Commit a050d20d authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman

powerpc/64s: Use relon prolog for EXC_VIRT_OOL_MASKABLE_HV handlers

Hypervisor Virtualization and Directed Hypervisor Doorbell interrupt handlers
use the macro EXC_VIRT_OOL_MASKABLE_HV for their relocation-on handlers, which
calls MASKABLE_RELON_EXCEPTION_HV_OOL, which uses the *real mode* interrupt
prolog. This means we needlessly rfid from virtual mode to virtual mode.

For POWER8 it only affects doorbell IPIs. Context switch microbenchmark between
threads with snooze disabled (which causes IPI) gets about 3% faster, about 370
cycles. Should be more important on POWER9 with global doorbells and HVI for
host interrupts.

Use the RELON variant instead to reduce overhead.

Fixes: 1707dd16 ("powerpc: Save CFAR before branching in interrupt entry paths")
Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
[mpe: Fold some more detail into the change log]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 686978b1
...@@ -522,7 +522,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943) ...@@ -522,7 +522,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
#define MASKABLE_RELON_EXCEPTION_HV_OOL(vec, label) \ #define MASKABLE_RELON_EXCEPTION_HV_OOL(vec, label) \
EXCEPTION_PROLOG_1(PACA_EXGEN, SOFTEN_TEST_HV, vec); \ EXCEPTION_PROLOG_1(PACA_EXGEN, SOFTEN_TEST_HV, vec); \
EXCEPTION_PROLOG_PSERIES_1(label, EXC_HV) EXCEPTION_RELON_PROLOG_PSERIES_1(label, EXC_HV)
/* /*
* Our exception common code can be passed various "additions" * Our exception common code can be passed various "additions"
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment