From ef5fa7d47741d008f8786f971fc138e6331fb46d Mon Sep 17 00:00:00 2001 From: lauwal01 Date: Mon, 24 Jun 2019 11:35:37 -0500 Subject: [PATCH] Workaround for Neoverse N1 erratum 1207823 Neoverse N1 erratum 1207823 is a Cat B erratum [1], present in older revisions of the Neoverse N1 processor core. The workaround is to set a bit in the implementation defined CPUACTLR2_EL1 system register. [1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.pjdoc-466751330-10325/index.html Change-Id: Ia932337821f1ef0d644db3612480462a8d924d21 Signed-off-by: Lauren Wehrmeister --- docs/design/cpu-specific-build-macros.rst | 3 +++ include/lib/cpus/aarch64/neoverse_n1.h | 1 + lib/cpus/aarch64/neoverse_n1.S | 33 +++++++++++++++++++++++ lib/cpus/cpu-ops.mk | 8 ++++++ 4 files changed, 45 insertions(+) diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst index fd99d8e90..ef24f2e39 100644 --- a/docs/design/cpu-specific-build-macros.rst +++ b/docs/design/cpu-specific-build-macros.rst @@ -237,6 +237,9 @@ For Neoverse N1, the following errata build flags are defined : - ``ERRATA_N1_1165347``: This applies errata 1165347 workaround to Neoverse-N1 CPU. This needs to be enabled only for revision <= r2p0 of the CPU. +- ``ERRATA_N1_1207823``: This applies errata 1207823 workaround to Neoverse-N1 + CPU. This needs to be enabled only for revision <= r2p0 of the CPU. + - ``ERRATA_N1_1315703``: This applies errata 1315703 workaround to Neoverse-N1 CPU. This needs to be enabled only for revision <= r3p0 of the CPU. diff --git a/include/lib/cpus/aarch64/neoverse_n1.h b/include/lib/cpus/aarch64/neoverse_n1.h index 7950cd220..8925827e9 100644 --- a/include/lib/cpus/aarch64/neoverse_n1.h +++ b/include/lib/cpus/aarch64/neoverse_n1.h @@ -41,6 +41,7 @@ #define NEOVERSE_N1_CPUACTLR2_EL1_BIT_0 (ULL(1) << 0) #define NEOVERSE_N1_CPUACTLR2_EL1_BIT_2 (ULL(1) << 2) +#define NEOVERSE_N1_CPUACTLR2_EL1_BIT_11 (ULL(1) << 11) #define NEOVERSE_N1_CPUACTLR2_EL1_BIT_15 (ULL(1) << 15) #define NEOVERSE_N1_CPUACTLR2_EL1_BIT_16 (ULL(1) << 16) #define NEOVERSE_N1_CPUACTLR2_EL1_BIT_59 (ULL(1) << 59) diff --git a/lib/cpus/aarch64/neoverse_n1.S b/lib/cpus/aarch64/neoverse_n1.S index a8ffa2546..c9bcea898 100644 --- a/lib/cpus/aarch64/neoverse_n1.S +++ b/lib/cpus/aarch64/neoverse_n1.S @@ -157,6 +157,33 @@ func check_errata_1165347 b cpu_rev_var_ls endfunc check_errata_1165347 +/* -------------------------------------------------- + * Errata Workaround for Neoverse N1 Errata #1207823 + * This applies to revision <=r2p0 of Neoverse N1. + * Inputs: + * x0: variant[4:7] and revision[0:3] of current cpu. + * Shall clobber: x0-x17 + * -------------------------------------------------- + */ +func errata_n1_1207823_wa + /* Compare x0 against revision r2p0 */ + mov x17, x30 + bl check_errata_1207823 + cbz x0, 1f + mrs x1, NEOVERSE_N1_CPUACTLR2_EL1 + orr x1, x1, NEOVERSE_N1_CPUACTLR2_EL1_BIT_11 + msr NEOVERSE_N1_CPUACTLR2_EL1, x1 + isb +1: + ret x17 +endfunc errata_n1_1207823_wa + +func check_errata_1207823 + /* Applies to <=r2p0 */ + mov x1, #0x20 + b cpu_rev_var_ls +endfunc check_errata_1207823 + /* -------------------------------------------------- * Errata Workaround for Neoverse N1 Erratum 1315703. * This applies to revision <= r3p0 of Neoverse N1. @@ -220,6 +247,11 @@ func neoverse_n1_reset_func bl errata_n1_1165347_wa #endif +#if ERRATA_N1_1207823 + mov x0, x18 + bl errata_n1_1207823_wa +#endif + #if ERRATA_N1_1315703 mov x0, x18 bl errata_n1_1315703_wa @@ -285,6 +317,7 @@ func neoverse_n1_errata_report report_errata ERRATA_N1_1073348, neoverse_n1, 1073348 report_errata ERRATA_N1_1130799, neoverse_n1, 1130799 report_errata ERRATA_N1_1165347, neoverse_n1, 1165347 + report_errata ERRATA_N1_1207823, neoverse_n1, 1207823 report_errata ERRATA_N1_1315703, neoverse_n1, 1315703 report_errata ERRATA_DSU_936184, neoverse_n1, dsu_936184 diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk index faaf1203b..78efbeb3c 100644 --- a/lib/cpus/cpu-ops.mk +++ b/lib/cpus/cpu-ops.mk @@ -250,6 +250,10 @@ ERRATA_N1_1130799 ?=0 # only to revision <= r2p0 of the Neoverse N1 cpu. ERRATA_N1_1165347 ?=0 +# Flag to apply erratum 1207823 workaround during reset. This erratum applies +# only to revision <= r2p0 of the Neoverse N1 cpu. +ERRATA_N1_1207823 ?=0 + # Flag to apply erratum 1315703 workaround during reset. This erratum applies # to revisions before r3p1 of the Neoverse N1 cpu. ERRATA_N1_1315703 ?=1 @@ -455,6 +459,10 @@ $(eval $(call add_define,ERRATA_N1_1130799)) $(eval $(call assert_boolean,ERRATA_N1_1165347)) $(eval $(call add_define,ERRATA_N1_1165347)) +# Process ERRATA_N1_1207823 flag +$(eval $(call assert_boolean,ERRATA_N1_1207823)) +$(eval $(call add_define,ERRATA_N1_1207823)) + # Process ERRATA_N1_1315703 flag $(eval $(call assert_boolean,ERRATA_N1_1315703)) $(eval $(call add_define,ERRATA_N1_1315703))