errata: workaround for Neoverse N2 erratum 2189731

Neoverse N2 erratum 2189731 is a Cat B erratum that applies to
revision r0p0 and is still open. The workaround is to set
CPUACTLR5_EL1[44] to 1 which will cause the CPP instruction to
invalidate the hardware prefetcher state trained from any EL.

SDEN can be found here:
https://developer.arm.com/documentation/SDEN1982442/latest

Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Change-Id: Iddc6a59adf9fa3cab560c46f2133e1f5a8b3ad03
This commit is contained in:
Bipin Ravi 2021-08-30 13:02:51 -05:00
parent afc2ed63f9
commit 7cfae93227
4 changed files with 51 additions and 1 deletions

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@ -386,7 +386,6 @@ For Cortex-A710, the following errata build flags are defined :
Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
of the CPU and is still open.
For Neoverse N2, the following errata build flags are defined :
- ``ERRATA_N2_2067956``: This applies errata 2067956 workaround to Neoverse-N2
@ -395,6 +394,10 @@ For Neoverse N2, the following errata build flags are defined :
- ``ERRATA_N2_2025414``: This applies errata 2025414 workaround to Neoverse-N2
CPU. This needs to be enabled for revision r0p0 of the CPU and is still open.
- ``ERRATA_N2_2189731``: This applies errata 2189731 workaround to Neoverse-N2
CPU. This needs to be enabled only for revision r0p0 of the CPU and is still
open.
DSU Errata Workarounds
----------------------

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@ -35,4 +35,10 @@
#define NEOVERSE_N2_CPUACTLR2_EL1 S3_0_C15_C1_1
#define NEOVERSE_N2_CPUACTLR2_EL1_BIT_2 (ULL(1) << 2)
/*******************************************************************************
* CPU Auxiliary Control register 5 specific definitions.
******************************************************************************/
#define NEOVERSE_N2_CPUACTLR5_EL1 S3_0_C15_C8_0
#define NEOVERSE_N2_CPUACTLR5_EL1_BIT_44 (ULL(1) << 44)
#endif /* NEOVERSE_N2_H */

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@ -114,6 +114,33 @@ func check_errata_2025414
b cpu_rev_var_ls
endfunc check_errata_2025414
/* ---------------------------------------------------------------
* Errata Workaround for Neoverse N2 Erratum 2189731.
* This applies to revision r0p0 of Neoverse N2 and is still open.
* Inputs:
* x0: variant[4:7] and revision[0:3] of current cpu.
* Shall clobber: x0-x17
* ---------------------------------------------------------------
*/
func errata_n2_2189731_wa
/* Compare x0 against revision r0p0 */
mov x17, x30
bl check_errata_2189731
cbz x0, 1f
mrs x1, NEOVERSE_N2_CPUACTLR5_EL1
orr x1, x1, NEOVERSE_N2_CPUACTLR5_EL1_BIT_44
msr NEOVERSE_N2_CPUACTLR5_EL1, x1
1:
ret x17
endfunc errata_n2_2189731_wa
func check_errata_2189731
/* Applies to r0p0 */
mov x1, #0x00
b cpu_rev_var_ls
endfunc check_errata_2189731
/* -------------------------------------------
* The CPU Ops reset function for Neoverse N2.
* -------------------------------------------
@ -144,6 +171,11 @@ func neoverse_n2_reset_func
bl errata_n2_2025414_wa
#endif
#if ERRATA_N2_2189731
mov x0, x18
bl errata_n2_2189731_wa
#endif
#if ENABLE_AMU
/* Make sure accesses from EL0/EL1 and EL2 are not trapped to EL3 */
mrs x0, cptr_el3
@ -207,6 +239,7 @@ func neoverse_n2_errata_report
report_errata ERRATA_N2_2002655, neoverse_n2, 2002655
report_errata ERRATA_N2_2067956, neoverse_n2, 2067956
report_errata ERRATA_N2_2025414, neoverse_n2, 2025414
report_errata ERRATA_N2_2189731, neoverse_n2, 2189731
ldp x8, x30, [sp], #16
ret

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@ -429,6 +429,10 @@ ERRATA_N2_2067956 ?=0
# to revision r0p0 of the Neoverse N2 cpu and is still open.
ERRATA_N2_2025414 ?=0
# Flag to apply erratum 2189731 workaround during reset. This erratum applies
# to revision r0p0 of the Neoverse N2 cpu and is still open.
ERRATA_N2_2189731 ?=0
# Flag to apply erratum 2055002 workaround during reset. This erratum applies
# to revision r1p0, r2p0 of the Cortex-A710 cpu and is still open.
ERRATA_A710_2055002 ?=0
@ -798,6 +802,10 @@ $(eval $(call add_define,ERRATA_N2_2067956))
$(eval $(call assert_boolean,ERRATA_N2_2025414))
$(eval $(call add_define,ERRATA_N2_2025414))
# Process ERRATA_N2_2189731 flag
$(eval $(call assert_boolean,ERRATA_N2_2189731))
$(eval $(call add_define,ERRATA_N2_2189731))
# Process ERRATA_A710_2055002 flag
$(eval $(call assert_boolean,ERRATA_A710_2055002))
$(eval $(call add_define,ERRATA_A710_2055002))