This patch reworks the arm64 exception handling to be more similar to
how it works on arm32. This includes a bunch of features like actually
saving and restoring more exception state in the exception_state
structure and supporting the same sort of partial reentrancy that is
useful for GDB. Since there's no instruction to directly load into or
store out of SP on arm64, we can't do quite the same thing where we use
that to read an exception_state_ptr variable right after exception entry
when no other register is available. But we can do something very
similar by (ab-)using the "high" stack pointer (SP_EL2) as a pointer to
the exception_state struct and providing a function to change it.
Change-Id: Ia16a1124be1824392a309ae1f4cb031547d184c1
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/29018
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
This patch adds the new, faster architectural register accessors to
libpayload that were already added to coreboot in CB:27881. It also
hardcodes the assumption that coreboot payloads run at EL2, which has
already been hardcoded in coreboot with CB:27880 (see rationale there).
This means we can drop all the read_current/write_current stuff which
added a lot of unnecessary helpers to check the current exception level.
This patch breaks payloads that used read_current/write_current
accessors, but it seems unlikely that many payloads deal with this stuff
anyway, and it should be a trivial fix (just replace them with the
respective _el2 versions).
Also add accessors for a couple of more registers that are required to
enable debug mode while I'm here.
Change-Id: Ic9dfa48411f3805747613f03611f8a134a51cc46
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/29017
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Allow more flexibility by reading and writing to system registers at current
EL. Instead of specifying what _ELx register to write to, code can specify
_current.
BUG=chrome-os-partner:31634
BRANCH=None
TEST=Compiles and boots to kernel on ryu
Change-Id: Id38b675bfe67ca1e25f8c268192114e3f0bee800
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 6d4d07e26fc964dc3aaebfe03db59596d90093e9
Original-Change-Id: Ic1d9e18e6fc016a04f17621a148e62d6cbd04ce7
Original-Signed-off-by: Furquan Shaikh <furquan@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/214577
Original-Tested-by: Furquan Shaikh <furquan@chromium.org>
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: http://review.coreboot.org/8785
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Julius Werner