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* [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6
@ 2021-09-24 15:30 Christian König
  2021-09-24 15:30 ` [PATCH 02/27] dma-buf: add dma_resv_for_each_fence Christian König
                   ` (25 more replies)
  0 siblings, 26 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:30 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Abstract the complexity of iterating over all the fences
in a dma_resv object.

The new loop handles the whole RCU and retry dance and
returns only fences where we can be sure we grabbed the
right one.

v2: fix accessing the shared fences while they might be freed,
    improve kerneldoc, rename _cursor to _iter, add
    dma_resv_iter_is_exclusive, add dma_resv_iter_begin/end

v3: restructor the code, move rcu_read_lock()/unlock() into the
    iterator, add dma_resv_iter_is_restarted()

v4: fix NULL deref when no explicit fence exists, drop superflous
    rcu_read_lock()/unlock() calls.

v5: fix typos in the documentation

v6: fix coding error when excl fence is NULL

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/dma-buf/dma-resv.c | 98 ++++++++++++++++++++++++++++++++++++++
 include/linux/dma-resv.h   | 95 ++++++++++++++++++++++++++++++++++++
 2 files changed, 193 insertions(+)

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index 84fbe60629e3..97af397304f3 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -323,6 +323,104 @@ void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence)
 }
 EXPORT_SYMBOL(dma_resv_add_excl_fence);
 
+/**
+ * dma_resv_iter_restart_unlocked - restart the unlocked iterator
+ * @cursor: The dma_resv_iter object to restart
+ *
+ * Restart the unlocked iteration by initializing the cursor object.
+ */
+static void dma_resv_iter_restart_unlocked(struct dma_resv_iter *cursor)
+{
+	cursor->seq = read_seqcount_begin(&cursor->obj->seq);
+	cursor->index = -1;
+	if (cursor->all_fences)
+		cursor->fences = dma_resv_shared_list(cursor->obj);
+	else
+		cursor->fences = NULL;
+	cursor->is_restarted = true;
+}
+
+/**
+ * dma_resv_iter_walk_unlocked - walk over fences in a dma_resv obj
+ * @cursor: cursor to record the current position
+ *
+ * Return all the fences in the dma_resv object which are not yet signaled.
+ * The returned fence has an extra local reference so will stay alive.
+ * If a concurrent modify is detected the whole iteration is started over again.
+ */
+static void dma_resv_iter_walk_unlocked(struct dma_resv_iter *cursor)
+{
+	struct dma_resv *obj = cursor->obj;
+
+	do {
+		/* Drop the reference from the previous round */
+		dma_fence_put(cursor->fence);
+
+		if (cursor->index == -1) {
+			cursor->fence = dma_resv_excl_fence(obj);
+			cursor->index++;
+			if (!cursor->fence)
+				continue;
+
+		} else if (!cursor->fences ||
+			   cursor->index >= cursor->fences->shared_count) {
+			cursor->fence = NULL;
+			break;
+
+		} else {
+			struct dma_resv_list *fences = cursor->fences;
+			unsigned int idx = cursor->index++;
+
+			cursor->fence = rcu_dereference(fences->shared[idx]);
+		}
+		cursor->fence = dma_fence_get_rcu(cursor->fence);
+	} while (cursor->fence && dma_fence_is_signaled(cursor->fence));
+}
+
+/**
+ * dma_resv_iter_first_unlocked - first fence in an unlocked dma_resv obj.
+ * @cursor: the cursor with the current position
+ *
+ * Returns the first fence from an unlocked dma_resv obj.
+ */
+struct dma_fence *dma_resv_iter_first_unlocked(struct dma_resv_iter *cursor)
+{
+	rcu_read_lock();
+	do {
+		dma_resv_iter_restart_unlocked(cursor);
+		dma_resv_iter_walk_unlocked(cursor);
+	} while (read_seqcount_retry(&cursor->obj->seq, cursor->seq));
+	rcu_read_unlock();
+
+	return cursor->fence;
+}
+EXPORT_SYMBOL(dma_resv_iter_first_unlocked);
+
+/**
+ * dma_resv_iter_next_unlocked - next fence in an unlocked dma_resv obj.
+ * @cursor: the cursor with the current position
+ *
+ * Returns the next fence from an unlocked dma_resv obj.
+ */
+struct dma_fence *dma_resv_iter_next_unlocked(struct dma_resv_iter *cursor)
+{
+	bool restart;
+
+	rcu_read_lock();
+	cursor->is_restarted = false;
+	restart = read_seqcount_retry(&cursor->obj->seq, cursor->seq);
+	do {
+		if (restart)
+			dma_resv_iter_restart_unlocked(cursor);
+		dma_resv_iter_walk_unlocked(cursor);
+		restart = true;
+	} while (read_seqcount_retry(&cursor->obj->seq, cursor->seq));
+	rcu_read_unlock();
+
+	return cursor->fence;
+}
+EXPORT_SYMBOL(dma_resv_iter_next_unlocked);
+
 /**
  * dma_resv_copy_fences - Copy all fences from src to dst.
  * @dst: the destination reservation object
diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h
index 9100dd3dc21f..5d7d28cb9008 100644
--- a/include/linux/dma-resv.h
+++ b/include/linux/dma-resv.h
@@ -149,6 +149,101 @@ struct dma_resv {
 	struct dma_resv_list __rcu *fence;
 };
 
+/**
+ * struct dma_resv_iter - current position into the dma_resv fences
+ *
+ * Don't touch this directly in the driver, use the accessor function instead.
+ */
+struct dma_resv_iter {
+	/** @obj: The dma_resv object we iterate over */
+	struct dma_resv *obj;
+
+	/** @all_fences: If all fences should be returned */
+	bool all_fences;
+
+	/** @fence: the currently handled fence */
+	struct dma_fence *fence;
+
+	/** @seq: sequence number to check for modifications */
+	unsigned int seq;
+
+	/** @index: index into the shared fences */
+	unsigned int index;
+
+	/** @fences: the shared fences */
+	struct dma_resv_list *fences;
+
+	/** @is_restarted: true if this is the first returned fence */
+	bool is_restarted;
+};
+
+struct dma_fence *dma_resv_iter_first_unlocked(struct dma_resv_iter *cursor);
+struct dma_fence *dma_resv_iter_next_unlocked(struct dma_resv_iter *cursor);
+
+/**
+ * dma_resv_iter_begin - initialize a dma_resv_iter object
+ * @cursor: The dma_resv_iter object to initialize
+ * @obj: The dma_resv object which we want to iterate over
+ * @all_fences: If all fences should be returned or just the exclusive one
+ */
+static inline void dma_resv_iter_begin(struct dma_resv_iter *cursor,
+				       struct dma_resv *obj,
+				       bool all_fences)
+{
+	cursor->obj = obj;
+	cursor->all_fences = all_fences;
+	cursor->fence = NULL;
+}
+
+/**
+ * dma_resv_iter_end - cleanup a dma_resv_iter object
+ * @cursor: the dma_resv_iter object which should be cleaned up
+ *
+ * Make sure that the reference to the fence in the cursor is properly
+ * dropped.
+ */
+static inline void dma_resv_iter_end(struct dma_resv_iter *cursor)
+{
+	dma_fence_put(cursor->fence);
+}
+
+/**
+ * dma_resv_iter_is_exclusive - test if the current fence is the exclusive one
+ * @cursor: the cursor of the current position
+ *
+ * Returns true if the currently returned fence is the exclusive one.
+ */
+static inline bool dma_resv_iter_is_exclusive(struct dma_resv_iter *cursor)
+{
+	return cursor->index == -1;
+}
+
+/**
+ * dma_resv_iter_is_restarted - test if this is the first fence after a restart
+ * @cursor: the cursor with the current position
+ *
+ * Return true if this is the first fence in an iteration after a restart.
+ */
+static inline bool dma_resv_iter_is_restarted(struct dma_resv_iter *cursor)
+{
+	return cursor->is_restarted;
+}
+
+/**
+ * dma_resv_for_each_fence_unlocked - unlocked fence iterator
+ * @cursor: a struct dma_resv_iter pointer
+ * @fence: the current fence
+ *
+ * Iterate over the fences in a struct dma_resv object without holding the
+ * &dma_resv.lock and using RCU instead. The cursor needs to be initialized
+ * with dma_resv_iter_begin() and cleaned up with dma_resv_iter_end(). Inside
+ * the iterator a reference to the dma_fence is held and the RCU lock dropped.
+ * When the dma_resv is modified the iteration starts over again.
+ */
+#define dma_resv_for_each_fence_unlocked(cursor, fence)			\
+	for (fence = dma_resv_iter_first_unlocked(cursor);		\
+	     fence; fence = dma_resv_iter_next_unlocked(cursor))
+
 #define dma_resv_held(obj) lockdep_is_held(&(obj)->lock.base)
 #define dma_resv_assert_held(obj) lockdep_assert_held(&(obj)->lock.base)
 
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 02/27] dma-buf: add dma_resv_for_each_fence
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
@ 2021-09-24 15:30 ` Christian König
  2021-09-24 15:30 ` [PATCH 03/27] dma-buf: add dma_resv selftest Christian König
                   ` (24 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:30 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

A simpler version of the iterator to be used when the dma_resv object is
locked.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/dma-buf/dma-resv.c | 46 ++++++++++++++++++++++++++++++++++++++
 include/linux/dma-resv.h   | 19 ++++++++++++++++
 2 files changed, 65 insertions(+)

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index 97af397304f3..98cb0050c615 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -421,6 +421,52 @@ struct dma_fence *dma_resv_iter_next_unlocked(struct dma_resv_iter *cursor)
 }
 EXPORT_SYMBOL(dma_resv_iter_next_unlocked);
 
