A fence can be attached to a buffer which is being filled or consumed by hw, to allow userspace to pass the buffer without waiting to another device. For example, userspace can call page_flip ioctl to display the next frame of graphics after kicking the GPU but while the GPU is still rendering. The display device sharing the buffer with the GPU would attach a callback to get notified when the GPU's rendering-complete IRQ fires, to update the scan-out address of the display, without having to wake up userspace.

A driver must allocate a fence context for each execution ring that can run in parallel. The function for this takes an argument with how many contexts to allocate: + fence_context_alloc()

A fence is transient, one-shot deal. It is allocated and attached to one or more dma-buf's. When the one that attached it is done, with the pending operation, it can signal the fence: + fence_signal()

To have a rough approximation whether a fence is fired, call: + fence_is_signaled()

The dma-buf-mgr handles tracking, and waiting on, the fences associated with a dma-buf.

The one pending on the fence can add an async callback: + fence_add_callback()

The callback can optionally be cancelled with: + fence_remove_callback()

To wait synchronously, optionally with a timeout: + fence_wait() + fence_wait_timeout()

When emitting a fence, call: + trace_fence_emit()

To annotate that a fence is blocking on another fence, call: + trace_fence_annotate_wait_on(fence, on_fence)

A default software-only implementation is provided, which can be used by drivers attaching a fence to a buffer when they have no other means for hw sync. But a memory backed fence is also envisioned, because it is common that GPU's can write to, or poll on some memory location for synchronization. For example:

fence = custom_get_fence(...); if ((seqno_fence = to_seqno_fence(fence)) != NULL) { dma_buf *fence_buf = seqno_fence->sync_buf; get_dma_buf(fence_buf);

... tell the hw the memory location to wait ... custom_wait_on(fence_buf, seqno_fence->seqno_ofs, fence->seqno); } else { /* fall-back to sw sync * / fence_add_callback(fence, my_cb); }

On SoC platforms, if some other hw mechanism is provided for synchronizing between IP blocks, it could be supported as an alternate implementation with it's own fence ops in a similar way.

enable_signaling callback is used to provide sw signaling in case a cpu waiter is requested or no compatible hardware signaling could be used.

The intention is to provide a userspace interface (presumably via eventfd) later, to be used in conjunction with dma-buf's mmap support for sw access to buffers (or for userspace apps that would prefer to do their own synchronization).

v1: Original v2: After discussion w/ danvet and mlankhorst on #dri-devel, we decided that dma-fence didn't need to care about the sw->hw signaling path (it can be handled same as sw->sw case), and therefore the fence->ops can be simplified and more handled in the core. So remove the signal, add_callback, cancel_callback, and wait ops, and replace with a simple enable_signaling() op which can be used to inform a fence supporting hw->hw signaling that one or more devices which do not support hw signaling are waiting (and therefore it should enable an irq or do whatever is necessary in order that the CPU is notified when the fence is passed). v3: Fix locking fail in attach_fence() and get_fence() v4: Remove tie-in w/ dma-buf.. after discussion w/ danvet and mlankorst we decided that we need to be able to attach one fence to N dma-buf's, so using the list_head in dma-fence struct would be problematic. v5: [ Maarten Lankhorst ] Updated for dma-bikeshed-fence and dma-buf-manager. v6: [ Maarten Lankhorst ] I removed dma_fence_cancel_callback and some comments about checking if fence fired or not. This is broken by design. waitqueue_active during destruction is now fatal, since the signaller should be holding a reference in enable_signalling until it signalled the fence. Pass the original dma_fence_cb along, and call __remove_wait in the dma_fence_callback handler, so that no cleanup needs to be performed. v7: [ Maarten Lankhorst ] Set cb->func and only enable sw signaling if fence wasn't signaled yet, for example for hardware fences that may choose to signal blindly. v8: [ Maarten Lankhorst ] Tons of tiny fixes, moved __dma_fence_init to header and fixed include mess. dma-fence.h now includes dma-buf.h All members are now initialized, so kmalloc can be used for allocating a dma-fence. More documentation added. v9: Change compiler bitfields to flags, change return type of enable_signaling to bool. Rework dma_fence_wait. Added dma_fence_is_signaled and dma_fence_wait_timeout. s/dma// and change exports to non GPL. Added fence_is_signaled and fence_enable_sw_signaling calls, add ability to override default wait operation. v10: remove event_queue, use a custom list, export try_to_wake_up from scheduler. Remove fence lock and use a global spinlock instead, this should hopefully remove all the locking headaches I was having on trying to implement this. enable_signaling is called with this lock held. v11: Use atomic ops for flags, lifting the need for some spin_lock_irqsaves. However I kept the guarantee that after fence_signal returns, it is guaranteed that enable_signaling has either been called to completion, or will not be called any more.

Add contexts and seqno to base fence implementation. This allows you to wait for less fences, by testing for seqno + signaled, and then only wait on the later fence.

Add FENCE_TRACE, FENCE_WARN, and FENCE_ERR. This makes debugging easier. An CONFIG_DEBUG_FENCE will be added to turn off the FENCE_TRACE spam, and another runtime option can turn it off at runtime. v12: Add CONFIG_FENCE_TRACE. Add missing documentation for the fence->context and fence->seqno members. v13: Fixup CONFIG_FENCE_TRACE kconfig description. Move fence_context_alloc to fence. Simplify fence_later. Kill priv member to fence_cb. v14: Remove priv argument from fence_add_callback, oops! v15: Remove priv from documentation. Explicitly include linux/atomic.h. v16: Add trace events. Import changes required by android syncpoints. v17: Use wake_up_state instead of try_to_wake_up. (Colin Cross) Fix up commit description for seqno_fence. (Rob Clark)

Signed-off-by: Maarten Lankhorst maarten.lankhorst@canonical.com Signed-off-by: Thierry Reding thierry.reding@gmail.com #use smp_mb__before_atomic() Reviewed-by: Rob Clark robdclark@gmail.com --- Documentation/DocBook/device-drivers.tmpl | 2 drivers/base/Kconfig | 9 + drivers/base/Makefile | 2 drivers/base/fence.c | 416 +++++++++++++++++++++++++++++ include/linux/fence.h | 333 +++++++++++++++++++++++ include/trace/events/fence.h | 128 +++++++++ 6 files changed, 889 insertions(+), 1 deletion(-) create mode 100644 drivers/base/fence.c create mode 100644 include/linux/fence.h create mode 100644 include/trace/events/fence.h

diff --git a/Documentation/DocBook/device-drivers.tmpl b/Documentation/DocBook/device-drivers.tmpl index cc63f30de166..7eef81069d1b 100644 --- a/Documentation/DocBook/device-drivers.tmpl +++ b/Documentation/DocBook/device-drivers.tmpl @@ -129,6 +129,8 @@ X!Edrivers/base/interface.c </sect1> <sect1><title>Device Drivers DMA Management</title> !Edrivers/base/dma-buf.c +!Edrivers/base/fence.c +!Iinclude/linux/fence.h !Edrivers/base/reservation.c !Iinclude/linux/reservation.h !Edrivers/base/dma-coherent.c diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index 23b8726962af..00e13ce5cbbd 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -208,6 +208,15 @@ config DMA_SHARED_BUFFER APIs extension; the file's descriptor can then be passed on to other driver.

