// SPDX-License-Identifier: GPL-2.0 OR MIT
/**************************************************************************
*
- * Copyright 2011-2023 VMware, Inc., Palo Alto, CA., USA
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the
- * "Software"), to deal in the Software without restriction, including
- * without limitation the rights to use, copy, modify, merge, publish,
- * distribute, sub license, and/or sell copies of the Software, and to
- * permit persons to whom the Software is furnished to do so, subject to
- * the following conditions:
- *
- * The above copyright notice and this permission notice (including the
- * next paragraph) shall be included in all copies or substantial portions
- * of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
- * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
- * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
- * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
- * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ * Copyright (c) 2009-2025 Broadcom. All Rights Reserved. The term
+ * “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.
*
**************************************************************************/
-#include <linux/sched/signal.h>
-
#include "vmwgfx_drv.h"
#define VMW_FENCE_WRAP (1 << 31)
struct vmw_private *dev_priv;
spinlock_t lock;
struct list_head fence_list;
- struct work_struct work;
bool fifo_down;
- struct list_head cleanup_list;
- uint32_t pending_actions[VMW_ACTION_MAX];
- struct mutex goal_irq_mutex;
- bool goal_irq_on; /* Protected by @goal_irq_mutex */
- bool seqno_valid; /* Protected by @lock, and may not be set to true
- without the @goal_irq_mutex held. */
u64 ctx;
};
};
/**
- * struct vmw_event_fence_action - fence action that delivers a drm event.
+ * struct vmw_event_fence_action - fence callback that delivers a DRM event.
*
- * @action: A struct vmw_fence_action to hook up to a fence.
+ * @base: For use with dma_fence_add_callback(...)
* @event: A pointer to the pending event.
- * @fence: A referenced pointer to the fence to keep it alive while @action
- * hangs on it.
* @dev: Pointer to a struct drm_device so we can access the event stuff.
* @tv_sec: If non-null, the variable pointed to will be assigned
* current time tv_sec val when the fence signals.
* be assigned the current time tv_usec val when the fence signals.
*/
struct vmw_event_fence_action {
- struct vmw_fence_action action;
+ struct dma_fence_cb base;
struct drm_pending_event *event;
- struct vmw_fence_obj *fence;
struct drm_device *dev;
uint32_t *tv_sec;
return container_of(fence->base.lock, struct vmw_fence_manager, lock);
}
-static u32 vmw_fence_goal_read(struct vmw_private *vmw)
-{
- if ((vmw->capabilities2 & SVGA_CAP2_EXTRA_REGS) != 0)
- return vmw_read(vmw, SVGA_REG_FENCE_GOAL);
- else
- return vmw_fifo_mem_read(vmw, SVGA_FIFO_FENCE_GOAL);
-}
-
-static void vmw_fence_goal_write(struct vmw_private *vmw, u32 value)
-{
- if ((vmw->capabilities2 & SVGA_CAP2_EXTRA_REGS) != 0)
- vmw_write(vmw, SVGA_REG_FENCE_GOAL, value);
- else
- vmw_fifo_mem_write(vmw, SVGA_FIFO_FENCE_GOAL, value);
-}
-
-/*
- * Note on fencing subsystem usage of irqs:
- * Typically the vmw_fences_update function is called
- *
- * a) When a new fence seqno has been submitted by the fifo code.
- * b) On-demand when we have waiters. Sleeping waiters will switch on the
- * ANY_FENCE irq and call vmw_fences_update function each time an ANY_FENCE
- * irq is received. When the last fence waiter is gone, that IRQ is masked
- * away.
- *
- * In situations where there are no waiters and we don't submit any new fences,
- * fence objects may not be signaled. This is perfectly OK, since there are
- * no consumers of the signaled data, but that is NOT ok when there are fence
- * actions attached to a fence. The fencing subsystem then makes use of the
- * FENCE_GOAL irq and sets the fence goal seqno to that of the next fence
- * which has an action attached, and each time vmw_fences_update is called,
- * the subsystem makes sure the fence goal seqno is updated.
- *
- * The fence goal seqno irq is on as long as there are unsignaled fence
- * objects with actions attached to them.