+/**
+ * dma_resv_iter_first - first fence from a locked dma_resv object
+ * @cursor: cursor to record the current position
+ *
+ * Return all the fences in the dma_resv object while holding the
+ * &dma_resv.lock.
+ */
+struct dma_fence *dma_resv_iter_first(struct dma_resv_iter *cursor)
+{
+	struct dma_fence *fence;
+
+	dma_resv_assert_held(cursor->obj);
+
+	cursor->index = -1;
+	cursor->fences = dma_resv_shared_list(cursor->obj);
+
+	fence = dma_resv_excl_fence(cursor->obj);
+	if (!fence)
+		fence = dma_resv_iter_next(cursor);
+
+	cursor->is_restarted = true;
+	return fence;
+}
+EXPORT_SYMBOL_GPL(dma_resv_iter_first);
+
+/**
+ * dma_resv_iter_next - next fence from a locked dma_resv object
+ * @cursor: cursor to record the current position
+ *
+ * Return all the fences in the dma_resv object while holding the
+ * &dma_resv.lock.
+ */
+struct dma_fence *dma_resv_iter_next(struct dma_resv_iter *cursor)
+{
+	dma_resv_assert_held(cursor->obj);
+
+	cursor->is_restarted = false;
+	if (!cursor->all_fences || !cursor->fences ||
+	    ++cursor->index >= cursor->fences->shared_count)
+		return NULL;
+
+	return rcu_dereference_protected(cursor->fences->shared[cursor->index],
+					 dma_resv_held(cursor->obj));
+}
+EXPORT_SYMBOL_GPL(dma_resv_iter_next);
+
 /**
  * dma_resv_copy_fences - Copy all fences from src to dst.
  * @dst: the destination reservation object
diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h
index 5d7d28cb9008..d4b4cd43f0f1 100644
--- a/include/linux/dma-resv.h
+++ b/include/linux/dma-resv.h
@@ -179,6 +179,8 @@ struct dma_resv_iter {
 
 struct dma_fence *dma_resv_iter_first_unlocked(struct dma_resv_iter *cursor);
 struct dma_fence *dma_resv_iter_next_unlocked(struct dma_resv_iter *cursor);
+struct dma_fence *dma_resv_iter_first(struct dma_resv_iter *cursor);
+struct dma_fence *dma_resv_iter_next(struct dma_resv_iter *cursor);
 
 /**
  * dma_resv_iter_begin - initialize a dma_resv_iter object
@@ -244,6 +246,23 @@ static inline bool dma_resv_iter_is_restarted(struct dma_resv_iter *cursor)
 	for (fence = dma_resv_iter_first_unlocked(cursor);		\
 	     fence; fence = dma_resv_iter_next_unlocked(cursor))
 
+/**
+ * dma_resv_for_each_fence - fence iterator
+ * @cursor: a struct dma_resv_iter pointer
+ * @obj: a dma_resv object pointer
+ * @all_fences: true if all fences should be returned
+ * @fence: the current fence
+ *
+ * Iterate over the fences in a struct dma_resv object while holding the
+ * &dma_resv.lock. @all_fences controls if the shared fences are returned as
+ * well. The cursor initialisation is part of the iterator and the fence stays
+ * valid as long as the lock is held.
+ */
+#define dma_resv_for_each_fence(cursor, obj, all_fences, fence)	\
+	for (dma_resv_iter_begin(cursor, obj, all_fences),	\
+	     fence = dma_resv_iter_first(cursor); fence;	\
+	     fence = dma_resv_iter_next(cursor))
+
 #define dma_resv_held(obj) lockdep_is_held(&(obj)->lock.base)
 #define dma_resv_assert_held(obj) lockdep_assert_held(&(obj)->lock.base)
 
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 03/27] dma-buf: add dma_resv selftest
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
  2021-09-24 15:30 ` [PATCH 02/27] dma-buf: add dma_resv_for_each_fence Christian König
@ 2021-09-24 15:30 ` Christian König
  2021-09-24 15:30 ` [PATCH 04/27] dma-buf: use new iterator in dma_resv_copy_fences Christian König
                   ` (23 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:30 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Just exercising a very minor subset of the functionality, but already
proven useful.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/dma-buf/Makefile      |   3 +-
 drivers/dma-buf/selftests.h   |   1 +
 drivers/dma-buf/st-dma-resv.c | 164 ++++++++++++++++++++++++++++++++++
 3 files changed, 167 insertions(+), 1 deletion(-)
 create mode 100644 drivers/dma-buf/st-dma-resv.c

diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
index 1ef021273a06..511805dbeb75 100644
--- a/drivers/dma-buf/Makefile
+++ b/drivers/dma-buf/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_DMABUF_SYSFS_STATS) += dma-buf-sysfs-stats.o
 dmabuf_selftests-y := \
 	selftest.o \
 	st-dma-fence.o \
-	st-dma-fence-chain.o
+	st-dma-fence-chain.o \
+	st-dma-resv.o
 
 obj-$(CONFIG_DMABUF_SELFTESTS)	+= dmabuf_selftests.o
diff --git a/drivers/dma-buf/selftests.h b/drivers/dma-buf/selftests.h
index bc8cea67bf1e..97d73aaa31da 100644
--- a/drivers/dma-buf/selftests.h
+++ b/drivers/dma-buf/selftests.h
@@ -12,3 +12,4 @@
 selftest(sanitycheck, __sanitycheck__) /* keep first (igt selfcheck) */
 selftest(dma_fence, dma_fence)
 selftest(dma_fence_chain, dma_fence_chain)
+selftest(dma_resv, dma_resv)
diff --git a/drivers/dma-buf/st-dma-resv.c b/drivers/dma-buf/st-dma-resv.c
new file mode 100644
index 000000000000..ea44769d058d
--- /dev/null
+++ b/drivers/dma-buf/st-dma-resv.c
@@ -0,0 +1,164 @@
+/* SPDX-License-Identifier: MIT */
+
+/*
+* Copyright © 2019 Intel Corporation
+*/
+
+//#include <linux/delay.h>
+//#include <linux/dma-fence.h>
+//#include <linux/kernel.h>
+//#include <linux/kthread.h>
+//#include <linux/sched/signal.h>
+
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/dma-resv.h>
+
+#include "selftest.h"
+
+static struct spinlock fence_lock;
+
+static const char *fence_name(struct dma_fence *f)
+{
+	return "selftest";
+}
+
+static const struct dma_fence_ops fence_ops = {
+	.get_driver_name = fence_name,
+	.get_timeline_name = fence_name,
+};
+
+static struct dma_fence *alloc_fence(void)
+{
+	struct dma_fence *f;
+
+	f = kmalloc(sizeof(*f), GFP_KERNEL);
+	if (!f)
+		return NULL;
+
+	dma_fence_init(f, &fence_ops, &fence_lock, 0, 0);
+	return f;
+}
+
+static int sanitycheck(void *arg)
+{
+	struct dma_fence *f;
+
+	f = alloc_fence();
+	if (!f)
+		return -ENOMEM;
+
+	dma_fence_signal(f);
+	dma_fence_put(f);
+	return 0;
+}
+
+static int test_excl_signaling(void *arg)
+{
+	struct dma_resv resv;
+	struct dma_fence *f;
+	int err = -EINVAL;
+
+	f = alloc_fence();
+	if (!f)
+		return -ENOMEM;
+
+	dma_resv_init(&resv);
+	dma_resv_add_excl_fence(&resv, f);
+	if (dma_resv_test_signaled(&resv, false)) {
+		pr_err("Resv unexpectedly signaled\n");
+		goto err_free;
+	}
+	dma_fence_signal(f);
+	if (!dma_resv_test_signaled(&resv, false)) {
+		pr_err("Resv not reporting signaled\n");
+		goto err_free;
+	}
+	err = 0;
+err_free:
+	dma_resv_fini(&resv);
+	dma_fence_put(f);
+	return err;
+}
+
+static int test_shared_signaling(void *arg)
+{
+	struct dma_resv resv;
+	struct dma_fence *f;
+	int err;
+
+	f = alloc_fence();
+	if (!f)
+		return -ENOMEM;
+
+	dma_resv_init(&resv);
+	err = dma_resv_reserve_shared(&resv, 1);
+	if (err) {
+		pr_err("Resv shared slot allocation failed\n");
+		goto err_free;
+	}
+
+	err = -EINVAL;
+	dma_resv_add_shared_fence(&resv, f);
+	if (dma_resv_test_signaled(&resv, true)) {
+		pr_err("Resv unexpectedly signaled\n");
+		goto err_free;
+	}
+	dma_fence_signal(f);
+	if (!dma_resv_test_signaled(&resv, true)) {
+		pr_err("Resv not reporting signaled\n");
+		goto err_free;
+	}
+	err = 0;
+err_free:
+	dma_resv_fini(&resv);
+	dma_fence_put(f);
+	return err;
+}
+
+static int test_excl_for_each(void *arg)
+{
+	struct dma_resv_iter cursor;
+	struct dma_fence *f, *fence;
+	struct dma_resv resv;
+	int err;
+
+	f = alloc_fence();
+	if (!f)
+		return -ENOMEM;
+
+	dma_resv_init(&resv);
+	dma_resv_add_excl_fence(&resv, f);
+
+	err = -EINVAL;
+	dma_resv_for_each_fence(&cursor, &resv, false, fence) {
+		if (f != fence) {
+			pr_err("Unexpected fence\n");
+			goto err_free;
+		}
+		err = 0;
+	}
+	if (err) {
+		pr_err("No fence found\n");
+		goto err_free;
+	}
+	dma_fence_signal(f);
+	err = 0;
+err_free:
+	dma_resv_fini(&resv);
+	dma_fence_put(f);
+	return err;
+}
+
+int dma_resv(void)
+{
+	static const struct subtest tests[] = {
+		SUBTEST(sanitycheck),
+		SUBTEST(test_excl_signaling),
+		SUBTEST(test_shared_signaling),
+		SUBTEST(test_excl_for_each),
+	};
+
+	spin_lock_init(&fence_lock);
+	return subtests(tests, NULL);
+}
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 04/27] dma-buf: use new iterator in dma_resv_copy_fences
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
  2021-09-24 15:30 ` [PATCH 02/27] dma-buf: add dma_resv_for_each_fence Christian König
  2021-09-24 15:30 ` [PATCH 03/27] dma-buf: add dma_resv selftest Christian König
@ 2021-09-24 15:30 ` Christian König
  2021-09-24 15:30 ` [PATCH 05/27] dma-buf: use new iterator in dma_resv_get_fences v3 Christian König
                   ` (22 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:30 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

This makes the function much simpler since the complex
retry logic is now handled else where.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/dma-buf/dma-resv.c | 84 +++++++++++++++-----------------------
 1 file changed, 32 insertions(+), 52 deletions(-)

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index 98cb0050c615..17ef7472830b 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -476,74 +476,54 @@ EXPORT_SYMBOL_GPL(dma_resv_iter_next);
  */
 int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src)
 {
-	struct dma_resv_list *src_list, *dst_list;
-	struct dma_fence *old, *new;
-	unsigned int i;
+	struct dma_resv_iter cursor;
+	struct dma_resv_list *list;
+	struct dma_fence *f, *excl;
 
 	dma_resv_assert_held(dst);
 
