arm-trusted-firmware/lib/cpus/aarch64/cortex_x3.S
Boyan Karatotev 89dba82dfa perf(cpus): make reset errata do fewer branches
Errata application is painful for performance. For a start, it's done
when the core has just come out of reset, which means branch predictors
and caches will be empty so a branch to a workaround function must be
fetched from memory and that round trip is very slow. Then it also runs
with the I-cache off, which means that the loop to iterate over the
workarounds must also be fetched from memory on each iteration.

We can remove both branches. First, we can simply apply every erratum
directly instead of defining a workaround function and jumping to it.
Currently, no errata that need to be applied at both reset and runtime,
with the same workaround function, exist. If the need arose in future,
this should be achievable with a reset + runtime wrapper combo.

Then, we can construct a function that applies each erratum linearly
instead of looping over the list. If this function is part of the reset
function, then the only "far" branches at reset will be for the checker
functions. Importantly, this mitigates the slowdown even when an erratum
is disabled.

The result is ~50% speedup on N1SDP and ~20% on AArch64 Juno on wakeup
from PSCI calls that end in powerdown. This is roughly back to the
baseline of v2.9, before the errata framework regressed on performance
(or a little better). It is important to note that there are other
slowdowns since then that remain unknown.

Change-Id: Ie4d5288a331b11fd648e5c4a0b652b74160b07b9
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
2025-02-24 09:36:11 +00:00

