From 59ce4039727ef408769ab0e1263ece893abe22bb Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Tue, 24 May 2016 15:31:24 +0200 Subject: of: reserved_mem: add support for using more than one region for given device This patch allows device drivers to initialize more than one reserved memory region assigned to given device. When driver needs to use more than one reserved memory region, it should allocate child devices and initialize regions by index for each of its child devices. Signed-off-by: Marek Szyprowski Acked-by: Rob Herring Signed-off-by: Sylwester Nawrocki --- drivers/of/of_reserved_mem.c | 85 +++++++++++++++++++++++++++++++++----------- 1 file changed, 64 insertions(+), 21 deletions(-) (limited to 'drivers/of') diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c index ed01c01..04e4fe5 100644 --- a/drivers/of/of_reserved_mem.c +++ b/drivers/of/of_reserved_mem.c @@ -21,6 +21,7 @@ #include #include #include +#include #define MAX_RESERVED_REGIONS 16 static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS]; @@ -289,53 +290,95 @@ static inline struct reserved_mem *__find_rmem(struct device_node *node) return NULL; } +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 + * of_reserved_mem_device_init_by_idx() - assign reserved memory region to + * given device + * @dev: Pointer to the device to configure + * @np: Pointer to the device_node with 'reserved-memory' property + * @idx: Index of selected region * - * This function assign memory region pointed by "memory-region" device tree - * property to the given device. + * This function assigns respective DMA-mapping operations based on reserved + * memory region specified by 'memory-region' property in @np node to the @dev + * device. 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. + * + * Returns error code or zero on success. */ -int of_reserved_mem_device_init(struct device *dev) +int of_reserved_mem_device_init_by_idx(struct device *dev, + struct device_node *np, int idx) { + struct rmem_assigned_device *rd; + struct device_node *target; struct reserved_mem *rmem; - struct device_node *np; int ret; - np = of_parse_phandle(dev->of_node, "memory-region", 0); - if (!np) - return -ENODEV; + if (!np || !dev) + return -EINVAL; + + target = of_parse_phandle(np, "memory-region", idx); + if (!target) + return -EINVAL; - rmem = __find_rmem(np); - of_node_put(np); + rmem = __find_rmem(target); + of_node_put(target); 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; } -EXPORT_SYMBOL_GPL(of_reserved_mem_device_init); +EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx); /** * 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; -- cgit v1.1 From 9f5a802b1d51dc80a27d828a5f7dcc8ec4a72f03 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Wed, 8 Jun 2016 03:51:53 -0300 Subject: [media] of: reserved_mem: restore old behavior when no region is defined Change return value back to -ENODEV when no region is defined for given device. This restores old behavior of this function, as some drivers rely on such error code. Fixes: 59ce4039727ef40 ("of: reserved_mem: add support for using more than one region for given device") Reported-by: Liviu Dudau Signed-off-by: Marek Szyprowski Reviewed-by: Sylwester Nawrocki Reviewed-by: Liviu Dudau Acked-by: Rob Herring Reviewed-by: Sumit Semwal --- drivers/of/of_reserved_mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/of') diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c index 04e4fe5..2b2291b 100644 --- a/drivers/of/of_reserved_mem.c +++ b/drivers/of/of_reserved_mem.c @@ -327,7 +327,7 @@ int of_reserved_mem_device_init_by_idx(struct device *dev, target = of_parse_phandle(np, "memory-region", idx); if (!target) - return -EINVAL; + return -ENODEV; rmem = __find_rmem(target); of_node_put(target); -- cgit v1.1