- */
-
static void vmw_fence_obj_destroy(struct dma_fence *f)
{
struct vmw_fence_obj *fence =
struct vmw_fence_manager *fman = fman_from_fence(fence);
if (!list_empty(&fence->head)) {
+ /* The fence manager still has an implicit reference to this
+ * fence via the fence list if head is set. Because the lock is
+ * required to be held when the fence manager updates the fence
+ * list either the fence will have been removed after we get
+ * the lock below or we can safely remove it and the fence
+ * manager will never see it. This implies the fence is being
+ * deleted without being signaled which is dubious but valid
+ * if there are no callbacks. The dma_fence code that calls
+ * this hook will warn about deleted unsignaled with callbacks
+ * so no need to warn again here.
+ */
spin_lock(&fman->lock);
list_del_init(&fence->head);
+ if (fence->waiter_added)
+ vmw_seqno_waiter_remove(fman->dev_priv);
spin_unlock(&fman->lock);
}
fence->destroy(fence);
return "svga";
}
+/* When we toggle signaling for the SVGA device there is a race period from
+ * the time we first read the fence seqno to the time we enable interrupts.
+ * If we miss the interrupt for a fence during this period its likely the driver
+ * will stall. As a result we need to re-read the seqno after interrupts are
+ * enabled. If interrupts were already enabled we just increment the number of
+ * seqno waiters.
+ */
static bool vmw_fence_enable_signaling(struct dma_fence *f)
{
+ u32 seqno;
struct vmw_fence_obj *fence =
container_of(f, struct vmw_fence_obj, base);
struct vmw_fence_manager *fman = fman_from_fence(fence);
struct vmw_private *dev_priv = fman->dev_priv;
-
- u32 seqno = vmw_fence_read(dev_priv);
- if (seqno - fence->base.seqno < VMW_FENCE_WRAP)
+check_for_race:
+ seqno = vmw_fence_read(dev_priv);
+ if (seqno - fence->base.seqno < VMW_FENCE_WRAP) {
+ if (fence->waiter_added) {
+ vmw_seqno_waiter_remove(dev_priv);
+ fence->waiter_added = false;
+ }
return false;
-
+ } else if (!fence->waiter_added) {
+ fence->waiter_added = true;
+ if (vmw_seqno_waiter_add(dev_priv))
+ goto check_for_race;
+ }
return true;
}
-struct vmwgfx_wait_cb {
- struct dma_fence_cb base;
- struct task_struct *task;
-};
-
-static void
-vmwgfx_wait_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
-{
- struct vmwgfx_wait_cb *wait =
- container_of(cb, struct vmwgfx_wait_cb, base);
-
- wake_up_process(wait->task);
-}
-
static u32 __vmw_fences_update(struct vmw_fence_manager *fman);
-static long vmw_fence_wait(struct dma_fence *f, bool intr, signed long timeout)
-{
- struct vmw_fence_obj *fence =
- container_of(f, struct vmw_fence_obj, base);
-
- struct vmw_fence_manager *fman = fman_from_fence(fence);
- struct vmw_private *dev_priv = fman->dev_priv;
- struct vmwgfx_wait_cb cb;
- long ret = timeout;
-
- if (likely(vmw_fence_obj_signaled(fence)))
- return timeout;
-
- vmw_seqno_waiter_add(dev_priv);
-
- spin_lock(f->lock);
-
- if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &f->flags))
- goto out;
-
- if (intr && signal_pending(current)) {
- ret = -ERESTARTSYS;
- goto out;
- }
-
- cb.base.func = vmwgfx_wait_cb;
- cb.task = current;
- list_add(&cb.base.node, &f->cb_list);
-
- for (;;) {
- __vmw_fences_update(fman);
-
- /*
- * We can use the barrier free __set_current_state() since
- * DMA_FENCE_FLAG_SIGNALED_BIT + wakeup is protected by the
- * fence spinlock.
- */
- if (intr)
- __set_current_state(TASK_INTERRUPTIBLE);
- else
- __set_current_state(TASK_UNINTERRUPTIBLE);
-
- if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &f->flags)) {
- if (ret == 0 && timeout > 0)
- ret = 1;
- break;
- }
-
- if (intr && signal_pending(current)) {
- ret = -ERESTARTSYS;
- break;
- }
-
- if (ret == 0)
- break;
-
- spin_unlock(f->lock);
-
- ret = schedule_timeout(ret);
-
- spin_lock(f->lock);
- }
- __set_current_state(TASK_RUNNING);
- if (!list_empty(&cb.base.node))
- list_del(&cb.base.node);
-
-out:
- spin_unlock(f->lock);
-
- vmw_seqno_waiter_remove(dev_priv);
-
- return ret;
-}
-
static const struct dma_fence_ops vmw_fence_ops = {
.get_driver_name = vmw_fence_get_driver_name,
.get_timeline_name = vmw_fence_get_timeline_name,
.enable_signaling = vmw_fence_enable_signaling,
- .wait = vmw_fence_wait,
.release = vmw_fence_obj_destroy,
};
-/*
- * Execute signal actions on fences recently signaled.