182 lines
6.4 KiB
ArmAsm

/*
* Copyright (c) 2021-2025, Arm Limited. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch.h>
#include <asm_macros.S>
#include <common/bl_common.h>
#include <cortex_x3.h>
#include <cpu_macros.S>
#include <plat_macros.S>
#include "wa_cve_2022_23960_bhb_vector.S"
/* Hardware handled coherency */
#if HW_ASSISTED_COHERENCY == 0
#error "Cortex-X3 must be compiled with HW_ASSISTED_COHERENCY enabled"
#endif
/* 64-bit only core */
#if CTX_INCLUDE_AARCH32_REGS == 1
#error "Cortex-X3 supports only AArch64. Compile with CTX_INCLUDE_AARCH32_REGS=0"
#endif
.global check_erratum_cortex_x3_3701769
add_erratum_entry cortex_x3, ERRATUM(3701769), ERRATA_X3_3701769
check_erratum_ls cortex_x3, ERRATUM(3701769), CPU_REV(1, 2)
#if WORKAROUND_CVE_2022_23960
wa_cve_2022_23960_bhb_vector_table CORTEX_X3_BHB_LOOP_COUNT, cortex_x3
#endif /* WORKAROUND_CVE_2022_23960 */
cpu_reset_prologue cortex_x3
/* Disable hardware page aggregation. Enables mitigation for `CVE-2024-5660` */
workaround_reset_start cortex_x3, CVE(2024, 5660), WORKAROUND_CVE_2024_5660
sysreg_bit_set CORTEX_X3_CPUECTLR_EL1, BIT(46)
workaround_reset_end cortex_x3, CVE(2024, 5660)
check_erratum_ls cortex_x3, CVE(2024, 5660), CPU_REV(1, 2)
workaround_reset_start cortex_x3, ERRATUM(2070301), ERRATA_X3_2070301
sysreg_bitfield_insert CORTEX_X3_CPUECTLR2_EL1, CORTEX_X3_CPUECTLR2_EL1_PF_MODE_CNSRV, \
CORTEX_X3_CPUECTLR2_EL1_PF_MODE_LSB, CORTEX_X3_CPUECTLR2_EL1_PF_MODE_WIDTH
workaround_reset_end cortex_x3, ERRATUM(2070301)
check_erratum_ls cortex_x3, ERRATUM(2070301), CPU_REV(1, 2)
workaround_reset_start cortex_x3, ERRATUM(2266875), ERRATA_X3_2266875
sysreg_bit_set CORTEX_X3_CPUACTLR_EL1, BIT(22)
workaround_reset_end cortex_x3, ERRATUM(2266875)
check_erratum_ls cortex_x3, ERRATUM(2266875), CPU_REV(1, 0)
workaround_reset_start cortex_x3, ERRATUM(2302506), ERRATA_X3_2302506
sysreg_bit_set CORTEX_X3_CPUACTLR2_EL1, BIT(0)
workaround_reset_end cortex_x3, ERRATUM(2302506)
check_erratum_ls cortex_x3, ERRATUM(2302506), CPU_REV(1, 1)
.global erratum_cortex_x3_2313909_wa
workaround_runtime_start cortex_x3, ERRATUM(2313909), ERRATA_X3_2313909
/* Set/unset bit 36 in ACTLR2_EL1. The first call will set it, applying
* the workaround. Second call clears it to undo it. */
sysreg_bit_toggle CORTEX_X3_CPUACTLR2_EL1, CORTEX_X3_CPUACTLR2_EL1_BIT_36
workaround_runtime_end cortex_x3, ERRATUM(2313909), NO_ISB
check_erratum_ls cortex_x3, ERRATUM(2313909), CPU_REV(1, 0)
workaround_reset_start cortex_x3, ERRATUM(2372204), ERRATA_X3_2372204
/* Set bit 40 in CPUACTLR2_EL1 */
sysreg_bit_set CORTEX_X3_CPUACTLR2_EL1, BIT(40)
workaround_reset_end cortex_x3, ERRATUM(2372204)
check_erratum_ls cortex_x3, ERRATUM(2372204), CPU_REV(1, 0)
workaround_reset_start cortex_x3, ERRATUM(2615812), ERRATA_X3_2615812
/* Disable retention control for WFI and WFE. */
mrs x0, CORTEX_X3_CPUPWRCTLR_EL1
bfi x0, xzr, #CORTEX_X3_CPUPWRCTLR_EL1_WFI_RET_CTRL_BITS_SHIFT, #3
bfi x0, xzr, #CORTEX_X3_CPUPWRCTLR_EL1_WFE_RET_CTRL_BITS_SHIFT, #3
msr CORTEX_X3_CPUPWRCTLR_EL1, x0
workaround_reset_end cortex_x3, ERRATUM(2615812)
check_erratum_ls cortex_x3, ERRATUM(2615812), CPU_REV(1, 1)
workaround_reset_start cortex_x3, ERRATUM(2641945), ERRATA_X3_2641945
sysreg_bit_set CORTEX_X3_CPUACTLR6_EL1, BIT(41)
workaround_reset_end cortex_x3, ERRATUM(2641945)
check_erratum_ls cortex_x3, ERRATUM(2641945), CPU_REV(1, 0)
workaround_reset_start cortex_x3, ERRATUM(2742421), ERRATA_X3_2742421
/* Set CPUACTLR5_EL1[56:55] to 2'b01 */
sysreg_bit_set CORTEX_X3_CPUACTLR5_EL1, CORTEX_X3_CPUACTLR5_EL1_BIT_55
sysreg_bit_clear CORTEX_X3_CPUACTLR5_EL1, CORTEX_X3_CPUACTLR5_EL1_BIT_56
workaround_reset_end cortex_x3, ERRATUM(2742421)
check_erratum_ls cortex_x3, ERRATUM(2742421), CPU_REV(1, 1)
workaround_runtime_start cortex_x3, ERRATUM(2743088), ERRATA_X3_2743088
/* dsb before isb of power down sequence */
dsb sy
workaround_runtime_end cortex_x3, ERRATUM(2743088), NO_ISB
check_erratum_ls cortex_x3, ERRATUM(2743088), CPU_REV(1, 1)
workaround_reset_start cortex_x3, ERRATUM(2779509), ERRATA_X3_2779509
/* Set CPUACTLR3_EL1 bit 47 */
sysreg_bit_set CORTEX_X3_CPUACTLR3_EL1, CORTEX_X3_CPUACTLR3_EL1_BIT_47
workaround_reset_end cortex_x3, ERRATUM(2779509)
check_erratum_ls cortex_x3, ERRATUM(2779509), CPU_REV(1, 1)
workaround_reset_start cortex_x3, CVE(2022, 23960), WORKAROUND_CVE_2022_23960
#if IMAGE_BL31
override_vector_table wa_cve_vbar_cortex_x3
#endif /* IMAGE_BL31 */
workaround_reset_end cortex_x3, CVE(2022, 23960)
check_erratum_chosen cortex_x3, CVE(2022, 23960), WORKAROUND_CVE_2022_23960
workaround_reset_start cortex_x3, CVE(2024, 7881), WORKAROUND_CVE_2024_7881
/* ---------------------------------
* Sets BIT41 of CPUACTLR6_EL1 which
* disables L1 Data cache prefetcher
* ---------------------------------
*/
sysreg_bit_set CORTEX_X3_CPUACTLR6_EL1, BIT(41)
workaround_reset_end cortex_x3, CVE(2024, 7881)
check_erratum_chosen cortex_x3, CVE(2024, 7881), WORKAROUND_CVE_2024_7881
cpu_reset_func_start cortex_x3
/* Disable speculative loads */
msr SSBS, xzr
cpu_reset_func_end cortex_x3
/* ----------------------------------------------------
* HW will do the cache maintenance while powering down
* ----------------------------------------------------
*/
func cortex_x3_core_pwr_dwn
apply_erratum cortex_x3, ERRATUM(2313909), ERRATA_X3_2313909, NO_GET_CPU_REV
/* ---------------------------------------------------
* Enable CPU power down bit in power control register
* ---------------------------------------------------
*/
sysreg_bit_set CORTEX_X3_CPUPWRCTLR_EL1, CORTEX_X3_CPUPWRCTLR_EL1_CORE_PWRDN_BIT
apply_erratum cortex_x3, ERRATUM(2743088), ERRATA_X3_2743088, NO_GET_CPU_REV
isb
ret
endfunc cortex_x3_core_pwr_dwn
/* ---------------------------------------------
* This function provides Cortex-X3-
* specific register information for crash
* reporting. It needs to return with x6
* pointing to a list of register names in ascii
* and x8 - x15 having values of registers to be
* reported.
* ---------------------------------------------
*/
.section .rodata.cortex_x3_regs, "aS"
cortex_x3_regs: /* The ascii list of register names to be reported */
.asciz "cpuectlr_el1", ""
func cortex_x3_cpu_reg_dump
adr x6, cortex_x3_regs
mrs x8, CORTEX_X3_CPUECTLR_EL1
ret
endfunc cortex_x3_cpu_reg_dump
declare_cpu_ops_wa_4 cortex_x3, CORTEX_X3_MIDR, \
cortex_x3_reset_func, \
CPU_NO_EXTRA1_FUNC, \
CPU_NO_EXTRA2_FUNC, \
CPU_NO_EXTRA3_FUNC, \
check_erratum_cortex_x3_7881, \
cortex_x3_core_pwr_dwn