From 35538d7822e86cb38015c21bb708a433f8814af0 Mon Sep 17 00:00:00 2001 From: Gustavo Padovan Date: Thu, 11 Aug 2016 12:26:44 -0300 Subject: dma-buf/sw_sync: de-stage SW_SYNC SW_SYNC allows to run tests on the sync_file framework via debugfs on /sync/sw_sync Opening and closing the file triggers creation and release of a sync timeline. To create fences on this timeline the SW_SYNC_IOC_CREATE_FENCE ioctl should be used. To increment the timeline value use SW_SYNC_IOC_INC. Also it exports Sync information on /sync/info Signed-off-by: Gustavo Padovan Reviewed-by: Eric Engestrom Signed-off-by: Greg Kroah-Hartman --- drivers/dma-buf/Kconfig | 13 ++ drivers/dma-buf/Makefile | 1 + drivers/dma-buf/sw_sync.c | 375 +++++++++++++++++++++++++++++++++++++++++++ drivers/dma-buf/sync_debug.c | 230 ++++++++++++++++++++++++++ drivers/dma-buf/sync_debug.h | 84 ++++++++++ drivers/dma-buf/sync_trace.h | 32 ++++ 6 files changed, 735 insertions(+) create mode 100644 drivers/dma-buf/sw_sync.c create mode 100644 drivers/dma-buf/sync_debug.c create mode 100644 drivers/dma-buf/sync_debug.h create mode 100644 drivers/dma-buf/sync_trace.h (limited to 'drivers/dma-buf') diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig index 25bcfa0b474f..2585821b24ab 100644 --- a/drivers/dma-buf/Kconfig +++ b/drivers/dma-buf/Kconfig @@ -17,4 +17,17 @@ config SYNC_FILE Files fds, to the DRM driver for example. More details at Documentation/sync_file.txt. +config SW_SYNC + bool "Sync File Validation Framework" + default n + depends on SYNC_FILE + depends on DEBUG_FS + ---help--- + A sync object driver that uses a 32bit counter to coordinate + synchronization. Useful when there is no hardware primitive backing + the synchronization. + + WARNING: improper use of this can result in deadlocking kernel + drivers from userspace. Intended for test and debug only. + endmenu diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile index f353db213a81..210a10bfad2b 100644 --- a/drivers/dma-buf/Makefile +++ b/drivers/dma-buf/Makefile @@ -1,2 +1,3 @@ obj-y := dma-buf.o fence.o reservation.o seqno-fence.o fence-array.o obj-$(CONFIG_SYNC_FILE) += sync_file.o +obj-$(CONFIG_SW_SYNC) += sw_sync.o sync_debug.o diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c new file mode 100644 index 000000000000..62e8e6dc7953 --- /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 +#include +#include +#include +#include + +#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: + * + * /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, +}; diff --git a/drivers/dma-buf/sync_debug.c b/drivers/dma-buf/sync_debug.c new file mode 100644 index 000000000000..fab95204cf74 --- /dev/null +++ b/drivers/dma-buf/sync_debug.c @@ -0,0 +1,230 @@ +/* + * Sync File validation framework and debug information + * + * 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 +#include "sync_debug.h" + +static struct dentry *dbgfs; + +static LIST_HEAD(sync_timeline_list_head); +static DEFINE_SPINLOCK(sync_timeline_list_lock); +static LIST_HEAD(sync_file_list_head); +static DEFINE_SPINLOCK(sync_file_list_lock); + +void sync_timeline_debug_add(struct sync_timeline *obj) +{ + unsigned long flags; + + spin_lock_irqsave(&sync_timeline_list_lock, flags); + list_add_tail(&obj->sync_timeline_list, &sync_timeline_list_head); + spin_unlock_irqrestore(&sync_timeline_list_lock, flags); +} + +void sync_timeline_debug_remove(struct sync_timeline *obj) +{ + unsigned long flags; + + spin_lock_irqsave(&sync_timeline_list_lock, flags); + list_del(&obj->sync_timeline_list); + spin_unlock_irqrestore(&sync_timeline_list_lock, flags); +} + +void sync_file_debug_add(struct sync_file *sync_file) +{ + unsigned long