- * This is done from a workqueue so we don't have to execute
- * signal actions from atomic context.
- */
-
-static void vmw_fence_work_func(struct work_struct *work)
-{
- struct vmw_fence_manager *fman =
- container_of(work, struct vmw_fence_manager, work);
- struct list_head list;
- struct vmw_fence_action *action, *next_action;
- bool seqno_valid;
-
- do {
- INIT_LIST_HEAD(&list);
- mutex_lock(&fman->goal_irq_mutex);
-
- spin_lock(&fman->lock);
- list_splice_init(&fman->cleanup_list, &list);
- seqno_valid = fman->seqno_valid;
- spin_unlock(&fman->lock);
-
- if (!seqno_valid && fman->goal_irq_on) {
- fman->goal_irq_on = false;
- vmw_goal_waiter_remove(fman->dev_priv);
- }
- mutex_unlock(&fman->goal_irq_mutex);
-
- if (list_empty(&list))
- return;
-
- /*
- * At this point, only we should be able to manipulate the
- * list heads of the actions we have on the private list.
- * hence fman::lock not held.
- */
-
- list_for_each_entry_safe(action, next_action, &list, head) {
- list_del_init(&action->head);
- if (action->cleanup)
- action->cleanup(action);
- }
- } while (1);
-}
-
struct vmw_fence_manager *vmw_fence_manager_init(struct vmw_private *dev_priv)
{
struct vmw_fence_manager *fman = kzalloc(sizeof(*fman), GFP_KERNEL);
fman->dev_priv = dev_priv;
spin_lock_init(&fman->lock);
INIT_LIST_HEAD(&fman->fence_list);
- INIT_LIST_HEAD(&fman->cleanup_list);
- INIT_WORK(&fman->work, &vmw_fence_work_func);
fman->fifo_down = true;
- mutex_init(&fman->goal_irq_mutex);
fman->ctx = dma_fence_context_alloc(1);
return fman;
{
bool lists_empty;
- (void) cancel_work_sync(&fman->work);
-
spin_lock(&fman->lock);
- lists_empty = list_empty(&fman->fence_list) &&
- list_empty(&fman->cleanup_list);
+ lists_empty = list_empty(&fman->fence_list);
spin_unlock(&fman->lock);
BUG_ON(!lists_empty);
dma_fence_init(&fence->base, &vmw_fence_ops, &fman->lock,
fman->ctx, seqno);
- INIT_LIST_HEAD(&fence->seq_passed_actions);
fence->destroy = destroy;
spin_lock(&fman->lock);
ret = -EBUSY;
goto out_unlock;
}
+ /* This creates an implicit reference to the fence from the fence
+ * manager. It will be dropped when the fence is signaled which is
+ * expected to happen before deletion. The dtor has code to catch
+ * the rare deletion before signaling case.
+ */
list_add_tail(&fence->head, &fman->fence_list);
out_unlock:
}
-static void vmw_fences_perform_actions(struct vmw_fence_manager *fman,
- struct list_head *list)
-{
- struct vmw_fence_action *action, *next_action;
-
- list_for_each_entry_safe(action, next_action, list, head) {
- list_del_init(&action->head);
- fman->pending_actions[action->type]--;
- if (action->seq_passed != NULL)
- action->seq_passed(action);
-
- /*
- * Add the cleanup action to the cleanup list so that
- * it will be performed by a worker task.
- */
-
- list_add_tail(&action->head, &fman->cleanup_list);
- }
-}
-
-/**
- * vmw_fence_goal_new_locked - Figure out a new device fence goal
- * seqno if needed.
- *
- * @fman: Pointer to a fence manager.
- * @passed_seqno: The seqno the device currently signals as passed.
- *
- * This function should be called with the fence manager lock held.
- * It is typically called when we have a new passed_seqno, and
- * we might need to update the fence goal. It checks to see whether
- * the current fence goal has already passed, and, in that case,
- * scans through all unsignaled fences to get the next fence object with an
- * action attached, and sets the seqno of that fence as a new fence goal.
- *
- * returns true if the device goal seqno was updated. False otherwise.