+config FENCE_TRACE + bool "Enable verbose FENCE_TRACE messages" + depends on DMA_SHARED_BUFFER + help + Enable the FENCE_TRACE printks. This will add extra + spam to the console log, but will make it easier to diagnose + lockup related problems for dma-buffers shared across multiple + devices. + config DMA_CMA bool "DMA Contiguous Memory Allocator" depends on HAVE_DMA_CONTIGUOUS && CMA diff --git a/drivers/base/Makefile b/drivers/base/Makefile index 04b314e0fa51..eb4864aee073 100644 --- a/drivers/base/Makefile +++ b/drivers/base/Makefile @@ -10,7 +10,7 @@ obj-$(CONFIG_DMA_CMA) += dma-contiguous.o obj-y += power/ obj-$(CONFIG_HAS_DMA) += dma-mapping.o obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o -obj-$(CONFIG_DMA_SHARED_BUFFER) += dma-buf.o reservation.o +obj-$(CONFIG_DMA_SHARED_BUFFER) += dma-buf.o fence.o reservation.o obj-$(CONFIG_ISA) += isa.o obj-$(CONFIG_FW_LOADER) += firmware_class.o obj-$(CONFIG_NUMA) += node.o diff --git a/drivers/base/fence.c b/drivers/base/fence.c new file mode 100644 index 000000000000..1da7f4d6542a --- /dev/null +++ b/drivers/base/fence.c @@ -0,0 +1,416 @@ +/* + * Fence mechanism for dma-buf and to allow for asynchronous dma access + * + * Copyright (C) 2012 Canonical Ltd + * Copyright (C) 2012 Texas Instruments + * + * Authors: + * Rob Clark robdclark@gmail.com + * Maarten Lankhorst maarten.lankhorst@canonical.com + * + * 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. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see http://www.gnu.org/licenses/. + */ + +#include <linux/slab.h> +#include <linux/export.h> +#include <linux/atomic.h> +#include <linux/fence.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/fence.h> + +EXPORT_TRACEPOINT_SYMBOL(fence_annotate_wait_on); +EXPORT_TRACEPOINT_SYMBOL(fence_emit); + +/** + * fence context counter: each execution context should have its own + * fence context, this allows checking if fences belong to the same + * context or not. One device can have multiple separate contexts, + * and they're used if some engine can run independently of another. + */ +static atomic_t fence_context_counter = ATOMIC_INIT(0); + +/** + * fence_context_alloc - allocate an array of fence contexts + * @num: [in] amount of contexts to allocate + * + * This function will return the first index of the number of fences allocated. + * The fence context is used for setting fence->context to a unique number. + */ +unsigned fence_context_alloc(unsigned num) +{ + BUG_ON(!num); + return atomic_add_return(num, &fence_context_counter) - num; +} +EXPORT_SYMBOL(fence_context_alloc); + +int __fence_signal(struct fence *fence) +{ + struct fence_cb *cur, *tmp; + int ret = 0; + + if (WARN_ON(!fence)) + return -EINVAL; + + if (!ktime_to_ns(fence->timestamp)) { + fence->timestamp = ktime_get(); + smp_mb__before_atomic(); + } + + if (test_and_set_bit(FENCE_FLAG_SIGNALED_BIT, &fence->flags)) { + ret = -EINVAL; + + /* + * we might have raced with the unlocked fence_signal, + * still run through all callbacks + */ + } else + trace_fence_signaled(fence); + + list_for_each_entry_safe(cur, tmp, &fence->cb_list, node) { + list_del_init(&cur->node); + cur->func(fence, cur); + } + return ret; +} +EXPORT_SYMBOL(__fence_signal); + +/** + * fence_signal - signal completion of a fence + * @fence: the fence to signal + * + * Signal completion for software callbacks on a fence, this will unblock + * fence_wait() calls and run all the callbacks added with + * fence_add_callback(). Can be called multiple times, but since a fence + * can only go from unsignaled to signaled state, it will only be effective + * the first time. + */ +int fence_signal(struct fence *fence) +{ + unsigned long flags; + + if (!fence) + return -EINVAL; + + if (!ktime_to_ns(fence->timestamp)) { + fence->timestamp = ktime_get(); + smp_mb__before_atomic(); + } + + if (test_and_set_bit(FENCE_FLAG_SIGNALED_BIT, &fence->flags)) + return -EINVAL; + + trace_fence_signaled(fence); + + if (test_bit(FENCE_FLAG_ENABLE_SIGNAL_BIT, &fence->flags)) { + struct fence_cb *cur, *tmp; + + spin_lock_irqsave(fence->lock, flags); + list_for_each_entry_safe(cur, tmp, &fence->cb_list, node) { + list_del_init(&cur->node); + cur->func(fence, cur); + } + spin_unlock_irqrestore(fence->lock, flags); + } + return 0; +} +EXPORT_SYMBOL(fence_signal); + +/** + * fence_wait_timeout - sleep until the fence gets signaled + * or until timeout elapses + * @fence: [in] the fence to wait on + * @intr: [in] if true, do an interruptible wait + * @timeout: [in] timeout value in jiffies, or MAX_SCHEDULE_TIMEOUT + * + * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or the + * remaining timeout in jiffies on success. Other error values may be + * returned on custom implementations. + * + * Performs a synchronous wait on this fence. It is assumed the caller + * directly or indirectly (buf-mgr between reservation and committing) + * holds a reference to the fence, otherwise the fence might be + * freed before return, resulting in undefined behavior. + */ +long +fence_wait_timeout(struct fence *fence, bool intr, signed long timeout) +{ + unsigned long ret; + + if (WARN_ON(timeout < 0)) + return -EINVAL; + + trace_fence_wait_start(fence); + ret = fence->ops->wait(fence, intr, timeout); + trace_fence_wait_end(fence); + return ret; +} +EXPORT_SYMBOL(fence_wait_timeout); + +void release_fence(struct kref *kref) +{ + struct fence *fence = + container_of(kref, struct fence, refcount); + + trace_fence_destroy(fence); + + BUG_ON(!list_empty(&fence->cb_list)); + + if (fence->ops->release) + fence->ops->release(fence); + else + kfree(fence); +} +EXPORT_SYMBOL(release_fence); + +/** + * fence_enable_sw_signaling - enable signaling on fence + * @fence: [in] the fence to enable + * + * this will request for sw signaling to be enabled, to make the fence + * complete as soon as possible + */ +void fence_enable_sw_signaling(struct fence *fence) +{ + unsigned long flags; + + if (!test_and_set_bit(FENCE_FLAG_ENABLE_SIGNAL_BIT, &fence->flags) && + !test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->flags)) { + trace_fence_enable_signal(fence); + + spin_lock_irqsave(fence->lock, flags); + + if (!fence->ops->enable_signaling(fence)) + __fence_signal(fence); + + spin_unlock_irqrestore(fence->lock, flags); + } +} +EXPORT_SYMBOL(fence_enable_sw_signaling); + +/** + * fence_add_callback - add a callback to be called when the fence + * is signaled + * @fence: [in] the fence to wait on + * @cb: [in] the callback to register + * @func: [in] the function to call + * + * cb will be initialized by fence_add_callback, no initialization + * by the caller is required. Any number of callbacks can be registered + * to a fence, but a callback can only be registered to one fence at a time. + * + * Note that the callback can be called from an atomic context. If + * fence is already signaled, this function will return -ENOENT (and + * *not* call the callback) + * + * Add a software callback to the fence. Same restrictions apply to + * refcount as it does to fence_wait, however the caller doesn't need to + * keep a refcount to fence afterwards: when software access is enabled, + * the creator of the fence is required to keep the fence alive until + * after it signals with fence_signal. The callback itself can be called + * from irq context. + * + */ +int fence_add_callback(struct fence *fence, struct fence_cb *cb, + fence_func_t func) +{ + unsigned long flags; + int ret = 0; + bool was_set; + + if (WARN_ON(!fence || !func)) + return -EINVAL; + + if (test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->flags)) { + INIT_LIST_HEAD(&cb->node); + return -ENOENT; + } + + spin_lock_irqsave(fence->lock, flags); + + was_set = test_and_set_bit(FENCE_FLAG_ENABLE_SIGNAL_BIT, &fence->flags); + + if (test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->flags)) + ret = -ENOENT; + else if (!was_set) { + trace_fence_enable_signal(fence); + + if (!fence->ops->enable_signaling(fence)) { + __fence_signal(fence); + ret = -ENOENT; + } + } + + if (!ret) { + cb->func = func; + list_add_tail(&cb->node, &fence->cb_list); + } else + INIT_LIST_HEAD(&cb->node); + spin_unlock_irqrestore(fence->lock, flags); + + return ret; +} +EXPORT_SYMBOL(fence_add_callback); + +/** + * fence_remove_callback - remove a callback from the signaling list + * @fence: [in] the fence to wait on + * @cb: [in] the callback to remove + * + * Remove a previously queued callback from the fence. This function returns + * true if the callback is succesfully removed, or false if the fence has + * already been signaled. + * + * *WARNING*: + * Cancelling a callback should only be done if you really know what you're + * doing, since deadlocks and race conditions could occur all too easily. For + * this reason, it should only ever be done on hardware lockup recovery, + * with a reference held to the fence. + */ +bool +fence_remove_callback(struct fence *fence, struct fence_cb *cb) +{ + unsigned long flags; + bool ret; + + spin_lock_irqsave(fence->lock, flags); + + ret = !list_empty(&cb->node); + if (ret) + list_del_init(&cb->node); + + spin_unlock_irqrestore(fence->lock, flags); + + return ret; +} +EXPORT_SYMBOL(fence_remove_callback); + +struct default_wait_cb { + struct fence_cb base; + struct task_struct *task; +}; + +static void +fence_default_wait_cb(struct fence *fence, struct fence_cb *cb) +{ + struct default_wait_cb *wait = + container_of(cb, struct default_wait_cb, base); + + wake_up_state(wait->task, TASK_NORMAL); +} + +/** + * fence_default_wait - default sleep until the fence gets signaled + * or until timeout elapses + * @fence: [in] the fence to wait on + * @intr: [in] if true, do an interruptible wait + * @timeout: [in] timeout value in jiffies, or MAX_SCHEDULE_TIMEOUT + * + * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or the + * remaining timeout in jiffies on success. + */ +long +fence_default_wait(struct fence *fence, bool intr, signed long timeout) +{ + struct default_wait_cb cb; + unsigned long flags; + long ret = timeout; + bool was_set; + + if (test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->flags)) + return timeout; + + spin_lock_irqsave(fence->lock, flags); + + if (intr && signal_pending(current)) { + ret = -ERESTARTSYS; + goto out; + } + + was_set = test_and_set_bit(FENCE_FLAG_ENABLE_SIGNAL_BIT, &fence->flags); + + if (test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->flags)) + goto out; + + if (!was_set) { + trace_fence_enable_signal(fence); + + if (!fence->ops->enable_signaling(fence)) { + __fence_signal(fence); + goto out; + } + } + + cb.base.func = fence_default_wait_cb; + cb.task = current; + list_add(&cb.base.node, &fence->cb_list); + + while (!test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->flags) && ret > 0) { + if (intr) + __set_current_state(TASK_INTERRUPTIBLE); + else + __set_current_state(TASK_UNINTERRUPTIBLE); + spin_unlock_irqrestore(fence->lock, flags); + + ret = schedule_timeout(ret); + + spin_lock_irqsave(fence->lock, flags); + if (ret > 0 && intr && signal_pending(current)) + ret = -ERESTARTSYS; + } + + if (!list_empty(&cb.base.node)) + list_del(&cb.base.node); + __set_current_state(TASK_RUNNING); + +out: + spin_unlock_irqrestore(fence->lock, flags); + return ret; +} +EXPORT_SYMBOL(fence_default_wait); + +/** + * __fence_init - Initialize a custom fence. + * @fence: [in] the fence to initialize + * @ops: [in] the fence_ops for operations on this fence + * @lock: [in] the irqsafe spinlock to use for locking this fence + * @context: [in] the execution context this fence is run on + * @seqno: [in] a linear increasing sequence number for this context + * + * Initializes an allocated fence, the caller doesn't have to keep its + * refcount after committing with this fence, but it will need to hold a + * refcount again if fence_ops.enable_signaling gets called. This can + * be used for other implementing other types of fence. + * + * context and seqno are used for easy comparison between fences, allowing + * to check which fence is later by simply using fence_later. + */ +void +__fence_init(struct fence *fence, const struct fence_ops *ops, + spinlock_t *lock, unsigned context, unsigned seqno) +{ + BUG_ON(!lock); + BUG_ON(!ops || !ops->wait || !ops->enable_signaling || + !ops->get_driver_name || !ops->get_timeline_name); + + kref_init(&fence->refcount); + fence->ops = ops; + INIT_LIST_HEAD(&fence->cb_list); + fence->lock = lock; + fence->context = context; + fence->seqno = seqno; + fence->flags = 0UL; + + trace_fence_init(fence); +} +EXPORT_SYMBOL(__fence_init); diff --git a/include/linux/fence.h b/include/linux/fence.h new file mode 100644 index 000000000000..65f2a01ee7e4 --- /dev/null +++ b/include/linux/fence.h @@ -0,0 +1,333 @@ +/* + * Fence mechanism for dma-buf to allow for asynchronous dma access + * + * Copyright (C) 2012 Canonical Ltd + * Copyright (C) 2012 Texas Instruments + * + * Authors: + * Rob Clark robdclark@gmail.com + * Maarten Lankhorst maarten.lankhorst@canonical.com + * + * 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. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see http://www.gnu.org/licenses/. + */ + +#ifndef __LINUX_FENCE_H +#define __LINUX_FENCE_H + +#include <linux/err.h> +#include <linux/wait.h> +#include <linux/list.h> +#include <linux/bitops.h> +#include <linux/kref.h> +#include <linux/sched.h> +#include <linux/printk.h> + +struct fence; +struct fence_ops; +struct fence_cb; + +/** + * struct fence - software synchronization primitive + * @refcount: refcount for this fence + * @ops: fence_ops associated with this fence + * @cb_list: list of all callbacks to call + * @lock: spin_lock_irqsave used for locking + * @context: execution context this fence belongs to, returned by + * fence_context_alloc() + * @seqno: the sequence number of this fence inside the execution context, + * can be compared to decide which fence would be signaled later. + * @flags: A mask of FENCE_FLAG_* defined below + * @timestamp: Timestamp when the fence was signaled. + * @status: Optional, only valid if < 0, must be set before calling + * fence_signal, indicates that the fence has completed with an error. + * + * the flags member must be manipulated and read using the appropriate + * atomic ops (bit_*), so taking the spinlock will not be needed most + * of the time. + * + * FENCE_FLAG_SIGNALED_BIT - fence is already signaled + * FENCE_FLAG_ENABLE_SIGNAL_BIT - enable_signaling might have been called* + * FENCE_FLAG_USER_BITS - start of the unused bits, can be used by the + * implementer of the fence for its own purposes. Can be used in different + * ways by different fence implementers, so do not rely on this. + * + * *) Since atomic bitops are used, this is not guaranteed to be the case. + * Particularly, if the bit was set, but fence_signal was called right + * before this bit was set, it would have been able to set the + * FENCE_FLAG_SIGNALED_BIT, before enable_signaling was called. + * Adding a check for FENCE_FLAG_SIGNALED_BIT after setting + * FENCE_FLAG_ENABLE_SIGNAL_BIT closes this race, and makes sure that + * after fence_signal was called, any enable_signaling call will have either + * been completed, or never called at all. + */ +struct fence { + struct kref refcount; + const struct fence_ops *ops; + struct list_head cb_list; + spinlock_t *lock; + unsigned context, seqno; + unsigned long flags; + ktime_t timestamp; + int status; +}; + +enum fence_flag_bits { + FENCE_FLAG_SIGNALED_BIT, + FENCE_FLAG_ENABLE_SIGNAL_BIT, + FENCE_FLAG_USER_BITS, /* must always be last member */ +}; + +typedef void (*fence_func_t)(struct fence *fence, struct fence_cb *cb); + +/** + * struct fence_cb - callback for fence_add_callback + * @node: used by fence_add_callback to append this struct to fence::cb_list + * @func: fence_func_t to call + * + * This struct will be initialized by fence_add_callback, additional + * data can be passed along by embedding fence_cb in another struct. + */ +struct fence_cb { + struct list_head node; + fence_func_t func; +}; + +/** + * struct fence_ops - operations implemented for fence + * @get_driver_name: returns the driver name. + * @get_timeline_name: return the name of the context this fence belongs to. + * @enable_signaling: enable software signaling of fence. + * @signaled: [optional] peek whether the fence is signaled, can be null. + * @wait: custom wait implementation, or fence_default_wait. + * @release: [optional] called on destruction of fence, can be null + * @fill_driver_data: [optional] callback to fill in free-form debug info + * Returns amount of bytes filled, or -errno. + * @fence_value_str: [optional] fills in the value of the fence as a string + * @timeline_value_str: [optional] fills in the current value of the timeline + * as a string + * + * Notes on enable_signaling: + * For fence implementations that have the capability for hw->hw + * signaling, they can implement this op to enable the necessary + * irqs, or insert commands into cmdstream, etc. This is called + * in the first wait() or add_callback() path to let the fence + * implementation know that there is another driver waiting on + * the signal (ie. hw->sw case). + * + * This function can be called called from atomic context, but not + * from irq context, so normal spinlocks can be used. + * + * A return value of false indicates the fence already passed, + * or some failure occured that made it impossible to enable + * signaling. True indicates succesful enabling. + * + * fence->status may be set in enable_signaling, but only when false is + * returned. + * + * Calling fence_signal before enable_signaling is called allows + * for a tiny race window in which enable_signaling is called during, + * before, or after fence_signal. To fight this, it is recommended + * that before enable_signaling returns true an extra reference is + * taken on the fence, to be released when the fence is signaled. + * This will mean fence_signal will still be called twice, but + * the second time will be a noop since it was already signaled. + * + * Notes on signaled: + * May set fence->status if returning true. + * + * Notes on wait: + * Must not be NULL, set to fence_default_wait for default implementation. + * the fence_default_wait implementation should work for any fence, as long + * as enable_signaling works correctly. + * + * Must return -ERESTARTSYS if the wait is intr = true and the wait was + * interrupted, and remaining jiffies if fence has signaled, or 0 if wait + * timed out. Can also return other error values on custom implementations, + * which should be treated as if the fence is signaled. For example a hardware + * lockup could be reported like that. + * + * Notes on release: + * Can be NULL, this function allows additional commands to run on + * destruction of the fence. Can be called from irq context. + * If pointer is set to NULL, kfree will get called instead. + */ + +struct fence_ops { + const char * (*get_driver_name)(struct fence *fence); + const char * (*get_timeline_name)(struct fence *fence); + bool (*enable_signaling)(struct fence *fence); + bool (*signaled)(struct fence *fence); + long (*wait)(struct fence *fence, bool intr, signed long timeout); + void (*release)(struct fence *fence); + + int (*fill_driver_data)(struct fence *fence, void *data, int size); + void (*fence_value_str)(struct fence *fence, char *str, int size); + void (*timeline_value_str)(struct fence *fence, char *str, int size); +}; + +void __fence_init(struct fence *fence, const struct fence_ops *ops, + spinlock_t *lock, unsigned context, unsigned seqno); + +/** + * fence_get - increases refcount of the fence + * @fence: [in] fence to increase refcount of + */ +static inline void fence_get(struct fence *fence) +{ + if (WARN_ON(!fence)) + return; + kref_get(&fence->refcount); +} + +extern void release_fence(struct kref *kref); + +/** + * fence_put - decreases refcount of the fence + * @fence: [in] fence to reduce refcount of + */ +static inline void fence_put(struct fence *fence) +{ + if (WARN_ON(!fence)) + return; + kref_put(&fence->refcount, release_fence); +} + +int fence_signal(struct fence *fence); +int __fence_signal(struct fence *fence); +long fence_default_wait(struct fence *fence, bool intr, signed long timeout); +int fence_add_callback(struct fence *fence, struct fence_cb *cb, + fence_func_t func); +bool fence_remove_callback(struct fence *fence, struct fence_cb *cb); +void fence_enable_sw_signaling(struct fence *fence); + +static inline bool +__fence_is_signaled(struct fence *fence) +{ + if (test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->flags)) + return true; + + if (fence->ops->signaled && fence->ops->signaled(fence)) { + __fence_signal(fence); + return true; + } + + return false; +} + +/** + * fence_is_signaled - Return an indication if the fence is signaled yet. + * @fence: [in] the fence to check + * + * Returns true if the fence was already signaled, false if not. Since this + * function doesn't enable signaling, it is not guaranteed to ever return true + * If fence_add_callback, fence_wait or fence_enable_sw_signaling + * haven't been called before. + * + * It's recommended for seqno fences to call fence_signal when the + * operation is complete, it makes it possible to prevent issues from + * wraparound between time of issue and time of use by checking the return + * value of this function before calling hardware-specific wait instructions. + */ +static inline bool +fence_is_signaled(struct fence *fence) +{ + if (test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->flags)) + return true; + + if (fence->ops->signaled && fence->ops->signaled(fence)) { + fence_signal(fence); + return true; + } + + return false; +} + +/** + * fence_later - return the chronologically later fence + * @f1: [in] the first fence from the same context + * @f2: [in] the second fence from the same context + * + * Returns NULL if both fences are signaled, otherwise the fence that would be + * signaled last. Both fences must be from the same context, since a seqno is + * not re-used across contexts. + */ +static inline struct fence *fence_later(struct fence *f1, struct fence *f2) +{ + BUG_ON(f1->context != f2->context); + + /* + * can't check just FENCE_FLAG_SIGNALED_BIT here, it may never have been + * set called if enable_signaling wasn't, and enabling that here is + * overkill. + */ + if (f2->seqno - f1->seqno <= INT_MAX) + return fence_is_signaled(f2) ? NULL : f2; + else + return fence_is_signaled(f1) ? NULL : f1; +} + +long fence_wait_timeout(struct fence *fence, bool intr, signed long timeout); + + +/** + * fence_wait - sleep until the fence gets signaled + * @fence: [in] the fence to wait on + * @intr: [in] if true, do an interruptible wait + * + * This function will return -ERESTARTSYS if interrupted by a signal, + * or 0 if the fence was signaled. Other error values may be + * returned on custom implementations. + * + * Performs a synchronous wait on this fence. It is assumed the caller + * directly or indirectly (buf-mgr between reservation and committing) + * holds a reference to the fence, otherwise the fence might be + * freed before return, resulting in undefined behavior. + */ +static inline long fence_wait(struct fence *fence, bool intr) +{ + long ret; + + /* Since fence_wait_timeout cannot timeout with + * MAX_SCHEDULE_TIMEOUT, only valid return values are + * -ERESTARTSYS and MAX_SCHEDULE_TIMEOUT. + */ + ret = fence_wait_timeout(fence, intr, MAX_SCHEDULE_TIMEOUT); + + return ret < 0 ? ret : 0; +} + +unsigned fence_context_alloc(unsigned num); + +#define FENCE_TRACE(f, fmt, args...) \ + do { \ + struct fence *__ff = (f); \ + if (config_enabled(CONFIG_FENCE_TRACE)) \ + pr_info("f %u#%u: " fmt, \ + __ff->context, __ff->seqno, ##args); \ + } while (0) + +#define FENCE_WARN(f, fmt, args...) \ + do { \ + struct fence *__ff = (f); \ + pr_warn("f %u#%u: " fmt, __ff->context, __ff->seqno, \ + ##args); \ + } while (0) + +#define FENCE_ERR(f, fmt, args...) \ + do { \ + struct fence *__ff = (f); \ + pr_err("f %u#%u: " fmt, __ff->context, __ff->seqno, \ + ##args); \ + } while (0) + +#endif /* __LINUX_FENCE_H */ diff --git a/include/trace/events/fence.h b/include/trace/events/fence.h new file mode 100644 index 000000000000..98feb1b82896 --- /dev/null +++ b/include/trace/events/fence.h @@ -0,0 +1,128 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM fence + +#if !defined(_TRACE_FENCE_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_FENCE_H + +#include <linux/tracepoint.h> + +struct fence; + +TRACE_EVENT(fence_annotate_wait_on, + + /* fence: the fence waiting on f1, f1: the fence to be waited on. */ + TP_PROTO(struct fence *fence, struct fence *f1), + + TP_ARGS(fence, f1), + + TP_STRUCT__entry( + __string(driver, fence->ops->get_driver_name(fence)) + __string(timeline, fence->ops->get_driver_name(fence)) + __field(unsigned int, context) + __field(unsigned int, seqno) + + __string(waiting_driver, f1->ops->get_driver_name(f1)) + __string(waiting_timeline, f1->ops->get_timeline_name(f1)) + __field(unsigned int, waiting_context) + __field(unsigned int, waiting_seqno) + ), + + TP_fast_assign( + __assign_str(driver, fence->ops->get_driver_name(fence)) + __assign_str(timeline, fence->ops->get_timeline_name(fence)) + __entry->context = fence->context; + __entry->seqno = fence->seqno; + + __assign_str(waiting_driver, f1->ops->get_driver_name(f1)) + __assign_str(waiting_timeline, f1->ops->get_timeline_name(f1)) + __entry->waiting_context = f1->context; + __entry->waiting_seqno = f1->seqno; + + ), + + TP_printk("driver=%s timeline=%s context=%u seqno=%u " \ + "waits on driver=%s timeline=%s context=%u seqno=%u", + __get_str(driver), __get_str(timeline), __entry->context, + __entry->seqno, + __get_str(waiting_driver), __get_str(waiting_timeline), + __entry->waiting_context, __entry->waiting_seqno) +); + +DECLARE_EVENT_CLASS(fence, + + TP_PROTO(struct fence *fence), + + TP_ARGS(fence), + + TP_STRUCT__entry( + __string(driver, fence->ops->get_driver_name(fence)) + __string(timeline, fence->ops->get_timeline_name(fence)) + __field(unsigned int, context) + __field(unsigned int, seqno) + ), + + TP_fast_assign( + __assign_str(driver, fence->ops->get_driver_name(fence)) + __assign_str(timeline, fence->ops->get_timeline_name(fence)) + __entry->context = fence->context; + __entry->seqno = fence->seqno; + ), + + TP_printk("driver=%s timeline=%s context=%u seqno=%u", + __get_str(driver), __get_str(timeline), __entry->context, + __entry->seqno) +); + +DEFINE_EVENT(fence, fence_emit, + + TP_PROTO(struct fence *fence), + + TP_ARGS(fence) +); + +DEFINE_EVENT(fence, fence_init, + + TP_PROTO(struct fence *fence), + + TP_ARGS(fence) +); + +DEFINE_EVENT(fence, fence_destroy, + + TP_PROTO(struct fence *fence), + + TP_ARGS(fence) +); + +DEFINE_EVENT(fence, fence_enable_signal, + + TP_PROTO(struct fence *fence), + + TP_ARGS(fence) +); + +DEFINE_EVENT(fence, fence_signaled, + + TP_PROTO(struct fence *fence), + + TP_ARGS(fence) +); + +DEFINE_EVENT(fence, fence_wait_start, + + TP_PROTO(struct fence *fence), + + TP_ARGS(fence) +); + +DEFINE_EVENT(fence, fence_wait_end, + + TP_PROTO(struct fence *fence), + + TP_ARGS(fence) +); + +#endif /* _TRACE_FENCE_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h>

