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| author | Max Filippov <jcmvbkbc@gmail.com> | 2022-04-15 13:05:31 +0300 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2022-05-02 05:51:23 +0300 |
| commit | 11e969bc964a0e50ae64cdba092048e3937d2389 (patch) | |
| tree | 99303eb470e622faf5397649005d6f221f46bdb0 /arch/xtensa/kernel/entry.S | |
| parent | f29cab2906346fa93831376256e01f5a6629f979 (diff) | |
| download | linux-11e969bc964a0e50ae64cdba092048e3937d2389.tar.xz | |
xtensa: support coprocessors on SMP
Current coprocessor support on xtensa only works correctly on
uniprocessor configurations. Make it work on SMP too and keep it lazy.
Make coprocessor_owner array per-CPU and move it to struct exc_table for
easy access from the fast_coprocessor exception handler. Allow task to
have live coprocessors only on single CPU, record this CPU number in the
struct thread_info::cp_owner_cpu. Change struct thread_info::cpenable
meaning to be 'coprocessors live on cp_owner_cpu'.
Introduce C-level coprocessor exception handler that flushes and
releases live coprocessors of the task taking 'coprocessor disabled'
exception and call it from the fast_coprocessor handler when the task
has live coprocessors on other CPU.
Make coprocessor_flush_all and coprocessor_release_all work correctly
when called from any CPU by sending IPI to the cp_owner_cpu. Add
function coprocessor_flush_release_all to do flush followed by release
atomically. Add function local_coprocessors_flush_release_all to flush
and release all coprocessors on the local CPU and use it to flush
coprocessor contexts from the CPU that goes offline.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa/kernel/entry.S')
| -rw-r--r-- | arch/xtensa/kernel/entry.S | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index f2c789a5a92a..3255d4f61844 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -2071,8 +2071,16 @@ ENTRY(_switch_to) #if (XTENSA_HAVE_COPROCESSORS || XTENSA_HAVE_IO_PORTS) l32i a3, a5, THREAD_CPENABLE - xsr a3, cpenable - s32i a3, a4, THREAD_CPENABLE +#ifdef CONFIG_SMP + beqz a3, 1f + memw # pairs with memw (2) in fast_coprocessor + l32i a6, a5, THREAD_CP_OWNER_CPU + l32i a7, a5, THREAD_CPU + beq a6, a7, 1f # load 0 into CPENABLE if current CPU is not the owner + movi a3, 0 +1: +#endif + wsr a3, cpenable #endif #if XCHAL_HAVE_EXCLUSIVE |