-	rcu_read_lock();
-	src_list = dma_resv_shared_list(src);
+	list = NULL;
+	excl = NULL;
 
-retry:
-	if (src_list) {
-		unsigned int shared_count = src_list->shared_count;
+	dma_resv_iter_begin(&cursor, src, true);
+	dma_resv_for_each_fence_unlocked(&cursor, f) {
 
-		rcu_read_unlock();
+		if (dma_resv_iter_is_restarted(&cursor)) {
+			dma_resv_list_free(list);
+			dma_fence_put(excl);
 
-		dst_list = dma_resv_list_alloc(shared_count);
-		if (!dst_list)
-			return -ENOMEM;
+			if (cursor.fences) {
+				unsigned int cnt = cursor.fences->shared_count;
 
-		rcu_read_lock();
-		src_list = dma_resv_shared_list(src);
-		if (!src_list || src_list->shared_count > shared_count) {
-			kfree(dst_list);
-			goto retry;
-		}
-
-		dst_list->shared_count = 0;
-		for (i = 0; i < src_list->shared_count; ++i) {
-			struct dma_fence __rcu **dst;
-			struct dma_fence *fence;
+				list = dma_resv_list_alloc(cnt);
+				if (!list) {
+					dma_resv_iter_end(&cursor);
+					return -ENOMEM;
+				}
 
-			fence = rcu_dereference(src_list->shared[i]);
-			if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
-				     &fence->flags))
-				continue;
+				list->shared_count = 0;
 
-			if (!dma_fence_get_rcu(fence)) {
-				dma_resv_list_free(dst_list);
-				src_list = dma_resv_shared_list(src);
-				goto retry;
+			} else {
+				list = NULL;
 			}
-
-			if (dma_fence_is_signaled(fence)) {
-				dma_fence_put(fence);
-				continue;
-			}
-
-			dst = &dst_list->shared[dst_list->shared_count++];
-			rcu_assign_pointer(*dst, fence);
+			excl = NULL;
 		}
-	} else {
-		dst_list = NULL;
-	}
 
-	new = dma_fence_get_rcu_safe(&src->fence_excl);
-	rcu_read_unlock();
-
-	src_list = dma_resv_shared_list(dst);
-	old = dma_resv_excl_fence(dst);
+		dma_fence_get(f);
+		if (dma_resv_iter_is_exclusive(&cursor))
+			excl = f;
+		else
+			RCU_INIT_POINTER(list->shared[list->shared_count++], f);
+	}
+	dma_resv_iter_end(&cursor);
 
 	write_seqcount_begin(&dst->seq);
-	/* write_seqcount_begin provides the necessary memory barrier */
-	RCU_INIT_POINTER(dst->fence_excl, new);
-	RCU_INIT_POINTER(dst->fence, dst_list);
+	excl = rcu_replace_pointer(dst->fence_excl, excl, dma_resv_held(dst));
+	list = rcu_replace_pointer(dst->fence, list, dma_resv_held(dst));
 	write_seqcount_end(&dst->seq);
 
-	dma_resv_list_free(src_list);
-	dma_fence_put(old);
+	dma_resv_list_free(list);
+	dma_fence_put(excl);
 
 	return 0;
 }
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 05/27] dma-buf: use new iterator in dma_resv_get_fences v3
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (2 preceding siblings ...)
  2021-09-24 15:30 ` [PATCH 04/27] dma-buf: use new iterator in dma_resv_copy_fences Christian König
@ 2021-09-24 15:30 ` Christian König
  2021-09-24 15:30 ` [PATCH 06/27] dma-buf: use new iterator in dma_resv_wait_timeout Christian König
                   ` (21 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:30 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

This makes the function much simpler since the complex
retry logic is now handled elsewhere.

v2: use sizeof(void*) instead
v3: fix rebase bug

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/dma-buf/dma-resv.c | 108 ++++++++++++-------------------------
 1 file changed, 35 insertions(+), 73 deletions(-)

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index 17ef7472830b..39a3eac28834 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -533,99 +533,61 @@ EXPORT_SYMBOL(dma_resv_copy_fences);
  * dma_resv_get_fences - Get an object's shared and exclusive
  * fences without update side lock held
  * @obj: the reservation object
- * @pfence_excl: the returned exclusive fence (or NULL)
- * @pshared_count: the number of shared fences returned
- * @pshared: the array of shared fence ptrs returned (array is krealloc'd to
+ * @fence_excl: the returned exclusive fence (or NULL)
+ * @shared_count: the number of shared fences returned
+ * @shared: the array of shared fence ptrs returned (array is krealloc'd to
  * the required size, and must be freed by caller)
  *
  * Retrieve all fences from the reservation object. If the pointer for the
  * exclusive fence is not specified the fence is put into the array of the
  * shared fences as well. Returns either zero or -ENOMEM.
  */
-int dma_resv_get_fences(struct dma_resv *obj, struct dma_fence **pfence_excl,
-			unsigned int *pshared_count,
-			struct dma_fence ***pshared)
+int dma_resv_get_fences(struct dma_resv *obj, struct dma_fence **fence_excl,
+			unsigned int *shared_count, struct dma_fence ***shared)
 {
-	struct dma_fence **shared = NULL;
-	struct dma_fence *fence_excl;
-	unsigned int shared_count;
-	int ret = 1;
-
-	do {
-		struct dma_resv_list *fobj;
-		unsigned int i, seq;
-		size_t sz = 0;
-
-		shared_count = i = 0;
-
-		rcu_read_lock();
-		seq = read_seqcount_begin(&obj->seq);
+	struct dma_resv_iter cursor;
+	struct dma_fence *fence;
 
-		fence_excl = dma_resv_excl_fence(obj);
-		if (fence_excl && !dma_fence_get_rcu(fence_excl))
-			goto unlock;
+	*shared_count = 0;
+	*shared = NULL;
 
-		fobj = dma_resv_shared_list(obj);
-		if (fobj)
-			sz += sizeof(*shared) * fobj->shared_max;
+	if (fence_excl)
+		*fence_excl = NULL;
 
-		if (!pfence_excl && fence_excl)
-			sz += sizeof(*shared);
+	dma_resv_iter_begin(&cursor, obj, true);
+	dma_resv_for_each_fence_unlocked(&cursor, fence) {
 
-		if (sz) {
-			struct dma_fence **nshared;
+		if (dma_resv_iter_is_restarted(&cursor)) {
+			unsigned int count;
 
-			nshared = krealloc(shared, sz,
-					   GFP_NOWAIT | __GFP_NOWARN);
-			if (!nshared) {
-				rcu_read_unlock();
+			while (*shared_count)
+				dma_fence_put((*shared)[--(*shared_count)]);
 
-				dma_fence_put(fence_excl);
-				fence_excl = NULL;
+			if (fence_excl)
+				dma_fence_put(*fence_excl);
 
-				nshared = krealloc(shared, sz, GFP_KERNEL);
-				if (nshared) {
-					shared = nshared;
-					continue;
-				}
+			count = cursor.fences ? cursor.fences->shared_count : 0;
+			count += fence_excl ? 0 : 1;
 
-				ret = -ENOMEM;
-				break;
+			/* Eventually re-allocate the array */
+			*shared = krealloc_array(*shared, count,
+						 sizeof(void *),
+						 GFP_KERNEL);
+			if (count && !*shared) {
+				dma_resv_iter_end(&cursor);
+				return -ENOMEM;
 			}
-			shared = nshared;
-			shared_count = fobj ? fobj->shared_count : 0;
-			for (i = 0; i < shared_count; ++i) {
-				shared[i] = rcu_dereference(fobj->shared[i]);
-				if (!dma_fence_get_rcu(shared[i]))
-					break;
-			}
-		}
-
-		if (i != shared_count || read_seqcount_retry(&obj->seq, seq)) {
-			while (i--)
-				dma_fence_put(shared[i]);
-			dma_fence_put(fence_excl);
-			goto unlock;
 		}
 
-		ret = 0;
-unlock:
-		rcu_read_unlock();
-	} while (ret);
-
-	if (pfence_excl)
-		*pfence_excl = fence_excl;
-	else if (fence_excl)
-		shared[shared_count++] = fence_excl;
-
-	if (!shared_count) {
-		kfree(shared);
-		shared = NULL;
+		dma_fence_get(fence);
+		if (dma_resv_iter_is_exclusive(&cursor) && fence_excl)
+			*fence_excl = fence;
+		else
+			(*shared)[(*shared_count)++] = fence;
 	}
+	dma_resv_iter_end(&cursor);
 
-	*pshared_count = shared_count;
-	*pshared = shared;
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(dma_resv_get_fences);
 
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 06/27] dma-buf: use new iterator in dma_resv_wait_timeout
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (3 preceding siblings ...)
  2021-09-24 15:30 ` [PATCH 05/27] dma-buf: use new iterator in dma_resv_get_fences v3 Christian König
@ 2021-09-24 15:30 ` Christian König
  2021-09-24 15:30 ` [PATCH 07/27] dma-buf: use new iterator in dma_resv_test_signaled Christian König
                   ` (20 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:30 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

This makes the function much simpler since the complex
retry logic is now handled elsewhere.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/dma-buf/dma-resv.c | 69 +++++---------------------------------
 1 file changed, 8 insertions(+), 61 deletions(-)

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index 39a3eac28834..ce6d0ac43911 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -609,74 +609,21 @@ long dma_resv_wait_timeout(struct dma_resv *obj, bool wait_all, bool intr,
 			   unsigned long timeout)
 {
 	long ret = timeout ? timeout : 1;
-	unsigned int seq, shared_count;
+	struct dma_resv_iter cursor;
 	struct dma_fence *fence;
-	int i;
-
-retry:
-	shared_count = 0;
-	seq = read_seqcount_begin(&obj->seq);
-	rcu_read_lock();
-	i = -1;
-
-	fence = dma_resv_excl_fence(obj);
-	if (fence && !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) {
-		if (!dma_fence_get_rcu(fence))
-			goto unlock_retry;
-
-		if (dma_fence_is_signaled(fence)) {
-			dma_fence_put(fence);
-			fence = NULL;
-		}
-
-	} else {
-		fence = NULL;
-	}
-
-	if (wait_all) {
-		struct dma_resv_list *fobj = dma_resv_shared_list(obj);
-
-		if (fobj)
-			shared_count = fobj->shared_count;
-
-		for (i = 0; !fence && i < shared_count; ++i) {
-			struct dma_fence *lfence;
-
-			lfence = rcu_dereference(fobj->shared[i]);
-			if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
-				     &lfence->flags))
-				continue;
 