- */
-static bool vmw_fence_goal_new_locked(struct vmw_fence_manager *fman,
- u32 passed_seqno)
-{
- u32 goal_seqno;
- struct vmw_fence_obj *fence, *next_fence;
-
- if (likely(!fman->seqno_valid))
- return false;
-
- goal_seqno = vmw_fence_goal_read(fman->dev_priv);
- if (likely(passed_seqno - goal_seqno >= VMW_FENCE_WRAP))
- return false;
-
- fman->seqno_valid = false;
- list_for_each_entry_safe(fence, next_fence, &fman->fence_list, head) {
- if (!list_empty(&fence->seq_passed_actions)) {
- fman->seqno_valid = true;
- vmw_fence_goal_write(fman->dev_priv,
- fence->base.seqno);
- break;
- }
- }
-
- return true;
-}
-
-
-/**
- * vmw_fence_goal_check_locked - Replace the device fence goal seqno if
- * needed.
- *
- * @fence: Pointer to a struct vmw_fence_obj the seqno of which should be
- * considered as a device fence goal.
- *
- * This function should be called with the fence manager lock held.
- * It is typically called when an action has been attached to a fence to
- * check whether the seqno of that fence should be used for a fence
- * goal interrupt. This is typically needed if the current fence goal is
- * invalid, or has a higher seqno than that of the current fence object.
- *
- * returns true if the device goal seqno was updated. False otherwise.
- */
-static bool vmw_fence_goal_check_locked(struct vmw_fence_obj *fence)
-{
- struct vmw_fence_manager *fman = fman_from_fence(fence);
- u32 goal_seqno;
-
- if (dma_fence_is_signaled_locked(&fence->base))
- return false;
-
- goal_seqno = vmw_fence_goal_read(fman->dev_priv);
- if (likely(fman->seqno_valid &&
- goal_seqno - fence->base.seqno < VMW_FENCE_WRAP))
- return false;
-
- vmw_fence_goal_write(fman->dev_priv, fence->base.seqno);
- fman->seqno_valid = true;
-
- return true;
-}
-
static u32 __vmw_fences_update(struct vmw_fence_manager *fman)
{
struct vmw_fence_obj *fence, *next_fence;
- struct list_head action_list;
- bool needs_rerun;
- uint32_t seqno, new_seqno;
+ const bool cookie = dma_fence_begin_signalling();
+ const u32 seqno = vmw_fence_read(fman->dev_priv);
- seqno = vmw_fence_read(fman->dev_priv);
-rerun:
list_for_each_entry_safe(fence, next_fence, &fman->fence_list, head) {
if (seqno - fence->base.seqno < VMW_FENCE_WRAP) {
list_del_init(&fence->head);
+ if (fence->waiter_added) {
+ vmw_seqno_waiter_remove(fman->dev_priv);
+ fence->waiter_added = false;
+ }
dma_fence_signal_locked(&fence->base);
- INIT_LIST_HEAD(&action_list);
- list_splice_init(&fence->seq_passed_actions,
- &action_list);
- vmw_fences_perform_actions(fman, &action_list);
} else
break;
}
-
- /*
- * Rerun if the fence goal seqno was updated, and the
- * hardware might have raced with that update, so that
- * we missed a fence_goal irq.
- */
-
- needs_rerun = vmw_fence_goal_new_locked(fman, seqno);
- if (unlikely(needs_rerun)) {
- new_seqno = vmw_fence_read(fman->dev_priv);
- if (new_seqno != seqno) {
- seqno = new_seqno;
- goto rerun;
- }
- }
-
- if (!list_empty(&fman->cleanup_list))
- (void) schedule_work(&fman->work);
+ dma_fence_end_signalling(cookie);
atomic_set_release(&fman->dev_priv->last_read_seqno, seqno);
return seqno;
}
struct vmw_fence_obj **p_fence)
{
struct vmw_fence_obj *fence;
- int ret;
+ int ret;
fence = kzalloc(sizeof(*fence), GFP_KERNEL);
if (unlikely(!fence))
return -ENOMEM;
- ret = vmw_fence_obj_init(fman, fence, seqno,
- vmw_fence_destroy);
+ ret = vmw_fence_obj_init(fman, fence, seqno, vmw_fence_destroy);
if (unlikely(ret != 0))
goto out_err_init;
void vmw_fence_fifo_down(struct vmw_fence_manager *fman)
{
- struct list_head action_list;
int ret;
/*
if (unlikely(ret != 0)) {
list_del_init(&fence->head);
dma_fence_signal(&fence->base);
- INIT_LIST_HEAD(&action_list);
- list_splice_init(&fence->seq_passed_actions,
- &action_list);
- vmw_fences_perform_actions(fman, &action_list);
}
BUG_ON(!list_empty(&fence->head));
* attached has passed. It queues the event on the submitter's event list.
