arm-trusted-firmware/lib/cpus/aarch64/cortex_gelas.S
Boyan Karatotev c9f352c362 fix(cpus): clear CPUPWRCTLR_EL1.CORE_PWRDN_EN_BIT on reset
The model has a bug where it will not clear CPUPWRCTLR_EL1 on reset,
even though the actual cores do. The write of 1 to the bit itself
triggers the powerdown sequnece, regardless of the value before the
write. As such, the bug does not impact functionality but it does throw
off software reading it.

Clear the bit on Travis and Gelas as they are the only ones to require
reading it back.

Change-Id: I765a7fa055733d522480be30d412e3b417af2bd7
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
2025-02-05 14:18:49 +00:00

80 lines
2.3 KiB
ArmAsm

/*
* Copyright (c) 2023-2025, 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_gelas.h>
#include <cpu_macros.S>
#include <plat_macros.S>
/* Hardware handled coherency */
#if HW_ASSISTED_COHERENCY == 0
#error "Gelas must be compiled with HW_ASSISTED_COHERENCY enabled"
#endif
/* 64-bit only core */
#if CTX_INCLUDE_AARCH32_REGS == 1
#error "Gelas supports only AArch64. Compile with CTX_INCLUDE_AARCH32_REGS=0"
#endif
#if FEAT_PABANDON == 0
#error "Gelas must be compiled with FEAT_PABANDON enabled"
#endif
#if ERRATA_SME_POWER_DOWN == 0
#error "Gelas needs ERRATA_SME_POWER_DOWN=1 to powerdown correctly"
#endif
cpu_reset_func_start cortex_gelas
/* ----------------------------------------------------
* Disable speculative loads
* ----------------------------------------------------
*/
msr SSBS, xzr
/* model bug: not cleared on reset */
sysreg_bit_clear CORTEX_GELAS_CPUPWRCTLR_EL1, \
CORTEX_GELAS_CPUPWRCTLR_EL1_CORE_PWRDN_BIT
cpu_reset_func_end cortex_gelas
/* ----------------------------------------------------
* HW will do the cache maintenance while powering down
* ----------------------------------------------------
*/
func cortex_gelas_core_pwr_dwn
/* ---------------------------------------------------
* Flip CPU power down bit in power control register.
* It will be set on powerdown and cleared on wakeup
* ---------------------------------------------------
*/
sysreg_bit_toggle CORTEX_GELAS_CPUPWRCTLR_EL1, \
CORTEX_GELAS_CPUPWRCTLR_EL1_CORE_PWRDN_BIT
isb
ret
endfunc cortex_gelas_core_pwr_dwn
/* ---------------------------------------------
* This function provides Gelas 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_gelas_regs, "aS"
cortex_gelas_regs: /* The ASCII list of register names to be reported */
.asciz "imp_cpuectlr_el1", ""
func cortex_gelas_cpu_reg_dump
adr x6, cortex_gelas_regs
mrs x8, CORTEX_GELAS_IMP_CPUECTLR_EL1
ret
endfunc cortex_gelas_cpu_reg_dump
declare_cpu_ops cortex_gelas, CORTEX_GELAS_MIDR, \
cortex_gelas_reset_func, \
cortex_gelas_core_pwr_dwn