genalloc:support allocating specific region

Add new algo for genalloc, it reserve a specific region of
memory

Signed-off-by: Zhao Qiang <qiang.zhao@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>

diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
index 3c676ce..29d4385 100644 (file)
--- a/include/linux/genalloc.h
+++ b/include/linux/genalloc.h
@@ -84,6 +84,13 @@ struct genpool_data_align {
        int align;              /* alignment by bytes for starting address */
 };
 
+/*
+ *  gen_pool data descriptor for gen_pool_fixed_alloc.
+ */
+struct genpool_data_fixed {
+       unsigned long offset;           /* The offset of the specific region */
+};
+
 extern struct gen_pool *gen_pool_create(int, int);
 extern phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long);
 extern int gen_pool_add_virt(struct gen_pool *, unsigned long, phys_addr_t,
@@ -124,6 +131,10 @@ extern unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size,
                unsigned long start, unsigned int nr, void *data,
                struct gen_pool *pool);
 
+extern unsigned long gen_pool_fixed_alloc(unsigned long *map,
+               unsigned long size, unsigned long start, unsigned int nr,
+               void *data, struct gen_pool *pool);
+
 extern unsigned long gen_pool_first_fit_align(unsigned long *map,
                unsigned long size, unsigned long start, unsigned int nr,
                void *data, struct gen_pool *pool);

diff --git a/lib/genalloc.c b/lib/genalloc.c
index b8cf89d..5ec83cd 100644 (file)
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -555,6 +555,38 @@ unsigned long gen_pool_first_fit_align(unsigned long *map, unsigned long size,
 }
 EXPORT_SYMBOL(gen_pool_first_fit_align);
 
+/**
+ * gen_pool_fixed_alloc - reserve a specific region
+ * @map: The address to base the search on
+ * @size: The bitmap size in bits
+ * @start: The bitnumber to start searching at
+ * @nr: The number of zeroed bits we're looking for
+ * @data: data for alignment
+ * @pool: pool to get order from
+ */
+unsigned long gen_pool_fixed_alloc(unsigned long *map, unsigned long size,
+               unsigned long start, unsigned int nr, void *data,
+               struct gen_pool *pool)
+{
+       struct genpool_data_fixed *fixed_data;
+       int order;
+       unsigned long offset_bit;
+       unsigned long start_bit;
+
+       fixed_data = data;
+       order = pool->min_alloc_order;
+       offset_bit = fixed_data->offset >> order;
+       if (WARN_ON(fixed_data->offset & (1UL << order - 1)))
+               return size;
+
+       start_bit = bitmap_find_next_zero_area(map, size,
+                       start + offset_bit, nr, 0);
+       if (start_bit != offset_bit)
+               start_bit = size;
+       return start_bit;
+}
+EXPORT_SYMBOL(gen_pool_fixed_alloc);
+
 /**
  * gen_pool_first_fit_order_align - find the first available region
  * of memory matching the size requirement. The region will be aligned