linux/arch/arm64
Will Deacon 9c413e25d9 arm64: debug: clear mdscr_el1 instead of taking the OS lock
During boot, we take the debug OS lock before interrupts are enabled.
This is required to prevent clearing of PSTATE.D on the interrupt entry
path, which could result in spurious debug exceptions before we've got
round to resetting things like the hardware breakpoints registers to a
sane state.

A problem with this approach is that taking the OS lock prevents an
external JTAG debugger from debugging the system, which is especially
irritating during boot, where JTAG debugging can be most useful.

This patch clears mdscr_el1 rather than taking the lock, clearing the
MDE and KDE bits and preventing self-hosted hardware debug exceptions
from occurring.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: stable@vger.kernel.org
2013-05-13 11:44:56 +01:00
..
boot arm64: dts: fix #address-cells for foundation-v8 2013-05-08 10:23:01 +01:00
configs arm64: vexpress: Enable ARMv8 RTSM model (SoC) support 2013-04-26 14:44:05 +01:00
include Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-05-10 09:21:05 -07:00
kernel arm64: debug: clear mdscr_el1 instead of taking the OS lock 2013-05-13 11:44:56 +01:00
lib arm64: Treat the bitops index argument as an 'int' 2013-05-08 10:33:17 +01:00
mm arm64: debug: clear mdscr_el1 instead of taking the OS lock 2013-05-13 11:44:56 +01:00
Kconfig Removal of GENERIC_GPIO for v3.10 2013-05-09 09:59:16 -07:00
Kconfig.debug arm64: Kconfig.debug: Remove unused CONFIG_DEBUG_ERRORS 2013-03-19 16:19:19 +00:00
Makefile arm64: Fix the dtbs target building 2012-12-10 20:24:57 -06:00