path: root/Documentation/remoteproc.txt
diff options
Diffstat (limited to 'Documentation/remoteproc.txt')
1 files changed, 14 insertions, 44 deletions
diff --git a/Documentation/remoteproc.txt b/Documentation/remoteproc.txt
index 70a048c..23a09b8 100644
--- a/Documentation/remoteproc.txt
+++ b/Documentation/remoteproc.txt
@@ -36,8 +36,7 @@ cost.
Note: to use this function you should already have a valid rproc
handle. There are several ways to achieve that cleanly (devres, pdata,
the way remoteproc_rpmsg.c does this, or, if this becomes prevalent, we
- might also consider using dev_archdata for this). See also
- rproc_get_by_name() below.
+ might also consider using dev_archdata for this).
void rproc_shutdown(struct rproc *rproc)
- Power off a remote processor (previously booted with rproc_boot()).
@@ -51,30 +50,6 @@ cost.
which means that the @rproc handle stays valid even after
rproc_shutdown() returns, and users can still use it with a subsequent
rproc_boot(), if needed.
- - don't call rproc_shutdown() to unroll rproc_get_by_name(), exactly
- because rproc_shutdown() _does not_ decrement the refcount of @rproc.
- To decrement the refcount of @rproc, use rproc_put() (but _only_ if
- you acquired @rproc using rproc_get_by_name()).
- struct rproc *rproc_get_by_name(const char *name)
- - Find an rproc handle using the remote processor's name, and then
- boot it. If it's already powered on, then just immediately return
- (successfully). 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.
- Note: currently rproc_get_by_name() and rproc_put() are not used anymore
- by the rpmsg bus and its drivers. We need to scrutinize the use cases
- that still need them, and see if we can migrate them to use the non
- name-based boot/shutdown interface.
- void rproc_put(struct rproc *rproc)
- - Decrement @rproc's power refcount and shut it down if it reaches zero
- (essentially by just calling rproc_shutdown), and then decrement @rproc's
- validity refcount too.
- After this function returns, @rproc may _not_ be used anymore, and its
- handle should be considered invalid.
- This function should be called _iff_ the @rproc handle was grabbed by
- calling rproc_get_by_name().
3. Typical usage
@@ -115,21 +90,21 @@ int dummy_rproc_example(struct rproc *my_rproc)
This function should be used by rproc implementations during
initialization of the remote processor.
After creating an rproc handle using this function, and when ready,
- implementations should then call rproc_register() to complete
+ implementations should then call rproc_add() to complete
the registration of the remote processor.
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_put().
- void rproc_free(struct rproc *rproc)
+ void rproc_put(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)
+ int rproc_add(struct rproc *rproc)
- Register @rproc with the remoteproc framework, after it has been
allocated with rproc_alloc().
This is called by the platform-specific rproc implementation, whenever
@@ -142,20 +117,15 @@ int dummy_rproc_example(struct rproc *my_rproc)
of registering this remote processor, additional virtio drivers might get
- 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.
+ int rproc_del(struct rproc *rproc)
+ - Unroll rproc_add().
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()
+ _only_ be called if a previous invocation of rproc_add()
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_del() returns, @rproc is still valid, and its
+ last refcount should be decremented by calling rproc_put().
Returns 0 on success and -EINVAL if @rproc isn't valid.