From 98551591f5371de2c2f0dee6be2e12b75653f04d Mon Sep 17 00:00:00 2001 From: Louis Mayencourt Date: Mon, 25 Feb 2019 14:57:57 +0000 Subject: [PATCH] Add workaround for errata 790748 for Cortex-A75 Internal timing conditions might cause the CPU to stop processing interrupts. Set bit 13 of CPUACTLR_EL1 to prevent this. Change-Id: Ifdd19dbcdb71bb0d9609cab1315c478aaedb03ba Signed-off-by: Louis Mayencourt --- docs/cpu-specific-build-macros.rst | 3 +++ lib/cpus/aarch64/cortex_a75.S | 36 ++++++++++++++++++++++++++++++ lib/cpus/cpu-ops.mk | 8 +++++++ 3 files changed, 47 insertions(+) diff --git a/docs/cpu-specific-build-macros.rst b/docs/cpu-specific-build-macros.rst index dbb18569b..73ed38230 100644 --- a/docs/cpu-specific-build-macros.rst +++ b/docs/cpu-specific-build-macros.rst @@ -142,6 +142,9 @@ For Cortex-A75, the following errata build flags are defined : - ``ERRATA_A75_764081``: This applies errata 764081 workaround to Cortex-A75 CPU. This needs to be enabled only for revision r0p0 of the CPU. +- ``ERRATA_A75_790748``: This applies errata 790748 workaround to Cortex-A75 + CPU. This needs to be enabled only for revision r0p0 of the CPU. + DSU Errata Workarounds ---------------------- diff --git a/lib/cpus/aarch64/cortex_a75.S b/lib/cpus/aarch64/cortex_a75.S index 8d04294dc..204018890 100644 --- a/lib/cpus/aarch64/cortex_a75.S +++ b/lib/cpus/aarch64/cortex_a75.S @@ -38,6 +38,34 @@ func check_errata_764081 b cpu_rev_var_ls endfunc check_errata_764081 + /* -------------------------------------------------- + * Errata Workaround for Cortex A75 Errata #790748. + * This applies only to revision r0p0 of Cortex A75. + * Inputs: + * x0: variant[4:7] and revision[0:3] of current cpu. + * Shall clobber: x0-x17 + * -------------------------------------------------- + */ +func errata_a75_790748_wa + /* + * Compare x0 against revision r0p0 + */ + mov x17, x30 + bl check_errata_790748 + cbz x0, 1f + mrs x1, CORTEX_A75_CPUACTLR_EL1 + orr x1, x1 ,#(1 << 13) + msr CORTEX_A75_CPUACTLR_EL1, x1 + isb +1: + ret x17 +endfunc errata_a75_790748_wa + +func check_errata_790748 + mov x1, #0x00 + b cpu_rev_var_ls +endfunc check_errata_790748 + /* ------------------------------------------------- * The CPU Ops reset function for Cortex-A75. * ------------------------------------------------- @@ -45,11 +73,18 @@ endfunc check_errata_764081 func cortex_a75_reset_func mov x19, x30 bl cpu_get_rev_var + mov x18, x0 #if ERRATA_A75_764081 + mov x0, x18 bl errata_a75_764081_wa #endif +#if ERRATA_A75_790748 + mov x0, x18 + bl errata_a75_790748_wa +#endif + #if IMAGE_BL31 && WORKAROUND_CVE_2017_5715 cpu_check_csv2 x0, 1f adr x0, wa_cve_2017_5715_bpiall_vbar @@ -148,6 +183,7 @@ func cortex_a75_errata_report * checking functions of each errata. */ report_errata ERRATA_A75_764081, cortex_a75, 764081 + report_errata ERRATA_A75_790748, cortex_a75, 790748 report_errata WORKAROUND_CVE_2017_5715, cortex_a75, cve_2017_5715 report_errata WORKAROUND_CVE_2018_3639, cortex_a75, cve_2018_3639 report_errata ERRATA_DSU_936184, cortex_a75, dsu_936184 diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk index be7d3bde8..a7acd2f8b 100644 --- a/lib/cpus/cpu-ops.mk +++ b/lib/cpus/cpu-ops.mk @@ -127,6 +127,10 @@ ERRATA_A73_855423 ?=0 # only to revision <= r0p0 of the Cortex A75 cpu. ERRATA_A75_764081 ?=0 +# Flag to apply erratum 790748 workaround during reset. This erratum applies +# only to revision <= r0p0 of the Cortex A75 cpu. +ERRATA_A75_790748 ?=0 + # Flag to apply T32 CLREX workaround during reset. This erratum applies # only to r0p0 and r1p0 of the Neoverse N1 cpu. ERRATA_N1_1043202 ?=1 @@ -204,6 +208,10 @@ $(eval $(call add_define,ERRATA_A73_855423)) $(eval $(call assert_boolean,ERRATA_A75_764081)) $(eval $(call add_define,ERRATA_A75_764081)) +# Process ERRATA_A75_790748 flag +$(eval $(call assert_boolean,ERRATA_A75_790748)) +$(eval $(call add_define,ERRATA_A75_790748)) + # Process ERRATA_N1_1043202 flag $(eval $(call assert_boolean,ERRATA_N1_1043202)) $(eval $(call add_define,ERRATA_N1_1043202))