This type of fence can be used with hardware synchronization for simple hardware that can block execution until the condition (dma_buf[offset] - value) >= 0 has been met when WAIT_GEQUAL is used, or (dma_buf[offset] != 0) has been met when WAIT_NONZERO is set.

A software fallback still has to be provided in case the fence is used with a device that doesn't support this mechanism. It is useful to expose this for graphics cards that have an op to support this.

Some cards like i915 can export those, but don't have an option to wait, so they need the software fallback.

I extended the original patch by Rob Clark.

v1: Original v2: Renamed from bikeshed to seqno, moved into dma-fence.c since not much was left of the file. Lots of documentation added. v3: Use fence_ops instead of custom callbacks. Moved to own file to avoid circular dependency between dma-buf.h and fence.h v4: Add spinlock pointer to seqno_fence_init v5: Add condition member to allow wait for != 0. Fix small style errors pointed out by checkpatch.

Signed-off-by: Maarten Lankhorst maarten.lankhorst@canonical.com Reviewed-by: Rob Clark robdclark@gmail.com #v4 --- Documentation/DocBook/device-drivers.tmpl | 1 drivers/base/fence.c | 52 +++++++++++++ include/linux/seqno-fence.h | 119 +++++++++++++++++++++++++++++ 3 files changed, 172 insertions(+) create mode 100644 include/linux/seqno-fence.h

diff --git a/Documentation/DocBook/device-drivers.tmpl b/Documentation/DocBook/device-drivers.tmpl index 7eef81069d1b..6ca7a11fb893 100644 --- a/Documentation/DocBook/device-drivers.tmpl +++ b/Documentation/DocBook/device-drivers.tmpl @@ -131,6 +131,7 @@ X!Edrivers/base/interface.c !Edrivers/base/dma-buf.c !Edrivers/base/fence.c !Iinclude/linux/fence.h +!Iinclude/linux/seqno-fence.h !Edrivers/base/reservation.c !Iinclude/linux/reservation.h !Edrivers/base/dma-coherent.c diff --git a/drivers/base/fence.c b/drivers/base/fence.c index 1da7f4d6542a..752a2dfa505f 100644 --- a/drivers/base/fence.c +++ b/drivers/base/fence.c @@ -25,6 +25,7 @@ #include <linux/export.h> #include <linux/atomic.h> #include <linux/fence.h> +#include <linux/seqno-fence.h>