-			if (!dma_fence_get_rcu(lfence))
-				goto unlock_retry;
-
-			if (dma_fence_is_signaled(lfence)) {
-				dma_fence_put(lfence);
-				continue;
-			}
+	dma_resv_iter_begin(&cursor, obj, wait_all);
+	dma_resv_for_each_fence_unlocked(&cursor, fence) {
 
-			fence = lfence;
-			break;
+		ret = dma_fence_wait_timeout(fence, intr, ret);
+		if (ret <= 0) {
+			dma_resv_iter_end(&cursor);
+			return ret;
 		}
 	}
+	dma_resv_iter_end(&cursor);
 
-	rcu_read_unlock();
-	if (fence) {
-		if (read_seqcount_retry(&obj->seq, seq)) {
-			dma_fence_put(fence);
-			goto retry;
-		}
-
-		ret = dma_fence_wait_timeout(fence, intr, ret);
-		dma_fence_put(fence);
-		if (ret > 0 && wait_all && (i + 1 < shared_count))
-			goto retry;
-	}
 	return ret;
-
-unlock_retry:
-	rcu_read_unlock();
-	goto retry;
 }
 EXPORT_SYMBOL_GPL(dma_resv_wait_timeout);
 
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 07/27] dma-buf: use new iterator in dma_resv_test_signaled
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (4 preceding siblings ...)
  2021-09-24 15:30 ` [PATCH 06/27] dma-buf: use new iterator in dma_resv_wait_timeout Christian König
@ 2021-09-24 15:30 ` Christian König
  2021-09-24 15:30 ` [PATCH 08/27] dma-buf: use the new iterator in dma_buf_debug_show Christian König
                   ` (19 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:30 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

This makes the function much simpler since the complex
retry logic is now handled elsewhere.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/dma-buf/dma-resv.c | 57 +++++---------------------------------
 1 file changed, 7 insertions(+), 50 deletions(-)

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index ce6d0ac43911..42ed72db9801 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -628,22 +628,6 @@ long dma_resv_wait_timeout(struct dma_resv *obj, bool wait_all, bool intr,
 EXPORT_SYMBOL_GPL(dma_resv_wait_timeout);
 
 
-static inline int dma_resv_test_signaled_single(struct dma_fence *passed_fence)
-{
-	struct dma_fence *fence, *lfence = passed_fence;
-	int ret = 1;
-
-	if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &lfence->flags)) {
-		fence = dma_fence_get_rcu(lfence);
-		if (!fence)
-			return -1;
-
-		ret = !!dma_fence_is_signaled(fence);
-		dma_fence_put(fence);
-	}
-	return ret;
-}
-
 /**
  * dma_resv_test_signaled - Test if a reservation object's fences have been
  * signaled.
@@ -660,43 +644,16 @@ static inline int dma_resv_test_signaled_single(struct dma_fence *passed_fence)
  */
 bool dma_resv_test_signaled(struct dma_resv *obj, bool test_all)
 {
+	struct dma_resv_iter cursor;
 	struct dma_fence *fence;
-	unsigned int seq;
-	int ret;
-
-	rcu_read_lock();
-retry:
-	ret = true;
-	seq = read_seqcount_begin(&obj->seq);
-
-	if (test_all) {
-		struct dma_resv_list *fobj = dma_resv_shared_list(obj);
-		unsigned int i, shared_count;
-
-		shared_count = fobj ? fobj->shared_count : 0;
-		for (i = 0; i < shared_count; ++i) {
-			fence = rcu_dereference(fobj->shared[i]);
-			ret = dma_resv_test_signaled_single(fence);
-			if (ret < 0)
-				goto retry;
-			else if (!ret)
-				break;
-		}
-	}
-
-	fence = dma_resv_excl_fence(obj);
-	if (ret && fence) {
-		ret = dma_resv_test_signaled_single(fence);
-		if (ret < 0)
-			goto retry;
 
+	dma_resv_iter_begin(&cursor, obj, test_all);
+	dma_resv_for_each_fence_unlocked(&cursor, fence) {
+		dma_resv_iter_end(&cursor);
+		return false;
 	}
-
-	if (read_seqcount_retry(&obj->seq, seq))
-		goto retry;
-
-	rcu_read_unlock();
-	return ret;
+	dma_resv_iter_end(&cursor);
+	return true;
 }
 EXPORT_SYMBOL_GPL(dma_resv_test_signaled);
 
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 08/27] dma-buf: use the new iterator in dma_buf_debug_show
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (5 preceding siblings ...)
  2021-09-24 15:30 ` [PATCH 07/27] dma-buf: use new iterator in dma_resv_test_signaled Christian König
@ 2021-09-24 15:30 ` Christian König
  2021-09-24 15:30 ` [PATCH 09/27] drm/ttm: use the new iterator in ttm_bo_flush_all_fences Christian König
                   ` (18 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:30 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Simplifying the code a bit.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/dma-buf/dma-buf.c | 24 ++++++------------------
 1 file changed, 6 insertions(+), 18 deletions(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 474de2d988ca..d35c71743ccb 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1368,10 +1368,9 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused)
 {
 	struct dma_buf *buf_obj;
 	struct dma_buf_attachment *attach_obj;
-	struct dma_resv *robj;
-	struct dma_resv_list *fobj;
+	struct dma_resv_iter cursor;
 	struct dma_fence *fence;
-	int count = 0, attach_count, shared_count, i;
+	int count = 0, attach_count;
 	size_t size = 0;
 	int ret;
 
@@ -1398,21 +1397,10 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused)
 				file_inode(buf_obj->file)->i_ino,
 				buf_obj->name ?: "");
 
-		robj = buf_obj->resv;
-		fence = dma_resv_excl_fence(robj);
-		if (fence)
-			seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n",
-				   fence->ops->get_driver_name(fence),
-				   fence->ops->get_timeline_name(fence),
-				   dma_fence_is_signaled(fence) ? "" : "un");
-
-		fobj = rcu_dereference_protected(robj->fence,
-						 dma_resv_held(robj));
-		shared_count = fobj ? fobj->shared_count : 0;
-		for (i = 0; i < shared_count; i++) {
-			fence = rcu_dereference_protected(fobj->shared[i],
-							  dma_resv_held(robj));
-			seq_printf(s, "\tShared fence: %s %s %ssignalled\n",
+		dma_resv_for_each_fence(&cursor, buf_obj->resv, true, fence) {
+			seq_printf(s, "\t%s fence: %s %s %ssignalled\n",
+				   dma_resv_iter_is_exclusive(&cursor) ?
+					"Exclusive" : "Shared",
 				   fence->ops->get_driver_name(fence),
 				   fence->ops->get_timeline_name(fence),
 				   dma_fence_is_signaled(fence) ? "" : "un");
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 09/27] drm/ttm: use the new iterator in ttm_bo_flush_all_fences
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (6 preceding siblings ...)
  2021-09-24 15:30 ` [PATCH 08/27] dma-buf: use the new iterator in dma_buf_debug_show Christian König
@ 2021-09-24 15:30 ` Christian König
  2021-09-24 15:30 ` [PATCH 10/27] drm/amdgpu: use the new iterator in amdgpu_sync_resv Christian König
                   ` (17 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:30 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

This is probably a fix since we didn't even grabed a reference to the
fences.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/ttm/ttm_bo.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 3b22c0013dbf..301b0b4b082e 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -269,23 +269,15 @@ static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo)
 static void ttm_bo_flush_all_fences(struct ttm_buffer_object *bo)
 {
 	struct dma_resv *resv = &bo->base._resv;
-	struct dma_resv_list *fobj;
+	struct dma_resv_iter cursor;
 	struct dma_fence *fence;
-	int i;
-
-	rcu_read_lock();
-	fobj = dma_resv_shared_list(resv);
-	fence = dma_resv_excl_fence(resv);
-	if (fence && !fence->ops->signaled)
-		dma_fence_enable_sw_signaling(fence);
-
-	for (i = 0; fobj && i < fobj->shared_count; ++i) {
-		fence = rcu_dereference(fobj->shared[i]);
 
+	dma_resv_iter_begin(&cursor, resv, true);
+	dma_resv_for_each_fence_unlocked(&cursor, fence) {
 		if (!fence->ops->signaled)
 			dma_fence_enable_sw_signaling(fence);
 	}
-	rcu_read_unlock();
+	dma_resv_iter_end(&cursor);
 }
 
 /**
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 10/27] drm/amdgpu: use the new iterator in amdgpu_sync_resv
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (7 preceding siblings ...)
  2021-09-24 15:30 ` [PATCH 09/27] drm/ttm: use the new iterator in ttm_bo_flush_all_fences Christian König
@ 2021-09-24 15:30 ` Christian König
  2021-09-24 15:30 ` [PATCH 11/27] drm/amdgpu: use new iterator in amdgpu_ttm_bo_eviction_valuable Christian König
                   ` (16 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:30 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Simplifying the code a bit.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c | 44 ++++++++----------------
 1 file changed, 14 insertions(+), 30 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
index 862eb3c1c4c5..f7d8487799b2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
@@ -252,41 +252,25 @@ int amdgpu_sync_resv(struct amdgpu_device *adev, struct amdgpu_sync *sync,
 		     struct dma_resv *resv, enum amdgpu_sync_mode mode,
 		     void *owner)
 {
-	struct dma_resv_list *flist;
+	struct dma_resv_iter cursor;
 	struct dma_fence *f;
-	unsigned i;
-	int r = 0;
+	int r;
 
 	if (resv == NULL)
 		return -EINVAL;
 
