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/*
* Copyright (c) 2022-2023, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch_features.h>
#include <common/debug.h>
#include <common/feat_detect.h>
static bool tainted;
/*******************************************************************************
* This section lists the wrapper modules for each feature to evaluate the
* feature states (FEAT_STATE_ALWAYS and FEAT_STATE_CHECK) and perform
* necessary action as below:
*
* It verifies whether the FEAT_XXX (eg: FEAT_SB) is supported by the PE or not.
* Without this check an exception would occur during context save/restore
* routines, if the feature is enabled but not supported by PE.
******************************************************************************/
#define feat_detect_panic(a, b) ((a) ? (void)0 : feature_panic(b))
/*******************************************************************************
* Function : feature_panic
* Customised panic function with error logging mechanism to list the feature
* not supported by the PE.
******************************************************************************/
static inline void feature_panic(char *feat_name)
{
ERROR("FEAT_%s not supported by the PE\n", feat_name);
panic();
}
/*******************************************************************************
* Function : check_feature
* Check for a valid combination of build time flags (ENABLE_FEAT_xxx) and
* feature availability on the hardware. <min> is the smallest feature
* ID field value that is required for that feature.
* Triggers a panic later if a feature is forcefully enabled, but not
* available on the PE. Also will panic if the hardware feature ID field
* is larger than the maximum known and supported number, specified by <max>.
*
* We force inlining here to let the compiler optimise away the whole check
* if the feature is disabled at build time (FEAT_STATE_DISABLED).
******************************************************************************/
static inline void __attribute((__always_inline__))
check_feature(int state, unsigned long field, const char *feat_name,
unsigned int min, unsigned int max)
{
if (state == FEAT_STATE_ALWAYS && field < min) {
ERROR("FEAT_%s not supported by the PE\n", feat_name);
tainted = true;
}
if (state >= FEAT_STATE_ALWAYS && field > max) {
ERROR("FEAT_%s is version %ld, but is only known up to version %d\n",
feat_name, field, max);
tainted = true;
}
}
/*******************************************************************************
* Feature : FEAT_RAS (Reliability, Availability, and Serviceability Extension)
******************************************************************************/
static void read_feat_ras(void)
{
#if (RAS_EXTENSION == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_2_feat_ras_present(), "RAS");
#endif
}
/************************************************
* Feature : FEAT_PAUTH (Pointer Authentication)
***********************************************/
static void read_feat_pauth(void)
{
#if (ENABLE_PAUTH == FEAT_STATE_ALWAYS) || (CTX_INCLUDE_PAUTH_REGS == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_3_pauth_present(), "PAUTH");
#endif
}
/************************************************************
* Feature : FEAT_DIT (Data Independent Timing Instructions)
***********************************************************/
static void read_feat_dit(void)
{
#if (ENABLE_FEAT_DIT == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_4_feat_dit_present(), "DIT");
#endif
}
/************************************************
* Feature : FEAT_MTE (Memory Tagging Extension)
***********************************************/
static void read_feat_mte(void)
{
#if (CTX_INCLUDE_MTE_REGS == FEAT_STATE_ALWAYS)
unsigned int mte = get_armv8_5_mte_support();
feat_detect_panic((mte != MTE_UNIMPLEMENTED), "MTE");
#endif
}
/****************************************************
* Feature : FEAT_BTI (Branch Target Identification)
***************************************************/
static void read_feat_bti(void)
{
#if (ENABLE_BTI == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_5_bti_present(), "BTI");
#endif
}
/**************************************************
* Feature : FEAT_RME (Realm Management Extension)
*************************************************/
static void read_feat_rme(void)
{
#if (ENABLE_RME == FEAT_STATE_ALWAYS)
feat_detect_panic((get_armv9_2_feat_rme_support() !=
ID_AA64PFR0_FEAT_RME_NOT_SUPPORTED), "RME");
#endif
}
/******************************************************************
* Feature : FEAT_RNG_TRAP (Trapping support for RNDR/RNDRRS)
*****************************************************************/
static void read_feat_rng_trap(void)
{
#if (ENABLE_FEAT_RNG_TRAP == FEAT_STATE_ALWAYS)
feat_detect_panic(is_feat_rng_trap_present(), "RNG_TRAP");
#endif
}
/***********************************************************************************
* TF-A supports many Arm architectural features starting from arch version
* (8.0 till 8.7+). These features are mostly enabled through build flags. This
* mechanism helps in validating these build flags in the early boot phase
* either in BL1 or BL31 depending on the platform and assists in identifying
* and notifying the features which are enabled but not supported by the PE.
