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refactor(cpufeat): enable FEAT_CSV2_2 for FEAT_STATE_CHECKED

At the moment we only support FEAT_CSV2_2 to be either unconditionally
compiled in, or to be not supported at all.

Add support for runtime detection (ENABLE_FEAT_CSV2_2=2), by splitting
is_armv8_0_feat_csv2_2_present() into an ID register reading function
and a second function to report the support status. That function
considers both build time settings and runtime information (if needed),
and is used before we access the SCXTNUM_EL2 system register.
Also move the context saving code from assembly to C, and use the new
is_feat_csv2_2_supported() function to guard its execution.

Change the FVP platform default to the now supported dynamic option (=2),
so the right decision can be made by the code at runtime.

Change-Id: I89c7bc883e6a65727fdbdd36eb3bfbffb2196da7
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
pull/1996/head
Andre Przywara 2 years ago
parent
commit
7db710f0cb
  1. 13
      common/feat_detect.c
  2. 18
      include/arch/aarch64/arch_features.h
  3. 2
      include/arch/aarch64/arch_helpers.h
  4. 4
      include/lib/el3_runtime/aarch64/context.h
  5. 24
      lib/el3_runtime/aarch64/context.S
  6. 34
      lib/el3_runtime/aarch64/context_mgmt.c
  7. 1
      plat/arm/board/fvp/platform.mk

13
common/feat_detect.c

@ -60,16 +60,6 @@ check_feature(int state, unsigned long field, const char *feat_name,
}
}
/******************************************************
* Feature : FEAT_CSV2_2 (Cache Speculation Variant 2)
*****************************************************/
static void read_feat_csv2_2(void)
{
#if (ENABLE_FEAT_CSV2_2 == FEAT_STATE_ALWAYS)
feat_detect_panic(is_armv8_0_feat_csv2_2_present(), "CSV2_2");
#endif
}
/*******************************************************************************
* Feature : FEAT_RAS (Reliability, Availability, and Serviceability Extension)
******************************************************************************/
@ -224,7 +214,8 @@ void detect_arch_features(void)
/* v8.0 features */
check_feature(ENABLE_FEAT_SB, read_feat_sb_id_field(), "SB", 1, 1);
read_feat_csv2_2();
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);

18
include/arch/aarch64/arch_features.h

@ -301,10 +301,22 @@ static inline unsigned int read_feat_sb_id_field(void)
/*********************************************************************************
* Function to identify the presence of FEAT_CSV2_2 (Cache Speculation Variant 2)
********************************************************************************/
static inline bool is_armv8_0_feat_csv2_2_present(void)
static inline unsigned int read_feat_csv2_id_field(void)
{
return (((read_id_aa64pfr0_el1() >> ID_AA64PFR0_CSV2_SHIFT) &
ID_AA64PFR0_CSV2_MASK) == ID_AA64PFR0_CSV2_2_SUPPORTED);
return ISOLATE_FIELD(read_id_aa64pfr0_el1(), ID_AA64PFR0_CSV2);
}
static inline bool is_feat_csv2_2_supported(void)
{
if (ENABLE_FEAT_CSV2_2 == FEAT_STATE_DISABLED) {
return false;
}
if (ENABLE_FEAT_CSV2_2 == FEAT_STATE_ALWAYS) {
return true;
}
return read_feat_csv2_id_field() >= ID_AA64PFR0_CSV2_2_SUPPORTED;
}
/**********************************************************************************

2
include/arch/aarch64/arch_helpers.h

@ -540,6 +540,8 @@ DEFINE_RENAME_SYSREG_READ_FUNC(erxaddr_el1, ERXADDR_EL1)
DEFINE_RENAME_SYSREG_READ_FUNC(erxmisc0_el1, ERXMISC0_EL1)
DEFINE_RENAME_SYSREG_READ_FUNC(erxmisc1_el1, ERXMISC1_EL1)
DEFINE_RENAME_SYSREG_RW_FUNCS(scxtnum_el2, SCXTNUM_EL2)
/* Armv8.1 VHE Registers */
DEFINE_RENAME_SYSREG_RW_FUNCS(contextidr_el2, CONTEXTIDR_EL2)
DEFINE_RENAME_SYSREG_RW_FUNCS(ttbr1_el2, TTBR1_EL2)

4
include/lib/el3_runtime/aarch64/context.h

@ -525,10 +525,6 @@ void el2_sysregs_context_restore_ras(el2_sysregs_t *regs);
void el2_sysregs_context_save_nv2(el2_sysregs_t *regs);
void el2_sysregs_context_restore_nv2(el2_sysregs_t *regs);
#endif /* CTX_INCLUDE_NEVE_REGS */
#if ENABLE_FEAT_CSV2_2
void el2_sysregs_context_save_csv2(el2_sysregs_t *regs);
void el2_sysregs_context_restore_csv2(el2_sysregs_t *regs);
#endif /* ENABLE_FEAT_CSV2_2 */
#endif /* CTX_INCLUDE_EL2_REGS */
#if CTX_INCLUDE_FPREGS