-	/* always sync to the exclusive fence */
-	f = dma_resv_excl_fence(resv);
-	dma_fence_chain_for_each(f, f) {
-		struct dma_fence_chain *chain = to_dma_fence_chain(f);
-
-		if (amdgpu_sync_test_fence(adev, mode, owner, chain ?
-					   chain->fence : f)) {
-			r = amdgpu_sync_fence(sync, f);
-			dma_fence_put(f);
-			if (r)
-				return r;
-			break;
-		}
-	}
-
-	flist = dma_resv_shared_list(resv);
-	if (!flist)
-		return 0;
-
-	for (i = 0; i < flist->shared_count; ++i) {
-		f = rcu_dereference_protected(flist->shared[i],
-					      dma_resv_held(resv));
-
-		if (amdgpu_sync_test_fence(adev, mode, owner, f)) {
-			r = amdgpu_sync_fence(sync, f);
-			if (r)
-				return r;
+	dma_resv_for_each_fence(&cursor, resv, true, f) {
+		dma_fence_chain_for_each(f, f) {
+			struct dma_fence_chain *chain = to_dma_fence_chain(f);
+
+			if (amdgpu_sync_test_fence(adev, mode, owner, chain ?
+						   chain->fence : f)) {
+				r = amdgpu_sync_fence(sync, f);
+				dma_fence_put(f);
+				if (r)
+					return r;
+				break;
+			}
 		}
 	}
 	return 0;
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 11/27] drm/amdgpu: use new iterator in amdgpu_ttm_bo_eviction_valuable
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (8 preceding siblings ...)
  2021-09-24 15:30 ` [PATCH 10/27] drm/amdgpu: use the new iterator in amdgpu_sync_resv Christian König
@ 2021-09-24 15:30 ` Christian König
  2021-09-24 15:30 ` [PATCH 12/27] drm/amdgpu: use new iterator in amdgpu_vm_prt_fini Christian König
                   ` (15 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:30 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Simplifying the code a bit.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 1129e17e9f09..4511cd15c3a6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1332,10 +1332,9 @@ static bool amdgpu_ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
 					    const struct ttm_place *place)
 {
 	unsigned long num_pages = bo->resource->num_pages;
+	struct dma_resv_iter resv_cursor;
 	struct amdgpu_res_cursor cursor;
-	struct dma_resv_list *flist;
 	struct dma_fence *f;
-	int i;
 
 	/* Swapout? */
 	if (bo->resource->mem_type == TTM_PL_SYSTEM)
@@ -1349,14 +1348,9 @@ static bool amdgpu_ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
 	 * If true, then return false as any KFD process needs all its BOs to
 	 * be resident to run successfully
 	 */
-	flist = dma_resv_shared_list(bo->base.resv);
-	if (flist) {
-		for (i = 0; i < flist->shared_count; ++i) {
-			f = rcu_dereference_protected(flist->shared[i],
-				dma_resv_held(bo->base.resv));
-			if (amdkfd_fence_check_mm(f, current->mm))
-				return false;
-		}
+	dma_resv_for_each_fence(&resv_cursor, bo->base.resv, true, f) {
+		if (amdkfd_fence_check_mm(f, current->mm))
+			return false;
 	}
 
 	switch (bo->resource->mem_type) {
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 12/27] drm/amdgpu: use new iterator in amdgpu_vm_prt_fini
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (9 preceding siblings ...)
  2021-09-24 15:30 ` [PATCH 11/27] drm/amdgpu: use new iterator in amdgpu_ttm_bo_eviction_valuable Christian König
@ 2021-09-24 15:30 ` Christian König
  2021-09-24 15:30 ` [PATCH 13/27] drm/msm: use new iterator in msm_gem_describe Christian König
                   ` (14 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:30 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

No need to actually allocate an array of fences here.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 26 +++++---------------------
 1 file changed, 5 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 6b15cad78de9..e42dd79ed6f4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2090,30 +2090,14 @@ static void amdgpu_vm_free_mapping(struct amdgpu_device *adev,
 static void amdgpu_vm_prt_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 {
 	struct dma_resv *resv = vm->root.bo->tbo.base.resv;
-	struct dma_fence *excl, **shared;
-	unsigned i, shared_count;
-	int r;
+	struct dma_resv_iter cursor;
+	struct dma_fence *fence;
 
-	r = dma_resv_get_fences(resv, &excl, &shared_count, &shared);
-	if (r) {
-		/* Not enough memory to grab the fence list, as last resort
-		 * block for all the fences to complete.
-		 */
-		dma_resv_wait_timeout(resv, true, false,
-						    MAX_SCHEDULE_TIMEOUT);
-		return;
-	}
-
-	/* Add a callback for each fence in the reservation object */
-	amdgpu_vm_prt_get(adev);
-	amdgpu_vm_add_prt_cb(adev, excl);
-
-	for (i = 0; i < shared_count; ++i) {
+	dma_resv_for_each_fence(&cursor, resv, true, fence) {
+		/* Add a callback for each fence in the reservation object */
 		amdgpu_vm_prt_get(adev);
-		amdgpu_vm_add_prt_cb(adev, shared[i]);
+		amdgpu_vm_add_prt_cb(adev, fence);
 	}
-
-	kfree(shared);
 }
 
 /**
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 13/27] drm/msm: use new iterator in msm_gem_describe
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (10 preceding siblings ...)
  2021-09-24 15:30 ` [PATCH 12/27] drm/amdgpu: use new iterator in amdgpu_vm_prt_fini Christian König
@ 2021-09-24 15:30 ` Christian König
  2021-09-24 15:31 ` [PATCH 14/27] drm/radeon: use new iterator in radeon_sync_resv Christian König
                   ` (13 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:30 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Simplifying the code a bit. Also drop the RCU read side lock since the
object is locked anyway.

Untested since I can't get the driver to compile on !ARM.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/msm/msm_gem.c | 19 +++++--------------
 1 file changed, 5 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 22308a1b66fc..14907622769f 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -880,7 +880,7 @@ void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m,
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 	struct dma_resv *robj = obj->resv;
-	struct dma_resv_list *fobj;
+	struct dma_resv_iter cursor;
 	struct dma_fence *fence;
 	struct msm_gem_vma *vma;
 	uint64_t off = drm_vma_node_start(&obj->vma_node);
@@ -955,22 +955,13 @@ void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m,
 		seq_puts(m, "\n");
 	}
 
-	rcu_read_lock();
-	fobj = dma_resv_shared_list(robj);
-	if (fobj) {
-		unsigned int i, shared_count = fobj->shared_count;
-
-		for (i = 0; i < shared_count; i++) {
-			fence = rcu_dereference(fobj->shared[i]);
+	dma_resv_for_each_fence(&cursor, robj, true, fence) {
+		if (dma_resv_iter_is_exclusive(&cursor))
+			describe_fence(fence, "Exclusive", m);
+		else
 			describe_fence(fence, "Shared", m);
-		}
 	}
 
-	fence = dma_resv_excl_fence(robj);
-	if (fence)
-		describe_fence(fence, "Exclusive", m);
-	rcu_read_unlock();
-
 	msm_gem_unlock(obj);
 }
 
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 14/27] drm/radeon: use new iterator in radeon_sync_resv
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (11 preceding siblings ...)
  2021-09-24 15:30 ` [PATCH 13/27] drm/msm: use new iterator in msm_gem_describe Christian König
@ 2021-09-24 15:31 ` Christian König
  2021-09-24 15:31 ` [PATCH 15/27] drm/scheduler: use new iterator in drm_sched_job_add_implicit_dependencies v2 Christian König
                   ` (12 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:31 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Simplifying the code a bit.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/radeon/radeon_sync.c | 22 +++-------------------
 1 file changed, 3 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_sync.c b/drivers/gpu/drm/radeon/radeon_sync.c
index 9257b60144c4..b991ba1bcd51 100644
--- a/drivers/gpu/drm/radeon/radeon_sync.c
+++ b/drivers/gpu/drm/radeon/radeon_sync.c
@@ -91,33 +91,17 @@ int radeon_sync_resv(struct radeon_device *rdev,
 		     struct dma_resv *resv,
 		     bool shared)
 {
-	struct dma_resv_list *flist;
-	struct dma_fence *f;
+	struct dma_resv_iter cursor;
 	struct radeon_fence *fence;
-	unsigned i;
+	struct dma_fence *f;
 	int r = 0;
 
-	/* always sync to the exclusive fence */
-	f = dma_resv_excl_fence(resv);
-	fence = f ? to_radeon_fence(f) : NULL;
-	if (fence && fence->rdev == rdev)
-		radeon_sync_fence(sync, fence);
-	else if (f)
-		r = dma_fence_wait(f, true);
-
-	flist = dma_resv_shared_list(resv);
-	if (shared || !flist || r)
-		return r;
-
-	for (i = 0; i < flist->shared_count; ++i) {
-		f = rcu_dereference_protected(flist->shared[i],
-					      dma_resv_held(resv));
+	dma_resv_for_each_fence(&cursor, resv, shared, f) {
 		fence = to_radeon_fence(f);
 		if (fence && fence->rdev == rdev)
 			radeon_sync_fence(sync, fence);
 		else
 			r = dma_fence_wait(f, true);
-
 		if (r)
 			break;
 	}
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 15/27] drm/scheduler: use new iterator in drm_sched_job_add_implicit_dependencies v2
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (12 preceding siblings ...)
  2021-09-24 15:31 ` [PATCH 14/27] drm/radeon: use new iterator in radeon_sync_resv Christian König
@ 2021-09-24 15:31 ` Christian König
  2021-09-24 15:31 ` [PATCH 16/27] drm/i915: use the new iterator in i915_gem_busy_ioctl v2 Christian König
                   ` (11 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:31 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Simplifying the code a bit.

v2: use dma_resv_for_each_fence

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/scheduler/sched_main.c | 26 ++++++--------------------
 1 file changed, 6 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index 042c16b5d54a..5bc5f775abe1 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -699,30 +699,16 @@ int drm_sched_job_add_implicit_dependencies(struct drm_sched_job *job,
 					    struct drm_gem_object *obj,
 					    bool write)
 {
+	struct dma_resv_iter cursor;
+	struct dma_fence *fence;
 	int ret;
-	struct dma_fence **fences;
-	unsigned int i, fence_count;
-
-	if (!write) {
-		struct dma_fence *fence = dma_resv_get_excl_unlocked(obj->resv);
-
-		return drm_sched_job_add_dependency(job, fence);
-	}
-
-	ret = dma_resv_get_fences(obj->resv, NULL, &fence_count, &fences);
-	if (ret || !fence_count)
-		return ret;
 
-	for (i = 0; i < fence_count; i++) {
-		ret = drm_sched_job_add_dependency(job, fences[i]);
+	dma_resv_for_each_fence(&cursor, obj->resv, write, fence) {
+		ret = drm_sched_job_add_dependency(job, fence);
 		if (ret)
-			break;
+			return ret;
 	}
-
-	for (; i < fence_count; i++)
-		dma_fence_put(fences[i]);
-	kfree(fences);
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(drm_sched_job_add_implicit_dependencies);
 