flags; + + spin_lock_irqsave(&sync_file_list_lock, flags); + list_add_tail(&sync_file->sync_file_list, &sync_file_list_head); + spin_unlock_irqrestore(&sync_file_list_lock, flags); +} + +void sync_file_debug_remove(struct sync_file *sync_file) +{ + unsigned long flags; + + spin_lock_irqsave(&sync_file_list_lock, flags); + list_del(&sync_file->sync_file_list); + spin_unlock_irqrestore(&sync_file_list_lock, flags); +} + +static const char *sync_status_str(int status) +{ + if (status == 0) + return "signaled"; + + if (status > 0) + return "active"; + + return "error"; +} + +static void sync_print_fence(struct seq_file *s, struct fence *fence, bool show) +{ + int status = 1; + struct sync_timeline *parent = fence_parent(fence); + + if (fence_is_signaled_locked(fence)) + status = fence->status; + + seq_printf(s, " %s%sfence %s", + show ? parent->name : "", + show ? "_" : "", + sync_status_str(status)); + + if (status <= 0) { + struct timespec64 ts64 = + ktime_to_timespec64(fence->timestamp); + + seq_printf(s, "@%lld.%09ld", (s64)ts64.tv_sec, ts64.tv_nsec); + } + + if (fence->ops->timeline_value_str && + fence->ops->fence_value_str) { + char value[64]; + bool success; + + fence->ops->fence_value_str(fence, value, sizeof(value)); + success = strlen(value); + + if (success) { + seq_printf(s, ": %s", value); + + fence->ops->timeline_value_str(fence, value, + sizeof(value)); + + if (strlen(value)) + seq_printf(s, " / %s", value); + } + } + + seq_puts(s, "\n"); +} + +static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj) +{ + struct list_head *pos; + unsigned long flags; + + seq_printf(s, "%s: %d\n", obj->name, obj->value); + + spin_lock_irqsave(&obj->child_list_lock, flags); + list_for_each(pos, &obj->child_list_head) { + struct sync_pt *pt = + container_of(pos, struct sync_pt, child_list); + sync_print_fence(s, &pt->base, false); + } + spin_unlock_irqrestore(&obj->child_list_lock, flags); +} + +static void sync_print_sync_file(struct seq_file *s, + struct sync_file *sync_file) +{ + int i; + + seq_printf(s, "[%p] %s: %s\n", sync_file, sync_file->name, + sync_status_str(atomic_read(&sync_file->status))); + + for (i = 0; i < sync_file->num_fences; ++i) + sync_print_fence(s, sync_file->cbs[i].fence, true); +} + +static int sync_debugfs_show(struct seq_file *s, void *unused) +{ + unsigned long flags; + struct list_head *pos; + + seq_puts(s, "objs:\n--------------\n"); + + spin_lock_irqsave(&sync_timeline_list_lock, flags); + list_for_each(pos, &sync_timeline_list_head) { + struct sync_timeline *obj = + container_of(pos, struct sync_timeline, + sync_timeline_list); + + sync_print_obj(s, obj); + seq_puts(s, "\n"); + } + spin_unlock_irqrestore(&sync_timeline_list_lock, flags); + + seq_puts(s, "fences:\n--------------\n"); + + spin_lock_irqsave(&sync_file_list_lock, flags); + list_for_each(pos, &sync_file_list_head) { + struct sync_file *sync_file = + container_of(pos, struct sync_file, sync_file_list); + + sync_print_sync_file(s, sync_file); + seq_puts(s, "\n"); + } + spin_unlock_irqrestore(&sync_file_list_lock, flags); + return 0; +} + +static int sync_info_debugfs_open(struct inode *inode, struct file *file) +{ + return single_open(file, sync_debugfs_show, inode->i_private); +} + +static const struct file_operations sync_info_debugfs_fops = { + .open = sync_info_debugfs_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static __init int sync_debugfs_init(void) +{ + dbgfs = debugfs_create_dir("sync", NULL); + + /* + * The debugfs files won't ever get removed and thus, there is + * no need to protect it against removal races. The use of + * debugfs_create_file_unsafe() is actually safe here. + */ + debugfs_create_file_unsafe("info", 0444, dbgfs, NULL, + &sync_info_debugfs_fops); + debugfs_create_file_unsafe("sw_sync", 