24
lib/el3_runtime/aarch64/context.S

@ -25,10 +25,6 @@
.global el2_sysregs_context_save_nv2
.global el2_sysregs_context_restore_nv2
#endif /* CTX_INCLUDE_NEVE_REGS */
#if ENABLE_FEAT_CSV2_2
.global el2_sysregs_context_save_csv2
.global el2_sysregs_context_restore_csv2
#endif /* ENABLE_FEAT_CSV2_2 */
#endif /* CTX_INCLUDE_EL2_REGS */
.global el1_sysregs_context_save
@ -262,26 +258,6 @@ func el2_sysregs_context_restore_nv2
endfunc el2_sysregs_context_restore_nv2
#endif /* CTX_INCLUDE_NEVE_REGS */
#if ENABLE_FEAT_CSV2_2
func el2_sysregs_context_save_csv2
/*
* SCXTNUM_EL2 register is saved only when FEAT_CSV2_2 is supported.
*/
mrs x13, scxtnum_el2
str x13, [x0, #CTX_SCXTNUM_EL2]
ret
endfunc el2_sysregs_context_save_csv2
func el2_sysregs_context_restore_csv2
/*
* SCXTNUM_EL2 register is restored only when FEAT_CSV2_2 is supported.
*/
ldr x13, [x0, #CTX_SCXTNUM_EL2]
msr scxtnum_el2, x13
ret
endfunc el2_sysregs_context_restore_csv2
#endif /* ENABLE_FEAT_CSV2_2 */
#endif /* CTX_INCLUDE_EL2_REGS */
/* ------------------------------------------------------------------

34
lib/el3_runtime/aarch64/context_mgmt.c

@ -171,10 +171,10 @@ static void setup_realm_context(cpu_context_t *ctx, const struct entry_point_inf
scr_el3 |= SCR_NS_BIT | SCR_NSE_BIT;
#if ENABLE_FEAT_CSV2_2
/* Enable access to the SCXTNUM_ELx registers. */
scr_el3 |= SCR_EnSCXT_BIT;
#endif
if (is_feat_csv2_2_supported()) {
/* Enable access to the SCXTNUM_ELx registers. */
scr_el3 |= SCR_EnSCXT_BIT;
}
write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
}
@ -227,10 +227,10 @@ static void setup_ns_context(cpu_context_t *ctx, const struct entry_point_info *
scr_el3 |= SCR_TERR_BIT;
#endif
#if ENABLE_FEAT_CSV2_2
/* Enable access to the SCXTNUM_ELx registers. */
scr_el3 |= SCR_EnSCXT_BIT;
#endif
if (is_feat_csv2_2_supported()) {
/* Enable access to the SCXTNUM_ELx registers. */
scr_el3 |= SCR_EnSCXT_BIT;
}
#ifdef IMAGE_BL31
/*
@ -976,9 +976,12 @@ void cm_el2_sysregs_context_save(uint32_t security_state)
if (is_feat_trf_supported()) {
write_ctx_reg(el2_sysregs_ctx, CTX_TRFCR_EL2, read_trfcr_el2());
}
#if ENABLE_FEAT_CSV2_2
el2_sysregs_context_save_csv2(el2_sysregs_ctx);
#endif
if (is_feat_csv2_2_supported()) {
write_ctx_reg(el2_sysregs_ctx, CTX_SCXTNUM_EL2,
read_scxtnum_el2());
}
if (is_feat_hcx_supported()) {
write_ctx_reg(el2_sysregs_ctx, CTX_HCRX_EL2, read_hcrx_el2());
}
@ -1039,9 +1042,12 @@ void cm_el2_sysregs_context_restore(uint32_t security_state)
if (is_feat_trf_supported()) {
write_trfcr_el2(read_ctx_reg(el2_sysregs_ctx, CTX_TRFCR_EL2));
}
#if ENABLE_FEAT_CSV2_2
el2_sysregs_context_restore_csv2(el2_sysregs_ctx);
#endif
if (is_feat_csv2_2_supported()) {
write_scxtnum_el2(read_ctx_reg(el2_sysregs_ctx,
CTX_SCXTNUM_EL2));
}
if (is_feat_hcx_supported()) {
write_hcrx_el2(read_ctx_reg(el2_sysregs_ctx, CTX_HCRX_EL2));
}

1
plat/arm/board/fvp/platform.mk

@ -470,6 +470,7 @@ ENABLE_FEAT_FGT := 2
ENABLE_FEAT_HCX := 2
ENABLE_FEAT_TCR2 := 2
ENABLE_FEAT_CSV2_2 := 2
ENABLE_FEAT_ECV := 2
ENABLE_FEAT_PAN := 2
ENABLE_FEAT_VHE := 2

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