From fec47d863587c272d6fbf4e50066209c953d5e60 Mon Sep 17 00:00:00 2001 From: Dave Gerlach Date: Fri, 22 May 2015 15:45:27 -0500 Subject: [PATCH] remoteproc: introduce rproc_get_by_phandle API Allow users of remoteproc the ability to get a handle to an rproc by passing a phandle supplied in the user's device tree node. This is useful in situations that require manual booting of the rproc. This patch uses the code removed by commit 40e575b1d0b3 ("remoteproc: remove the get_by_name/put API") for the ref counting but is modified to use a simple list and locking mechanism and has rproc_get_by_name replaced with an rproc_get_by_phandle API. Signed-off-by: Dave Gerlach Signed-off-by: Suman Anna [fix order of Signed-off-by tags] Signed-off-by: Ohad Ben-Cohen --- Documentation/remoteproc.txt | 6 ++++ drivers/remoteproc/remoteproc_core.c | 50 ++++++++++++++++++++++++++++ include/linux/remoteproc.h | 7 ++-- 3 files changed, 60 insertions(+), 3 deletions(-) diff --git a/Documentation/remoteproc.txt b/Documentation/remoteproc.txt index e6469fdcf89a..ef0219fa4bb4 100644 --- a/Documentation/remoteproc.txt +++ b/Documentation/remoteproc.txt @@ -51,6 +51,12 @@ cost. rproc_shutdown() returns, and users can still use it with a subsequent rproc_boot(), if needed. + struct rproc *rproc_get_by_phandle(phandle phandle) + - Find an rproc handle using a device tree phandle. Returns the rproc + handle on success, and NULL on failure. This function increments + the remote processor's refcount, so always use rproc_put() to + decrement it back once rproc isn't needed anymore. + 3. Typical usage #include diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c index e991512e04ed..e1a6d693b8bb 100644 --- a/drivers/remoteproc/remoteproc_core.c +++ b/drivers/remoteproc/remoteproc_core.c @@ -44,6 +44,9 @@ #include "remoteproc_internal.h" +static DEFINE_MUTEX(rproc_list_mutex); +static LIST_HEAD(rproc_list); + typedef int (*rproc_handle_resources_t)(struct rproc *rproc, struct resource_table *table, int len); typedef int (*rproc_handle_resource_t)(struct rproc *rproc, @@ -1144,6 +1147,43 @@ out: } EXPORT_SYMBOL(rproc_shutdown); +/** + * rproc_get_by_phandle() - find a remote processor by phandle + * @phandle: phandle to the rproc + * + * Finds an rproc handle using the remote processor's phandle, and then + * return a handle to the rproc. + * + * This function increments the remote processor's refcount, so always + * use rproc_put() to decrement it back once rproc isn't needed anymore. + * + * Returns the rproc handle on success, and NULL on failure. + */ +struct rproc *rproc_get_by_phandle(phandle phandle) +{ + struct rproc *rproc = NULL, *r; + struct device_node *np; + + np = of_find_node_by_phandle(phandle); + if (!np) + return NULL; + + mutex_lock(&rproc_list_mutex); + list_for_each_entry(r, &rproc_list, node) { + if (r->dev.parent && r->dev.parent->of_node == np) { + rproc = r; + get_device(&rproc->dev); + break; + } + } + mutex_unlock(&rproc_list_mutex); + + of_node_put(np); + + return rproc; +} +EXPORT_SYMBOL(rproc_get_by_phandle); + /** * rproc_add() - register a remote processor * @rproc: the remote processor handle to register @@ -1173,6 +1213,11 @@ int rproc_add(struct rproc *rproc) if (ret < 0) return ret; + /* expose to rproc_get_by_phandle users */ + mutex_lock(&rproc_list_mutex); + list_add(&rproc->node, &rproc_list); + mutex_unlock(&rproc_list_mutex); + dev_info(dev, "%s is available\n", rproc->name); dev_info(dev, "Note: remoteproc is still under development and considered experimental.\n"); @@ -1360,6 +1405,11 @@ int rproc_del(struct rproc *rproc) /* Free the copy of the resource table */ kfree(rproc->cached_table); + /* the rproc is downref'ed as soon as it's removed from the klist */ + mutex_lock(&rproc_list_mutex); + list_del(&rproc->node); + mutex_unlock(&rproc_list_mutex); + device_del(&rproc->dev); return 0; diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h index 78b8a9b9d40a..56739e5df1e6 100644 --- a/include/linux/remoteproc.h +++ b/include/linux/remoteproc.h @@ -36,11 +36,11 @@ #define REMOTEPROC_H #include -#include #include #include #include #include +#include /** * struct resource_table - firmware resource table header @@ -375,7 +375,7 @@ enum rproc_crash_type { /** * struct rproc - represents a physical remote processor device - * @node: klist node of this rproc object + * @node: list node of this rproc object * @domain: iommu domain * @name: human readable name of the rproc * @firmware: name of firmware file to be loaded @@ -407,7 +407,7 @@ enum rproc_crash_type { * @has_iommu: flag to indicate if remote processor is behind an MMU */ struct rproc { - struct klist_node node; + struct list_head node; struct iommu_domain *domain; const char *name; const char *firmware; @@ -481,6 +481,7 @@ struct rproc_vdev { u32 rsc_offset; }; +struct rproc *rproc_get_by_phandle(phandle phandle); struct rproc *rproc_alloc(struct device *dev, const char *name, const struct rproc_ops *ops, const char *firmware, int len); -- 2.20.1