#define CREATE_TRACE_POINTS #include <trace/events/fence.h> @@ -414,3 +415,54 @@ __fence_init(struct fence *fence, const struct fence_ops *ops, trace_fence_init(fence); } EXPORT_SYMBOL(__fence_init); + +static const char *seqno_fence_get_driver_name(struct fence *fence) +{ + struct seqno_fence *seqno_fence = to_seqno_fence(fence); + return seqno_fence->ops->get_driver_name(fence); +} + +static const char *seqno_fence_get_timeline_name(struct fence *fence) +{ + struct seqno_fence *seqno_fence = to_seqno_fence(fence); + return seqno_fence->ops->get_timeline_name(fence); +} + +static bool seqno_enable_signaling(struct fence *fence) +{ + struct seqno_fence *seqno_fence = to_seqno_fence(fence); + return seqno_fence->ops->enable_signaling(fence); +} + +static bool seqno_signaled(struct fence *fence) +{ + struct seqno_fence *seqno_fence = to_seqno_fence(fence); + return seqno_fence->ops->signaled && seqno_fence->ops->signaled(fence); +} + +static void seqno_release(struct fence *fence) +{ + struct seqno_fence *f = to_seqno_fence(fence); + + dma_buf_put(f->sync_buf); + if (f->ops->release) + f->ops->release(fence); + else + kfree(f); +} + +static long seqno_wait(struct fence *fence, bool intr, signed long timeout) +{ + struct seqno_fence *f = to_seqno_fence(fence); + return f->ops->wait(fence, intr, timeout); +} + +const struct fence_ops seqno_fence_ops = { + .get_driver_name = seqno_fence_get_driver_name, + .get_timeline_name = seqno_fence_get_timeline_name, + .enable_signaling = seqno_enable_signaling, + .signaled = seqno_signaled, + .wait = seqno_wait, + .release = seqno_release, +}; +EXPORT_SYMBOL(seqno_fence_ops); diff --git a/include/linux/seqno-fence.h b/include/linux/seqno-fence.h new file mode 100644 index 000000000000..b4d4aad3cadc --- /dev/null +++ b/include/linux/seqno-fence.h @@ -0,0 +1,119 @@ +/* + * seqno-fence, using a dma-buf to synchronize fencing + * + * Copyright (C) 2012 Texas Instruments + * Copyright (C) 2012 Canonical Ltd + * Authors: + * Rob Clark robdclark@gmail.com + * Maarten Lankhorst maarten.lankhorst@canonical.com + * + * 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. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see http://www.gnu.org/licenses/. + */ + +#ifndef __LINUX_SEQNO_FENCE_H +#define __LINUX_SEQNO_FENCE_H + +#include <linux/fence.h> +#include <linux/dma-buf.h> + +enum seqno_fence_condition { + SEQNO_FENCE_WAIT_GEQUAL, + SEQNO_FENCE_WAIT_NONZERO +}; + +struct seqno_fence { + struct fence base; + + const struct fence_ops *ops; + struct dma_buf *sync_buf; + uint32_t seqno_ofs; + enum seqno_fence_condition condition; +}; + +extern const struct fence_ops seqno_fence_ops; + +/** + * to_seqno_fence - cast a fence to a seqno_fence + * @fence: fence to cast to a seqno_fence + * + * Returns NULL if the fence is not a seqno_fence, + * or the seqno_fence otherwise. + */ +static inline struct seqno_fence * +to_seqno_fence(struct fence *fence) +{ + if (fence->ops != &seqno_fence_ops) + return NULL; + return container_of(fence, struct seqno_fence, base); +} + +/** + * seqno_fence_init - initialize a seqno fence + * @fence: seqno_fence to initialize + * @lock: pointer to spinlock to use for fence + * @sync_buf: buffer containing the memory location to signal on + * @context: the execution context this fence is a part of + * @seqno_ofs: the offset within @sync_buf + * @seqno: the sequence # to signal on + * @ops: the fence_ops for operations on this seqno fence + * + * This function initializes a struct seqno_fence with passed parameters, + * and takes a reference on sync_buf which is released on fence destruction. + * + * A seqno_fence is a dma_fence which can complete in software when + * enable_signaling is called, but it also completes when + * (s32)((sync_buf)[seqno_ofs] - seqno) >= 0 is true + * + * The seqno_fence will take a refcount on the sync_buf until it's + * destroyed, but actual lifetime of sync_buf may be longer if one of the + * callers take a reference to it. + * + * Certain hardware have instructions to insert this type of wait condition + * in the command stream, so no intervention from software would be needed. + * This type of fence can be destroyed before completed, however a reference + * on the sync_buf dma-buf can be taken. It is encouraged to re-use the same + * dma-buf for sync_buf, since mapping or unmapping the sync_buf to the + * device's vm can be expensive. + * + * It is recommended for creators of seqno_fence to call fence_signal + * before destruction. This will prevent possible issues from wraparound at + * time of issue vs time of check, since users can check fence_is_signaled + * before submitting instructions for the hardware to wait on the fence. + * However, when ops.enable_signaling is not called, it doesn't have to be + * done as soon as possible, just before there's any real danger of seqno + * wraparound. + */ +static inline void +seqno_fence_init(struct seqno_fence *fence, spinlock_t *lock, + struct dma_buf *sync_buf, uint32_t context, + uint32_t seqno_ofs, uint32_t seqno, + enum seqno_fence_condition cond, + const struct fence_ops *ops) +{ + BUG_ON(!fence || !sync_buf || !ops); + BUG_ON(!ops->wait || !ops->enable_signaling || + !ops->get_driver_name || !ops->get_timeline_name); + + /* + * ops is used in __fence_init for get_driver_name, so needs to be + * initialized first + */ + fence->ops = ops; + __fence_init(&fence->base, &seqno_fence_ops, lock, context, seqno); + get_dma_buf(sync_buf); + fence->sync_buf = sync_buf; + fence->seqno_ofs = seqno_ofs; + fence->condition = cond; +} + +#endif /* __LINUX_SEQNO_FENCE_H */

Just to show it's easy.

Android syncpoints can be mapped to a timeline. This removes the need to maintain a separate api for synchronization. I've left the android trace events in place, but the core fence events should already be sufficient for debugging.

v2: - Call fence_remove_callback in sync_fence_free if not all fences have fired. v3: - Merge Colin Cross' bugfixes, and the android fence merge optimization. v4: - Merge with the upstream fixes. v5: - Fix small style issues pointed out by Thomas Hellstrom.

Signed-off-by: Maarten Lankhorst maarten.lankhorst@canonical.com Acked-by: John Stultz john.stultz@linaro.org --- drivers/staging/android/Kconfig | 1 drivers/staging/android/Makefile | 2 drivers/staging/android/sw_sync.c | 6 drivers/staging/android/sync.c | 913 +++++++++++----------------------- drivers/staging/android/sync.h | 79 ++- drivers/staging/android/sync_debug.c | 247 +++++++++ drivers/staging/android/trace/sync.h | 12 7 files changed, 609 insertions(+), 651 deletions(-) create mode 100644 drivers/staging/android/sync_debug.c

diff --git a/drivers/staging/android/Kconfig b/drivers/staging/android/Kconfig index 99e484f845f2..51607e9aa049 100644 --- a/drivers/staging/android/Kconfig +++ b/drivers/staging/android/Kconfig @@ -88,6 +88,7 @@ config SYNC bool "Synchronization framework" default n select ANON_INODES + select DMA_SHARED_BUFFER ---help--- This option enables the framework for synchronization between multiple drivers. Sync implementations can take advantage of hardware diff --git a/drivers/staging/android/Makefile b/drivers/staging/android/Makefile index 0a01e1914905..517ad5ffa429 100644 --- a/drivers/staging/android/Makefile +++ b/drivers/staging/android/Makefile @@ -9,5 +9,5 @@ obj-$(CONFIG_ANDROID_TIMED_OUTPUT) += timed_output.o obj-$(CONFIG_ANDROID_TIMED_GPIO) += timed_gpio.o obj-$(CONFIG_ANDROID_LOW_MEMORY_KILLER) += lowmemorykiller.o obj-$(CONFIG_ANDROID_INTF_ALARM_DEV) += alarm-dev.o -obj-$(CONFIG_SYNC) += sync.o +obj-$(CONFIG_SYNC) += sync.o sync_debug.o obj-$(CONFIG_SW_SYNC) += sw_sync.o diff --git a/drivers/staging/android/sw_sync.c b/drivers/staging/android/sw_sync.c index 12a136ec1cec..a76db3ff87cb 100644 --- a/drivers/staging/android/sw_sync.c +++ b/drivers/staging/android/sw_sync.c @@ -50,7 +50,7 @@ static struct sync_pt *sw_sync_pt_dup(struct sync_pt *sync_pt) { struct sw_sync_pt *pt = (struct sw_sync_pt *) sync_pt; struct sw_sync_timeline *obj = - (struct sw_sync_timeline *)sync_pt->parent; + (struct sw_sync_timeline *)sync_pt_parent(sync_pt);

return (struct sync_pt *) sw_sync_pt_create(obj, pt->value); } @@ -59,7 +59,7 @@ static int sw_sync_pt_has_signaled(struct sync_pt *sync_pt) { struct sw_sync_pt *pt = (struct sw_sync_pt *)sync_pt; struct sw_sync_timeline *obj = - (struct sw_sync_timeline *)sync_pt->parent; + (struct sw_sync_timeline *)sync_pt_parent(sync_pt);

return sw_sync_cmp(obj->value, pt->value) >= 0; } @@ -97,7 +97,6 @@ static void sw_sync_pt_value_str(struct sync_pt *sync_pt, char *str, int size) { struct sw_sync_pt *pt = (struct sw_sync_pt *)sync_pt; - snprintf(str, size, "%d", pt->value); }

@@ -157,7 +156,6 @@ static int sw_sync_open(struct inode *inode, struct file *file) static int sw_sync_release(struct inode *inode, struct file *file) { struct sw_sync_timeline *obj = file->private_data; - sync_timeline_destroy(&obj->obj); return 0; } diff --git a/drivers/staging/android/sync.c b/drivers/staging/android/sync.c index 18174f7c871c..70b09b5001ba 100644 --- a/drivers/staging/android/sync.c +++ b/drivers/staging/android/sync.c @@ -31,22 +31,13 @@ #define CREATE_TRACE_POINTS #include "trace/sync.h"

-static void sync_fence_signal_pt(struct sync_pt *pt); -static int _sync_pt_has_signaled(struct sync_pt *pt); -static void sync_fence_free(struct kref *kref); -static void sync_dump(void); - -static LIST_HEAD(sync_timeline_list_head); -static DEFINE_SPINLOCK(sync_timeline_list_lock); - -static LIST_HEAD(sync_fence_list_head); -static DEFINE_SPINLOCK(sync_fence_list_lock); +static const struct fence_ops android_fence_ops; +static const struct file_operations sync_fence_fops;

struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops, int size, const char *name) { struct sync_timeline *obj; - unsigned long flags;

if (size < sizeof(struct sync_timeline)) return NULL; @@ -57,17 +48,14 @@ struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops,

kref_init(&obj->kref); obj->ops = ops; + obj->context = fence_context_alloc(1); strlcpy(obj->name, name, sizeof(obj->name));

INIT_LIST_HEAD(&obj->child_list_head); - spin_lock_init(&obj->child_list_lock); - INIT_LIST_HEAD(&obj->active_list_head); - spin_lock_init(&obj->active_list_lock); + spin_lock_init(&obj->child_list_lock);

- 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); + sync_timeline_debug_add(obj);

return obj; } @@ -77,11 +65,8 @@ static void sync_timeline_free(struct kref *kref) { struct sync_timeline *obj = container_of(kref, struct sync_timeline, kref); - 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); + sync_timeline_debug_remove(obj);

if (obj->ops->release_obj) obj->ops->release_obj(obj); @@ -89,6 +74,16 @@ static void sync_timeline_free(struct kref *kref) 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); +} + void sync_timeline_destroy(struct sync_timeline *obj) { obj->destroyed = true; @@ -102,75 +97,33 @@ void sync_timeline_destroy(struct sync_timeline *obj) * signal any children that their parent is going away. */ sync_timeline_signal(obj); - - kref_put(&obj->kref, sync_timeline_free); + sync_timeline_put(obj); } EXPORT_SYMBOL(sync_timeline_destroy);

-static void sync_timeline_add_pt(struct sync_timeline *obj, struct sync_pt *pt) -{ - unsigned long flags; - - pt->parent = obj; - - spin_lock_irqsave(&obj->child_list_lock, flags); - list_add_tail(&pt->child_list, &obj->child_list_head); - spin_unlock_irqrestore(&obj->child_list_lock, flags); -} - -static void sync_timeline_remove_pt(struct sync_pt *pt) -{ - struct sync_timeline *obj = pt->parent; - unsigned long flags; - - spin_lock_irqsave(&obj->active_list_lock, flags); - if (!list_empty(&pt->active_list)) - list_del_init(&pt->active_list); - spin_unlock_irqrestore(&obj->active_list_lock, flags); - - spin_lock_irqsave(&obj->child_list_lock, flags); - if (!list_empty(&pt->child_list)) - list_del_init(&pt->child_list); - - spin_unlock_irqrestore(&obj->child_list_lock, flags); -} - void sync_timeline_signal(struct sync_timeline *obj) { unsigned long flags; LIST_HEAD(signaled_pts); - struct list_head *pos, *n; + struct sync_pt *pt, *next;

trace_sync_timeline(obj);

- spin_lock_irqsave(&obj->active_list_lock, flags); - - list_for_each_safe(pos, n, &obj->active_list_head) { - struct sync_pt *pt = - container_of(pos, struct sync_pt, active_list); + spin_lock_irqsave(&obj->child_list_lock, flags);

- if (_sync_pt_has_signaled(pt)) { - list_del_init(pos); - list_add(&pt->signaled_list, &signaled_pts); - kref_get(&pt->fence->kref); - } + list_for_each_entry_safe(pt, next, &obj->active_list_head, + active_list) { + if (__fence_is_signaled(&pt->base)) + list_del(&pt->active_list); }

- spin_unlock_irqrestore(&obj->active_list_lock, flags); - - list_for_each_safe(pos, n, &signaled_pts) { - struct sync_pt *pt = - container_of(pos, struct sync_pt, signaled_list); - - list_del_init(pos); - sync_fence_signal_pt(pt); - kref_put(&pt->fence->kref, sync_fence_free); - } + spin_unlock_irqrestore(&obj->child_list_lock, flags); } EXPORT_SYMBOL(sync_timeline_signal);