*
* It reads all the enabled features ID-registers and ensures the features
* are supported by the PE.
* In case if they aren't it stops booting at an early phase and logs the error
* messages, notifying the platforms about the features that are not supported.
*
* Further the procedure is implemented with a tri-state approach for each feature:
* ENABLE_FEAT_xxx = 0 : The feature is disabled statically at compile time
* ENABLE_FEAT_xxx = 1 : The feature is enabled and must be present in hardware.
* There will be panic if feature is not present at cold boot.
* ENABLE_FEAT_xxx = 2 : The feature is enabled but dynamically enabled at runtime
* depending on hardware capability.
*
* For better readability, state values are defined with macros, namely:
* { FEAT_STATE_DISABLED, FEAT_STATE_ALWAYS, FEAT_STATE_CHECK }, taking values
* { 0, 1, 2 }, respectively, as their naming.
**********************************************************************************/
void detect_arch_features(void)
{
tainted = false;
/* v8.0 features */
check_feature(ENABLE_FEAT_SB, read_feat_sb_id_field(), "SB", 1, 1);
check_feature(ENABLE_FEAT_CSV2_2, read_feat_csv2_id_field(),
"CSV2_2", 2, 3);
/* v8.1 features */
check_feature(ENABLE_FEAT_PAN, read_feat_pan_id_field(), "PAN", 1, 3);
check_feature(ENABLE_FEAT_VHE, read_feat_vhe_id_field(), "VHE", 1, 1);
/* v8.2 features */
read_feat_ras();
check_feature(ENABLE_SVE_FOR_NS, read_feat_sve_id_field(),
"SVE", 1, 1);
/* v8.3 features */
read_feat_pauth();
/* v8.4 features */
read_feat_dit();
check_feature(ENABLE_FEAT_AMU, read_feat_amu_id_field(),
"AMUv1", 1, 2);
check_feature(ENABLE_MPAM_FOR_LOWER_ELS, read_feat_mpam_version(),
"MPAM", 1, 17);
check_feature(CTX_INCLUDE_NEVE_REGS, read_feat_nv_id_field(),
"NV2", 2, 2);
check_feature(ENABLE_FEAT_SEL2, read_feat_sel2_id_field(),
"SEL2", 1, 1);
check_feature(ENABLE_TRF_FOR_NS, read_feat_trf_id_field(),
"TRF", 1, 1);
/* v8.5 features */
read_feat_mte();
check_feature(ENABLE_FEAT_RNG, read_feat_rng_id_field(), "RNG", 1, 1);
read_feat_bti();
read_feat_rng_trap();
/* v8.6 features */
check_feature(ENABLE_FEAT_AMUv1p1, read_feat_amu_id_field(),
"AMUv1p1", 2, 2);
check_feature(ENABLE_FEAT_FGT, read_feat_fgt_id_field(), "FGT", 1, 1);
check_feature(ENABLE_FEAT_ECV, read_feat_ecv_id_field(), "ECV", 1, 2);
check_feature(ENABLE_FEAT_TWED, read_feat_twed_id_field(),
"TWED", 1, 1);
/* v8.7 features */
check_feature(ENABLE_FEAT_HCX, read_feat_hcx_id_field(), "HCX", 1, 1);
/* v8.9 features */
check_feature(ENABLE_FEAT_TCR2, read_feat_tcrx_id_field(),
"TCR2", 1, 1);
check_feature(ENABLE_FEAT_S2PIE, read_feat_s2pie_id_field(),
"S2PIE", 1, 1);
check_feature(ENABLE_FEAT_S1PIE, read_feat_s1pie_id_field(),
"S1PIE", 1, 1);
check_feature(ENABLE_FEAT_S2POE, read_feat_s2poe_id_field(),
"S2POE", 1, 1);
check_feature(ENABLE_FEAT_S1POE, read_feat_s1poe_id_field(),
"S1POE", 1, 1);
/* v9.0 features */
check_feature(ENABLE_BRBE_FOR_NS, read_feat_brbe_id_field(),
"BRBE", 1, 2);
check_feature(ENABLE_TRBE_FOR_NS, read_feat_trbe_id_field(),
"TRBE", 1, 1);
/* v9.2 features */
check_feature(ENABLE_SME_FOR_NS, read_feat_sme_id_field(),
"SME", 1, 2);
read_feat_rme();
if (tainted) {
panic();
}
}
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