summaryrefslogtreecommitdiffstats
path: root/drivers/dma-buf/sw_sync.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-05 14:50:51 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-05 14:50:51 -0700
commit41844e36206be90cd4d962ea49b0abc3612a99d0 (patch)
treece0b3a3403bc6abdb28f52779d0d7b57a51a5c86 /drivers/dma-buf/sw_sync.c
parent5691f0e9a3e7855832d5fd094801bf600347c2d0 (diff)
parentfc1e2c8ea85e109acf09e74789e9b852f6eed251 (diff)
downloadop-kernel-dev-41844e36206be90cd4d962ea49b0abc3612a99d0.zip
op-kernel-dev-41844e36206be90cd4d962ea49b0abc3612a99d0.tar.gz
Merge tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging and IIO updates from Greg KH: "Here is the big staging and IIO driver pull request for 4.9-rc1. There are a lot of patches in here, the majority due to the drivers/staging/greybus/ subsystem being merged in with full development history that went back a few years, in order to preserve the work that those developers did over time. Lots and lots of tiny cleanups happened in the tree as well, due to the Outreachy application process and lots of other developers showing up for the first time to clean code up. Along with those changes, we deleted a wireless driver, and added a raspberrypi driver (currently marked broken), and lots of new iio drivers. Overall the tree still shrunk with more lines removed than added, about 10 thousand lines removed in total. Full details are in the very long shortlog below. All of this has been in the linux-next tree with no issues. There will be some merge problems with other subsystem trees, but those are all minor problems and shouldn't be hard to work out when they happen (MAINTAINERS and some lustre build problems with the IB tree)" And furter from me asking for clarification about greybus: "Right now there is a phone from Motorola shipping with this code (a slightly older version, but the same tree), so even though Ara is not alive in the same form, the functionality is happening. We are working with the developers of that phone to merge the newer stuff in with their fork so they can use the upstream version in future versions of their phone product line. Toshiba has at least one chip shipping in their catalog that needs/uses this protocol over a Unipro link, and rumor has it that there might be more in the future. There are also other users of the greybus protocols, there is a talk next week at ELC that shows how it is being used across a network connection to control a device, and previous ELC talks have showed the protocol stack being used over USB to drive embedded Linux boards. I've also talked to some people who are starting to work to add a host controller driver to control arduinos as the greybus PHY protocols are very useful to control a serial/i2c/spio/whatever device across a random physical link, as it is a way to have a self-describing device be attached to a host without needing manual configuration. So yes, people are using it, and there is still the chance that it will show up in a phone/laptop/tablet/whatever from Google in the future as well, the tech isn't dead, even if the original large phone project happens to be" * tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (3703 commits) Staging: fbtft: Fix bug in fbtft-core staging: rtl8188eu: fix double unlock error in rtw_resume_process() staging:r8188eu: remove GEN_MLME_EXT_HANDLER macro staging:r8188eu: remove GEN_DRV_CMD_HANDLER macro staging:r8188eu: remove GEN_EVT_CODE macro staging:r8188eu: remove GEN_CMD_CODE macro staging:r8188eu: remove pkt_newalloc member of the recv_buf structure staging:r8188eu: remove rtw_handle_dualmac declaration staging:r8188eu: remove (RGTRY|BSSID)_(OFT|SZ) macros staging:r8188eu: change rtl8188e_process_phy_info function argument type Staging: fsl-mc: Remove blank lines Staging: fsl-mc: Fix unaligned * in block comments Staging: comedi: Align the * in block comments Staging : ks7010 : Fix block comments warninig Staging: vt6655: Remove explicit NULL comparison using Coccinelle staging: rtl8188eu: core: rtw_xmit: Use macros instead of constants staging: rtl8188eu: core: rtw_xmit: Move constant of the right side staging: dgnc: Fix lines longer than 80 characters Staging: dgnc: constify attribute_group structures Staging: most: hdm-dim2: constify attribute_group structures ...
Diffstat (limited to 'drivers/dma-buf/sw_sync.c')
-rw-r--r--drivers/dma-buf/sw_sync.c375
1 files changed, 375 insertions, 0 deletions
diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c
new file mode 100644
index 0000000..62e8e6d
--- /dev/null
+++ b/drivers/dma-buf/sw_sync.c
@@ -0,0 +1,375 @@
+/*
+ * Sync File validation framework
+ *
+ * Copyright (C) 2012 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/sync_file.h>
+
+#include "sync_debug.h"
+
+#define CREATE_TRACE_POINTS
+#include "sync_trace.h"
+
+/*
+ * SW SYNC validation framework
+ *
+ * A sync object driver that uses a 32bit counter to coordinate
+ * synchronization. Useful when there is no hardware primitive backing
+ * the synchronization.
+ *
+ * To start the framework just open:
+ *
+ * <debugfs>/sync/sw_sync
+ *
+ * That will create a sync timeline, all fences created under this timeline
+ * file descriptor will belong to the this timeline.
+ *
+ * The 'sw_sync' file can be opened many times as to create different
+ * timelines.