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 16/27] drm/i915: use the new iterator in i915_gem_busy_ioctl v2
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (13 preceding siblings ...)
  2021-09-24 15:31 ` [PATCH 15/27] drm/scheduler: use new iterator in drm_sched_job_add_implicit_dependencies v2 Christian König
@ 2021-09-24 15:31 ` Christian König
  2021-09-24 15:31 ` [PATCH 17/27] drm/i915: use the new iterator in i915_sw_fence_await_reservation v3 Christian König
                   ` (10 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:31 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

This makes the function much simpler since the complex
retry logic is now handled else where.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_busy.c | 35 ++++++++++--------------
 1 file changed, 14 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_busy.c b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
index 6234e17259c1..dc72b36dae54 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_busy.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
@@ -82,8 +82,8 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
 {
 	struct drm_i915_gem_busy *args = data;
 	struct drm_i915_gem_object *obj;
-	struct dma_resv_list *list;
-	unsigned int seq;
+	struct dma_resv_iter cursor;
+	struct dma_fence *fence;
 	int err;
 
 	err = -ENOENT;
@@ -109,27 +109,20 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
 	 * to report the overall busyness. This is what the wait-ioctl does.
 	 *
 	 */
-retry:
-	seq = raw_read_seqcount(&obj->base.resv->seq);
-
-	/* Translate the exclusive fence to the READ *and* WRITE engine */
-	args->busy = busy_check_writer(dma_resv_excl_fence(obj->base.resv));
-
-	/* Translate shared fences to READ set of engines */
-	list = dma_resv_shared_list(obj->base.resv);
-	if (list) {
-		unsigned int shared_count = list->shared_count, i;
-
-		for (i = 0; i < shared_count; ++i) {
-			struct dma_fence *fence =
-				rcu_dereference(list->shared[i]);
-
+	args->busy = 0;
+	dma_resv_iter_begin(&cursor, obj->base.resv, true);
+	dma_resv_for_each_fence_unlocked(&cursor, fence) {
+		if (dma_resv_iter_is_restarted(&cursor))
+			args->busy = 0;
+
+		if (dma_resv_iter_is_exclusive(&cursor))
+			/* Translate the exclusive fence to the READ *and* WRITE engine */
+			args->busy |= busy_check_writer(fence);
+		else
+			/* Translate shared fences to READ set of engines */
 			args->busy |= busy_check_reader(fence);
-		}
 	}
-
-	if (args->busy && read_seqcount_retry(&obj->base.resv->seq, seq))
-		goto retry;
+	dma_resv_iter_end(&cursor);
 
 	err = 0;
 out:
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 17/27] drm/i915: use the new iterator in i915_sw_fence_await_reservation v3
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (14 preceding siblings ...)
  2021-09-24 15:31 ` [PATCH 16/27] drm/i915: use the new iterator in i915_gem_busy_ioctl v2 Christian König
@ 2021-09-24 15:31 ` Christian König
  2021-09-24 15:31 ` [PATCH 18/27] drm/i915: use the new iterator in i915_request_await_object v2 Christian König
                   ` (9 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:31 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Simplifying the code a bit.

v2: use dma_resv_for_each_fence instead, according to Tvrtko the lock is
    held here anyway.
v3: back to using dma_resv_for_each_fence_unlocked.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/i915/i915_sw_fence.c | 53 ++++++----------------------
 1 file changed, 11 insertions(+), 42 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c b/drivers/gpu/drm/i915/i915_sw_fence.c
index c589a681da77..7ea0dbf81530 100644
--- a/drivers/gpu/drm/i915/i915_sw_fence.c
+++ b/drivers/gpu/drm/i915/i915_sw_fence.c
@@ -572,56 +572,25 @@ int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
 				    unsigned long timeout,
 				    gfp_t gfp)
 {
-	struct dma_fence *excl;
+	struct dma_resv_iter cursor;
+	struct dma_fence *f;
 	int ret = 0, pending;
 
 	debug_fence_assert(fence);
 	might_sleep_if(gfpflags_allow_blocking(gfp));
 
-	if (write) {
-		struct dma_fence **shared;
-		unsigned int count, i;
-
-		ret = dma_resv_get_fences(resv, &excl, &count, &shared);
-		if (ret)
-			return ret;
-
-		for (i = 0; i < count; i++) {
-			if (shared[i]->ops == exclude)
-				continue;
-
-			pending = i915_sw_fence_await_dma_fence(fence,
-								shared[i],
-								timeout,
-								gfp);
-			if (pending < 0) {
-				ret = pending;
-				break;
-			}
-
-			ret |= pending;
-		}
-
-		for (i = 0; i < count; i++)
-			dma_fence_put(shared[i]);
-		kfree(shared);
-	} else {
-		excl = dma_resv_get_excl_unlocked(resv);
-	}
-
-	if (ret >= 0 && excl && excl->ops != exclude) {
-		pending = i915_sw_fence_await_dma_fence(fence,
-							excl,
-							timeout,
+	dma_resv_iter_begin(&cursor, resv, write);
+	dma_resv_for_each_fence_unlocked(&cursor, f) {
+		pending = i915_sw_fence_await_dma_fence(fence, f, timeout,
 							gfp);
-		if (pending < 0)
+		if (pending < 0) {
 			ret = pending;
-		else
-			ret |= pending;
-	}
-
-	dma_fence_put(excl);
+			break;
+		}
 
+		ret |= pending;
+	}
+	dma_resv_iter_end(&cursor);
 	return ret;
 }
 
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 18/27] drm/i915: use the new iterator in i915_request_await_object v2
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (15 preceding siblings ...)
  2021-09-24 15:31 ` [PATCH 17/27] drm/i915: use the new iterator in i915_sw_fence_await_reservation v3 Christian König
@ 2021-09-24 15:31 ` Christian König
  2021-09-24 15:31 ` [PATCH 19/27] drm/i915: use new iterator in i915_gem_object_wait_reservation Christian König
                   ` (8 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:31 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Simplifying the code a bit.

v2: add missing rcu_read_lock()/rcu_read_unlock()
v3: use dma_resv_for_each_fence instead

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
 drivers/gpu/drm/i915/i915_request.c | 34 +++++------------------------
 1 file changed, 5 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index ce446716d092..3839712ebd23 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1509,38 +1509,14 @@ i915_request_await_object(struct i915_request *to,
 			  struct drm_i915_gem_object *obj,
 			  bool write)
 {
-	struct dma_fence *excl;
+	struct dma_resv_iter cursor;
+	struct dma_fence *fence;
 	int ret = 0;
 
-	if (write) {
-		struct dma_fence **shared;
-		unsigned int count, i;
-
-		ret = dma_resv_get_fences(obj->base.resv, &excl, &count,
-					  &shared);
+	dma_resv_for_each_fence(&cursor, obj->base.resv, write, fence) {
+		ret = i915_request_await_dma_fence(to, fence);
 		if (ret)
-			return ret;
-
-		for (i = 0; i < count; i++) {
-			ret = i915_request_await_dma_fence(to, shared[i]);
-			if (ret)
-				break;
-
-			dma_fence_put(shared[i]);
-		}
-
-		for (; i < count; i++)
-			dma_fence_put(shared[i]);
-		kfree(shared);
-	} else {
-		excl = dma_resv_get_excl_unlocked(obj->base.resv);
-	}
-
-	if (excl) {
-		if (ret == 0)
-			ret = i915_request_await_dma_fence(to, excl);
-
-		dma_fence_put(excl);
+			break;
 	}
 
 	return ret;
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 19/27] drm/i915: use new iterator in i915_gem_object_wait_reservation
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (16 preceding siblings ...)
  2021-09-24 15:31 ` [PATCH 18/27] drm/i915: use the new iterator in i915_request_await_object v2 Christian König
@ 2021-09-24 15:31 ` Christian König
  2021-09-24 15:31 ` [PATCH 20/27] drm/i915: use new iterator in i915_gem_object_wait_priority Christian König
                   ` (7 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:31 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Simplifying the code a bit.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_wait.c | 51 +++++-------------------
 1 file changed, 9 insertions(+), 42 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_wait.c b/drivers/gpu/drm/i915/gem/i915_gem_wait.c
index f909aaa09d9c..a13193db1dba 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_wait.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_wait.c
@@ -37,55 +37,22 @@ i915_gem_object_wait_reservation(struct dma_resv *resv,
 				 unsigned int flags,
 				 long timeout)
 {
-	struct dma_fence *excl;
-	bool prune_fences = false;
-
-	if (flags & I915_WAIT_ALL) {
-		struct dma_fence **shared;
-		unsigned int count, i;
-		int ret;
+	struct dma_resv_iter cursor;
+	struct dma_fence *fence;
 
-		ret = dma_resv_get_fences(resv, &excl, &count, &shared);
-		if (ret)
-			return ret;
-
-		for (i = 0; i < count; i++) {
-			timeout = i915_gem_object_wait_fence(shared[i],
-							     flags, timeout);
-			if (timeout < 0)
-				break;
-
-			dma_fence_put(shared[i]);
-		}
-
-		for (; i < count; i++)
-			dma_fence_put(shared[i]);
-		kfree(shared);
-
-		/*
-		 * If both shared fences and an exclusive fence exist,
-		 * then by construction the shared fences must be later
-		 * than the exclusive fence. If we successfully wait for
-		 * all the shared fences, we know that the exclusive fence
-		 * must all be signaled. If all the shared fences are
-		 * signaled, we can prune the array and recover the
-		 * floating references on the fences/requests.
-		 */
-		prune_fences = count && timeout >= 0;
-	} else {
-		excl = dma_resv_get_excl_unlocked(resv);
+	dma_resv_iter_begin(&cursor, resv, flags & I915_WAIT_ALL);
+	dma_resv_for_each_fence_unlocked(&cursor, fence) {
+		timeout = i915_gem_object_wait_fence(fence, flags, timeout);
+		if (timeout < 0)
+			break;
 	}
-
-	if (excl && timeout >= 0)
-		timeout = i915_gem_object_wait_fence(excl, flags, timeout);
-
-	dma_fence_put(excl);
+	dma_resv_iter_end(&cursor);
 
