@@ -397,3 +397,29 @@ void of_reserved_mem_device_release(struct device *dev)
rmem->ops->device_release(rmem, dev);
}
EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
+
+/**
+ * of_reserved_mem_get() - acquire reserved_mem from a device node
+ * @np: node pointer of the desired reserved-memory region
+ *
+ * This function allows drivers to acquire a reference to the reserved_mem
+ * struct based on a device node handle.
+ *
+ * Returns a reserved_mem reference, or NULL on error.
+ */
+struct reserved_mem *of_reserved_mem_get(struct device_node *np)
+{
+ const char *name;
+ int i;
+
+ if (!np->full_name)
+ return NULL;
+
+ name = kbasename(np->full_name);
+ for (i = 0; i < reserved_mem_count; i++)
+ if (!strcmp(reserved_mem[i].name, name))
+ return &reserved_mem[i];
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_get);
@@ -44,6 +44,7 @@ int early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
void fdt_init_reserved_mem(void);
void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
phys_addr_t base, phys_addr_t size);
+struct reserved_mem *of_reserved_mem_get(struct device_node *np);
#else
static inline int of_reserved_mem_device_init_by_idx(struct device *dev,
struct device_node *np, int idx)
@@ -55,6 +56,10 @@ static inline void of_reserved_mem_device_release(struct device *pdev) { }
static inline void fdt_init_reserved_mem(void) { }
static inline void fdt_reserved_mem_save_node(unsigned long node,
const char *uname, phys_addr_t base, phys_addr_t size) { }
+static inline struct reserved_mem *of_reserved_mem_get(struct device_node *np)
+{
+ return NULL;
+}
#endif
/**
In some cases drivers referencing a reserved-memory region might want to remap the entire region, but when defining the reserved-memory by "size" the client driver has no means to know the associated base address of the reserved memory region. This patch adds an accessor for such drivers to acquire a handle to their associated reserved-memory for this purpose. A complicating factor for the implementation is that the reserved_mem objects are created from the flattened DeviceTree, as such we can't use the device_node address for comparison. Fortunately the name of the node will be used as "name" of the reserved_mem and will be used when building the full_name, so we can compare the "name" with the basename of the full_name to find the match. Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> --- Changes since v1: - Previous patch provided interface to resolve memory-region reference, instead of direct lookup by device_node drivers/of/of_reserved_mem.c | 26 ++++++++++++++++++++++++++ include/linux/of_reserved_mem.h | 5 +++++ 2 files changed, 31 insertions(+) -- 2.12.0