DEV;
+        rsv->target.dev   = target;
+        rsv->type         = cmd->type;
+        rsv->max_mas      = cmd->max_mas;
+        rsv->min_mas      = cmd->min_mas;
+        rsv->max_interval = cmd->max_interval;
 
         ret = uwb_rsv_establish(rsv);
         if (ret)
                 uwb_rsv_destroy(rsv);
-        else
+        else {
+                spin_lock(&(rc->dbg)->list_lock);
                 list_add_tail(&rsv->pal_node, &rc->dbg->rsvs);
-
+                spin_unlock(&(rc->dbg)->list_lock);
+        }
         return ret;
 }
 
@@ -151,17 +144,24 @@ static int cmd_rsv_terminate(struct uwb_rc *rc,
         struct uwb_rsv *rsv, *found = NULL;
         int i = 0;
 
+        spin_lock(&(rc->dbg)->list_lock);
+
         list_for_each_entry(rsv, &rc->dbg->rsvs, pal_node) {
                 if (i == cmd->index) {
                         found = rsv;
+                        uwb_rsv_get(found);
                         break;
                 }
                 i++;
         }
+
+        spin_unlock(&(rc->dbg)->list_lock);
+
         if (!found)
                 return -EINVAL;
 
         uwb_rsv_terminate(found);
+        uwb_rsv_put(found);
 
         return 0;
 }
@@ -191,7 +191,7 @@ static ssize_t command_write(struct file *file, const char __user *buf,
         struct uwb_rc *rc = file->private_data;
         struct uwb_dbg_cmd cmd;
         int ret = 0;
-
+        
         if (len != sizeof(struct uwb_dbg_cmd))
                 return -EINVAL;
 
@@ -325,7 +325,9 @@ static void uwb_dbg_new_rsv(struct uwb_pal *pal, struct uwb_rsv *rsv)
         struct uwb_dbg *dbg = container_of(pal, struct uwb_dbg, pal);
 
         if (dbg->accept) {
+                spin_lock(&dbg->list_lock);
                 list_add_tail(&rsv->pal_node, &dbg->rsvs);
+                spin_unlock(&dbg->list_lock);
                 uwb_rsv_accept(rsv, uwb_dbg_rsv_cb, dbg);
         }
 }
@@ -341,6 +343,7 @@ void uwb_dbg_add_rc(struct uwb_rc *rc)
                 return;
 
         INIT_LIST_HEAD(&rc->dbg->rsvs);
+        spin_lock_init(&(rc->dbg)->list_lock);
 
         uwb_pal_init(&rc->dbg->pal);
         rc->dbg->pal.rc = rc;