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()).
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
#include <linux/remoteproc.h>
#include <linux/iommu.h>
#include <linux/idr.h>
-#include <linux/klist.h>
#include <linux/elf.h>
#include <linux/virtio_ids.h>
#include <linux/virtio_ring.h>
#include "remoteproc_internal.h"
-static void klist_rproc_get(struct klist_node *n);
-static void klist_rproc_put(struct klist_node *n);
-
-/*
- * klist of the available remote processors.
- *
- * We need this in order to support name-based lookups (needed by the
- * rproc_get_by_name()).
- *
- * That said, we don't use rproc_get_by_name() at this point.
- * The use cases that do require its existence should be
- * scrutinized, and hopefully migrated to rproc_boot() using device-based
- * binding.
- *
- * If/when this materializes, we could drop the klist (and the by_name
- * API).
- */
-static DEFINE_KLIST(rprocs, klist_rproc_get, klist_rproc_put);
-
typedef int (*rproc_handle_resources_t)(struct rproc *rproc,
struct resource_table *table, int len);
typedef int (*rproc_handle_resource_t)(struct rproc *rproc, void *, int avail);
* 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()).
*/
void rproc_shutdown(struct rproc *rproc)
{
}
EXPORT_SYMBOL(rproc_shutdown);
-/* will be called when an rproc is added to the rprocs klist */
-static void klist_rproc_get(struct klist_node *n)
-{
- struct rproc *rproc = container_of(n, struct rproc, node);
-
- get_device(&rproc->dev);
-}
-
-/* will be called when an rproc is removed from the rprocs klist */
-static void klist_rproc_put(struct klist_node *n)
-{
- struct rproc *rproc = container_of(n, struct rproc, node);
-
- put_device(&rproc->dev);
-}
-
-static struct rproc *next_rproc(struct klist_iter *i)
-{
- struct klist_node *n;
-
- n = klist_next(i);
- if (!n)
- return NULL;
-
- return container_of(n, struct rproc, node);
-}
-
-/**
- * rproc_get_by_name() - find a remote processor by name and boot it
- * @name: name of the remote processor
- *
- * Finds 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 this function (and its counterpart rproc_put()) are not
- * being used. 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.
- */
-struct rproc *rproc_get_by_name(const char *name)
-{
- struct rproc *rproc;
- struct klist_iter i;
- int ret;
-
- /* find the remote processor, and upref its refcount */
- klist_iter_init(&rprocs, &i);
- while ((rproc = next_rproc(&i)) != NULL)
- if (!strcmp(rproc->name, name)) {
- get_device(&rproc->dev);
- break;
- }
- klist_iter_exit(&i);
-
- /* can't find this rproc ? */
- if (!rproc) {
- pr_err("can't find remote processor %s\n", name);
- return NULL;
- }
-
- ret = rproc_boot(rproc);
- if (ret < 0) {
- put_device(&rproc->dev);
- return NULL;
- }
-
- return rproc;
-}
-EXPORT_SYMBOL(rproc_get_by_name);
-
-/**
- * rproc_put() - decrement the refcount of a remote processor, and shut it down
- * @rproc: the remote processor
- *
- * This function tries to shutdown @rproc, and it then decrements its
- * refcount.
- *
- * 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().
- */
-void rproc_put(struct rproc *rproc)
-{
- /* try to power off the remote processor */
- rproc_shutdown(rproc);
-
- /* downref rproc's refcount */
- put_device(&rproc->dev);
-}
-EXPORT_SYMBOL(rproc_put);
-
/**
* rproc_register() - register a remote processor
* @rproc: the remote processor handle to register
if (ret < 0)
return ret;
- /* expose to rproc_get_by_name users */
- klist_add_tail(&rproc->node, &rprocs);
-
dev_info(dev, "%s is available\n", rproc->name);
dev_info(dev, "Note: remoteproc is still under development and considered experimental.\n");
if (ret < 0) {
dev_err(dev, "request_firmware_nowait failed: %d\n", ret);
complete_all(&rproc->firmware_loading_complete);
- klist_remove(&rproc->node);
}
return ret;
list_for_each_entry_safe(rvdev, tmp, &rproc->rvdevs, node)
rproc_remove_virtio_dev(rvdev);
- /* the rproc is downref'ed as soon as it's removed from the klist */
- klist_del(&rproc->node);
-
device_del(&rproc->dev);
return 0;
projects / linux-2.6-block.git / commitdiff