 	/*
 	 * Opportunistically prune the fences iff we know they have *all* been
 	 * signaled.
 	 */
-	if (prune_fences)
+	if (timeout > 0)
 		dma_resv_prune(resv);
 
 	return timeout;
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 20/27] drm/i915: use new iterator in i915_gem_object_wait_priority
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (17 preceding siblings ...)
  2021-09-24 15:31 ` [PATCH 19/27] drm/i915: use new iterator in i915_gem_object_wait_reservation Christian König
@ 2021-09-24 15:31 ` Christian König
  2021-09-24 15:31 ` [PATCH 21/27] drm/i915: use new cursor in intel_prepare_plane_fb Christian König
                   ` (6 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:31 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Simplifying the code a bit.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_wait.c | 31 +++++-------------------
 1 file changed, 6 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_wait.c b/drivers/gpu/drm/i915/gem/i915_gem_wait.c
index a13193db1dba..569658c7859c 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_wait.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_wait.c
@@ -118,32 +118,13 @@ i915_gem_object_wait_priority(struct drm_i915_gem_object *obj,
 			      unsigned int flags,
 			      const struct i915_sched_attr *attr)
 {
-	struct dma_fence *excl;
-
-	if (flags & I915_WAIT_ALL) {
-		struct dma_fence **shared;
-		unsigned int count, i;
-		int ret;
-
-		ret = dma_resv_get_fences(obj->base.resv, &excl, &count,
-					  &shared);
-		if (ret)
-			return ret;
-
-		for (i = 0; i < count; i++) {
-			i915_gem_fence_wait_priority(shared[i], attr);
-			dma_fence_put(shared[i]);
-		}
-
-		kfree(shared);
-	} else {
-		excl = dma_resv_get_excl_unlocked(obj->base.resv);
-	}
+	struct dma_resv_iter cursor;
+	struct dma_fence *fence;
 
-	if (excl) {
-		i915_gem_fence_wait_priority(excl, attr);
-		dma_fence_put(excl);
-	}
+	dma_resv_iter_begin(&cursor, obj->base.resv, flags & I915_WAIT_ALL);
+	dma_resv_for_each_fence_unlocked(&cursor, fence)
+		i915_gem_fence_wait_priority(fence, attr);
+	dma_resv_iter_end(&cursor);
 	return 0;
 }
 
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 21/27] drm/i915: use new cursor in intel_prepare_plane_fb
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (18 preceding siblings ...)
  2021-09-24 15:31 ` [PATCH 20/27] drm/i915: use new iterator in i915_gem_object_wait_priority Christian König
@ 2021-09-24 15:31 ` Christian König
  2021-09-24 15:31 ` [PATCH 22/27] drm: use new iterator in drm_gem_fence_array_add_implicit v3 Christian König
                   ` (5 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:31 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Simplifying the code a bit.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/i915/display/intel_display.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 134a6acbd8fb..d32137a84694 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -11290,6 +11290,7 @@ intel_prepare_plane_fb(struct drm_plane *_plane,
 	i915_gem_object_flush_frontbuffer(obj, ORIGIN_DIRTYFB);
 
 	if (!new_plane_state->uapi.fence) { /* implicit fencing */
+		struct dma_resv_iter cursor;
 		struct dma_fence *fence;
 
 		ret = i915_sw_fence_await_reservation(&state->commit_ready,
@@ -11300,12 +11301,12 @@ intel_prepare_plane_fb(struct drm_plane *_plane,
 		if (ret < 0)
 			goto unpin_fb;
 
-		fence = dma_resv_get_excl_unlocked(obj->base.resv);
-		if (fence) {
+		dma_resv_iter_begin(&cursor, obj->base.resv, false);
+		dma_resv_for_each_fence_unlocked(&cursor, fence) {
 			add_rps_boost_after_vblank(new_plane_state->hw.crtc,
 						   fence);
-			dma_fence_put(fence);
 		}
+		dma_resv_iter_end(&cursor);
 	} else {
 		add_rps_boost_after_vblank(new_plane_state->hw.crtc,
 					   new_plane_state->uapi.fence);
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 22/27] drm: use new iterator in drm_gem_fence_array_add_implicit v3
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (19 preceding siblings ...)
  2021-09-24 15:31 ` [PATCH 21/27] drm/i915: use new cursor in intel_prepare_plane_fb Christian König
@ 2021-09-24 15:31 ` Christian König
  2021-09-24 15:31 ` [PATCH 23/27] drm: use new iterator in drm_gem_plane_helper_prepare_fb Christian König
                   ` (4 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:31 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Simplifying the code a bit.

v2: add missing rcu_read_lock()/unlock()
v3: switch to locked version

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/drm_gem.c | 26 +++++---------------------
 1 file changed, 5 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 09c820045859..4dcdec6487bb 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1340,31 +1340,15 @@ int drm_gem_fence_array_add_implicit(struct xarray *fence_array,
 				     struct drm_gem_object *obj,
 				     bool write)
 {
-	int ret;
-	struct dma_fence **fences;
-	unsigned int i, fence_count;
-
-	if (!write) {
-		struct dma_fence *fence =
-			dma_resv_get_excl_unlocked(obj->resv);
-
-		return drm_gem_fence_array_add(fence_array, fence);
-	}
+	struct dma_resv_iter cursor;
+	struct dma_fence *fence;
+	int ret = 0;
 
-	ret = dma_resv_get_fences(obj->resv, NULL,
-						&fence_count, &fences);
-	if (ret || !fence_count)
-		return ret;
-
-	for (i = 0; i < fence_count; i++) {
-		ret = drm_gem_fence_array_add(fence_array, fences[i]);
+	dma_resv_for_each_fence(&cursor, obj->resv, write, fence) {
+		ret = drm_gem_fence_array_add(fence_array, fence);
 		if (ret)
 			break;
 	}
-
-	for (; i < fence_count; i++)
-		dma_fence_put(fences[i]);
-	kfree(fences);
 	return ret;
 }
 EXPORT_SYMBOL(drm_gem_fence_array_add_implicit);
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 23/27] drm: use new iterator in drm_gem_plane_helper_prepare_fb
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (20 preceding siblings ...)
  2021-09-24 15:31 ` [PATCH 22/27] drm: use new iterator in drm_gem_fence_array_add_implicit v3 Christian König
@ 2021-09-24 15:31 ` Christian König
  2021-09-24 15:31 ` [PATCH 24/27] drm/nouveau: use the new iterator in nouveau_fence_sync Christian König
                   ` (3 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:31 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Makes the handling a bit more complex, but avoids the use of
dma_resv_get_excl_unlocked().

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/drm_gem_atomic_helper.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_atomic_helper.c b/drivers/gpu/drm/drm_gem_atomic_helper.c
index e570398abd78..21ed930042b8 100644
--- a/drivers/gpu/drm/drm_gem_atomic_helper.c
+++ b/drivers/gpu/drm/drm_gem_atomic_helper.c
@@ -143,6 +143,7 @@
  */
 int drm_gem_plane_helper_prepare_fb(struct drm_plane *plane, struct drm_plane_state *state)
 {
+	struct dma_resv_iter cursor;
 	struct drm_gem_object *obj;
 	struct dma_fence *fence;
 
@@ -150,9 +151,17 @@ int drm_gem_plane_helper_prepare_fb(struct drm_plane *plane, struct drm_plane_st
 		return 0;
 
 	obj = drm_gem_fb_get_obj(state->fb, 0);
-	fence = dma_resv_get_excl_unlocked(obj->resv);
-	drm_atomic_set_fence_for_plane(state, fence);
+	dma_resv_iter_begin(&cursor, obj->resv, false);
+	dma_resv_for_each_fence_unlocked(&cursor, fence) {
+		dma_fence_get(fence);
+		dma_resv_iter_end(&cursor);
+		/* TODO: We only use the first write fence here */
+		drm_atomic_set_fence_for_plane(state, fence);
+		return 0;
+	}
+	dma_resv_iter_end(&cursor);
 
+	drm_atomic_set_fence_for_plane(state, NULL);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(drm_gem_plane_helper_prepare_fb);
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 24/27] drm/nouveau: use the new iterator in nouveau_fence_sync
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (21 preceding siblings ...)
  2021-09-24 15:31 ` [PATCH 23/27] drm: use new iterator in drm_gem_plane_helper_prepare_fb Christian König
@ 2021-09-24 15:31 ` Christian König
  2021-09-24 15:31 ` [PATCH 25/27] drm/nouveau: use the new interator in nv50_wndw_prepare_fb Christian König
                   ` (2 subsequent siblings)
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:31 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Simplifying the code a bit.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/nouveau/nouveau_fence.c | 48 +++++++------------------
 1 file changed, 12 insertions(+), 36 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.c b/drivers/gpu/drm/nouveau/nouveau_fence.c
index 05d0b3eb3690..26f9299df881 100644
--- a/drivers/gpu/drm/nouveau/nouveau_fence.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fence.c
@@ -339,14 +339,15 @@ nouveau_fence_wait(struct nouveau_fence *fence, bool lazy, bool intr)
 }
 
 int
-nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool exclusive, bool intr)
+nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan,
+		   bool exclusive, bool intr)
 {
 	struct nouveau_fence_chan *fctx = chan->fence;
-	struct dma_fence *fence;
 	struct dma_resv *resv = nvbo->bo.base.resv;
-	struct dma_resv_list *fobj;
+	struct dma_resv_iter cursor;
+	struct dma_fence *fence;
 	struct nouveau_fence *f;
-	int ret = 0, i;
+	int ret;
 
 	if (!exclusive) {
 		ret = dma_resv_reserve_shared(resv, 1);
@@ -355,10 +356,7 @@ nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool e
 			return ret;
 	}
 
-	fobj = dma_resv_shared_list(resv);
-	fence = dma_resv_excl_fence(resv);
-
-	if (fence) {
+	dma_resv_for_each_fence(&cursor, resv, exclusive, fence) {
 		struct nouveau_channel *prev = NULL;
 		bool must_wait = true;
 
@@ -366,41 +364,19 @@ nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool e
 		if (f) {
 			rcu_read_lock();
 			prev = rcu_dereference(f->channel);
-			if (prev && (prev == chan || fctx->sync(f, prev, chan) == 0))
+			if (prev && (prev == chan ||
+				     fctx->sync(f, prev, chan) == 0))
 				must_wait = false;
 			rcu_read_unlock();
 		}
 
-		if (must_wait)
+		if (must_wait) {
 			ret = dma_fence_wait(fence, intr);
-
-		return ret;
-	}
-
-	if (!exclusive || !fobj)
-		return ret;
-
-	for (i = 0; i < fobj->shared_count && !ret; ++i) {
-		struct nouveau_channel *prev = NULL;
-		bool must_wait = true;
-
-		fence = rcu_dereference_protected(fobj->shared[i],
-						dma_resv_held(resv));
-
-		f = nouveau_local_fence(fence, chan->drm);
-		if (f) {
-			rcu_read_lock();
-			prev = rcu_dereference(f->channel);
-			if (prev && (prev == chan || fctx->sync(f, prev, chan) == 0))
-				must_wait = false;
-			rcu_read_unlock();
+			if (ret)
+				return ret;
 		}
-
-		if (must_wait)
-			ret = dma_fence_wait(fence, intr);
 	}
-
-	return ret;
+	return 0;
 }
 
 void
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 25/27] drm/nouveau: use the new interator in nv50_wndw_prepare_fb
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (22 preceding siblings ...)
  2021-09-24 15:31 ` [PATCH 24/27] drm/nouveau: use the new iterator in nouveau_fence_sync Christian König
@ 2021-09-24 15:31 ` Christian König
  2021-09-24 15:31 ` [PATCH 26/27] drm/etnaviv: use new iterator in etnaviv_gem_describe Christian König
  2021-09-24 15:31 ` [PATCH 27/27] drm/etnaviv: replace dma_resv_get_excl_unlocked Christian König
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:31 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Makes the handling a bit more complex, but avoids the use of
dma_resv_get_excl_unlocked().

