lib: logic_pio: Add logic_pio_unregister_range()

commit b884e2de2afc68ce30f7093747378ef972dde253 upstream. Add a function to unregister a logical PIO range. Logical PIO space can still be leaked when unregistering certain LOGIC_PIO_CPU_MMIO regions, but this acceptable for now since there are no callers to unregister LOGIC_PIO_CPU_MMIO regions, and the logical PIO region allocation scheme would need significant work to improve this. Cc: [email protected] Signed-off-by: John Garry <[email protected]> Signed-off-by: Wei Xu <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
akeromi · Sep 6, 2019 · c4616a9 · c4616a9
1 parent 7faef13
commit c4616a9
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diff --git a/include/linux/logic_pio.h b/include/linux/logic_pio.h
@@ -117,6 +117,7 @@ struct logic_pio_hwaddr *find_io_range_by_fwnode(struct fwnode_handle *fwnode);
 unsigned long logic_pio_trans_hwaddr(struct fwnode_handle *fwnode,
 			resource_size_t hw_addr, resource_size_t size);
 int logic_pio_register_range(struct logic_pio_hwaddr *newrange);
+void logic_pio_unregister_range(struct logic_pio_hwaddr *range);
 resource_size_t logic_pio_to_hwaddr(unsigned long pio);
 unsigned long logic_pio_trans_cpuaddr(resource_size_t hw_addr);
 

diff --git a/lib/logic_pio.c b/lib/logic_pio.c
@@ -98,6 +98,20 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
 	return ret;
 }
 
+/**
+ * logic_pio_unregister_range - unregister a logical PIO range for a host
+ * @range: pointer to the IO range which has been already registered.
+ *
+ * Unregister a previously-registered IO range node.
+ */
+void logic_pio_unregister_range(struct logic_pio_hwaddr *range)
+{
+	mutex_lock(&io_range_mutex);
+	list_del_rcu(&range->list);
+	mutex_unlock(&io_range_mutex);
+	synchronize_rcu();
+}
+
 /**
  * find_io_range_by_fwnode - find logical PIO range for given FW node
  * @fwnode: FW node handle associated with logical PIO range