+ *
+ * Fences can be created with SW_SYNC_IOC_CREATE_FENCE ioctl with struct
+ * sw_sync_ioctl_create_fence as parameter.
+ *
+ * To increment the timeline counter, SW_SYNC_IOC_INC ioctl should be used
+ * with the increment as u32. This will update the last signaled value
+ * from the timeline and signal any fence that has a seqno smaller or equal
+ * to it.
+ *
+ * struct sw_sync_ioctl_create_fence
+ * @value: the seqno to initialise the fence with
+ * @name: the name of the new sync point
+ * @fence: return the fd of the new sync_file with the created fence
+ */
+struct sw_sync_create_fence_data {
+ __u32 value;
+ char name[32];
+ __s32 fence; /* fd of new fence */
+};
+
+#define SW_SYNC_IOC_MAGIC 'W'
+
+#define SW_SYNC_IOC_CREATE_FENCE _IOWR(SW_SYNC_IOC_MAGIC, 0,\
+ struct sw_sync_create_fence_data)
+
+#define SW_SYNC_IOC_INC _IOW(SW_SYNC_IOC_MAGIC, 1, __u32)
+
+static const struct fence_ops timeline_fence_ops;
+
+static inline struct sync_pt *fence_to_sync_pt(struct fence *fence)
+{
+ if (fence->ops != &timeline_fence_ops)
+ return NULL;
+ return container_of(fence, struct sync_pt, base);
+}
+
+/**
+ * sync_timeline_create() - creates a sync object
+ * @name: sync_timeline name
+ *
+ * Creates a new sync_timeline. Returns the sync_timeline object or NULL in
+ * case of error.
+ */
+struct sync_timeline *sync_timeline_create(const char *name)
+{
+ struct sync_timeline *obj;
+
+ obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+ if (!obj)
+ return NULL;
+
+ kref_init(&obj->kref);
+ obj->context = fence_context_alloc(1);
+ strlcpy(obj->name, name, sizeof(obj->name));
+
+ INIT_LIST_HEAD(&obj->child_list_head);
+ INIT_LIST_HEAD(&obj->active_list_head);
+ spin_lock_init(&obj->child_list_lock);
+
+ sync_timeline_debug_add(obj);
+
+ return obj;
+}
+
+static void sync_timeline_free(struct kref *kref)
+{
+ struct sync_timeline *obj =
+ container_of(kref, struct sync_timeline, kref);
+
+ sync_timeline_debug_remove(obj);
+
+ kfree(obj);
+}
+
+static void sync_timeline_get(struct sync_timeline *obj)
+{
+ kref_get(&obj->kref);
+}
+
+static void sync_timeline_put(struct sync_timeline *obj)
+{
+ kref_put(&obj->kref, sync_timeline_free);
+}
+
+/**
+ * sync_timeline_signal() - signal a status change on a sync_timeline
+ * @obj: sync_timeline to signal
+ * @inc: num to increment on timeline->value
+ *
+ * A sync implementation should call this any time one of it's fences
+ * has signaled or has an error condition.
+ */
+static void sync_timeline_signal(struct sync_timeline *obj, unsigned int inc)
+{
+ unsigned long flags;
+ struct sync_pt *pt, *next;
+
+ trace_sync_timeline(obj);
+
+ spin_lock_irqsave(&obj->child_list_lock, flags);
+
+ obj->value += inc;
+
+ list_for_each_entry_safe(pt, next, &obj->active_list_head,
+ active_list) {
+ if (fence_is_signaled_locked(&pt->base))
+ list_del_init(&pt->active_list);
+ }
+
+ spin_unlock_irqrestore(&obj->child_list_lock, flags);
+}
+
+/**
+ * sync_pt_create() - creates a sync pt
+ * @parent: fence's parent sync_timeline
+ * @size: size to allocate for this pt
+ * @inc: value of the fence
+ *
+ * Creates a new sync_pt as a child of @parent. @size bytes will be
+ * allocated allowing for implementation specific data to be kept after
+ * the generic sync_timeline struct. Returns the sync_pt object or
+ * NULL in case of error.