-struct sync_pt *sync_pt_create(struct sync_timeline *parent, int size) +struct sync_pt *sync_pt_create(struct sync_timeline *obj, int size) { + unsigned long flags; struct sync_pt *pt;

if (size < sizeof(struct sync_pt)) @@ -180,87 +133,28 @@ struct sync_pt *sync_pt_create(struct sync_timeline *parent, int size) if (pt == NULL) return NULL;

+ spin_lock_irqsave(&obj->child_list_lock, flags); + sync_timeline_get(obj); + __fence_init(&pt->base, &android_fence_ops, &obj->child_list_lock, + obj->context, ++obj->value); + list_add_tail(&pt->child_list, &obj->child_list_head); INIT_LIST_HEAD(&pt->active_list); - kref_get(&parent->kref); - sync_timeline_add_pt(parent, pt); - + spin_unlock_irqrestore(&obj->child_list_lock, flags); return pt; } EXPORT_SYMBOL(sync_pt_create);

void sync_pt_free(struct sync_pt *pt) { - if (pt->parent->ops->free_pt) - pt->parent->ops->free_pt(pt); - - sync_timeline_remove_pt(pt); - - kref_put(&pt->parent->kref, sync_timeline_free); - - kfree(pt); + fence_put(&pt->base); } EXPORT_SYMBOL(sync_pt_free);

-/* call with pt->parent->active_list_lock held */ -static int _sync_pt_has_signaled(struct sync_pt *pt) -{ - int old_status = pt->status; - - if (!pt->status) - pt->status = pt->parent->ops->has_signaled(pt); - - if (!pt->status && pt->parent->destroyed) - pt->status = -ENOENT; - - if (pt->status != old_status) - pt->timestamp = ktime_get(); - - return pt->status; -} - -static struct sync_pt *sync_pt_dup(struct sync_pt *pt) -{ - return pt->parent->ops->dup(pt); -} - -/* Adds a sync pt to the active queue. Called when added to a fence */ -static void sync_pt_activate(struct sync_pt *pt) -{ - struct sync_timeline *obj = pt->parent; - unsigned long flags; - int err; - - spin_lock_irqsave(&obj->active_list_lock, flags); - - err = _sync_pt_has_signaled(pt); - if (err != 0) - goto out; - - list_add_tail(&pt->active_list, &obj->active_list_head); - -out: - spin_unlock_irqrestore(&obj->active_list_lock, flags); -} - -static int sync_fence_release(struct inode *inode, struct file *file); -static unsigned int sync_fence_poll(struct file *file, poll_table *wait); -static long sync_fence_ioctl(struct file *file, unsigned int cmd, - unsigned long arg); - - -static const struct file_operations sync_fence_fops = { - .release = sync_fence_release, - .poll = sync_fence_poll, - .unlocked_ioctl = sync_fence_ioctl, - .compat_ioctl = sync_fence_ioctl, -}; - -static struct sync_fence *sync_fence_alloc(const char *name) +static struct sync_fence *sync_fence_alloc(int size, const char *name) { struct sync_fence *fence; - unsigned long flags;

- fence = kzalloc(sizeof(struct sync_fence), GFP_KERNEL); + fence = kzalloc(size, GFP_KERNEL); if (fence == NULL) return NULL;

@@ -272,16 +166,8 @@ static struct sync_fence *sync_fence_alloc(const char *name) kref_init(&fence->kref); strlcpy(fence->name, name, sizeof(fence->name));

- INIT_LIST_HEAD(&fence->pt_list_head); - INIT_LIST_HEAD(&fence->waiter_list_head); - spin_lock_init(&fence->waiter_list_lock); - init_waitqueue_head(&fence->wq);

- spin_lock_irqsave(&sync_fence_list_lock, flags); - list_add_tail(&fence->sync_fence_list, &sync_fence_list_head); - spin_unlock_irqrestore(&sync_fence_list_lock, flags); - return fence;

err: @@ -289,120 +175,42 @@ err: return NULL; }

-/* TODO: implement a create which takes more that one sync_pt */ -struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt) +static void fence_check_cb_func(struct fence *f, struct fence_cb *cb) { + struct sync_fence_cb *check; struct sync_fence *fence;

- if (pt->fence) - return NULL; - - fence = sync_fence_alloc(name); - if (fence == NULL) - return NULL; - - pt->fence = fence; - list_add(&pt->pt_list, &fence->pt_list_head); - sync_pt_activate(pt); - - /* - * signal the fence in case pt was activated before - * sync_pt_activate(pt) was called - */ - sync_fence_signal_pt(pt); + check = container_of(cb, struct sync_fence_cb, cb); + fence = check->fence;

- return fence; + if (atomic_dec_and_test(&fence->status)) + wake_up_all(&fence->wq); } -EXPORT_SYMBOL(sync_fence_create); - -static int sync_fence_copy_pts(struct sync_fence *dst, struct sync_fence *src) -{ - struct list_head *pos; - - list_for_each(pos, &src->pt_list_head) { - struct sync_pt *orig_pt = - container_of(pos, struct sync_pt, pt_list); - struct sync_pt *new_pt = sync_pt_dup(orig_pt);

- if (new_pt == NULL) - return -ENOMEM; - - new_pt->fence = dst; - list_add(&new_pt->pt_list, &dst->pt_list_head); - } - - return 0; -} - -static int sync_fence_merge_pts(struct sync_fence *dst, struct sync_fence *src) -{ - struct list_head *src_pos, *dst_pos, *n; - - list_for_each(src_pos, &src->pt_list_head) { - struct sync_pt *src_pt = - container_of(src_pos, struct sync_pt, pt_list); - bool collapsed = false; - - list_for_each_safe(dst_pos, n, &dst->pt_list_head) { - struct sync_pt *dst_pt = - container_of(dst_pos, struct sync_pt, pt_list); - /* collapse two sync_pts on the same timeline - * to a single sync_pt that will signal at - * the later of the two - */ - if (dst_pt->parent == src_pt->parent) { - if (dst_pt->parent->ops->compare(dst_pt, src_pt) - == -1) { - struct sync_pt *new_pt = - sync_pt_dup(src_pt); - if (new_pt == NULL) - return -ENOMEM; - - new_pt->fence = dst; - list_replace(&dst_pt->pt_list, - &new_pt->pt_list); - sync_pt_free(dst_pt); - } - collapsed = true; - break; - } - } - - if (!collapsed) { - struct sync_pt *new_pt = sync_pt_dup(src_pt); - - if (new_pt == NULL) - return -ENOMEM; - - new_pt->fence = dst; - list_add(&new_pt->pt_list, &dst->pt_list_head); - } - } - - return 0; -} - -static void sync_fence_detach_pts(struct sync_fence *fence) +/* TODO: implement a create which takes more that one sync_pt */ +struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt) { - struct list_head *pos, *n; + struct sync_fence *fence;

- list_for_each_safe(pos, n, &fence->pt_list_head) { - struct sync_pt *pt = container_of(pos, struct sync_pt, pt_list); + fence = sync_fence_alloc(offsetof(struct sync_fence, cbs[1]), name); + if (fence == NULL) + return NULL;

- sync_timeline_remove_pt(pt); - } -} + fence->num_fences = 1; + atomic_set(&fence->status, 1);

-static void sync_fence_free_pts(struct sync_fence *fence) -{ - struct list_head *pos, *n; + fence_get(&pt->base); + fence->cbs[0].sync_pt = &pt->base; + fence->cbs[0].fence = fence; + if (fence_add_callback(&pt->base, &fence->cbs[0].cb, + fence_check_cb_func)) + atomic_dec(&fence->status);

- list_for_each_safe(pos, n, &fence->pt_list_head) { - struct sync_pt *pt = container_of(pos, struct sync_pt, pt_list); + sync_fence_debug_add(fence);

- sync_pt_free(pt); - } + return fence; } +EXPORT_SYMBOL(sync_fence_create);

struct sync_fence *sync_fence_fdget(int fd) { @@ -434,197 +242,155 @@ void sync_fence_install(struct sync_fence *fence, int fd) } EXPORT_SYMBOL(sync_fence_install);

-static int sync_fence_get_status(struct sync_fence *fence) +static void sync_fence_add_pt(struct sync_fence *fence, + int *i, struct fence *pt) { - struct list_head *pos; - int status = 1; - - list_for_each(pos, &fence->pt_list_head) { - struct sync_pt *pt = container_of(pos, struct sync_pt, pt_list); - int pt_status = pt->status; - - if (pt_status < 0) { - status = pt_status; - break; - } else if (status == 1) { - status = pt_status; - } - } + fence->cbs[*i].sync_pt = pt; + fence->cbs[*i].fence = fence;

- return status; + if (!fence_add_callback(pt, &fence->cbs[*i].cb, fence_check_cb_func)) { + fence_get(pt); + (*i)++; + } }

struct sync_fence *sync_fence_merge(const char *name, struct sync_fence *a, struct sync_fence *b) { + int num_fences = a->num_fences + b->num_fences; struct sync_fence *fence; - struct list_head *pos; - int err; + int i, i_a, i_b; + unsigned long size = offsetof(struct sync_fence, cbs[num_fences]);

- fence = sync_fence_alloc(name); + fence = sync_fence_alloc(size, name); if (fence == NULL) return NULL;

- err = sync_fence_copy_pts(fence, a); - if (err < 0) - goto err; + atomic_set(&fence->status, num_fences);

- err = sync_fence_merge_pts(fence, b); - if (err < 0) - goto err; + /* + * Assume sync_fence a and b are both ordered and have no + * duplicates with the same context. + * + * If a sync_fence can only be created with sync_fence_merge + * and sync_fence_create, this is a reasonable assumption. + */ + for (i = i_a = i_b = 0; i_a < a->num_fences && i_b < b->num_fences; ) { + struct fence *pt_a = a->cbs[i_a].sync_pt; + struct fence *pt_b = b->cbs[i_b].sync_pt; + + if (pt_a->context < pt_b->context) { + sync_fence_add_pt(fence, &i, pt_a); + + i_a++; + } else if (pt_a->context > pt_b->context) { + sync_fence_add_pt(fence, &i, pt_b);

- list_for_each(pos, &fence->pt_list_head) { - struct sync_pt *pt = - container_of(pos, struct sync_pt, pt_list); - sync_pt_activate(pt); + i_b++; + } else { + if (pt_a->seqno - pt_b->seqno <= INT_MAX) + sync_fence_add_pt(fence, &i, pt_a); + else + sync_fence_add_pt(fence, &i, pt_b); + + i_a++; + i_b++; + } }

- /* - * signal the fence in case one of it's pts were activated before - * they were activated - */ - sync_fence_signal_pt(list_first_entry(&fence->pt_list_head, - struct sync_pt, - pt_list)); + for (; i_a < a->num_fences; i_a++) + sync_fence_add_pt(fence, &i, a->cbs[i_a].sync_pt);

+ for (; i_b < b->num_fences; i_b++) + sync_fence_add_pt(fence, &i, b->cbs[i_b].sync_pt); + + if (num_fences > i) + atomic_sub(num_fences - i, &fence->status); + fence->num_fences = i; + + sync_fence_debug_add(fence); return fence; -err: - sync_fence_free_pts(fence); - kfree(fence); - return NULL; } EXPORT_SYMBOL(sync_fence_merge);

-static void sync_fence_signal_pt(struct sync_pt *pt) +int sync_fence_wake_up_wq(wait_queue_t *curr, unsigned mode, + int wake_flags, void *key) { - LIST_HEAD(signaled_waiters); - struct sync_fence *fence = pt->fence; - struct list_head *pos; - struct list_head *n; - unsigned long flags; - int status; - - status = sync_fence_get_status(fence); - - spin_lock_irqsave(&fence->waiter_list_lock, flags); - /* - * this should protect against two threads racing on the signaled - * false -> true transition - */ - if (status && !fence->status) { - list_for_each_safe(pos, n, &fence->waiter_list_head) - list_move(pos, &signaled_waiters); - - fence->status = status; - } else { - status = 0; - } - spin_unlock_irqrestore(&fence->waiter_list_lock, flags); + struct sync_fence_waiter *wait;

- if (status) { - list_for_each_safe(pos, n, &signaled_waiters) { - struct sync_fence_waiter *waiter = - container_of(pos, struct sync_fence_waiter, - waiter_list); + wait = container_of(curr, struct sync_fence_waiter, work); + list_del_init(&wait->work.task_list);

- list_del(pos); - waiter->callback(fence, waiter); - } - wake_up(&fence->wq); - } + wait->callback(wait->work.private, wait); + return 1; }

int sync_fence_wait_async(struct sync_fence *fence, struct sync_fence_waiter *waiter) { + int err = atomic_read(&fence->status); unsigned long flags; - int err = 0;

- spin_lock_irqsave(&fence->waiter_list_lock, flags); + if (err < 0) + return err;

- if (fence->status) { - err = fence->status; - goto out; - } + if (!err) + return 1;

