From 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 2 Sep 2026 15:31:14 -0700 Subject: treewide: refresh kmalloc_obj() conversions This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook --- include/drm/task_barrier.h | 107 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 include/drm/task_barrier.h (limited to 'include/drm/task_barrier.h') diff --git a/include/drm/task_barrier.h b/include/drm/task_barrier.h new file mode 100644 index 000000000..f6e6ed529 --- /dev/null +++ b/include/drm/task_barrier.h @@ -0,0 +1,107 @@ +/* + * Copyright 2019 Advanced Micro Devices, Inc. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + * + */ +#include +#include + +/* + * Reusable 2 PHASE task barrier (rendez-vous point) implementation for N tasks. + * Based on the Little book of semaphores - https://greenteapress.com/wp/semaphores/ + */ + + + +#ifndef DRM_TASK_BARRIER_H_ +#define DRM_TASK_BARRIER_H_ + +/* + * Represents an instance of a task barrier. + */ +struct task_barrier { + unsigned int n; + atomic_t count; + struct semaphore enter_turnstile; + struct semaphore exit_turnstile; +}; + +static inline void task_barrier_signal_turnstile(struct semaphore *turnstile, + unsigned int n) +{ + int i; + + for (i = 0 ; i < n; i++) + up(turnstile); +} + +static inline void task_barrier_init(struct task_barrier *tb) +{ + tb->n = 0; + atomic_set(&tb->count, 0); + sema_init(&tb->enter_turnstile, 0); + sema_init(&tb->exit_turnstile, 0); +} + +static inline void task_barrier_add_task(struct task_barrier *tb) +{ + tb->n++; +} + +static inline void task_barrier_rem_task(struct task_barrier *tb) +{ + tb->n--; +} + +/* + * Lines up all the threads BEFORE the critical point. + * + * When all thread passed this code the entry barrier is back to locked state. + */ +static inline void task_barrier_enter(struct task_barrier *tb) +{ + if (atomic_inc_return(&tb->count) == tb->n) + task_barrier_signal_turnstile(&tb->enter_turnstile, tb->n); + + down(&tb->enter_turnstile); +} + +/* + * Lines up all the threads AFTER the critical point. + * + * This function is used to avoid any one thread running ahead if the barrier is + * used repeatedly . + */ +static inline void task_barrier_exit(struct task_barrier *tb) +{ + if (atomic_dec_return(&tb->count) == 0) + task_barrier_signal_turnstile(&tb->exit_turnstile, tb->n); + + down(&tb->exit_turnstile); +} + +/* Convinieince function when nothing to be done in between entry and exit */ +static inline void task_barrier_full(struct task_barrier *tb) +{ + task_barrier_enter(tb); + task_barrier_exit(tb); +} + +#endif -- cgit v1.3.1