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. --- drivers/bcma/README | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 drivers/bcma/README (limited to 'drivers/bcma/README') diff --git a/drivers/bcma/README b/drivers/bcma/README new file mode 100644 index 000000000..f7e7ce46c --- /dev/null +++ b/drivers/bcma/README @@ -0,0 +1,19 @@ +Broadcom introduced new bus as replacement for older SSB. It is based on AMBA, +however from programming point of view there is nothing AMBA specific we use. + +Standard AMBA drivers are platform specific, have hardcoded addresses and use +AMBA standard fields like CID and PID. + +In case of Broadcom's cards every device consists of: +1) Broadcom specific AMBA device. It is put on AMBA bus, but can not be treated + as standard AMBA device. Reading it's CID or PID can cause machine lockup. +2) AMBA standard devices called ports or wrappers. They have CIDs (AMBA_CID) + and PIDs (0x103BB369), but we do not use that info for anything. One of that + devices is used for managing Broadcom specific core. + +Addresses of AMBA devices are not hardcoded in driver and have to be read from +EPROM. + +In this situation we decided to introduce separated bus. It can contain up to +16 devices identified by Broadcom specific fields: manufacturer, id, revision +and class. -- cgit v1.3.1