diff --git a/docs/cpu-specific-build-macros.rst b/docs/cpu-specific-build-macros.rst index 65e1c84..85e5642 100644 --- a/docs/cpu-specific-build-macros.rst +++ b/docs/cpu-specific-build-macros.rst @@ -108,6 +108,9 @@ - ``ERRATA_A55_798797``: This applies errata 798797 workaround to Cortex-A55 CPU. This needs to be enabled only for revision r0p0 of the CPU. +- ``ERRATA_A55_846532``: This applies errata 846532 workaround to Cortex-A55 + CPU. This needs to be enabled only for revision <= r0p1 of the CPU. + For Cortex-A57, the following errata build flags are defined : - ``ERRATA_A57_806969``: This applies errata 806969 workaround to Cortex-A57 diff --git a/lib/cpus/aarch64/cortex_a55.S b/lib/cpus/aarch64/cortex_a55.S index b0d5d4d..3099971 100644 --- a/lib/cpus/aarch64/cortex_a55.S +++ b/lib/cpus/aarch64/cortex_a55.S @@ -110,6 +110,38 @@ b cpu_rev_var_ls endfunc check_errata_798797 + /* -------------------------------------------------------------------- + * Errata Workaround for Cortex A55 Errata #846532. + * This applies only to revisions <= r0p1 of Cortex A55. + * Disabling dual-issue has a small impact on performance. Disabling a + * power optimization feature is an alternate workaround with no impact + * on performance but with an increase in power consumption (see errata + * notice). + * Inputs: + * x0: variant[4:7] and revision[0:3] of current cpu. + * Shall clobber: x0-x17 + * -------------------------------------------------------------------- + */ +func errata_a55_846532_wa + /* + * Compare x0 against revision r0p1 + */ + mov x17, x30 + bl check_errata_846532 + cbz x0, 1f + mrs x1, CORTEX_A55_CPUACTLR_EL1 + orr x1, x1, #CORTEX_A55_CPUACTLR_EL1_DISABLE_DUAL_ISSUE + msr CORTEX_A55_CPUACTLR_EL1, x1 + isb +1: + ret x17 +endfunc errata_a55_846532_wa + +func check_errata_846532 + mov x1, #0x01 + b cpu_rev_var_ls +endfunc check_errata_846532 + func cortex_a55_reset_func mov x19, x30 @@ -135,6 +167,11 @@ bl errata_a55_798797_wa #endif +#if ERRATA_A55_846532 + mov x0, x18 + bl errata_a55_846532_wa +#endif + ret x19 endfunc cortex_a55_reset_func @@ -171,6 +208,7 @@ report_errata ERRATA_A55_768277, cortex_a55, 768277 report_errata ERRATA_A55_778703, cortex_a55, 778703 report_errata ERRATA_A55_798797, cortex_a55, 798797 + report_errata ERRATA_A55_846532, cortex_a55, 846532 ldp x8, x30, [sp], #16 ret diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk index dc1540d..644c9cd 100644 --- a/lib/cpus/cpu-ops.mk +++ b/lib/cpus/cpu-ops.mk @@ -91,6 +91,10 @@ # only to revision r0p0 of the Cortex A55 cpu. ERRATA_A55_798797 ?=0 +# Flag to apply erratum 846532 workaround during reset. This erratum applies +# only to revision <= r0p1 of the Cortex A55 cpu. +ERRATA_A55_846532 ?=0 + # Flag to apply erratum 806969 workaround during reset. This erratum applies # only to revision r0p0 of the Cortex A57 cpu. ERRATA_A57_806969 ?=0 @@ -172,6 +176,10 @@ $(eval $(call assert_boolean,ERRATA_A55_798797)) $(eval $(call add_define,ERRATA_A55_798797)) +# Process ERRATA_A55_846532 flag +$(eval $(call assert_boolean,ERRATA_A55_846532)) +$(eval $(call add_define,ERRATA_A55_846532)) + # Process ERRATA_A57_806969 flag $(eval $(call assert_boolean,ERRATA_A57_806969)) $(eval $(call add_define,ERRATA_A57_806969))