+ */
+static struct sync_pt *sync_pt_create(struct sync_timeline *obj, int size,
+ unsigned int value)
+{
+ unsigned long flags;
+ struct sync_pt *pt;
+
+ if (size < sizeof(*pt))
+ return NULL;
+
+ pt = kzalloc(size, GFP_KERNEL);
+ if (!pt)
+ return NULL;
+
+ spin_lock_irqsave(&obj->child_list_lock, flags);
+ sync_timeline_get(obj);
+ fence_init(&pt->base, &timeline_fence_ops, &obj->child_list_lock,
+ obj->context, value);
+ list_add_tail(&pt->child_list, &obj->child_list_head);
+ INIT_LIST_HEAD(&pt->active_list);
+ spin_unlock_irqrestore(&obj->child_list_lock, flags);
+ return pt;
+}
+
+static const char *timeline_fence_get_driver_name(struct fence *fence)
+{
+ return "sw_sync";
+}
+
+static const char *timeline_fence_get_timeline_name(struct fence *fence)
+{
+ struct sync_timeline *parent = fence_parent(fence);
+
+ return parent->name;
+}
+
+static void timeline_fence_release(struct fence *fence)
+{
+ struct sync_pt *pt = fence_to_sync_pt(fence);
+ struct sync_timeline *parent = fence_parent(fence);
+ unsigned long flags;
+
+ spin_lock_irqsave(fence->lock, flags);
+ list_del(&pt->child_list);
+ if (!list_empty(&pt->active_list))
+ list_del(&pt->active_list);
+ spin_unlock_irqrestore(fence->lock, flags);
+
+ sync_timeline_put(parent);
+ fence_free(fence);
+}
+
+static bool timeline_fence_signaled(struct fence *fence)
+{
+ struct sync_timeline *parent = fence_parent(fence);
+
+ return (fence->seqno > parent->value) ? false : true;
+}
+
+static bool timeline_fence_enable_signaling(struct fence *fence)
+{
+ struct sync_pt *pt = fence_to_sync_pt(fence);
+ struct sync_timeline *parent = fence_parent(fence);
+
+ if (timeline_fence_signaled(fence))
+ return false;
+
+ list_add_tail(&pt->active_list, &parent->active_list_head);
+ return true;
+}
+
+static void timeline_fence_value_str(struct fence *fence,
+ char *str, int size)
+{
+ snprintf(str, size, "%d", fence->seqno);
+}
+
+static void timeline_fence_timeline_value_str(struct fence *fence,
+ char *str, int size)
+{
+ struct sync_timeline *parent = fence_parent(fence);
+
+ snprintf(str, size, "%d", parent->value);
+}
+
+static const struct fence_ops timeline_fence_ops = {
+ .get_driver_name = timeline_fence_get_driver_name,
+ .get_timeline_name = timeline_fence_get_timeline_name,
+ .enable_signaling = timeline_fence_enable_signaling,
+ .signaled = timeline_fence_signaled,
+ .wait = fence_default_wait,
+ .release = timeline_fence_release,
+ .fence_value_str = timeline_fence_value_str,
+ .timeline_value_str = timeline_fence_timeline_value_str,
+};
+
+/*
+ * *WARNING*
+ *
+ * improper use of this can result in deadlocking kernel drivers from userspace.
+ */
+
+/* opening sw_sync create a new sync obj */
+static int sw_sync_debugfs_open(struct inode *inode, struct file *file)
+{
+ struct sync_timeline *obj;
+ char task_comm[TASK_COMM_LEN];
+
+ get_task_comm(task_comm, current);
+
+ obj = sync_timeline_create(task_comm);
+ if (!obj)
+ return -ENOMEM;
+
+ file->private_data = obj;
+
+ return 0;
+}
+
+static int sw_sync_debugfs_release(struct inode *inode, struct file *file)
+{
+ struct sync_timeline *obj = file->private_data;
+
+ smp_wmb();
+
+ sync_timeline_put(obj);
+ return 0;
+}
+
+static long sw_sync_ioctl_create_fence(struct sync_timeline *obj,
+ unsigned long arg)
+{
+ int fd = get_unused_fd_flags(O_CLOEXEC);
+ int err;
+ struct sync_pt *pt;
+ struct sync_file *sync_file;
+ struct sw_sync_create_fence_data data;
+
+ if (fd < 0)
+ return fd;
+
+ if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
+ err = -EFAULT;
+ goto err;
+ }
+
+ pt = sync_pt_create(obj, sizeof(*pt), data.value);
+ if (!pt) {
+ err = -ENOMEM;
+ goto err;
+ }
+
+ sync_file = sync_file_create(&pt->base);
+ if (!sync_file) {
+ fence_put(&pt->base);
+ err = -ENOMEM;
+ goto err;
+ }
+
+ data.fence = fd;
+ if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
+ fput(sync_file->file);
+ err = -EFAULT;
+ goto err;
+ }
+
+ fd_install(fd, sync_file->file);
+
+ return 0;
+
+err:
+ put_unused_fd(fd);
+ return err;
+}
+
+static long sw_sync_ioctl_inc(struct sync_timeline *obj, unsigned long arg)
+{
+ u32 value;
+
+ if (copy_from_user(&value, (void __user *)arg, sizeof(value)))
+ return -EFAULT;
+
+ sync_timeline_signal(obj, value);
+
+ return 0;
+}
+
+static long sw_sync_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct sync_timeline *obj = file->private_data;
+
+ switch (cmd) {
+ case SW_SYNC_IOC_CREATE_FENCE:
+ return sw_sync_ioctl_create_fence(obj, arg);
+
+ case SW_SYNC_IOC_INC:
+ return sw_sync_ioctl_inc(obj, arg);
+
+ default:
+ return -ENOTTY;
+ }
+}
+
+const struct file_operations sw_sync_debugfs_fops = {
+ .open = sw_sync_debugfs_open,
+ .release = sw_sync_debugfs_release,
+ .unlocked_ioctl = sw_sync_ioctl,
+ .compat_ioctl = sw_sync_ioctl,
+};
OpenPOWER on IntegriCloud