The file drivers/dma-buf/dma-fence-unwrap.c was incorrectly added to
the 5.15.y stable branch in commit 4e82b9c11d3c ("dma-buf: add
dma_fence_timestamp helper") as a new file, but it was never enabled in
the Makefile, and its header include/linux/dma-fence-unwrap.h was not
present, making it uncompilable.
A full revert of commit 4e82b9c11d3c ("dma-buf: add dma_fence_timestamp
helper") is not desirable because that commit also introduced the valid
dma_fence_timestamp() helper and fixed legitimate timestamp race
windows in drivers/dma-buf/sync_file.c and
drivers/gpu/drm/scheduler/sched_main.c.
Since there are no users of dma-fence-unwrap in the 5.15.y branch,
remove the unused file to clean up the tree and avoid confusion.
Fixes: 4e82b9c11d3c ("dma-buf: add dma_fence_timestamp helper")
Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/dma-buf/dma-fence-unwrap.c | 176 -------------------------------------
1 file changed, 176 deletions(-)
diff --git a/drivers/dma-buf/dma-fence-unwrap.c
b/drivers/dma-buf/dma-fence-unwrap.c
deleted file mode 100644
index 628af51c81af..000000000000
--- a/drivers/dma-buf/dma-fence-unwrap.c
+++ /dev/null
@@ -1,176 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * dma-fence-util: misc functions for dma_fence objects
- *
- * Copyright (C) 2022 Advanced Micro Devices, Inc.
- * Authors:
- * Christian König <[email protected]>
- */
-
-#include <linux/dma-fence.h>
-#include <linux/dma-fence-array.h>
-#include <linux/dma-fence-chain.h>
-#include <linux/dma-fence-unwrap.h>
-#include <linux/slab.h>
-
-/* Internal helper to start new array iteration, don't use directly */
-static struct dma_fence *
-__dma_fence_unwrap_array(struct dma_fence_unwrap *cursor)
-{
- cursor->array = dma_fence_chain_contained(cursor->chain);
- cursor->index = 0;
- return dma_fence_array_first(cursor->array);
-}
-
-/**
- * dma_fence_unwrap_first - return the first fence from fence containers
- * @head: the entrypoint into the containers
- * @cursor: current position inside the containers
- *
- * Unwraps potential dma_fence_chain/dma_fence_array containers and return the
- * first fence.
- */
-struct dma_fence *dma_fence_unwrap_first(struct dma_fence *head,
- struct dma_fence_unwrap *cursor)
-{
- cursor->chain = dma_fence_get(head);
- return __dma_fence_unwrap_array(cursor);
-}
-EXPORT_SYMBOL_GPL(dma_fence_unwrap_first);
-
-/**
- * dma_fence_unwrap_next - return the next fence from a fence containers
- * @cursor: current position inside the containers
- *
- * Continue unwrapping the dma_fence_chain/dma_fence_array containers and
return
- * the next fence from them.
- */
-struct dma_fence *dma_fence_unwrap_next(struct dma_fence_unwrap *cursor)
-{
- struct dma_fence *tmp;
-
- ++cursor->index;
- tmp = dma_fence_array_next(cursor->array, cursor->index);
- if (tmp)
- return tmp;
-
- cursor->chain = dma_fence_chain_walk(cursor->chain);
- return __dma_fence_unwrap_array(cursor);
-}
-EXPORT_SYMBOL_GPL(dma_fence_unwrap_next);
-
-/* Implementation for the dma_fence_merge() marco, don't use directly */
-struct dma_fence *__dma_fence_unwrap_merge(unsigned int num_fences,
- struct dma_fence **fences,
- struct dma_fence_unwrap *iter)
-{
- struct dma_fence_array *result;
- struct dma_fence *tmp, **array;
- ktime_t timestamp;
- unsigned int i;
- size_t count;
-
- count = 0;
- timestamp = ns_to_ktime(0);
- for (i = 0; i < num_fences; ++i) {
- dma_fence_unwrap_for_each(tmp, &iter[i], fences[i]) {
- if (!dma_fence_is_signaled(tmp)) {
- ++count;
- } else {
- ktime_t t = dma_fence_timestamp(tmp);
-
- if (ktime_after(t, timestamp))
- timestamp = t;
- }
- }
- }
-
- /*
- * If we couldn't find a pending fence just return a private signaled
- * fence with the timestamp of the last signaled one.
- */
- if (count == 0)
- return dma_fence_allocate_private_stub(timestamp);
-
- array = kmalloc_array(count, sizeof(*array), GFP_KERNEL);
- if (!array)
- return NULL;
-
- /*
- * This trashes the input fence array and uses it as position for the
- * following merge loop. This works because the dma_fence_merge()
- * wrapper macro is creating this temporary array on the stack together
- * with the iterators.
- */
- for (i = 0; i < num_fences; ++i)
- fences[i] = dma_fence_unwrap_first(fences[i], &iter[i]);
-
- count = 0;
- do {
- unsigned int sel;
-
-restart:
- tmp = NULL;
- for (i = 0; i < num_fences; ++i) {
- struct dma_fence *next;
-
- while (fences[i] && dma_fence_is_signaled(fences[i]))
- fences[i] = dma_fence_unwrap_next(&iter[i]);
-
- next = fences[i];
- if (!next)
- continue;
-
- /*
- * We can't guarantee that inpute fences are ordered by
- * context, but it is still quite likely when this
- * function is used multiple times. So attempt to order
- * the fences by context as we pass over them and merge
- * fences with the same context.
- */
- if (!tmp || tmp->context > next->context) {
- tmp = next;
- sel = i;
-
- } else if (tmp->context < next->context) {
- continue;
-
- } else if (dma_fence_is_later(tmp, next)) {
- fences[i] = dma_fence_unwrap_next(&iter[i]);
- goto restart;
- } else {
- fences[sel] = dma_fence_unwrap_next(&iter[sel]);
- goto restart;
- }
- }
-
- if (tmp) {
- array[count++] = dma_fence_get(tmp);
- fences[sel] = dma_fence_unwrap_next(&iter[sel]);
- }
- } while (tmp);
-
- if (count == 0) {
- tmp = dma_fence_allocate_private_stub(ktime_get());
- goto return_tmp;
- }
-
- if (count == 1) {
- tmp = array[0];
- goto return_tmp;
- }
-
- result = dma_fence_array_create(count, array,
- dma_fence_context_alloc(1),
- 1, false);
- if (!result) {
- tmp = NULL;
- goto return_tmp;
- }
- return &result->base;
-
-return_tmp:
- kfree(array);
- return tmp;
-}
-EXPORT_SYMBOL_GPL(__dma_fence_unwrap_merge);
---
base-commit: eceeec79dbc646d6dace49ed1ba2f656683d5537
change-id: 20260703-5-15-dma-fence-unwrap-0f4a6c03daf2
Best regards,
--
Tudor Ambarus <[email protected]>
