From c6b5a27628faf6657b741d828a1462d832d0dbc5 Mon Sep 17 00:00:00 2001 From: Ohad Ben-Cohen Date: Mon, 2 Jul 2012 11:41:16 +0300 Subject: remoteproc: simplify unregister/free interfaces Simplify the unregister/free interfaces, and make them easier to understand and use, by moving to a symmetric and consistent alloc() -> register() -> unregister() -> free() flow. To create and register an rproc instance, one needed to invoke rproc_alloc() followed by rproc_register(). To unregister and free an rproc instance, one now needs to invoke rproc_unregister() followed by rproc_free(). Cc: Stephen Boyd Signed-off-by: Ohad Ben-Cohen --- Documentation/remoteproc.txt | 21 ++++++++------------- drivers/remoteproc/omap_remoteproc.c | 5 ++++- drivers/remoteproc/remoteproc_core.c | 25 ++++++++----------------- 3 files changed, 20 insertions(+), 31 deletions(-) diff --git a/Documentation/remoteproc.txt b/Documentation/remoteproc.txt index 70a048cd3fa3..ad6ded4bca5c 100644 --- a/Documentation/remoteproc.txt +++ b/Documentation/remoteproc.txt @@ -120,14 +120,14 @@ int dummy_rproc_example(struct rproc *my_rproc) On success, the new rproc is returned, and on failure, NULL. Note: _never_ directly deallocate @rproc, even if it was not registered - yet. Instead, if you just need to unroll rproc_alloc(), use rproc_free(). + yet. Instead, when you need to unroll rproc_alloc(), use rproc_free(). void rproc_free(struct rproc *rproc) - Free an rproc handle that was allocated by rproc_alloc. - This function should _only_ be used if @rproc was only allocated, - but not registered yet. - If @rproc was already successfully registered (by calling - rproc_register()), then use rproc_unregister() instead. + This function essentially unrolls rproc_alloc(), by decrementing the + rproc's refcount. It doesn't directly free rproc; that would happen + only if there are no other references to rproc and its refcount now + dropped to zero. int rproc_register(struct rproc *rproc) - Register @rproc with the remoteproc framework, after it has been @@ -143,19 +143,14 @@ int dummy_rproc_example(struct rproc *my_rproc) probed. int rproc_unregister(struct rproc *rproc) - - Unregister a remote processor, and decrement its refcount. - If its refcount drops to zero, then @rproc will be freed. If not, - it will be freed later once the last reference is dropped. - + - Unroll rproc_register(). This function should be called when the platform specific rproc implementation decides to remove the rproc device. it should _only_ be called if a previous invocation of rproc_register() has completed successfully. - After rproc_unregister() returns, @rproc is _not_ valid anymore and - it shouldn't be used. More specifically, don't call rproc_free() - or try to directly free @rproc after rproc_unregister() returns; - none of these are needed, and calling them is a bug. + After rproc_unregister() returns, @rproc is still valid, and its + last refcount should be decremented by calling rproc_free(). Returns 0 on success and -EINVAL if @rproc isn't valid. diff --git a/drivers/remoteproc/omap_remoteproc.c b/drivers/remoteproc/omap_remoteproc.c index b5e6d2981741..4f2fe8fd7fe6 100644 --- a/drivers/remoteproc/omap_remoteproc.c +++ b/drivers/remoteproc/omap_remoteproc.c @@ -214,7 +214,10 @@ static int __devexit omap_rproc_remove(struct platform_device *pdev) { struct rproc *rproc = platform_get_drvdata(pdev); - return rproc_unregister(rproc); + rproc_unregister(rproc); + rproc_free(rproc); + + return 0; } static struct platform_driver omap_rproc_driver = { diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c index aa713aade30e..4a77dc1df3d8 100644 --- a/drivers/remoteproc/remoteproc_core.c +++ b/drivers/remoteproc/remoteproc_core.c @@ -1472,7 +1472,7 @@ static struct device_type rproc_type = { * On success the new rproc is returned, and on failure, NULL. * * Note: _never_ directly deallocate @rproc, even if it was not registered - * yet. Instead, if you just need to unroll rproc_alloc(), use rproc_free(). + * yet. Instead, when you need to unroll rproc_alloc(), use rproc_free(). */ struct rproc *rproc_alloc(struct device *dev, const char *name, const struct rproc_ops *ops, @@ -1526,14 +1526,13 @@ struct rproc *rproc_alloc(struct device *dev, const char *name, EXPORT_SYMBOL(rproc_alloc); /** - * rproc_free() - free an rproc handle that was allocated by rproc_alloc + * rproc_free() - unroll rproc_alloc() * @rproc: the remote processor handle * - * This function should _only_ be used if @rproc was only allocated, - * but not registered yet. + * This function decrements the rproc dev refcount. * - * If @rproc was already successfully registered (by calling rproc_register()), - * then use rproc_unregister() instead. + * If no one holds any reference to rproc anymore, then its refcount would + * now drop to zero, and it would be freed. */ void rproc_free(struct rproc *rproc) { @@ -1545,19 +1544,14 @@ EXPORT_SYMBOL(rproc_free); * rproc_unregister() - unregister a remote processor * @rproc: rproc handle to unregister * - * Unregisters a remote processor, and decrements its refcount. - * If its refcount drops to zero, then @rproc will be freed. If not, - * it will be freed later once the last reference is dropped. - * * This function should be called when the platform specific rproc * implementation decides to remove the rproc device. it should * _only_ be called if a previous invocation of rproc_register() * has completed successfully. * - * After rproc_unregister() returns, @rproc is _not_ valid anymore and - * it shouldn't be used. More specifically, don't call rproc_free() - * or try to directly free @rproc after rproc_unregister() returns; - * none of these are needed, and calling them is a bug. + * After rproc_unregister() returns, @rproc isn't freed yet, because + * of the outstanding reference created by rproc_alloc. To decrement that + * one last refcount, one still needs to call rproc_free(). * * Returns 0 on success and -EINVAL if @rproc isn't valid. */ @@ -1580,9 +1574,6 @@ int rproc_unregister(struct rproc *rproc) device_del(&rproc->dev); - /* unroll rproc_alloc. TODO: we may want to let the users do that */ - put_device(&rproc->dev); - return 0; } EXPORT_SYMBOL(rproc_unregister); -- cgit v1.2.2