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| author | Soby Mathew <soby.mathew@arm.com> | 2019-09-25 14:03:41 +0100 |
|---|---|---|
| committer | Olivier Deprez <olivier.deprez@arm.com> | 2019-10-04 10:19:35 +0200 |
| commit | c97cba4ea44910df1f7b1af5dba79013fb44c383 (patch) | |
| tree | 9d2965a2b9610413dea548a95e2f5094fc84b6e8 /Makefile | |
| parent | ace23683beb81354d6edbc61c087ab8c384d0631 (diff) | |
Fix the CAS spinlock implementation
Make the spinlock implementation use ARMv8.1-LSE CAS instruction based
on a platform build option. The CAS-based implementation used to be
unconditionally selected for all ARM8.1+ platforms.
The previous CAS spinlock implementation had a bug wherein the spin_unlock()
implementation had an `sev` after `stlr` which is not sufficient. A dsb is
needed to ensure that the stlr completes prior to the sev. Having a dsb is
heavyweight and a better solution would be to use load exclusive semantics
to monitor the lock and wake up from wfe when a store happens to the lock.
The patch implements the same.
Change-Id: I5283ce4a889376e4cc01d1b9d09afa8229a2e522
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Diffstat (limited to 'Makefile')
| -rw-r--r-- | Makefile | 11 |
1 files changed, 11 insertions, 0 deletions
@@ -141,6 +141,15 @@ else $(error Unknown BRANCH_PROTECTION value ${BRANCH_PROTECTION}) endif +# USE_SPINLOCK_CAS requires AArch64 build +ifeq (${USE_SPINLOCK_CAS},1) +ifneq (${ARCH},aarch64) + $(error USE_SPINLOCK_CAS requires AArch64) +else + $(info USE_SPINLOCK_CAS is an experimental feature) +endif +endif + ################################################################################ # Toolchain ################################################################################ @@ -690,6 +699,7 @@ $(eval $(call assert_boolean,WARMBOOT_ENABLE_DCACHE_EARLY)) $(eval $(call assert_boolean,BL2_AT_EL3)) $(eval $(call assert_boolean,BL2_IN_XIP_MEM)) $(eval $(call assert_boolean,BL2_INV_DCACHE)) +$(eval $(call assert_boolean,USE_SPINLOCK_CAS)) $(eval $(call assert_numeric,ARM_ARCH_MAJOR)) $(eval $(call assert_numeric,ARM_ARCH_MINOR)) @@ -755,6 +765,7 @@ $(eval $(call add_define,WARMBOOT_ENABLE_DCACHE_EARLY)) $(eval $(call add_define,BL2_AT_EL3)) $(eval $(call add_define,BL2_IN_XIP_MEM)) $(eval $(call add_define,BL2_INV_DCACHE)) +$(eval $(call add_define,USE_SPINLOCK_CAS)) ifeq (${SANITIZE_UB},trap) $(eval $(call add_define,MONITOR_TRAPS)) |