This patch keeps all created pools in a global list and adds two
functions that allow to retrieve the gen_pool pointer from a known
physical address and from a device tree node.

Signed-off-by: Philipp Zabel <p.za...@pengutronix.de>
---
 include/linux/genalloc.h |   14 +++++++++
 lib/genalloc.c           |   77 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 91 insertions(+)

diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
index 5e98eeb..46ff435 100644
--- a/include/linux/genalloc.h
+++ b/include/linux/genalloc.h
@@ -33,6 +33,7 @@
  *  General purpose special memory pool descriptor.
  */
 struct gen_pool {
+       struct list_head next_pool;     /* pool in global list */
        spinlock_t lock;
        struct list_head chunks;        /* list of chunks in this pool */
        int min_alloc_order;            /* minimum allocation order */
@@ -78,4 +79,17 @@ extern void gen_pool_for_each_chunk(struct gen_pool *,
        void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *);
 extern size_t gen_pool_avail(struct gen_pool *);
 extern size_t gen_pool_size(struct gen_pool *);
+extern struct gen_pool *gen_pool_find_by_phys(phys_addr_t phys);
+
+#ifdef CONFIG_OF
+struct device_node;
+extern struct gen_pool *of_get_named_gen_pool(struct device_node *np,
+       const char *propname, int index);
+#else
+inline struct gen_pool *of_get_named_gen_pool(struct device_node *np,
+       const char *propname, int index)
+{
+       return NULL;
+}
+#endif
 #endif /* __GENALLOC_H__ */
diff --git a/lib/genalloc.c b/lib/genalloc.c
index 6bc04aa..df2d8f9 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -34,6 +34,11 @@
 #include <linux/rculist.h>
 #include <linux/interrupt.h>
 #include <linux/genalloc.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+
+static LIST_HEAD(pools);
+static DEFINE_SPINLOCK(list_lock);
 
 static int set_bits_ll(unsigned long *addr, unsigned long mask_to_set)
 {
@@ -152,6 +157,9 @@ struct gen_pool *gen_pool_create(int min_alloc_order, int 
nid)
                spin_lock_init(&pool->lock);
                INIT_LIST_HEAD(&pool->chunks);
                pool->min_alloc_order = min_alloc_order;
+               spin_lock(&list_lock);
+               list_add_rcu(&pool->next_pool, &pools);
+               spin_unlock(&list_lock);
        }
        return pool;
 }
@@ -234,6 +242,9 @@ void gen_pool_destroy(struct gen_pool *pool)
        int order = pool->min_alloc_order;
        int bit, end_bit;
 
+       spin_lock(&list_lock);
+       list_del_rcu(&pool->next_pool);
+       spin_unlock(&list_lock);
        list_for_each_safe(_chunk, _next_chunk, &pool->chunks) {
                chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
                list_del(&chunk->next_chunk);
@@ -400,3 +411,69 @@ size_t gen_pool_size(struct gen_pool *pool)
        return size;
 }
 EXPORT_SYMBOL_GPL(gen_pool_size);
+
+/**
+ * gen_pool_find_by_phys - find a pool by physical start address
+ * @phys: physical address as added with gen_pool_add_virt
+ *
+ * Returns the pool that contains the chunk starting at phys,
+ * or NULL if not found.
+ */
+struct gen_pool *gen_pool_find_by_phys(phys_addr_t phys)
+{
+       struct gen_pool *pool, *found = NULL;
+       struct gen_pool_chunk *chunk;
+
+       rcu_read_lock();
+       list_for_each_entry_rcu(pool, &pools, next_pool) {
+               list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
+                       if (phys == chunk->phys_addr) {
+                               found = pool;
+                               break;
+                       }
+               }
+       }
+       rcu_read_unlock();
+
+       return found;
+}
+EXPORT_SYMBOL_GPL(gen_pool_find_by_phys);
+
+#ifdef CONFIG_OF
+/**
+ * of_get_named_gen_pool - find a pool by the physical address in
+ * @np: device node
+ *
+ * Returns the pool that contains the chunk starting at the physical
+ * address of the np device node, or NULL if not found.
+ */
+struct gen_pool *of_get_named_gen_pool(struct device_node *np,
+       const char *propname, int index)
+{
+       struct property *prop;
+       const __be32 *list;
+       int size;
+       phandle phandle;
+       struct device_node *np_pool;
+       const u32 *reg;
+       u64 addr;
+
+       prop = of_find_property(np, propname, &size);
+       if (!prop)
+               return NULL;
+       list = prop->value;
+       size /= sizeof(*list);
+       phandle = be32_to_cpup(list);
+       np_pool = of_find_node_by_phandle(phandle);
+       if (!np_pool)
+               return NULL;
+       reg = of_get_property(np_pool, "reg", NULL);
+       if (!reg)
+               return NULL;
+       addr = of_translate_address(np_pool, reg);
+       if (addr == OF_BAD_ADDR)
+               return NULL;
+       return gen_pool_find_by_phys((phys_addr_t) addr);
+}
+EXPORT_SYMBOL_GPL(of_get_named_gen_pool);
+#endif /* CONFIG_OF */
-- 
1.7.10.4

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