From 9380f754181a56abe20c3c4e9152b3604ae30c65 Mon Sep 17 00:00:00 2001 From: nayanpatel-arm Date: Fri, 6 Aug 2021 17:46:10 -0700 Subject: [PATCH] errata: workaround for Neoverse-N2 errata 2002655 Neoverse-N2 erratum 2002655 is a Cat B erratum present in r0p0 of the Neoverse-N2 processor core, and it is still open. Neoverse-N2 SDEN: https://documentation-service.arm.com/static/61098b4e3d73a34b640e32c9?token= Signed-off-by: nayanpatel-arm Change-Id: I1380418146807527abd97cdd4918265949ba5c01 --- docs/design/cpu-specific-build-macros.rst | 5 ++ lib/cpus/aarch64/neoverse_n2.S | 67 ++++++++++++++++++++++- lib/cpus/cpu-ops.mk | 8 +++ 3 files changed, 78 insertions(+), 2 deletions(-) diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst index 2dfaf7865..b2b751fbb 100644 --- a/docs/design/cpu-specific-build-macros.rst +++ b/docs/design/cpu-specific-build-macros.rst @@ -333,6 +333,11 @@ For Neoverse N1, the following errata build flags are defined : CPU. This needs to be enabled for revisions r3p0, r3p1, r4p0, and r4p1, for revisions r0p0, r1p0, and r2p0 there is no workaround. +For Neoverse N2, the following errata build flags are defined : + +- ``ERRATA_N2_2002655``: This applies errata 2002655 workaround to Neoverse-N2 + CPU. This needs to be enabled for revision r0p0 of the CPU, it is still open. + For Neoverse V1, the following errata build flags are defined : - ``ERRATA_V1_1774420``: This applies errata 1774420 workaround to Neoverse-V1 diff --git a/lib/cpus/aarch64/neoverse_n2.S b/lib/cpus/aarch64/neoverse_n2.S index 8d646cba5..44db0b3a3 100644 --- a/lib/cpus/aarch64/neoverse_n2.S +++ b/lib/cpus/aarch64/neoverse_n2.S @@ -19,11 +19,55 @@ #error "Neoverse-N2 supports only AArch64. Compile with CTX_INCLUDE_AARCH32_REGS=0" #endif +/* -------------------------------------------------- + * Errata Workaround for Neoverse N2 Erratum 2002655. + * This applies to revision r0p0 of Neoverse N2. it is still open. + * Inputs: + * x0: variant[4:7] and revision[0:3] of current cpu. + * Shall clobber: x0-x17 + * -------------------------------------------------- + */ +func errata_n2_2002655_wa + /* Check revision. */ + mov x17, x30 + bl check_errata_2002655 + cbz x0, 1f + + /* Apply instruction patching sequence */ + ldr x0,=0x6 + msr S3_6_c15_c8_0,x0 + ldr x0,=0xF3A08002 + msr S3_6_c15_c8_2,x0 + ldr x0,=0xFFF0F7FE + msr S3_6_c15_c8_3,x0 + ldr x0,=0x40000001003ff + msr S3_6_c15_c8_1,x0 + ldr x0,=0x7 + msr S3_6_c15_c8_0,x0 + ldr x0,=0xBF200000 + msr S3_6_c15_c8_2,x0 + ldr x0,=0xFFEF0000 + msr S3_6_c15_c8_3,x0 + ldr x0,=0x40000001003f3 + msr S3_6_c15_c8_1,x0 + isb +1: + ret x17 +endfunc errata_n2_2002655_wa + +func check_errata_2002655 + /* Applies to r0p0 */ + mov x1, #0x00 + b cpu_rev_var_ls +endfunc check_errata_2002655 + /* ------------------------------------------------- * The CPU Ops reset function for Neoverse N2. * ------------------------------------------------- */ func neoverse_n2_reset_func + mov x19, x30 + /* Check if the PE implements SSBS */ mrs x0, id_aa64pfr1_el1 tst x0, #(ID_AA64PFR1_EL1_SSBS_MASK << ID_AA64PFR1_EL1_SSBS_SHIFT) @@ -58,8 +102,16 @@ func neoverse_n2_reset_func msr NEOVERSE_N2_CPUECTLR_EL1, x0 #endif + bl cpu_get_rev_var + mov x18, x0 + +#if ERRATA_N2_2002655 + mov x0, x18 + bl errata_n2_2002655_wa +#endif + isb - ret + ret x19 endfunc neoverse_n2_reset_func func neoverse_n2_core_pwr_dwn @@ -80,7 +132,18 @@ endfunc neoverse_n2_core_pwr_dwn * Errata printing function for Neoverse N2 cores. Must follow AAPCS. */ func neoverse_n2_errata_report - /* No errata reported for Neoverse N2 cores */ + stp x8, x30, [sp, #-16]! + + bl cpu_get_rev_var + mov x8, x0 + + /* + * Report all errata. The revision-variant information is passed to + * checking functions of each errata. + */ + report_errata ERRATA_N2_2002655, neoverse_n2, 2002655 + + ldp x8, x30, [sp], #16 ret endfunc neoverse_n2_errata_report #endif diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk index e81471ec3..a46d3b6d0 100644 --- a/lib/cpus/cpu-ops.mk +++ b/lib/cpus/cpu-ops.mk @@ -380,6 +380,10 @@ ERRATA_N1_1868343 ?=0 # exists in revisions r0p0, r1p0, and r2p0 as well but there is no workaround. ERRATA_N1_1946160 ?=0 +# Flag to apply erratum 2002655 workaround during reset. This erratum applies +# to revisions r0p0 of the Neoverse-N2 cpu, it is still open. +ERRATA_N2_2002655 ?=0 + # Flag to apply erratum 1774420 workaround during reset. This erratum applies # to revisions r0p0 and r1p0 of the Neoverse V1 core, and was fixed in r1p1. ERRATA_V1_1774420 ?=0 @@ -722,6 +726,10 @@ $(eval $(call add_define,ERRATA_N1_1868343)) $(eval $(call assert_boolean,ERRATA_N1_1946160)) $(eval $(call add_define,ERRATA_N1_1946160)) +# Process ERRATA_N2_2002655 flag +$(eval $(call assert_boolean,ERRATA_N2_2002655)) +$(eval $(call add_define,ERRATA_N2_2002655)) + # Process ERRATA_V1_1774420 flag $(eval $(call assert_boolean,ERRATA_V1_1774420)) $(eval $(call add_define,ERRATA_V1_1774420))