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 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html