arm64: debug: remove debug exception registration infrastructure
authorAda Couprie Diaz <ada.coupriediaz@arm.com>
Mon, 7 Jul 2025 11:41:09 +0000 (12:41 +0100)
committerWill Deacon <will@kernel.org>
Tue, 8 Jul 2025 12:27:42 +0000 (13:27 +0100)
commita8b8cce9d96d65dfe3d89abf02033151f8b7d670
tree9fedbcfcffdd668040aec442ba2b89344e267641
parentfc5e5d0477c532054ce8692fd16fdaab2cb8946f
arm64: debug: remove debug exception registration infrastructure

Now that debug exceptions are handled individually and without the need
for dynamic registration, remove the unused registration infrastructure.

This removes the external caller for `debug_exception_enter()` and
`debug_exception_exit()`.
Make them static again and remove them from the header.

Remove `early_brk64()` as it has been made redundant by
(arm64: debug: split brk64 exception entry) and is not used anymore.
Note : in `early_brk64()` `bug_brk_handler()` is called unconditionally
as a fall-through, but now `call_break_hook()` only calls it if the
immediate matches.
This does not change the behaviour in early boot, as if
`bug_brk_handler()` was called on a non-BUG immediate it would return
DBG_HOOK_ERROR anyway, which `call_break_hook()` will do if no immediate
matches.

Remove `trap_init()`, as it would be empty and a weak definition already
exists in `init/main.c`.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-14-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
arch/arm64/include/asm/debug-monitors.h
arch/arm64/include/asm/exception.h
arch/arm64/include/asm/system_misc.h
arch/arm64/kernel/debug-monitors.c
arch/arm64/kernel/entry-common.c
arch/arm64/kernel/traps.c
arch/arm64/mm/fault.c