* This function is always called from atomic context.
*/
-static void vmw_event_fence_action_seq_passed(struct vmw_fence_action *action)
+static void vmw_event_fence_action_seq_passed(struct dma_fence *f,
+ struct dma_fence_cb *cb)
{
struct vmw_event_fence_action *eaction =
- container_of(action, struct vmw_event_fence_action, action);
+ container_of(cb, struct vmw_event_fence_action, base);
struct drm_device *dev = eaction->dev;
struct drm_pending_event *event = eaction->event;
if (likely(eaction->tv_sec != NULL)) {
struct timespec64 ts;
- ktime_get_ts64(&ts);
+ ktime_to_timespec64(f->timestamp);
/* monotonic time, so no y2038 overflow */
*eaction->tv_sec = ts.tv_sec;
*eaction->tv_usec = ts.tv_nsec / NSEC_PER_USEC;
drm_send_event_locked(dev, eaction->event);
eaction->event = NULL;
spin_unlock_irq(&dev->event_lock);
-}
-
-/**
- * vmw_event_fence_action_cleanup
- *
- * @action: The struct vmw_fence_action embedded in a struct
- * vmw_event_fence_action.
- *
- * This function is the struct vmw_fence_action destructor. It's typically
- * called from a workqueue.
- */
-static void vmw_event_fence_action_cleanup(struct vmw_fence_action *action)
-{
- struct vmw_event_fence_action *eaction =
- container_of(action, struct vmw_event_fence_action, action);
-
- vmw_fence_obj_unreference(&eaction->fence);
+ dma_fence_put(f);
kfree(eaction);
}
-
-/**
- * vmw_fence_obj_add_action - Add an action to a fence object.
- *
- * @fence: The fence object.
- * @action: The action to add.
- *
- * Note that the action callbacks may be executed before this function
- * returns.
- */
-static void vmw_fence_obj_add_action(struct vmw_fence_obj *fence,
- struct vmw_fence_action *action)
-{
- struct vmw_fence_manager *fman = fman_from_fence(fence);
- bool run_update = false;
-
- mutex_lock(&fman->goal_irq_mutex);
- spin_lock(&fman->lock);
-
- fman->pending_actions[action->type]++;
- if (dma_fence_is_signaled_locked(&fence->base)) {
- struct list_head action_list;
-
- INIT_LIST_HEAD(&action_list);
- list_add_tail(&action->head, &action_list);
- vmw_fences_perform_actions(fman, &action_list);
- } else {
- list_add_tail(&action->head, &fence->seq_passed_actions);
-
- /*
- * This function may set fman::seqno_valid, so it must
- * be run with the goal_irq_mutex held.
- */
- run_update = vmw_fence_goal_check_locked(fence);
- }
-
- spin_unlock(&fman->lock);
-
- if (run_update) {
- if (!fman->goal_irq_on) {
- fman->goal_irq_on = true;
- vmw_goal_waiter_add(fman->dev_priv);
- }
- vmw_fences_update(fman);
- }
- mutex_unlock(&fman->goal_irq_mutex);
-
-}
-
/**
* vmw_event_fence_action_queue - Post an event for sending when a fence
* object seqno has passed.
return -ENOMEM;
eaction->event = event;
-
- eaction->action.seq_passed = vmw_event_fence_action_seq_passed;
- eaction->action.cleanup = vmw_event_fence_action_cleanup;
- eaction->action.type = VMW_ACTION_EVENT;
-
- eaction->fence = vmw_fence_obj_reference(fence);
eaction->dev = &fman->dev_priv->drm;
eaction->tv_sec = tv_sec;
eaction->tv_usec = tv_usec;
- vmw_fence_obj_add_action(fence, &eaction->action);
-
+ vmw_fence_obj_reference(fence); // Dropped in CB
+ if (dma_fence_add_callback(&fence->base, &eaction->base,
+ vmw_event_fence_action_seq_passed) < 0)
+ vmw_event_fence_action_seq_passed(&fence->base, &eaction->base);
return 0;
}
projects / thirdparty / linux.git / commitdiff
