diff options
author | 2016-04-11 10:41:07 +0300 | |
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committer | 2016-04-13 08:17:18 +0300 | |
commit | e09b41010ba33a20a87472ee821fa407a5b8da36 (patch) | |
tree | d10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/drivers/misc/mic/scif/scif_peer_bus.c | |
parent | f93b97fd65072de626c074dbe099a1fff05ce060 (diff) |
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page.
During the rebasing, the following patch collided:
Force tick interrupt and get rid of softirq magic(I70131fb85).
Collisions have been removed because its logic was found on the
source already.
Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/drivers/misc/mic/scif/scif_peer_bus.c')
-rw-r--r-- | kernel/drivers/misc/mic/scif/scif_peer_bus.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/kernel/drivers/misc/mic/scif/scif_peer_bus.c b/kernel/drivers/misc/mic/scif/scif_peer_bus.c new file mode 100644 index 000000000..6ffa3bdbd --- /dev/null +++ b/kernel/drivers/misc/mic/scif/scif_peer_bus.c @@ -0,0 +1,183 @@ +/* + * Intel MIC Platform Software Stack (MPSS) + * + * Copyright(c) 2014 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * Intel SCIF driver. + */ +#include "scif_main.h" +#include "../bus/scif_bus.h" +#include "scif_peer_bus.h" + +static inline struct scif_peer_dev * +dev_to_scif_peer(struct device *dev) +{ + return container_of(dev, struct scif_peer_dev, dev); +} + +struct bus_type scif_peer_bus = { + .name = "scif_peer_bus", +}; + +static void scif_peer_release_dev(struct device *d) +{ + struct scif_peer_dev *sdev = dev_to_scif_peer(d); + struct scif_dev *scifdev = &scif_dev[sdev->dnode]; + + scif_cleanup_scifdev(scifdev); + kfree(sdev); +} + +static int scif_peer_initialize_device(struct scif_dev *scifdev) +{ + struct scif_peer_dev *spdev; + int ret; + + spdev = kzalloc(sizeof(*spdev), GFP_KERNEL); + if (!spdev) { + ret = -ENOMEM; + goto err; + } + + spdev->dev.parent = scifdev->sdev->dev.parent; + spdev->dev.release = scif_peer_release_dev; + spdev->dnode = scifdev->node; + spdev->dev.bus = &scif_peer_bus; + dev_set_name(&spdev->dev, "scif_peer-dev%u", spdev->dnode); + + device_initialize(&spdev->dev); + get_device(&spdev->dev); + rcu_assign_pointer(scifdev->spdev, spdev); + + mutex_lock(&scif_info.conflock); + scif_info.total++; + scif_info.maxid = max_t(u32, spdev->dnode, scif_info.maxid); + mutex_unlock(&scif_info.conflock); + return 0; +err: + dev_err(&scifdev->sdev->dev, + "dnode %d: initialize_device rc %d\n", scifdev->node, ret); + return ret; +} + +static int scif_peer_add_device(struct scif_dev *scifdev) +{ + struct scif_peer_dev *spdev = rcu_dereference(scifdev->spdev); + char pool_name[16]; + int ret; + + ret = device_add(&spdev->dev); + put_device(&spdev->dev); + if (ret) { + dev_err(&scifdev->sdev->dev, + "dnode %d: peer device_add failed\n", scifdev->node); + goto put_spdev; + } + + scnprintf(pool_name, sizeof(pool_name), "scif-%d", spdev->dnode); + scifdev->signal_pool = dmam_pool_create(pool_name, &scifdev->sdev->dev, + sizeof(struct scif_status), 1, + 0); + if (!scifdev->signal_pool) { + dev_err(&scifdev->sdev->dev, + "dnode %d: dmam_pool_create failed\n", scifdev->node); + ret = -ENOMEM; + goto del_spdev; + } + dev_dbg(&spdev->dev, "Added peer dnode %d\n", spdev->dnode); + return 0; +del_spdev: + device_del(&spdev->dev); +put_spdev: + RCU_INIT_POINTER(scifdev->spdev, NULL); + synchronize_rcu(); + put_device(&spdev->dev); + + mutex_lock(&scif_info.conflock); + scif_info.total--; + mutex_unlock(&scif_info.conflock); + return ret; +} + +void scif_add_peer_device(struct work_struct *work) +{ + struct scif_dev *scifdev = container_of(work, struct scif_dev, + peer_add_work); + + scif_peer_add_device(scifdev); +} + +/* + * Peer device registration is split into a device_initialize and a device_add. + * The reason for doing this is as follows: First, peer device registration + * itself cannot be done in the message processing thread and must be delegated + * to another workqueue, otherwise if SCIF client probe, called during peer + * device registration, calls scif_connect(..), it will block the message + * processing thread causing a deadlock. Next, device_initialize is done in the + * "top-half" message processing thread and device_add in the "bottom-half" + * workqueue. If this is not done, SCIF_CNCT_REQ message processing executing + * concurrently with SCIF_INIT message processing is unable to get a reference + * on the peer device, thereby failing the connect request. + */ +void scif_peer_register_device(struct scif_dev *scifdev) +{ + int ret; + + mutex_lock(&scifdev->lock); + ret = scif_peer_initialize_device(scifdev); + if (ret) + goto exit; + schedule_work(&scifdev->peer_add_work); +exit: + mutex_unlock(&scifdev->lock); +} + +int scif_peer_unregister_device(struct scif_dev *scifdev) +{ + struct scif_peer_dev *spdev; + + mutex_lock(&scifdev->lock); + /* Flush work to ensure device register is complete */ + flush_work(&scifdev->peer_add_work); + + /* + * Continue holding scifdev->lock since theoretically unregister_device + * can be called simultaneously from multiple threads + */ + spdev = rcu_dereference(scifdev->spdev); + if (!spdev) { + mutex_unlock(&scifdev->lock); + return -ENODEV; + } + + RCU_INIT_POINTER(scifdev->spdev, NULL); + synchronize_rcu(); + mutex_unlock(&scifdev->lock); + + dev_dbg(&spdev->dev, "Removing peer dnode %d\n", spdev->dnode); + device_unregister(&spdev->dev); + + mutex_lock(&scif_info.conflock); + scif_info.total--; + mutex_unlock(&scif_info.conflock); + return 0; +} + +int scif_peer_bus_init(void) +{ + return bus_register(&scif_peer_bus); +} + +void scif_peer_bus_exit(void) +{ + bus_unregister(&scif_peer_bus); +} |