powerpc/64s/exception: machine check improve labels and comments

Short forward and backward branches can be given number labels,
but larger significant divergences in code path a more readable
if they're given descriptive names.

Also adjusts a comment to account for guest delivery.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190802105709.27696-17-npiggin@gmail.com
This commit is contained in:
Nicholas Piggin 2019-08-02 20:56:41 +10:00 committed by Michael Ellerman
parent fce16d4822
commit b3fe35261e

View file

@ -1052,7 +1052,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
*/
lbz r11,HSTATE_IN_GUEST(r13)
cmpwi r11,0 /* Check if coming from guest */
bne 9f /* continue if we are. */
bne mce_deliver /* continue if we are. */
#endif
/*
@ -1060,7 +1060,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
* exception handler which will deliver the MC event to this kernel.
*/
andi. r11,r12,MSR_PR /* See if coming from user. */
bne 9f /* continue in V mode if we are. */
bne mce_deliver /* continue in V mode if we are. */
/*
* At this point we are coming from kernel context.
@ -1088,8 +1088,14 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
MACHINE_CHECK_HANDLER_WINDUP
RFI_TO_KERNEL
9:
/* Deliver the machine check to host kernel in V mode. */
mce_deliver:
/*
* This is a host user or guest MCE. Restore all registers, then
* run the "late" handler. For host user, this will run the
* machine_check_exception handler in virtual mode like a normal
* interrupt handler. For guest, this will trigger the KVM test
* and branch to the KVM interrupt similarly to other interrupts.
*/
BEGIN_FTR_SECTION
ld r10,ORIG_GPR3(r1)
mtspr SPRN_CFAR,r10