0644, dbgfs, NULL, + &sw_sync_debugfs_fops); + + return 0; +} +late_initcall(sync_debugfs_init); + +#define DUMP_CHUNK 256 +static char sync_dump_buf[64 * 1024]; +void sync_dump(void) +{ + struct seq_file s = { + .buf = sync_dump_buf, + .size = sizeof(sync_dump_buf) - 1, + }; + int i; + + sync_debugfs_show(&s, NULL); + + for (i = 0; i < s.count; i += DUMP_CHUNK) { + if ((s.count - i) > DUMP_CHUNK) { + char c = s.buf[i + DUMP_CHUNK]; + + s.buf[i + DUMP_CHUNK] = 0; + pr_cont("%s", s.buf + i); + s.buf[i + DUMP_CHUNK] = c; + } else { + s.buf[s.count] = 0; + pr_cont("%s", s.buf + i); + } + } +} diff --git a/drivers/dma-buf/sync_debug.h b/drivers/dma-buf/sync_debug.h new file mode 100644 index 000000000000..d269aa6783aa --- /dev/null +++ b/drivers/dma-buf/sync_debug.h @@ -0,0 +1,84 @@ +/* + * Sync File validation framework and debug infomation + * + * Copyright (C) 2012 Google, Inc. + * + * 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. + * + */ + +#ifndef _LINUX_SYNC_H +#define _LINUX_SYNC_H + +#include +#include +#include + +#include +#include + +/** + * struct sync_timeline - sync object + * @kref: reference count on fence. + * @name: name of the sync_timeline. Useful for debugging + * @child_list_head: list of children sync_pts for this sync_timeline + * @child_list_lock: lock protecting @child_list_head and fence.status + * @active_list_head: list of active (unsignaled/errored) sync_pts + * @sync_timeline_list: membership in global sync_timeline_list + */ +struct sync_timeline { + struct kref kref; + char name[32]; + + /* protected by child_list_lock */ + u64 context; + int value; + + struct list_head child_list_head; + spinlock_t child_list_lock; + + struct list_head active_list_head; + + struct list_head sync_timeline_list; +}; + +static inline struct sync_timeline *fence_parent(struct fence *fence) +{ + return container_of(fence->lock, struct sync_timeline, + child_list_lock); +} + +/** + * struct sync_pt - sync_pt object + * @base: base fence object + * @child_list: sync timeline child's list + * @active_list: sync timeline active child's list + */ +struct sync_pt { + struct fence base; + struct list_head child_list; + struct list_head active_list; +}; + +#ifdef CONFIG_SW_SYNC + +extern const struct file_operations sw_sync_debugfs_fops; + +void sync_timeline_debug_add(struct sync_timeline *obj); +void sync_timeline_debug_remove(struct sync_timeline *obj); +void sync_file_debug_add(struct sync_file *fence); +void sync_file_debug_remove(struct sync_file *fence); +void sync_dump(void); + +#else +# define sync_timeline_debug_add(obj) +# define sync_timeline_debug_remove(obj) +# define sync_file_debug_add(fence) +# define sync_file_debug_remove(fence) +# define sync_dump() +#endif + +#endif /* _LINUX_SYNC_H */ diff --git a/drivers/dma-buf/sync_trace.h b/drivers/dma-buf/sync_trace.h new file mode 100644 index 000000000000..d13d59ff1b85 --- /dev/null +++ b/drivers/dma-buf/sync_trace.h @@ -0,0 +1,32 @@ +#undef TRACE_SYSTEM +#define TRACE_INCLUDE_PATH ../../drivers/dma-buf +#define TRACE_SYSTEM sync_trace + +#if !defined(_TRACE_SYNC_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_SYNC_H + +#include "sync_debug.h" +#include + +TRACE_EVENT(sync_timeline, + TP_PROTO(struct sync_timeline *timeline), + + TP_ARGS(timeline), + + TP_STRUCT__entry( + __string(name, timeline->name) + __field(u32, value) + ), + + TP_fast_assign( + __assign_str(name, timeline->name); + __entry->value = timeline->value; + ), + + TP_printk("name=%s value=%d", __get_str(name), __entry->value) +); + +#endif /* if !defined(_TRACE_SYNC_H) || defined(TRACE_HEADER_MULTI_READ) */ + +/* This part must be outside protection */ +#include -- cgit v1.2.3