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 tudor.ambarus@linaro.org --- Changes in v2: - add To: stable@vger.kernel.org - Link to v1: https://lore.kernel.org/r/20260703-5-15-dma-fence-unwrap-v1-1-0cf644bc501f@l... --- 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 christian.koenig@amd.com - */ - -#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,