This patch allows device drivers to use more than one reserved memory
region assigned to given device. When NULL name is passed to
of_reserved_mem_device_init(), the default (first) region is used.
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
drivers/of/of_reserved_mem.c | 101 +++++++++++++++++++++++++++++++---------
include/linux/of_reserved_mem.h | 6 ++-
2 files changed, 84 insertions(+), 23 deletions(-)
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 1a3556a9e9ea..0a0b23b73004 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -21,6 +21,7 @@
#include <linux/sizes.h>
#include <linux/of_reserved_mem.h>
#include <linux/sort.h>
+#include <linux/slab.h>
#define MAX_RESERVED_REGIONS 16
static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
@@ -287,31 +288,84 @@ static inline struct reserved_mem *__find_rmem(struct device_node *node)
return NULL;
}
+static struct reserved_mem *__node_to_rmem(struct device_node *node,
+ const char *name)
+{
+ struct reserved_mem *rmem;
+ struct device_node *target;
+ int idx = 0;
+
+ if (!node)
+ return NULL;
+
+ if (name) {
+ idx = of_property_match_string(node,
+ "memory-region-names", name);
+ if (idx < 0)
+ return NULL;
+ }
+
+ target = of_parse_phandle(node, "memory-region", idx);
+ if (!target)
+ return NULL;
+ rmem = __find_rmem(target);
+ of_node_put(target);
+
+ return rmem;
+}
+
+struct rmem_assigned_device {
+ struct device *dev;
+ struct reserved_mem *rmem;
+ struct list_head list;
+};
+
+static LIST_HEAD(of_rmem_assigned_device_list);
+static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
+
/**
* of_reserved_mem_device_init() - assign reserved memory region to given device
+ * @dev: Pointer to the device to configure
+ * @np: Pointer to the device_node with 'reserved-memory' property
+ * @name: Optional name of the selected region (can be NULL)
+ *
+ * This function assigns respective DMA-mapping operations based on reserved
+ * memory regionspecified by 'memory-region' property in @np node, named @name
+ * to the @dev device. When NULL name is provided, the default (first) memory
+ * region is used. When driver needs to use more than one reserved memory
+ * region, it should allocate child devices and initialize regions by name for
+ * each of child device.
*
- * This function assign memory region pointed by "memory-region" device tree
- * property to the given device.
+ * Returns error code or zero on success.
*/
-int of_reserved_mem_device_init(struct device *dev)
+int of_reserved_mem_device_init(struct device *dev, struct device_node *np,
+ const char *name)
{
+ struct rmem_assigned_device *rd;
struct reserved_mem *rmem;
- struct device_node *np;
int ret;
- np = of_parse_phandle(dev->of_node, "memory-region", 0);
- if (!np)
- return -ENODEV;
-
- rmem = __find_rmem(np);
- of_node_put(np);
-
+ rmem = __node_to_rmem(np, name);
if (!rmem || !rmem->ops || !rmem->ops->device_init)
return -EINVAL;
+ rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
+ if (!rd)
+ return -ENOMEM;
+
ret = rmem->ops->device_init(rmem, dev);
- if (ret == 0)
+ if (ret == 0) {
+ rd->dev = dev;
+ rd->rmem = rmem;
+
+ mutex_lock(&of_rmem_assigned_device_mutex);
+ list_add(&rd->list, &of_rmem_assigned_device_list);
+ mutex_unlock(&of_rmem_assigned_device_mutex);
+
dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
+ } else {
+ kfree(rd);
+ }
return ret;
}
@@ -319,21 +373,26 @@ EXPORT_SYMBOL_GPL(of_reserved_mem_device_init);
/**
* of_reserved_mem_device_release() - release reserved memory device structures
+ * @dev: Pointer to the device to deconfigure
*
* This function releases structures allocated for memory region handling for
* the given device.
*/
void of_reserved_mem_device_release(struct device *dev)
{
- struct reserved_mem *rmem;
- struct device_node *np;
-
- np = of_parse_phandle(dev->of_node, "memory-region", 0);
- if (!np)
- return;
-
- rmem = __find_rmem(np);
- of_node_put(np);
+ struct rmem_assigned_device *rd;
+ struct reserved_mem *rmem = NULL;
+
+ mutex_lock(&of_rmem_assigned_device_mutex);
+ list_for_each_entry(rd, &of_rmem_assigned_device_list, list) {
+ if (rd->dev == dev) {
+ rmem = rd->rmem;
+ list_del(&rd->list);
+ kfree(rd);
+ break;
+ }
+ }
+ mutex_unlock(&of_rmem_assigned_device_mutex);
if (!rmem || !rmem->ops || !rmem->ops->device_release)
return;
diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
index ad2f67054372..05dd38490657 100644
--- a/include/linux/of_reserved_mem.h
+++ b/include/linux/of_reserved_mem.h
@@ -28,14 +28,16 @@ typedef int (*reservedmem_of_init_fn)(struct reserved_mem *rmem);
_OF_DECLARE(reservedmem, name, compat, init, reservedmem_of_init_fn)
#ifdef CONFIG_OF_RESERVED_MEM
-int of_reserved_mem_device_init(struct device *dev);
+int of_reserved_mem_device_init(struct device *dev, struct device_node *np,
+ const char *name);
void of_reserved_mem_device_release(struct device *dev);
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);
#else
-static inline int of_reserved_mem_device_init(struct device *dev)
+static inline int of_reserved_mem_device_init(struct device *dev,
+ struct device_node *np, const char *name)
{
return -ENOSYS;
}
--
1.9.2
--
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