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/nouveau/dispnv50/wndw.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/dispnv50/wndw.c b/drivers/gpu/drm/nouveau/dispnv50/wndw.c
index 8d048bacd6f0..30712a681e2a 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/wndw.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/wndw.c
@@ -539,6 +539,8 @@ nv50_wndw_prepare_fb(struct drm_plane *plane, struct drm_plane_state *state)
 	struct nouveau_bo *nvbo;
 	struct nv50_head_atom *asyh;
 	struct nv50_wndw_ctxdma *ctxdma;
+	struct dma_resv_iter cursor;
+	struct dma_fence *fence;
 	int ret;
 
 	NV_ATOMIC(drm, "%s prepare: %p\n", plane->name, fb);
@@ -561,7 +563,13 @@ nv50_wndw_prepare_fb(struct drm_plane *plane, struct drm_plane_state *state)
 			asyw->image.handle[0] = ctxdma->object.handle;
 	}
 
-	asyw->state.fence = dma_resv_get_excl_unlocked(nvbo->bo.base.resv);
+	dma_resv_iter_begin(&cursor, nvbo->bo.base.resv, false);
+	dma_resv_for_each_fence_unlocked(&cursor, fence) {
+		/* TODO: We only use the first writer here */
+		asyw->state.fence = dma_fence_get(fence);
+		break;
+	}
+	dma_resv_iter_end(&cursor);
 	asyw->image.offset[0] = nvbo->offset;
 
 	if (wndw->func->prepare) {
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 26/27] drm/etnaviv: use new iterator in etnaviv_gem_describe
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (23 preceding siblings ...)
  2021-09-24 15:31 ` [PATCH 25/27] drm/nouveau: use the new interator in nv50_wndw_prepare_fb Christian König
@ 2021-09-24 15:31 ` Christian König
  2021-09-24 15:31 ` [PATCH 27/27] drm/etnaviv: replace dma_resv_get_excl_unlocked Christian König
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:31 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

Instead of hand rolling the logic.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/etnaviv/etnaviv_gem.c | 31 ++++++++++-----------------
 1 file changed, 11 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index 8f1b5af47dd6..0eeb33de2ff4 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -428,19 +428,17 @@ int etnaviv_gem_wait_bo(struct etnaviv_gpu *gpu, struct drm_gem_object *obj,
 static void etnaviv_gem_describe_fence(struct dma_fence *fence,
 	const char *type, struct seq_file *m)
 {
-	if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
-		seq_printf(m, "\t%9s: %s %s seq %llu\n",
-			   type,
-			   fence->ops->get_driver_name(fence),
-			   fence->ops->get_timeline_name(fence),
-			   fence->seqno);
+	seq_printf(m, "\t%9s: %s %s seq %llu\n", type,
+		   fence->ops->get_driver_name(fence),
+		   fence->ops->get_timeline_name(fence),
+		   fence->seqno);
 }
 
 static void etnaviv_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
 {
 	struct etnaviv_gem_object *etnaviv_obj = to_etnaviv_bo(obj);
 	struct dma_resv *robj = obj->resv;
-	struct dma_resv_list *fobj;
+	struct dma_resv_iter cursor;
 	struct dma_fence *fence;
 	unsigned long off = drm_vma_node_start(&obj->vma_node);
 
@@ -449,21 +447,14 @@ static void etnaviv_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
 			obj->name, kref_read(&obj->refcount),
 			off, etnaviv_obj->vaddr, obj->size);
 
-	rcu_read_lock();
-	fobj = dma_resv_shared_list(robj);
-	if (fobj) {
-		unsigned int i, shared_count = fobj->shared_count;
-
-		for (i = 0; i < shared_count; i++) {
-			fence = rcu_dereference(fobj->shared[i]);
+	dma_resv_iter_begin(&cursor, robj, true);
+	dma_resv_for_each_fence_unlocked(&cursor, fence) {
+		if (dma_resv_iter_is_exclusive(&cursor))
+			etnaviv_gem_describe_fence(fence, "Exclusive", m);
+		else
 			etnaviv_gem_describe_fence(fence, "Shared", m);
-		}
 	}
-
-	fence = dma_resv_excl_fence(robj);
-	if (fence)
-		etnaviv_gem_describe_fence(fence, "Exclusive", m);
-	rcu_read_unlock();
+	dma_resv_iter_end(&cursor);
 }
 
 void etnaviv_gem_describe_objects(struct etnaviv_drm_private *priv,
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH 27/27] drm/etnaviv: replace dma_resv_get_excl_unlocked
  2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
                   ` (24 preceding siblings ...)
  2021-09-24 15:31 ` [PATCH 26/27] drm/etnaviv: use new iterator in etnaviv_gem_describe Christian König
@ 2021-09-24 15:31 ` Christian König
  25 siblings, 0 replies; 27+ messages in thread
From: Christian König @ 2021-09-24 15:31 UTC (permalink / raw)
  To: linaro-mm-sig, dri-devel, linux-media, intel-gfx; +Cc: daniel, tvrtko.ursulin

We certainly hold the reservation lock here, no need for the RCU dance.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
index 4dd7d9d541c0..7e17bc2b5df1 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
@@ -195,7 +195,7 @@ static int submit_fence_sync(struct etnaviv_gem_submit *submit)
 			if (ret)
 				return ret;
 		} else {
-			bo->excl = dma_resv_get_excl_unlocked(robj);
+			bo->excl = dma_fence_get(dma_resv_excl_fence(robj));
 		}
 
 	}
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 27+ messages in thread

end of thread, other threads:[~2021-09-24 15:32 UTC | newest]

Thread overview: 27+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-24 15:30 [PATCH 01/27] dma-buf: add dma_resv_for_each_fence_unlocked v6 Christian König
2021-09-24 15:30 ` [PATCH 02/27] dma-buf: add dma_resv_for_each_fence Christian König
2021-09-24 15:30 ` [PATCH 03/27] dma-buf: add dma_resv selftest Christian König
2021-09-24 15:30 ` [PATCH 04/27] dma-buf: use new iterator in dma_resv_copy_fences Christian König
2021-09-24 15:30 ` [PATCH 05/27] dma-buf: use new iterator in dma_resv_get_fences v3 Christian König
2021-09-24 15:30 ` [PATCH 06/27] dma-buf: use new iterator in dma_resv_wait_timeout Christian König
2021-09-24 15:30 ` [PATCH 07/27] dma-buf: use new iterator in dma_resv_test_signaled Christian König
2021-09-24 15:30 ` [PATCH 08/27] dma-buf: use the new iterator in dma_buf_debug_show Christian König
2021-09-24 15:30 ` [PATCH 09/27] drm/ttm: use the new iterator in ttm_bo_flush_all_fences Christian König
2021-09-24 15:30 ` [PATCH 10/27] drm/amdgpu: use the new iterator in amdgpu_sync_resv Christian König
2021-09-24 15:30 ` [PATCH 11/27] drm/amdgpu: use new iterator in amdgpu_ttm_bo_eviction_valuable Christian König
2021-09-24 15:30 ` [PATCH 12/27] drm/amdgpu: use new iterator in amdgpu_vm_prt_fini Christian König
2021-09-24 15:30 ` [PATCH 13/27] drm/msm: use new iterator in msm_gem_describe Christian König
2021-09-24 15:31 ` [PATCH 14/27] drm/radeon: use new iterator in radeon_sync_resv Christian König
2021-09-24 15:31 ` [PATCH 15/27] drm/scheduler: use new iterator in drm_sched_job_add_implicit_dependencies v2 Christian König
2021-09-24 15:31 ` [PATCH 16/27] drm/i915: use the new iterator in i915_gem_busy_ioctl v2 Christian König
2021-09-24 15:31 ` [PATCH 17/27] drm/i915: use the new iterator in i915_sw_fence_await_reservation v3 Christian König
2021-09-24 15:31 ` [PATCH 18/27] drm/i915: use the new iterator in i915_request_await_object v2 Christian König
2021-09-24 15:31 ` [PATCH 19/27] drm/i915: use new iterator in i915_gem_object_wait_reservation Christian König
2021-09-24 15:31 ` [PATCH 20/27] drm/i915: use new iterator in i915_gem_object_wait_priority Christian König
2021-09-24 15:31 ` [PATCH 21/27] drm/i915: use new cursor in intel_prepare_plane_fb Christian König
2021-09-24 15:31 ` [PATCH 22/27] drm: use new iterator in drm_gem_fence_array_add_implicit v3 Christian König
2021-09-24 15:31 ` [PATCH 23/27] drm: use new iterator in drm_gem_plane_helper_prepare_fb Christian König
2021-09-24 15:31 ` [PATCH 24/27] drm/nouveau: use the new iterator in nouveau_fence_sync Christian König
2021-09-24 15:31 ` [PATCH 25/27] drm/nouveau: use the new interator in nv50_wndw_prepare_fb Christian König
2021-09-24 15:31 ` [PATCH 26/27] drm/etnaviv: use new iterator in etnaviv_gem_describe Christian König
2021-09-24 15:31 ` [PATCH 27/27] drm/etnaviv: replace dma_resv_get_excl_unlocked Christian König

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