- list_add_tail(&waiter->waiter_list, &fence->waiter_list_head); -out: - spin_unlock_irqrestore(&fence->waiter_list_lock, flags); + init_waitqueue_func_entry(&waiter->work, sync_fence_wake_up_wq); + waiter->work.private = fence;

- return err; + spin_lock_irqsave(&fence->wq.lock, flags); + err = atomic_read(&fence->status); + if (err > 0) + __add_wait_queue_tail(&fence->wq, &waiter->work); + spin_unlock_irqrestore(&fence->wq.lock, flags); + + if (err < 0) + return err; + + return !err; } EXPORT_SYMBOL(sync_fence_wait_async);

int sync_fence_cancel_async(struct sync_fence *fence, struct sync_fence_waiter *waiter) { - struct list_head *pos; - struct list_head *n; unsigned long flags; - int ret = -ENOENT; + int ret = 0;

- spin_lock_irqsave(&fence->waiter_list_lock, flags); - /* - * Make sure waiter is still in waiter_list because it is possible for - * the waiter to be removed from the list while the callback is still - * pending. - */ - list_for_each_safe(pos, n, &fence->waiter_list_head) { - struct sync_fence_waiter *list_waiter = - container_of(pos, struct sync_fence_waiter, - waiter_list); - if (list_waiter == waiter) { - list_del(pos); - ret = 0; - break; - } - } - spin_unlock_irqrestore(&fence->waiter_list_lock, flags); + spin_lock_irqsave(&fence->wq.lock, flags); + if (!list_empty(&waiter->work.task_list)) + list_del_init(&waiter->work.task_list); + else + ret = -ENOENT; + spin_unlock_irqrestore(&fence->wq.lock, flags); return ret; } EXPORT_SYMBOL(sync_fence_cancel_async);

-static bool sync_fence_check(struct sync_fence *fence) -{ - /* - * Make sure that reads to fence->status are ordered with the - * wait queue event triggering - */ - smp_rmb(); - return fence->status != 0; -} - int sync_fence_wait(struct sync_fence *fence, long timeout) { - int err = 0; - struct sync_pt *pt; - - trace_sync_wait(fence, 1); - list_for_each_entry(pt, &fence->pt_list_head, pt_list) - trace_sync_pt(pt); + long ret; + int i;

- if (timeout > 0) { + if (timeout < 0) + timeout = MAX_SCHEDULE_TIMEOUT; + else timeout = msecs_to_jiffies(timeout); - err = wait_event_interruptible_timeout(fence->wq, - sync_fence_check(fence), - timeout); - } else if (timeout < 0) { - err = wait_event_interruptible(fence->wq, - sync_fence_check(fence)); - } - trace_sync_wait(fence, 0);

- if (err < 0) - return err; - - if (fence->status < 0) { - pr_info("fence error %d on [%p]\n", fence->status, fence); - sync_dump(); - return fence->status; - } + trace_sync_wait(fence, 1); + for (i = 0; i < fence->num_fences; ++i) + trace_sync_pt(fence->cbs[i].sync_pt); + ret = wait_event_interruptible_timeout(fence->wq, + atomic_read(&fence->status) <= 0, + timeout); + trace_sync_wait(fence, 0);

- if (fence->status == 0) { - if (timeout > 0) { + if (ret < 0) + return ret; + else if (ret == 0) { + if (timeout) { pr_info("fence timeout on [%p] after %dms\n", fence, jiffies_to_msecs(timeout)); sync_dump(); @@ -632,15 +398,136 @@ int sync_fence_wait(struct sync_fence *fence, long timeout) return -ETIME; }

- return 0; + ret = atomic_read(&fence->status); + if (ret) { + pr_info("fence error %ld on [%p]\n", ret, fence); + sync_dump(); + } + return ret; } EXPORT_SYMBOL(sync_fence_wait);

+static const char *android_fence_get_driver_name(struct fence *fence) +{ + struct sync_pt *pt = container_of(fence, struct sync_pt, base); + struct sync_timeline *parent = sync_pt_parent(pt); + + return parent->ops->driver_name; +} + +static const char *android_fence_get_timeline_name(struct fence *fence) +{ + struct sync_pt *pt = container_of(fence, struct sync_pt, base); + struct sync_timeline *parent = sync_pt_parent(pt); + + return parent->name; +} + +static void android_fence_release(struct fence *fence) +{ + struct sync_pt *pt = container_of(fence, struct sync_pt, base); + struct sync_timeline *parent = sync_pt_parent(pt); + unsigned long flags; + + spin_lock_irqsave(fence->lock, flags); + list_del(&pt->child_list); + if (WARN_ON_ONCE(!list_empty(&pt->active_list))) + list_del(&pt->active_list); + spin_unlock_irqrestore(fence->lock, flags); + + if (parent->ops->free_pt) + parent->ops->free_pt(pt); + + sync_timeline_put(parent); + kfree(pt); +} + +static bool android_fence_signaled(struct fence *fence) +{ + struct sync_pt *pt = container_of(fence, struct sync_pt, base); + struct sync_timeline *parent = sync_pt_parent(pt); + int ret; + + ret = parent->ops->has_signaled(pt); + if (ret < 0) + fence->status = ret; + return ret; +} + +static bool android_fence_enable_signaling(struct fence *fence) +{ + struct sync_pt *pt = container_of(fence, struct sync_pt, base); + struct sync_timeline *parent = sync_pt_parent(pt); + + if (android_fence_signaled(fence)) + return false; + + list_add_tail(&pt->active_list, &parent->active_list_head); + return true; +} + +static int android_fence_fill_driver_data(struct fence *fence, + void *data, int size) +{ + struct sync_pt *pt = container_of(fence, struct sync_pt, base); + struct sync_timeline *parent = sync_pt_parent(pt); + + if (!parent->ops->fill_driver_data) + return 0; + return parent->ops->fill_driver_data(pt, data, size); +} + +static void android_fence_value_str(struct fence *fence, + char *str, int size) +{ + struct sync_pt *pt = container_of(fence, struct sync_pt, base); + struct sync_timeline *parent = sync_pt_parent(pt); + + if (!parent->ops->pt_value_str) { + if (size) + *str = 0; + return; + } + parent->ops->pt_value_str(pt, str, size); +} + +static void android_fence_timeline_value_str(struct fence *fence, + char *str, int size) +{ + struct sync_pt *pt = container_of(fence, struct sync_pt, base); + struct sync_timeline *parent = sync_pt_parent(pt); + + if (!parent->ops->timeline_value_str) { + if (size) + *str = 0; + return; + } + parent->ops->timeline_value_str(parent, str, size); +} + +static const struct fence_ops android_fence_ops = { + .get_driver_name = android_fence_get_driver_name, + .get_timeline_name = android_fence_get_timeline_name, + .enable_signaling = android_fence_enable_signaling, + .signaled = android_fence_signaled, + .wait = fence_default_wait, + .release = android_fence_release, + .fill_driver_data = android_fence_fill_driver_data, + .fence_value_str = android_fence_value_str, + .timeline_value_str = android_fence_timeline_value_str, +}; + static void sync_fence_free(struct kref *kref) { struct sync_fence *fence = container_of(kref, struct sync_fence, kref); + int i, status = atomic_read(&fence->status);

- sync_fence_free_pts(fence); + for (i = 0; i < fence->num_fences; ++i) { + if (status) + fence_remove_callback(fence->cbs[i].sync_pt, + &fence->cbs[i].cb); + fence_put(fence->cbs[i].sync_pt); + }

kfree(fence); } @@ -648,44 +535,25 @@ static void sync_fence_free(struct kref *kref) static int sync_fence_release(struct inode *inode, struct file *file) { struct sync_fence *fence = file->private_data; - unsigned long flags; - - /* - * We need to remove all ways to access this fence before droping - * our ref. - * - * start with its membership in the global fence list - */ - spin_lock_irqsave(&sync_fence_list_lock, flags); - list_del(&fence->sync_fence_list); - spin_unlock_irqrestore(&sync_fence_list_lock, flags);

- /* - * remove its pts from their parents so that sync_timeline_signal() - * can't reference the fence. - */ - sync_fence_detach_pts(fence); + sync_fence_debug_remove(fence);

kref_put(&fence->kref, sync_fence_free); - return 0; }

static unsigned int sync_fence_poll(struct file *file, poll_table *wait) { struct sync_fence *fence = file->private_data; + int status;

poll_wait(file, &fence->wq, wait);

- /* - * Make sure that reads to fence->status are ordered with the - * wait queue event triggering - */ - smp_rmb(); + status = atomic_read(&fence->status);

- if (fence->status == 1) + if (!status) return POLLIN; - else if (fence->status < 0) + else if (status < 0) return POLLERR; else return 0; @@ -750,7 +618,7 @@ err_put_fd: return err; }

-static int sync_fill_pt_info(struct sync_pt *pt, void *data, int size) +static int sync_fill_pt_info(struct fence *fence, void *data, int size) { struct sync_pt_info *info = data; int ret; @@ -760,20 +628,24 @@ static int sync_fill_pt_info(struct sync_pt *pt, void *data, int size)

info->len = sizeof(struct sync_pt_info);

- if (pt->parent->ops->fill_driver_data) { - ret = pt->parent->ops->fill_driver_data(pt, info->driver_data, - size - sizeof(*info)); + if (fence->ops->fill_driver_data) { + ret = fence->ops->fill_driver_data(fence, info->driver_data, + size - sizeof(*info)); if (ret < 0) return ret;

info->len += ret; }

- strlcpy(info->obj_name, pt->parent->name, sizeof(info->obj_name)); - strlcpy(info->driver_name, pt->parent->ops->driver_name, + strlcpy(info->obj_name, fence->ops->get_timeline_name(fence), + sizeof(info->obj_name)); + strlcpy(info->driver_name, fence->ops->get_driver_name(fence), sizeof(info->driver_name)); - info->status = pt->status; - info->timestamp_ns = ktime_to_ns(pt->timestamp); + if (fence_is_signaled(fence)) + info->status = fence->status >= 0 ? 1 : fence->status; + else + info->status = 0; + info->timestamp_ns = ktime_to_ns(fence->timestamp);

return info->len; } @@ -782,10 +654,9 @@ static long sync_fence_ioctl_fence_info(struct sync_fence *fence, unsigned long arg) { struct sync_fence_info_data *data; - struct list_head *pos; __u32 size; __u32 len = 0; - int ret; + int ret, i;

if (copy_from_user(&size, (void __user *)arg, sizeof(size))) return -EFAULT; @@ -801,12 +672,14 @@ static long sync_fence_ioctl_fence_info(struct sync_fence *fence, return -ENOMEM;

strlcpy(data->name, fence->name, sizeof(data->name)); - data->status = fence->status; + data->status = atomic_read(&fence->status); + if (data->status >= 0) + data->status = !data->status; + len = sizeof(struct sync_fence_info_data);

- list_for_each(pos, &fence->pt_list_head) { - struct sync_pt *pt = - container_of(pos, struct sync_pt, pt_list); + for (i = 0; i < fence->num_fences; ++i) { + struct fence *pt = fence->cbs[i].sync_pt;

ret = sync_fill_pt_info(pt, (u8 *)data + len, size - len);

@@ -833,7 +706,6 @@ static long sync_fence_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct sync_fence *fence = file->private_data; - switch (cmd) { case SYNC_IOC_WAIT: return sync_fence_ioctl_wait(fence, arg); @@ -849,181 +721,10 @@ static long sync_fence_ioctl(struct file *file, unsigned int cmd, } }

