From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- sound/firewire/packets-buffer.c | 77 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 sound/firewire/packets-buffer.c (limited to 'sound/firewire/packets-buffer.c') diff --git a/sound/firewire/packets-buffer.c b/sound/firewire/packets-buffer.c new file mode 100644 index 000000000..2093a5fbd --- /dev/null +++ b/sound/firewire/packets-buffer.c @@ -0,0 +1,77 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * helpers for managing a buffer for many packets + * + * Copyright (c) Clemens Ladisch + */ + +#include +#include +#include +#include "packets-buffer.h" + +/** + * iso_packets_buffer_init - allocates the memory for packets + * @b: the buffer structure to initialize + * @unit: the device at the other end of the stream + * @count: the number of packets + * @packet_size: the (maximum) size of a packet, in bytes + * @direction: %DMA_TO_DEVICE or %DMA_FROM_DEVICE + */ +int iso_packets_buffer_init(struct iso_packets_buffer *b, struct fw_unit *unit, + unsigned int count, unsigned int packet_size, + enum dma_data_direction direction) +{ + unsigned int packets_per_page, pages; + unsigned int i, page_index, offset_in_page; + void *p; + int err; + + b->packets = kmalloc_objs(*b->packets, count); + if (!b->packets) { + err = -ENOMEM; + goto error; + } + + packet_size = L1_CACHE_ALIGN(packet_size); + packets_per_page = PAGE_SIZE / packet_size; + if (WARN_ON(!packets_per_page)) { + err = -EINVAL; + goto err_packets; + } + pages = DIV_ROUND_UP(count, packets_per_page); + + err = fw_iso_buffer_init(&b->iso_buffer, fw_parent_device(unit)->card, + pages, direction); + if (err < 0) + goto err_packets; + + for (i = 0; i < count; ++i) { + page_index = i / packets_per_page; + p = page_address(b->iso_buffer.pages[page_index]); + offset_in_page = (i % packets_per_page) * packet_size; + b->packets[i].buffer = p + offset_in_page; + b->packets[i].offset = page_index * PAGE_SIZE + offset_in_page; + } + + return 0; + +err_packets: + kfree(b->packets); +error: + return err; +} +EXPORT_SYMBOL(iso_packets_buffer_init); + +/** + * iso_packets_buffer_destroy - frees packet buffer resources + * @b: the buffer structure to free + * @unit: the device at the other end of the stream + */ +void iso_packets_buffer_destroy(struct iso_packets_buffer *b, + struct fw_unit *unit) +{ + fw_iso_buffer_destroy(&b->iso_buffer, fw_parent_device(unit)->card); + kfree(b->packets); +} +EXPORT_SYMBOL(iso_packets_buffer_destroy); -- cgit v1.3.1