-#ifdef CONFIG_DEBUG_FS -static const char *sync_status_str(int status) -{ - if (status > 0) - return "signaled"; - else if (status == 0) - return "active"; - else - return "error"; -} - -static void sync_print_pt(struct seq_file *s, struct sync_pt *pt, bool fence) -{ - int status = pt->status; - - seq_printf(s, " %s%spt %s", - fence ? pt->parent->name : "", - fence ? "_" : "", - sync_status_str(status)); - if (pt->status) { - struct timeval tv = ktime_to_timeval(pt->timestamp); - - seq_printf(s, "@%ld.%06ld", tv.tv_sec, tv.tv_usec); - } - - if (pt->parent->ops->timeline_value_str && - pt->parent->ops->pt_value_str) { - char value[64]; - - pt->parent->ops->pt_value_str(pt, value, sizeof(value)); - seq_printf(s, ": %s", value); - if (fence) { - pt->parent->ops->timeline_value_str(pt->parent, value, - sizeof(value)); - seq_printf(s, " / %s", value); - } - } else if (pt->parent->ops->print_pt) { - seq_puts(s, ": "); - pt->parent->ops->print_pt(s, pt); - } - - 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 %s", obj->name, obj->ops->driver_name); - - if (obj->ops->timeline_value_str) { - char value[64]; - - obj->ops->timeline_value_str(obj, value, sizeof(value)); - seq_printf(s, ": %s", value); - } else if (obj->ops->print_obj) { - seq_puts(s, ": "); - obj->ops->print_obj(s, obj); - } - - seq_puts(s, "\n"); - - 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_pt(s, pt, false); - } - spin_unlock_irqrestore(&obj->child_list_lock, flags); -} - -static void sync_print_fence(struct seq_file *s, struct sync_fence *fence) -{ - struct list_head *pos; - unsigned long flags; - - seq_printf(s, "[%p] %s: %s\n", fence, fence->name, - sync_status_str(fence->status)); - - list_for_each(pos, &fence->pt_list_head) { - struct sync_pt *pt = - container_of(pos, struct sync_pt, pt_list); - sync_print_pt(s, pt, true); - } - - spin_lock_irqsave(&fence->waiter_list_lock, flags); - list_for_each(pos, &fence->waiter_list_head) { - struct sync_fence_waiter *waiter = - container_of(pos, struct sync_fence_waiter, - waiter_list); - - seq_printf(s, "waiter %pF\n", waiter->callback); - } - spin_unlock_irqrestore(&fence->waiter_list_lock, flags); -} - -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_fence_list_lock, flags); - list_for_each(pos, &sync_fence_list_head) { - struct sync_fence *fence = - container_of(pos, struct sync_fence, sync_fence_list); - - sync_print_fence(s, fence); - seq_puts(s, "\n"); - } - spin_unlock_irqrestore(&sync_fence_list_lock, flags); - return 0; -} - -static int sync_debugfs_open(struct inode *inode, struct file *file) -{ - return single_open(file, sync_debugfs_show, inode->i_private); -} - -static const struct file_operations sync_debugfs_fops = { - .open = sync_debugfs_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, +static const struct file_operations sync_fence_fops = { + .release = sync_fence_release, + .poll = sync_fence_poll, + .unlocked_ioctl = sync_fence_ioctl, + .compat_ioctl = sync_fence_ioctl, };

-static __init int sync_debugfs_init(void) -{ - debugfs_create_file("sync", S_IRUGO, NULL, NULL, &sync_debugfs_fops); - return 0; -} -late_initcall(sync_debugfs_init); - -#define DUMP_CHUNK 256 -static char sync_dump_buf[64 * 1024]; -static 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); - } - } -} -#else -static void sync_dump(void) -{ -} -#endif diff --git a/drivers/staging/android/sync.h b/drivers/staging/android/sync.h index eaf57cccf626..66b0f431f63e 100644 --- a/drivers/staging/android/sync.h +++ b/drivers/staging/android/sync.h @@ -19,6 +19,7 @@ #include <linux/list.h> #include <linux/spinlock.h> #include <linux/wait.h> +#include <linux/fence.h>

#include "uapi/sync.h"

@@ -40,8 +41,6 @@ struct sync_fence; * -1 if a will signal before b * @free_pt: called before sync_pt is freed * @release_obj: called before sync_timeline is freed - * @print_obj: deprecated - * @print_pt: deprecated * @fill_driver_data: write implementation specific driver data to data. * should return an error if there is not enough room * as specified by size. This information is returned @@ -67,13 +66,6 @@ struct sync_timeline_ops { /* optional */ void (*release_obj)(struct sync_timeline *sync_timeline);

- /* deprecated */ - void (*print_obj)(struct seq_file *s, - struct sync_timeline *sync_timeline); - - /* deprecated */ - void (*print_pt)(struct seq_file *s, struct sync_pt *sync_pt); - /* optional */ int (*fill_driver_data)(struct sync_pt *syncpt, void *data, int size);

@@ -104,19 +96,21 @@ struct sync_timeline {

/* protected by child_list_lock */ bool destroyed; + int context, value;

struct list_head child_list_head; spinlock_t child_list_lock;

struct list_head active_list_head; - spinlock_t active_list_lock;

+#ifdef CONFIG_DEBUG_FS struct list_head sync_timeline_list; +#endif };

/** * struct sync_pt - sync point - * @parent: sync_timeline to which this sync_pt belongs + * @fence: base fence class * @child_list: membership in sync_timeline.child_list_head * @active_list: membership in sync_timeline.active_list_head * @signaled_list: membership in temporary signaled_list on stack @@ -127,19 +121,22 @@ struct sync_timeline { * signaled or error. */ struct sync_pt { - struct sync_timeline *parent; - struct list_head child_list; + struct fence base;

+ struct list_head child_list; struct list_head active_list; - struct list_head signaled_list; - - struct sync_fence *fence; - struct list_head pt_list; +};

- /* protected by parent->active_list_lock */ - int status; +static inline struct sync_timeline *sync_pt_parent(struct sync_pt *pt) +{ + return container_of(pt->base.lock, struct sync_timeline, + child_list_lock); +}

- ktime_t timestamp; +struct sync_fence_cb { + struct fence_cb cb; + struct fence *sync_pt; + struct sync_fence *fence; };

/** @@ -149,9 +146,7 @@ struct sync_pt { * @name: name of sync_fence. Useful for debugging * @pt_list_head: list of sync_pts in the fence. immutable once fence * is created - * @waiter_list_head: list of asynchronous waiters on this fence - * @waiter_list_lock: lock protecting @waiter_list_head and @status - * @status: 1: signaled, 0:active, <0: error + * @status: 0: signaled, >0:active, <0: error * * @wq: wait queue for fence signaling * @sync_fence_list: membership in global fence list @@ -160,17 +155,15 @@ struct sync_fence { struct file *file; struct kref kref; char name[32]; - - /* this list is immutable once the fence is created */ - struct list_head pt_list_head; - - struct list_head waiter_list_head; - spinlock_t waiter_list_lock; /* also protects status */ - int status; +#ifdef CONFIG_DEBUG_FS + struct list_head sync_fence_list; +#endif + int num_fences;

wait_queue_head_t wq; + atomic_t status;

- struct list_head sync_fence_list; + struct sync_fence_cb cbs[]; };

struct sync_fence_waiter; @@ -184,14 +177,14 @@ typedef void (*sync_callback_t)(struct sync_fence *fence, * @callback_data: pointer to pass to @callback */ struct sync_fence_waiter { - struct list_head waiter_list; - - sync_callback_t callback; + wait_queue_t work; + sync_callback_t callback; };

static inline void sync_fence_waiter_init(struct sync_fence_waiter *waiter, sync_callback_t callback) { + INIT_LIST_HEAD(&waiter->work.task_list); waiter->callback = callback; }

@@ -341,4 +334,22 @@ int sync_fence_cancel_async(struct sync_fence *fence, */ int sync_fence_wait(struct sync_fence *fence, long timeout);

+#ifdef CONFIG_DEBUG_FS + +extern void sync_timeline_debug_add(struct sync_timeline *obj); +extern void sync_timeline_debug_remove(struct sync_timeline *obj); +extern void sync_fence_debug_add(struct sync_fence *fence); +extern void sync_fence_debug_remove(struct sync_fence *fence); +extern void sync_dump(void); + +#else +# define sync_timeline_debug_add(obj) +# define sync_timeline_debug_remove(obj) +# define sync_fence_debug_add(fence) +# define sync_fence_debug_remove(fence) +# define sync_dump() +#endif +int sync_fence_wake_up_wq(wait_queue_t *curr, unsigned mode, + int wake_flags, void *key); + #endif /* _LINUX_SYNC_H */ diff --git a/drivers/staging/android/sync_debug.c b/drivers/staging/android/sync_debug.c new file mode 100644 index 000000000000..00efaf9d8aa2 --- /dev/null +++ b/drivers/staging/android/sync_debug.c @@ -0,0 +1,247 @@ +/* + * drivers/base/sync.c + * + * 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/debugfs.h> +#include <linux/export.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/kernel.h> +#include <linux/poll.h> +#include <linux/sched.h> +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/anon_inodes.h> +#include "sync.h" + +#ifdef CONFIG_DEBUG_FS + +static LIST_HEAD(sync_timeline_list_head); +static DEFINE_SPINLOCK(sync_timeline_list_lock); +static LIST_HEAD(sync_fence_list_head); +static DEFINE_SPINLOCK(sync_fence_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_fence_debug_add(struct sync_fence *fence) +{ + unsigned long flags; + + spin_lock_irqsave(&sync_fence_list_lock, flags); + list_add_tail(&fence->sync_fence_list, &sync_fence_list_head); + spin_unlock_irqrestore(&sync_fence_list_lock, flags); +} + +void sync_fence_debug_remove(struct sync_fence *fence) +{ + unsigned long flags; + + spin_lock_irqsave(&sync_fence_list_lock, flags); + list_del(&fence->sync_fence_list); + spin_unlock_irqrestore(&sync_fence_list_lock, flags); +} + +static const char *sync_status_str(int status) +{ + if (status == 0) + return "signaled"; + else if (status > 0) + return "active"; + else + return "error"; +} + +static void sync_print_pt(struct seq_file *s, struct sync_pt *pt, bool fence) +{ + int status = 1; + struct sync_timeline *parent = sync_pt_parent(pt); + + if (__fence_is_signaled(&pt->base)) + status = pt->base.status; + + seq_printf(s, " %s%spt %s", + fence ? parent->name : "", + fence ? "_" : "", + sync_status_str(status)); + + if (status <= 0) { + struct timeval tv = ktime_to_timeval(pt->base.timestamp); + seq_printf(s, "@%ld.%06ld", tv.tv_sec, tv.tv_usec); + } + + if (parent->ops->timeline_value_str && + parent->ops->pt_value_str) { + char value[64]; + parent->ops->pt_value_str(pt, value, sizeof(value)); + seq_printf(s, ": %s", value); + if (fence) { + parent->ops->timeline_value_str(parent, value, + sizeof(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 %s", obj->name, obj->ops->driver_name); + + if (obj->ops->timeline_value_str) { + char value[64]; + obj->ops->timeline_value_str(obj, value, sizeof(value)); + seq_printf(s, ": %s", value); + } + + seq_puts(s, "\n"); + + 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_pt(s, pt, false); + } + spin_unlock_irqrestore(&obj->child_list_lock, flags); +} + +static void sync_print_fence(struct seq_file *s, struct sync_fence *fence) +{ + wait_queue_t *pos; + unsigned long flags; + int i; + + seq_printf(s, "[%p] %s: %s\n", fence, fence->name, + sync_status_str(atomic_read(&fence->status))); + + for (i = 0; i < fence->num_fences; ++i) { + struct sync_pt *pt = + container_of(fence->cbs[i].sync_pt, + struct sync_pt, base); + + sync_print_pt(s, pt, true); + } + + spin_lock_irqsave(&fence->wq.lock, flags); + list_for_each_entry(pos, &fence->wq.task_list, task_list) { + struct sync_fence_waiter *waiter; + + if (pos->func != &sync_fence_wake_up_wq) + continue; + + waiter = container_of(pos, struct sync_fence_waiter, work); + + seq_printf(s, "waiter %pF\n", waiter->callback); + } + spin_unlock_irqrestore(&fence->wq.lock, flags); +} + +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_fence_list_lock, flags); + list_for_each(pos, &sync_fence_list_head) { + struct sync_fence *fence = + container_of(pos, struct sync_fence, sync_fence_list); + + sync_print_fence(s, fence); + seq_puts(s, "\n"); + } + spin_unlock_irqrestore(&sync_fence_list_lock, flags); + return 0; +} + +static int sync_debugfs_open(struct inode *inode, struct file *file) +{ + return single_open(file, sync_debugfs_show, inode->i_private); +} + +static const struct file_operations sync_debugfs_fops = { + .open = sync_debugfs_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static __init int sync_debugfs_init(void) +{ + debugfs_create_file("sync", S_IRUGO, NULL, NULL, &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); + } + } +} + +#endif diff --git a/drivers/staging/android/trace/sync.h b/drivers/staging/android/trace/sync.h index 95462359ba57..77edb977a7bf 100644 --- a/drivers/staging/android/trace/sync.h +++ b/drivers/staging/android/trace/sync.h @@ -45,7 +45,7 @@ TRACE_EVENT(sync_wait,

TP_fast_assign( __assign_str(name, fence->name); - __entry->status = fence->status; + __entry->status = atomic_read(&fence->status); __entry->begin = begin; ),

@@ -54,19 +54,19 @@ TRACE_EVENT(sync_wait, );

TRACE_EVENT(sync_pt, - TP_PROTO(struct sync_pt *pt), + TP_PROTO(struct fence *pt),

TP_ARGS(pt),

TP_STRUCT__entry( - __string(timeline, pt->parent->name) + __string(timeline, pt->ops->get_timeline_name(pt)) __array(char, value, 32) ),

TP_fast_assign( - __assign_str(timeline, pt->parent->name); - if (pt->parent->ops->pt_value_str) { - pt->parent->ops->pt_value_str(pt, __entry->value, + __assign_str(timeline, pt->ops->get_timeline_name(pt)); + if (pt->ops->fence_value_str) { + pt->ops->fence_value_str(pt, __entry->value, sizeof(__entry->value)); } else { __entry->value[0] = '\0';

Signed-off-by: Maarten Lankhorst maarten.lankhorst@canonical.com Reviewed-by: Rob Clark robdclark@gmail.com --- include/linux/reservation.h | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/include/linux/reservation.h b/include/linux/reservation.h index 813dae960ebd..f3f57460a205 100644 --- a/include/linux/reservation.h +++ b/include/linux/reservation.h @@ -6,7 +6,7 @@ * Copyright (C) 2012 Texas Instruments * * Authors: - * Rob Clark rob.clark@linaro.org + * Rob Clark robdclark@gmail.com * Maarten Lankhorst maarten.lankhorst@canonical.com * Thomas Hellstrom <thellstrom-at-vmware-dot-com> * @@ -40,22 +40,40 @@ #define _LINUX_RESERVATION_H

#include <linux/ww_mutex.h> +#include <linux/fence.h> +#include <linux/slab.h>

extern struct ww_class reservation_ww_class;

struct reservation_object { struct ww_mutex lock; + + struct fence *fence_excl; + struct fence **fence_shared; + u32 fence_shared_count, fence_shared_max; };

static inline void reservation_object_init(struct reservation_object *obj) { ww_mutex_init(&obj->lock, &reservation_ww_class); + + obj->fence_shared_count = obj->fence_shared_max = 0; + obj->fence_shared = NULL; + obj->fence_excl = NULL; }

static inline void reservation_object_fini(struct reservation_object *obj) { + int i; + + if (obj->fence_excl) + fence_put(obj->fence_excl); + for (i = 0; i < obj->fence_shared_count; ++i) + fence_put(obj->fence_shared[i]); + kfree(obj->fence_shared); + ww_mutex_destroy(&obj->lock); }

Move the list of shared fences to a struct, and return it in reservation_object_get_list(). Add reservation_object_get_excl to get the exclusive fence.

Add reservation_object_reserve_shared(), which reserves space in the reservation_object for 1 more shared fence.

reservation_object_add_shared_fence() and reservation_object_add_excl_fence() are used to assign a new fence to a reservation_object pointer, to complete a reservation.

Signed-off-by: Maarten Lankhorst maarten.lankhorst@canonical.com

Changes since v1: - Add reservation_object_get_excl, reorder code a bit. --- drivers/base/dma-buf.c | 35 +++++++--- drivers/base/fence.c | 4 + drivers/base/reservation.c | 156 +++++++++++++++++++++++++++++++++++++++++++ include/linux/fence.h | 6 ++ include/linux/reservation.h | 56 ++++++++++++++- 5 files changed, 236 insertions(+), 21 deletions(-)

diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c index 25e8c4165936..cb8379dfeed5 100644 --- a/drivers/base/dma-buf.c +++ b/drivers/base/dma-buf.c @@ -134,7 +134,10 @@ static unsigned int dma_buf_poll(struct file *file, poll_table *poll) { struct dma_buf *dmabuf; struct reservation_object *resv; + struct reservation_object_list *fobj; + struct fence *fence_excl; unsigned long events; + unsigned shared_count;

dmabuf = file->private_data; if (!dmabuf || !dmabuf->resv) @@ -150,12 +153,18 @@ static unsigned int dma_buf_poll(struct file *file, poll_table *poll)

ww_mutex_lock(&resv->lock, NULL);

- if (resv->fence_excl && (!(events & POLLOUT) || - resv->fence_shared_count == 0)) { + fobj = resv->fence; + if (!fobj) + goto out; + + shared_count = fobj->shared_count; + fence_excl = resv->fence_excl; + + if (fence_excl && (!(events & POLLOUT) || shared_count == 0)) { struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl; unsigned long pevents = POLLIN;

- if (resv->fence_shared_count == 0) + if (shared_count == 0) pevents |= POLLOUT;

spin_lock_irq(&dmabuf->poll.lock); @@ -167,19 +176,20 @@ static unsigned int dma_buf_poll(struct file *file, poll_table *poll) spin_unlock_irq(&dmabuf->poll.lock);

if (events & pevents) { - if (!fence_add_callback(resv->fence_excl, - &dcb->cb, dma_buf_poll_cb)) + if (!fence_add_callback(fence_excl, &dcb->cb, + dma_buf_poll_cb)) { events &= ~pevents; - else + } else { /* * No callback queued, wake up any additional * waiters. */ dma_buf_poll_cb(NULL, &dcb->cb); + } } }

- if ((events & POLLOUT) && resv->fence_shared_count > 0) { + if ((events & POLLOUT) && shared_count > 0) { struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared; int i;

@@ -194,15 +204,18 @@ static unsigned int dma_buf_poll(struct file *file, poll_table *poll) if (!(events & POLLOUT)) goto out;

- for (i = 0; i < resv->fence_shared_count; ++i) - if (!fence_add_callback(resv->fence_shared[i], - &dcb->cb, dma_buf_poll_cb)) { + for (i = 0; i < shared_count; ++i) { + struct fence *fence = fobj->shared[i]; + + if (!fence_add_callback(fence, &dcb->cb, + dma_buf_poll_cb)) { events &= ~POLLOUT; break; } + }

/* No callback queued, wake up any additional waiters. */ - if (i == resv->fence_shared_count) + if (i == shared_count) dma_buf_poll_cb(NULL, &dcb->cb); }

diff --git a/drivers/base/fence.c b/drivers/base/fence.c index 752a2dfa505f..74d1f7bcb467 100644 --- a/drivers/base/fence.c +++ b/drivers/base/fence.c @@ -170,7 +170,7 @@ void release_fence(struct kref *kref) if (fence->ops->release) fence->ops->release(fence); else - kfree(fence); + free_fence(fence); } EXPORT_SYMBOL(release_fence);

@@ -448,7 +448,7 @@ static void seqno_release(struct fence *fence) if (f->ops->release) f->ops->release(fence); else - kfree(f); + free_fence(fence); }

static long seqno_wait(struct fence *fence, bool intr, signed long timeout) diff --git a/drivers/base/reservation.c b/drivers/base/reservation.c index a73fbf3b8e56..e6166723a9ae 100644 --- a/drivers/base/reservation.c +++ b/drivers/base/reservation.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2012-2013 Canonical Ltd + * Copyright (C) 2012-2014 Canonical Ltd (Maarten Lankhorst) * * Based on bo.c which bears the following copyright notice, * but is dual licensed: @@ -37,3 +37,157 @@

DEFINE_WW_CLASS(reservation_ww_class); EXPORT_SYMBOL(reservation_ww_class); + +/* + * Reserve space to add a shared fence to a reservation_object, + * must be called with obj->lock held. + */ +int reservation_object_reserve_shared(struct reservation_object *obj) +{ + struct reservation_object_list *fobj, *old; + u32 max; + + old = reservation_object_get_list(obj); + + if (old && old->shared_max) { + if (old->shared_count < old->shared_max) { + /* perform an in-place update */ + kfree(obj->staged); + obj->staged = NULL; + return 0; + } else + max = old->shared_max * 2; + } else + max = 4; + + /* + * resize obj->staged or allocate if it doesn't exist, + * noop if already correct size + */ + fobj = krealloc(obj->staged, offsetof(typeof(*fobj), shared[max]), + GFP_KERNEL); + if (!fobj) + return -ENOMEM; + + obj->staged = fobj; + fobj->shared_max = max; + return 0; +} +EXPORT_SYMBOL(reservation_object_reserve_shared); + +static void +reservation_object_add_shared_inplace(struct reservation_object *obj, + struct reservation_object_list *fobj, + struct fence *fence) +{ + u32 i; + + for (i = 0; i < fobj->shared_count; ++i) { + if (fobj->shared[i]->context == fence->context) { + struct fence *old_fence = fobj->shared[i]; + + fence_get(fence); + + fobj->shared[i] = fence; + + fence_put(old_fence); + return; + } + } + + fence_get(fence); + fobj->shared[fobj->shared_count] = fence; + /* + * make the new fence visible before incrementing + * fobj->shared_count + */ + smp_wmb(); + fobj->shared_count++; +} + +static void +reservation_object_add_shared_replace(struct reservation_object *obj, + struct reservation_object_list *old, + struct reservation_object_list *fobj, + struct fence *fence) +{ + unsigned i; + + fence_get(fence); + + if (!old) { + fobj->shared[0] = fence; + fobj->shared_count = 1; + goto done; + } + + /* + * no need to bump fence refcounts, rcu_read access + * requires the use of kref_get_unless_zero, and the + * references from the old struct are carried over to + * the new. + */ + fobj->shared_count = old->shared_count; + + for (i = 0; i < old->shared_count; ++i) { + if (fence && old->shared[i]->context == fence->context) { + fence_put(old->shared[i]); + fobj->shared[i] = fence; + fence = NULL; + } else + fobj->shared[i] = old->shared[i]; + } + if (fence) + fobj->shared[fobj->shared_count++] = fence; + +done: + obj->fence = fobj; + kfree(old); +} + +/* + * Add a fence to a shared slot, obj->lock must be held, and + * reservation_object_reserve_shared_fence has been called. + */ +void reservation_object_add_shared_fence(struct reservation_object *obj, + struct fence *fence) +{ + struct reservation_object_list *old, *fobj = obj->staged; + + old = reservation_object_get_list(obj); + obj->staged = NULL; + + if (!fobj) { + BUG_ON(old->shared_count == old->shared_max); + reservation_object_add_shared_inplace(obj, old, fence); + } else + reservation_object_add_shared_replace(obj, old, fobj, fence); +} +EXPORT_SYMBOL(reservation_object_add_shared_fence); + +void reservation_object_add_excl_fence(struct reservation_object *obj, + struct fence *fence) +{ + struct fence *old_fence = obj->fence_excl; + struct reservation_object_list *old; + u32 i = 0; + + old = reservation_object_get_list(obj); + if (old) { + i = old->shared_count; + old->shared_count = 0; + } + + if (fence) + fence_get(fence); + + obj->fence_excl = fence; + + /* inplace update, no shared fences */ + while (i--) + fence_put(old->shared[i]); + + if (old_fence) + fence_put(old_fence); +} +EXPORT_SYMBOL(reservation_object_add_excl_fence); diff --git a/include/linux/fence.h b/include/linux/fence.h index 65f2a01ee7e4..d13b5ab61726 100644 --- a/include/linux/fence.h +++ b/include/linux/fence.h @@ -31,6 +31,7 @@ #include <linux/kref.h> #include <linux/sched.h> #include <linux/printk.h> +#include <linux/slab.h>

struct fence; struct fence_ops; @@ -191,6 +192,11 @@ static inline void fence_get(struct fence *fence)

extern void release_fence(struct kref *kref);

+static inline void free_fence(struct fence *fence) +{ + kfree(fence); +} + /** * fence_put - decreases refcount of the fence * @fence: [in] fence to reduce refcount of diff --git a/include/linux/reservation.h b/include/linux/reservation.h index f3f57460a205..2affe67dea6e 100644 --- a/include/linux/reservation.h +++ b/include/linux/reservation.h @@ -45,36 +45,78 @@

extern struct ww_class reservation_ww_class;

+struct reservation_object_list { + u32 shared_count, shared_max; + struct fence *shared[]; +}; + struct reservation_object { struct ww_mutex lock;

struct fence *fence_excl; - struct fence **fence_shared; - u32 fence_shared_count, fence_shared_max; + struct reservation_object_list *fence; + struct reservation_object_list *staged; };

+#define reservation_object_assert_held(obj) \ + lockdep_assert_held(&(obj)->lock.base) + static inline void reservation_object_init(struct reservation_object *obj) { ww_mutex_init(&obj->lock, &reservation_ww_class);

- obj->fence_shared_count = obj->fence_shared_max = 0; - obj->fence_shared = NULL; obj->fence_excl = NULL; + obj->fence = NULL; + obj->staged = NULL; }

static inline void reservation_object_fini(struct reservation_object *obj) { int i; + struct reservation_object_list *fobj;

+ /* + * This object should be dead and all references must have + * been released to it. + */ if (obj->fence_excl) fence_put(obj->fence_excl); - for (i = 0; i < obj->fence_shared_count; ++i) - fence_put(obj->fence_shared[i]); - kfree(obj->fence_shared); + + fobj = obj->fence; + if (fobj) { + for (i = 0; i < fobj->shared_count; ++i) + fence_put(fobj->shared[i]); + + kfree(fobj); + } + kfree(obj->staged);

ww_mutex_destroy(&obj->lock); }

+static inline struct reservation_object_list * +reservation_object_get_list(struct reservation_object *obj) +{ + reservation_object_assert_held(obj); + + return obj->fence; +} + +static inline struct fence * +reservation_object_get_excl(struct reservation_object *obj) +{ + reservation_object_assert_held(obj); + + return obj->fence_excl; +} + +int reservation_object_reserve_shared(struct reservation_object *obj); +void reservation_object_add_shared_fence(struct reservation_object *obj, + struct fence *fence); + +void reservation_object_add_excl_fence(struct reservation_object *obj, + struct fence *fence); + #endif /* _LINUX_RESERVATION_H */